Sunday, January 20, 2008

4. So, What is Flash Value Lock?




I've written in my previous posts about the fact that the flash metering system measures only the center of the frame. This means that if the subject is not in the center of the frame, the brightness of the subject will likely be wrong.

Above is an example of a subject that is not in the center. I used FV Lock to make sure the subject was exposed properly by the flash. I was outdoors at a reception on a pitch dark night, so there was zero ambient light, and I wanted the very dimly lit waterfall to come out in the background, so I used my D200 handheld in manual mode, ISO 400, 1/8 sec, f/2.8 and my flash in TTL.

I first pointed my flash at the subjects and pushed the FV Lock button to fire the preflashes and lock in the correct flash power. Then, I recomposed the shot to place the subject on the left 1/3 line (rule of thirds), and released the shutter. Notice that the subject is sharp despite the very slow 1/8th second shutter speed, because the flash stopped any motion. But, look at the waterfall. There is definite motion blur there, but I used f/2.8 to make sure it was out of focus so the motion blur from handholding the camera wouldn't show.

If I had just framed it as above to start with and taken the shot without using FV Lock, the flash would have metered the center of the frame, which was the waterfall about 70 feet away, and it would have set a very high power. The subjects would have been totally blown out.

One very important thing to know when using FV Lock is that once it is pushed the flash value remains locked at that power setting until one of three things takes place: 1) FV Lock is pushed a second time, 2) the camera is turned off, or 3) the light meter in the camera times out. Since the default light meter reset time is very short (only 6 seconds on my D200), you need to use your camera menus to extend the light meter timeout to as long as possible when you are using FV Lock.

Don't forget to return the light meter timeout to its default time after you are finished with FV Lock, or it will run your camera batteries down faster than normal.

FV Lock is very useful for shooting a series of shots of a group of people, so that all the images will look exactly the same from one shot to the next.

It is also useful for those rare people who are 'fast blinkers'. A fast blinker can blink at the preflash and their eyes will be closed by the time the main flash happens. Lot's of animals are fast blinkers, so FV Lock is also good for them.

Next: A Study in Camera Compensation while using Flash

102 comments:

Anonymous said...

Hi Russ,

I’ve just come across your brilliant blog site that covers CLS flash photography etc.. I was just wondering in this sample you mentioned you used manual for that wedding shot but was wondering did you use ‘slow sync flash’ ? as I have been trying to get similar results using my D70s and a SB600..

Russ MacDonald said...

There are two reasons for slow sync flash. First, in P and A modes, slow sync will allow the camera metering to set the shutter to go to very slow speeds to make a proper exposure from the ambient portion of the shot, which greatly brightens the background. Second, slow sync is also 'rear' sync, so the ghost trails will fall behind the sharp image from the flash when there is movement.

Note: In this email I am only talking about indoor party shots, and I always use the flash on TTL for those.

When you shoot in camera Manual mode, slow sync has no effect on shutter speed because you set any speed you want to. However, if I am expecting motion, I will often shoot in slow sync to get the flash to fire at the end of the shutter. In most shots, the ghost trails are insignificant, so I just leave the flash on normal sync. I prefer camera Manual mode, so I can simply adjust the shutter speed to brighten or darken the background.

So, the question you might ask is how do you choose your shutter and aperture when you shoot flash shots in camera Manual mode. Simple, trial and error, and experience. For indoor party shots where I want a lot of background contribution, and I'm in camera Manual mode, I set the shutter to about 1/15th, the aperture to around f/3.5, and the ISO to 400. Then, I make sure the flash is turned down by about -1.0 ev, This will make the background very bright and the flash will nicely 'fill' the subject. There will sometimes be some ghosting that adds a certain etherial quality in many cases. Setting the shutter really slow like this and using the flash to make the exposure is called 'dragging the shutter'. That is what 'slow sync' does for you automatically when shooting in A or P modes, but then you can't adjust the brightness of the background. If you try to adjust the background with the camera ev settings, you will aso affect the flash power, so camera Manual is almost always the best choice.

One problem when dragging the shutter is that you get two distinct flashes when in TTL flash mode, and they are farther apart depending on how slow your shutter speed is. You get the preflash before the shutter opens and then the main flash waits until just before the shutter closes. This makes for lots of closed eyes in your party shots. That's one reason why I usually use normal sync even when dragging the shutter for party shots.

Sometimes, I use the flash in A mode when dragging the shutter, because A mode does not use preflashes. But A mode doesn't expose the subject as quite as consistantly as TTL.

Russ

Anthony C said...

Russ,

Echoing what others have said throughout your many posts, I'd like to offer you my compliments. I've just discovered your blog and have ripped through just about every topic!

Pardon me if I have missed the obvious, but how does one actually engage the Flash Value Lock? I couldn't even find it on Nikon's site. They mention the FV lock and what it can do (illustrated by the off-center piano player) but never say exactly how to employ it.

Also, if I may, another topic that would no doubt benefit from your analysis would be the D "distance" functionality in certain lenses. It seems to be quite mysterious to me and many others.

Thank you.

Russ MacDonald said...

Anthony,

Thanks for the nice comments!

The method for using FV Lock is camera dependent. The only two cameras I use are the D70 and the D200, so I can only tell you how to use FV Lock for those two. Other Nikon cameras should be similar, but I don't know about any of them except the ones I use.

On the D70 and D70s, you have to use menu CSM 15 to change the AE-L/AF-L button to do FV Lock function.

On the D200, FV Lock is assigned by default to the Function button (the lower button on the front of the camera that you push with your right hand).

I think the D300 works the same as the D200.

Russ

Russ MacDonald said...

Anthony,

I missed your request about D lenses, but I am studying that and working on another blog now about that. I intend to show in a practical way how distance is used to modify the flash power when using a D or G lens. It's very interesting. Should be done in a few days.

Russ

Anthony C said...

Thanks, Russ. The D70 is what I have so I will try this right away.

This illustrates even more the confusion that surrounds D "distance" lenses and what they are supposed to do, especially when using flash.

Up until learning about the FV lock function here on your blog, when taking off-center flash shots I have simply been AF-ing on the off-center subject, and while holding the shutter button partway down to keep the focus locked, I've swung around to re-compose. The result has usually been an overexposed subject, and I've been very frustrated about why this would happen.

I thought the "D" function of the lens was supposed to take care of this. In other words, the camera/lens could tell I was locked on focus on something only 6feet away, and it would (supposedly) put out only that amount of light and not try to fill up the infinity of space in the center of the frame. Clearly, it doesn't work that way.

Thanks again. I look forward to more insightful postings.

Russ MacDonald said...

Anthony,
I have just finished a study of Distance and it's effect on Flash.

See it on my blog here: http://nikonclspracticalguide.blogspot.com/2008/03/ttl-and-ttl-bl-study.html

My conclusion is that Focal Distance is not included when flash power is calculated when using TTL but it is included when using TTL-BL.

Russ

David said...

Russ,

Thank you for the very informative guide to using CLS properly!

Regarding your "dragging the shutter technique" below, could this same effect be accomplished if I simply set my Flash Shutter Speed (Menu e2 on D300) to 1/15s or even 1/8s and then leave camera in P or A mode. I'm still very much a novice when it comes to flash photography and not confident enough to take it to M mode, although your blog certainly has given me the inspiration. Thanks again.

Russ MacDonald said...

David,

The important thing to understand when shooting flash in TTL mode is that the flash metering system will automate things regardless of what mode you have the camera in. Placing the camera in Manual mode doesn't change that. It is still an automatic process.

The only thing that Camera Manual mode does when shooting flash is adjust the brightness of the background.

Yes, you might be able to get there by playing with the settings in the menu for flash shutter speed, but it really is much simpler to just use camera Manual mode.

Now, there is one caveat. This works best when inside in dim ambient light - like for party shots. If the ambient is brighter, then you don't need to drag the shutter, so you will want to use one of the automatic modes.

Indoors in bright ambient, A mode generally works best.

When shooting flash outdoors in daylight (fill flash), P mode generally works best. S mode also works well.

Hope this helps,

Russ

David said...

Thanks Russ. I actually re-read your blog topic #5 just now where you made the point on the independence between background exposure and subject exposure very clearly. It's probably one the most lucid and succint presentation on this topic.

rbeal said...

Setting FV Lock
The D300 isn't quite the same as the D200.
You can set the AE-L/AF-L button to FV Lock using f6
or set the Preview button using f5
Or set the FUNC (Fn) button using f4 (my prefered option)

Russ MacDonald said...

rbeal,
Yes, I was aware that there are differences between the D200 and D300 in the various programmable options. Someday, I hope to get a D300 and then I will write additional blogs to document the differences.
Thanks, Russ

Attila B. said...

Hello Russ,

First of all thank you for your absolutely brilliant blog - in my opinion this is the best resource on Nikon flash photography.

I have a question regarding this topic. When you halfway press the shutter-release button does it actually lock the flash value? I'm not sure about it. If it did lock it you could have taken the shot above with the couple and the waterfall by keeping your focus point in the center, halfway pressing the shutter-release button which would lock the focus and maybe the flash value too, keeping the shutter-release button halfway pressed and recomposing the picture. Am I right on this?

Thanks very much for your concern in advance.

Russ MacDonald said...

Hi Attila B.

When you half-press the shutter button it has no effect on the flash and doesn't lock it.

You activate FV Lock by pushing the FUNC button while pointed at the subject. This fires the preflash metering pulses which reflect off the subject and are used to calculate the proper flash power which is then locked in.

Then you half-press the shutter button which locks focus on the subject. The half-press also locks exposure which affects only the background in low ambient conditions (that's why it is best to use Matrix metering - so you will get a good background exposure setting). Then you recompose and push the shutter button the rest of the way to take the picture.

To say this another way: When you half-press the shutter button, using default menu settings, you lock in focus and exposure settings on the camera but those settings don't affect the flash portion of the image when the flash is dominant (overpowering the ambient on the subject). In this case, the ambient was very weak and did not have any affect on the subject, so the flash was clearly dominant. In this situation the camera settings only affect the brightness of the background.

Hope this helps,

Russ

Attila B. said...

Hello Russ,

Thank you for the clear explanation. I was obviously wrong when thought that the shutter-release button also locks the flash value. Thanks for the clarification. I can't wait to take my first test shots...

Anthony C said...

Hi Russ,

I starting using the FV lock thanks to your advice here. However, I just noticed that on both my cameras (D70 and D70S) it works with the pop-up flash but not when my SB-800 is mounted. I don't have another modern speedlight to test this with, but can this be correct?

Thank you.

Russ MacDonald said...

Hi Anthony,

I am on vacation now with only my D200. I will check this on my D70 when I get home in a week.

On my D200 FV Lock works the same with both the on-board flash and the SB-800 and 600.

Russ

Anthony C said...

Thanks, Russ. I look forward to your response. Enjoy your vacation. I hope you're restoring some brain cells in preparation for your next new topic on the blog. Can't wait to see what it might be!

Anthony

Anthony C said...

Russ,

I found a D70S manual and it says that the SB-800 and SB-600 should, indeed, fire with FV lock same as the pop-up flash.

With two cameras tested, I doubt I have a malfunctioning camera, so suspicion now rests on my SB-800.

Ariel said...

Russ,

Thanks for the very best input about Nikon CLS that I ever read.

Just curious about metering. What metering should I use in low ambient and bright ambient? Because I usually use center weighted metering for both of the situations.

And one more thing, which position is the best for tilting the flash head in both conditions? Should I use a bounce card?

Thanks in advance...

Russ MacDonald said...

Hi Ariel,

I'm glad you find my blogs helpful; thanks!

The way you worded you question makes me wonder if you totally understand that the camera metering is totally separate from the flash metering when shooting in straight TTL flash mode. Camera metering does not affect the flash power in TTL mode.

Also, in dim ambient conditions, the camera settings (f/ stop, shutter, and ISO) only affect the background brightness and not the subject brightness.

So in dim ambient conditions (like indoors in artificial light), you meter the background ambient one time and then you set the ISO, f/ stop, and aperture into the camera using camera manual mode. The TTL flash metering, which is totally separate from the camera metering, does all the rest. It doesn't make any difference which metering mode is selected on the camera when shooting TTL flash shots. The camera metering mode has no effect on the flash power.

TTL-BL is another story. TTL-BL is used when the ambient conditions are bright and the subject needs fill flaqsh to lift shadows.

Outdoors in bright daylight, TTL-BL flash mode will automatically provide fill flash. This means that the image is mostly illuminated by the ambient light, and the flash is used only to 'fill' or 'lift' shadows on the face of the subject.

In this situation, the metering on the camera matters a lot because it determines the basic brightness of the entire image. I always use matrix metering when shooting TTL-BL fill flash, so the maximum amount of background data will be collected. You can also use center-weighted metering for fill, but it doesn't determine the ambient as accurately as matrix does. You cannot select TTL-BL if you have spot metering selected, because spot metering mode doesn't provide any background brightness data to the flash.

So, in summary:

Camera metering mode doesn't matter when shooting indoors in dim ambient conditions.

Matrix metering is best when outdoors in daylight shooting in TTL-BL mode.

Hope this helps,

Russ

Russ MacDonald said...

Ariel,

You also asked: "And one more thing, which position is the best for tilting the flash head in both conditions? Should I use a bounce card?"

When shooting indoors in dim ambient light, you should always tilt the flash head to bounce as much as you can. This softens the light and makes much better portraits. The actual angle used depends on what you want to aim at to bounce. If you tilt the flash to 60 degrees, then some of the light from the flash will go directly to the subject and some will bounce off the ceiling. The direct light is always harsh, but you might want to allow a little direct light to make a catch-light reflection in the subject's eyes.

The bounce card is also used to direct a small amount of light directly towards the subject to make a catchlight.

The direct light portion of the flash shot also helps fill shadows under the eye sockets and chin that result from a bounce off the ceiling.

The diffusion dome helps a lot indoors to scatter the light around so it bounces off the ceilings and the walls. That's when you want to tilt the head down to allow a little direct light to go to the subject.

The goal is to use only a small amount of direct light and mostly bounce light for softer people shots.

Outdoors, there is nothing to bounce from, so you have to shoot direct. The diffusion dome and bounce card are basically useless outdoors. All they will do is waste flash power which will run down your flash batteries faster. The trick outdoors is to remember that the primary light is coming from ambient and the flash is used to just barely lift the shadows, so be careful not to overdo the flash. A little bit of fill flash goes a long way. You should keep the flash power turned down so that you can't tell that you used flash at all in the final image.

Regards,

Russ

Vu Hung said...

Another observation:

The FV lock work in TTL mode only not in TTL-BL. So if you took a photo without FV lock, it could be in TTL-BF, the exposition won't be the same with FV-lock, in TTL is often more exposed than TTL-BF.

Russ MacDonald said...

Vu Hung,

I'm not sure I completely understand your point. I suspect that you may not fully understand what the normal use is for TTL and TTL-BL.

FV Lock does work in TTL-BL mode, but I can never think of a time when you would use it that way. FV Lock is for TTL (as you said, but I think maybe for the wrong reasons).

TTL is for use as primary light for low ambient light conditions, like indoors at night or in a studio.

TTL-BL is for fill flash ONLY, like outdoors in bright ambient light. TTL-BL is not designed for use as primary light.

You would only use FV Lock when the flash was the primary light, so you would only use FV Lock when using normal TTL.

If you use TTL-BL in low ambient conditions, you will get unpredictable results, usually underexposed. Using FV Lock in this situation would only make things worse.

Russ

Vu Hung said...

Russ,

You can do the test by your self:

Put a external flash on the hot shoe. Take a shot in TTL-BL mode, take another shot of the same scene with FV lock before firing. The exposure will differ (lighter with FV lock). Now, take another shot in TTL mode, the flash exposure will be the same than the one with FV lock.

Do it with external flash so you could change control from TTL to TTL-BF.

Russ MacDonald said...

Vu,

In your test, what is the ambient lighting condition?

Is it dim ambient like indoors at night?

Or is it bright ambient like daylight outdoors?

Russ

Vu Hung said...

Russ,

In indoor ambiance light with morning overcast sky outside through big windows

I could do another test outside for BF. I have a flash meter so it could probably detect the difference.

My point is I like to play with FV lock to recompose the scene because the internal flash meter will always be center-point. But with FV lock, even the flash said that you're in TTL-BL mode, you are not.

Russ MacDonald said...

Vu,

I tried the experiment that you described, with the additional requirement that the subject be backlighted so TTL-BL would work correctly. TTL-BL will only work correctly if the subject is darker than the background to start with.

I used a dark brown statue sitting in front of a window with bright daylight behind it.

Then I shot four images as follows:

1) TTL-BL without using FV Lock: The subject brightness was matched to the background as it should be, with the subject bright enough to be seen clearly but still dark enough to appear natural. This is exactly the way TTL-BL should work.

2) TTL-BL using FV Lock:
The subject was much brighter and looked unnatural as it appeared to jump out of the image. The flash was clearly primary in this image as it overpowered the daylight from behind. It seems that the flash computer set up standard TTL flash power instead of TTL-BL (just as you said).

3) TTL without using FV Lock:
The image looked identical to 2).

4) TTL using FV Lock:
The image looked identical to 2).

The obvious conclusion is that FV Lock always locks in the flash value for TTL Mode and does not consider TTL-BL (just as you said).

This is very interesting, and I will add it and these images to my blog, and give you credit for bringing it to my attention.

If you find any more odd bits of information like this about the Nikon CLS, please send it to me.

Thank you,

Russ

Vu Hung said...

Russ,

I don't know if you did mention this or not:

The flash meter is always at the center of the frame. Moving the focus point outside the center will affect the camera metering but not the flash metering system. This limitation and the fact that FV lock work only in TTL mode means that you can`t have a BL flash if the sujet is not in the center of the frame !

Russ MacDonald said...

Vu,

Yes, I have discussed about the flash always metering on the center of the frame. That's why FV Lock was invented.

I also like to recompose my image and use FV Lock quite often. However, I never noticed that FV Lock only worked in TTL before. I guess the brighter subject was still useable.

Your point about not being able to use TTL-BL and recompose is correct.

Thanks,

Russ

Vu Hung said...

I juste did the test with a flash meter and it give the same aperture in TTL and TTL-BF with FV-lock. The aperture is smaller in TTL-BF without FV-lock so the photo will be less exposed than in FV-lock mode.

The BF depend on the camera matrix metering and it is not activated when pre-flashed with FV lock button.

Anyways, TTL-BF is so limited (flash on camera, matrix metering, sujet must be in the center of the frame) so it's better to use TTL off camera and dial ev compensation to control the exposition.

Russ MacDonald said...

Vu,

I have used TTL-BL (you keep typing BF) very successfully for many years. Even though it is a centered weighted system, I think the weighting is weak and covers most of the frame. It definitely does work well most of the time.

I always use TTL-BL when my subject is backlighted, and I also normally recompose. I have not noticed any problems with the flash not measuring the subject correctly, even though the subject is not perfectly centered.

Have you read my other article on TTL-BL here: http://nikonclspracticalguide.blogspot.com/2008/03/ttl-and-ttl-bl-study.html.

The tests I ran showed that the flash metering began to adjust the exposure based on reflected energy on the very edge of the frame. Even though it is true that reflected energy from the center of the frame has a larger effect, there is enough effect from the rest of the frame for TTL-BL to work well even when the subject is not centered.

Russ

Mohanpreet said...

Hi Russ
It would be repetition of what others have already said..but i Have to say it. Thanks a lot for writing a brilliant blog on the most confusing topic (at least for me).Nikon Should pay you for clarifying all these things for the customers who buy Nikon.I have spent so much of money and time buying and reading books..but nothing was as helpful as your blog.
One question - when shooting in dim ambient indoor (TTL)I cover my flash with sto fen diffuser and tilt it 45-60 degree while bouncing it. But if i can not bounce it, i keep flash forward but i keep the diffuser on. I do same for outdoor pictures, flash straight forward with Sto fen diffuser on. Am i doing it right ?Thanks.

Russ MacDonald said...

Hi Mohan,

Thanks for your nice feedback!

Indoors in dim ambient light, it is usually best to put the Sto-Fen diffuser on the flash and point it straight up. The goal is to minimize the direct light going from the flash to the subject, because that direct light is still very harsh. The diffuser does nothing to soften direct light, because it is so small.

The reason the diffuser makes the nice soft light is due to the bouncing off the walls and ceilings. You want to maximize that bouncing.

Outdoors, you cannot bounce, so the diffuser does nothing at all for you except to raise the source of the light up an extra couple of inches if you leave it pointed straight up. If you point it directly at the subject, then all it does is waste your flash batteries.

So, outdoors it is better to remove any small diffusers and just point the flash directly at the subject. At least your batteries will last longer.

Now, if you happen to own a large diffuser like the Gary Fong Light Sphere, that does increase the apparent size of the flash enough to provide some softening out to about six or eight feet.

If your outdoor pictures will be for 'fill' in bright daylight, then you should switch to TTL-BL and take the diffuser off. It doesn't matter if fill is harsh or not most of the time.

Hope that helps,

Russ

Mohanpreet said...

Russ
Thanks a lot for quick response.
Just one more question about this -
If I am using Gary Fong LS II, should i Keep the dome cover on indoors and outdoors ? Also When i can not bounce (Indoors or outdoors) while using Gary Fong LS, should I point my flash forward towards the model ?
Thanks again.

Russ MacDonald said...

Hi again Mohan,

The goal is to make your flash appear as large as possible. Indoors, you do that by bouncing off the walls and ceiling. Outdoors, you have no bouncing, so the only way to make you flash appear larger is with a large diffuser.

If you turn the Light Sphere down and point it at the subject, you will actually make you flash appear smaller than when the unit is pointed straight up.

This is something that is wrong even in the Gary Fong videos. It gives you softer light if you leave it pointed straight up at all times - indoors or outdoors.

Indoors, take the inverted dome off to get more bouncing off the ceiling, which always makes the light softer.

Outdoors always keep the inverted dome installed to keep from sending quite as much of your light uselessly into the sky.

Outdoors, if you are beyond about 10 feet from the subject, you won't get any softening from the LS, so just take it off and use the flash bare.

Russ

Mohanpreet said...

Thanks a lot Russ. I can't help but tell my friends about your great blog.

Joe S said...

Hi Russ,

I am a new reader of your blog. I think it's a great blog and you sure have provided lot's of useful information here.

On the subject of FV lock. I will be trying your suggestions very soon. However I am thinking this will not work in a fast moving situation such as at a wedding reception and as long as FV is locked you might wind up with a lot of bad exposures. For us we are moving around faily quickly in a darkened room. What setting for flash do you suggest in that kind of situation? I guess we are, if you will excuse the expression, flying by the seat of our pants just leaving the flash in TTL. Camera in manual maybe f5.6 at a high shutter speed so as not to pick up a lot of blured available lights in the background. I will admit that exposures can get a little crazy at times with this method and a lot of time is spent in Lightroom fixing things.

Am I also understanding right that FV will remain locked for all exposures until you either turn off the camera or push the FV button again. And if you push the FV button again won't you be creating another FV? If so then I guess you must turn off the camera to clear it. Right?

I hope someone else has not asked this question before and I just missed it.

Thanks,
Joe S

Russ MacDonald said...

Hi Joe S,

Thanks for the compliments on my articles!

I also shoot weddings, and I very rarely use FV Lock unless there is a compelling reason. I normally leave the flash in TTL mode for indoor work and TTL-BL for outdoor daylight fill flash.

One very important thing I left out of my article is that FV Lock resets itself when the light meter in the camera times out.

The default for the light meter is only 6 seconds on my D200, so you have to extend that time to as long as possible to make FV Lock more useful.

Russ

Joe S said...

Thanks for clearing up those few things. I wish Nikons instruction books were as easy to understand as you blog.

Thanks again and I look forward to reading your blog.

Ronal:D said...

Hi Russ,
I come from HK and please forgive my bad english firstly.

I would like to ask how you can use TTL directly in wedding(or moving subject) and get the correct exposure without FV-LOCK?

PS: I am getting trouble if use FV-LOCK firstly in each shooting as it always confused my girl-friend who think the shoot is completed.

As the TTL always meter the center point, is that if the subject is 'big' enough to fill the screen so we can use the TTL without FV-LOCK?

Thank you very much

Russ MacDonald said...

Hi Ronald,

Yes, if the subject fills the frame there is normally no reason to use FV Lock. Just use normal TTL for indoors and TTL-BL for outdoors in daylight.

However, if you are shooting a subject who blinks quickly, and you are shooting a series of pictures from the same distance (like group pictures on a tripod), you might want to use FV Lock once, before shooting the pictures. Then, there will be no preflashes other than that first one. This will sometimes reduce blinking problems.

Hope that helps,

Russ

Ronal:D said...

Thanks Russ's reply..
But I found you said:"I also shoot weddings, and I very rarely use FV Lock unless there is a compelling reason. I normally leave the flash in TTL mode for indoor work and TTL-BL for outdoor daylight fill flash."

Because I always set the subject(my Girl friend) at the right or left hand side of the photo when shooting. Then means I should use FV-lock everytime?(I rarely shoot with same distance in series photos).... Seems so trouble -_-'

Russ MacDonald said...

Hi again Ronald,

It all depends on how much of the frame your subject occupies and how dark the background is. If your subject is at the very edge of the frame and the background is pitch dark, then FV Lock is needed. If she is only slightly off-center then regular TTL works fine.

For instance, if your subject is at the very edge of the frame, and the background is pitch dark and far away, then the flash will try to expose the background, and it will overexpose your subject. That's when you need FV Lock.

Also, it is important to understand that the flash metering is center-weighted and NOT a 'spot' system. It meters all the way to the edge of the frame, but the influence becomes less and less as the subject gets towards the edge of the frame.

Have you read my blog article here: http://nikonclspracticalguide.blogspot.com/2008/03/ttl-and-ttl-bl-study.html ? It shows you how the metering is influenced by the position of the subject.

Russ

Anonymous said...

I just reached this 3rd page and sometimes back and forward from the first page. I ensured my self to fully understand the lessons you gave before I read the next one.

The more I read the more nikon's secretes revealed and enriched my knowledge.
I've never found such a clear explanation like your blog. Warm regards and billions thanks Russ.

Hanif

Russ MacDonald said...

Hanif,

I am really glad it is all making sense to you!

I try to write clearly enough so that everyone can understand.

Regards,

Russ

Kati van Helden said...

Hi Russ, you are in fantastic.
BETTER than the Nikon user manual.
But something i don't understand...
Usuelly is your Aperture between 2.8-3.5/wedding/ what happening with the Depth of Field?
en what is your recommandent WB for GF Lightsphere?
greatz. Kati
p.s.sorry for my bad english, i coming from Holland and I Born in Hungary/ever/

Russ MacDonald said...

Hi Kati,

Thanks for the nice feedback!

When shooting flash, there is always a trade-off between depth of field and maximum flash distance. I use f/2.8 - f/3.5 most of the time to assure my flash power is sufficient to reach the distances I normally encounter at a wedding reception. If I am up close to my subject, I sometimes go as small as f/5.6, but that greatly reduces the flash range when using a diffuser to around six feet.

Yes, depth of field is shallow at those apertures, but it is sufficient for most situations. Most of the time it is desirable to have the subject sharp and the background focus blurred. I always try to focus on the face of the subject and recompose, and at f/2.8, that will usually keep the entire face and body of an individual sharp.

When I shoot groups of individuals, I am always very careful to position their faces so they are all as close as possible to the plane of focus, and I use the smallest aperture I can - usually about f/4. That will keep all the faces sharp.

One advantage of the DX camera is that the apparent depth of field is not as shallow as when using 35mm film or FX. If you are using an FX camera, f/2.8 will likely be too shallow for some situations.

I keep white balance on 'flash' for all shots with the Light Sphere. Of course, I also shoot 'raw', so I can always change it later if necessary.

Hope that all makes sense,

Russ

Kati said...

When I use the Gary Fong Light Sphere, the scattering light around the Lightshpere is very irritant for the people behind me. The around/scattering/ light is very hars.
greatz, Kati

Russ MacDonald said...

Hi Kati,

I'm not sure what your question has to with FV Lock (the topic of this blog).

The whole point of the Light Sphere is to send light in all directions so it bounces off everything including people behind you. I have not found this to ever irritate anyone. In any case, the only way to avoid it and still get some diffusion would be to use something like a Demb Diffuser which uses a bounce card system, but in my opinion, this results in a slightly lower quality image than the Light Sphere.

Regards,

Russ

bubble lee said...

I want to ask sth about FV lock.

It is very useful when the object is not at the centre.

But if we are taking snap shot?
It is impossible to do FV lock when the object is not placed at centre! But if we use TTL, the object will overexprosure since the centre aiming the background.

So what can I do in this case?

Many thx!!

Russ MacDonald said...

Hi Bubble,

For ordinary snapshots, I rarely use FV Lock. However, I am careful not to place the subject at the extreme edge of the frame. I always make sure that part of the subject extends into about the 1/3 point of the frame. Then, the flash will usually get it close enough for snapshots.

FV Lock is required when the subject will be very close to the camera, and very close to the edge of the frame, and the background is very dark.

Also, on most cameras FV Lock is very easy and quick to use, so you can use it on snapshots very easily as well if you want to.

Russ

Anonymous said...

Russ:
Whot do you do about exposure lock and focus lock when you press flash value lock? You didn't mention those. Do you lock them also when you lock flash value. So now, you are holding 2 buttons while trying to compose the shot.
Why doesn't pushing one button lock all three?
Is there an easier way to do this all at the same time?

Thanks,
Richard

Russ MacDonald said...

Hi Richard,

Normally when using FV Lock, you don't want to lock the exposure on the subject. Remember, the flash will handle the exposure of the subject.

You normally want the camera to expose the background correctly where you are aiming it after recomposing.

Russ

Anonymous said...

Russ:

But, but, but, but....won't that mess up your focus lock? Don't you have to aim at the subject, then half press the shutter, then recompose, then shoot?

If I have AE-L and AF-L both set ON, then when I aim at the subject don't I lock the focus and exposure when I half press the shutter?

Sorry, I'm really confused about this one.

Richard

Anonymous said...

Russ:
OK, after reading your response again, I think I get it now....

So what you do is, turn off AE-L in the menus so that when you half press the shutter, it only locks the focus, and NOT the exposure?

Did I get it?

Richard

Russ MacDonald said...

Hi again Richard,

No. When you half-press the shutter only the focus is locked. The exposure still changes as you recompose.

That's what the AE-L/AF-L button is for; to lock the exposure and the focus, so neither will change as you recompose.

Also, the AE-L/AF-L button is usually programmable to change what parameter(s) it locks, and whether you have to hold it in or can release it leaving it locked.

Russ

Anonymous said...

Russ:

Wow! When it all comes together....it's beautiful!!!

Thanks a lot:
Richard

John Meyer said...

Great blog!

Maurizio said...

Hi Russ,
you wrote"I first pointed my flash at the subjects and pushed the FV Lock button to fire the preflashes and lock in the correct flash power. Then, I recomposed the shot to place the subject on the left..."
when you recomposed the shot and fired, flash was pointed in forward position or you turn the head of flash and point it on subjects?
What is better when subject isn't in the center of frame?
Maurizio

Russ MacDonald said...

Hi Maurizio,

Since the flash will cover the whole frame evenly, it doesn't matter that you were initially pointed at the subject and after recomposing, you are pointed elsewhere. The subject will still be lighted at the same amount.

However, it is almost always better to diffuse the flash rather than pointing it directly at the subject whether you are using FV Lock or not. Bouncing from a white ceiling or using a Gary Fong Light Sphere works extremely well. FV Lock works well for all diffusion possibilities.

Russ

Anonymous said...

Russ:

Still reaching to understand.....

Can you lock FV and focus at the same time on a D80?

Still trying to understand the EXACT procedure for taking a shot.

1) If subject is NOT in center, aim camera at subject and press FV lock

2) Recompose shot

3) Press shutter halfway to set exposure

4) Shoot.....WHOA????

Didn't you loose focus between step 1 and step 3?

When to you lock focus on the non-centered subject?

Thanks again,
Rick Hollingsworth

Anonymous said...

Russ....

You said earlier....

"You would only use FV Lock when the flash was the primary light, so you would only use FV Lock when using normal TTL"

Does that also apply to TTL-BL when subject is off-center?

Wouldn't you still need as, as before, to aim at subject and FV Lock the flash, then re-compose -- even for Fill?????

Thanks,
Rick Hollingsworth

Russ MacDonald said...

Rick,

When you use FV Lock, it only sets the power of the flash. It has nothing to do with focus or shutter.

If you want the subject to be in focus, then you have to take other steps. Sometimes you will want the subject in focus and other times not.

Assuming you want the subject to be in focus; after you push FV Lock, you half-press the shutter to lock focus on the subject.

Then, you recompose and push the shutter the rest of the way to take the picture.

Be careful that the FV Lock has not timed out and reset itself by the time you shoot the shot.

Russ

Russ MacDonald said...

Rick,

To answer your other question; when shooting TTL-BL (ie, fill), I never use FV Lock.

I keep the flash head pointed directly forward and let the flash power be set by the distance the lens reports.

Russ

Anonymous said...

Russ:

Ok, I THINK I FINALLY understand enough.....to finally ask my question properly....I think...

So, how do you take the shot (both low and high ambient light), so that the subject (off center) is in focus, flash is set properly, AND...also expose properly so that the background will be a nice soft blurr...nice "bokeh"(sp?), even????

In the pics I sent to you of my daughter, they are either full body, or zoomed in...she MOSTLY fills the frame....and sometimes, the background was nice soft blur, and sometimes it was just dark, and not really there.....Problem is, I really don't know why some came out good, and others did not?

Thanks again,
Rick Hollingsworth

Anonymous said...

Russ:

Look at the picture at the beginning of this article. That is exactly what I am trying to do, yet having so much trouble with....

Exactly, where and when did you focus on them? At the same time you set the FV Lock, or later???

It's setting the focus properly, AND locking the FV that is causing me problems. I can't seem to do both at the same time. When I take the exposure after setting the FV Lock, I loose focus on the subject. It re-focuses when I re-compose the shot and press the shutter.

Thanks,
Rick Hollingsworth

Russ MacDonald said...

Hi Rick,

RE: Focus and recompose problems.

I looked again at your pictures that you emailed me, and I think I see at least part of your focus problem.

Note: Your focus problem has nothing to do with the flash or FV Lock.

There are several ways to do what you are trying to do. I will tell you how I do it.

As a general rule, I use the minimum amount of automation that I need to do the job. In your case, I think you were using some automation you don't want.


The main problem is that you have your camera focus mode set to AF-A. This allows the camera to automatically choose between AF-S and AF-C. If it happens to choose AF-C, then the focus won't stay locked on the half-press. If it chooses AF-S, then the focus will stay locked. You need complete control, so my method is to set the camera to AF-S and use only one focus point. I normally use the center focus point, but you can select any one of the points by using the multiselector arrows on the back of the camera.

Then wherever you place your selected focus point, and half-press the shutter, the focus will be locked in at that distance. Then you can recompose and the subject will stay in focus.

Hope that helps,

Russ

Anonymous said...

Russ:

Thanks, I will try that today, along with the advise you emailed.

Thanks again,
Rick Hollingsworth

Anonymous said...

First, THANK YOU for your effort here!

If I use TTL-BL I don't have to lock FV I understood and I've tested it yesterday. So, why did you use FV lock on the picture with the waterfall background? (TTL-BL should do the job right, shouldn't it?)

One important thing to me: the FV lock you mentioned (thanx again) helps avoiding the "blinkers". REALLY helpful!

Kind Regards from Germany

Klaus

Anonymous said...

one add: I've tested TTL-BL with subject NOT centered and everything worked well.

Klaus

Russ MacDonald said...

Hi Klaus,

I used FV Lock on my example photo because I also used a diffuser and it was pointed up. That means that TTL-BL was relying totally on the monitor preflashes to set the flash power (ie, distance information from the lens was not being used).

FV Lock is always useful for situations where the flash metering is relying totally on the reflected monitor preflashes.

However, if the subject extends significantly into the frame, the center-weighted flash metering will see it and set the exposure fairly close without FV Lock. In my example, I probably would have gotten an acceptable exposure without FV Lock, but it would have tended to be overexposed due to the center area of the frame being quite dark.

Russ

norcon said...

Mr. McDonald, as soon as i read your blog for 15 minutes, i went to amazon to find your book on nikon's cls flash. no book! please put all of your wisdom in a book, it is written in such a clear and practical way, i've already understood much more than the manual or a D700 book taught me. nora

Russ MacDonald said...

Hi norcon,

Thanks for the compliment!

I do this blog for fun and to help other photographers. I think a book would be way too much like work!

Thanks,

Russ

Anonymous said...

Hi Russ,

Very informative blog you have. I have some questions regarding the FV lock.

1. Do we have to aim at the subject using the central focus point (moving the focus point to the centre) and then press the FUNC to lock FV? Or we can actually use any focus points?

2. Do we have to focus on the subject first before we lock FV? So that the TTL can actually know the distance of the subject.

Thank you for your time and response.

Russ MacDonald said...

To Anonymous,

(please sign your name when you ask a question - there entirely too many Anonymous's)

The flash always meters the center of the frame regardless of which focus area is chosen. So, choosing different focus areas has no effect on the flash power.

You just center your subject in the frame and push FV Lock. It doesn't matter which focus area you have chosen.

I actually studied this in my blog #16 here: http://nikonclspracticalguide.blogspot.com/2009/10/does-moving-focus-points-affect-flash.html

Regards,

Russ

filipe m. said...

Hello Russ,

First of all, thanks for all your work in explaining to "normal" people what CLS is. The ammount of work you've put into this is nothing short of amazing.

Just a quick question, though:
Second, slow sync is also 'rear' sync, so the ghost trails will fall behind the sharp image from the flash when there is movement.

I thought these two settings were independent, i.e., you can set "slow sync" to allow the cameras P and A modes to fall below the custom set minimum flash speed, but still get the flash to fire at first curtain? At the same time, you can set "rear sync" at any sync speed (not that it matters that much above 1/200s or so...).

Can you please confirm this?

Thanks,

Filipe

Russ MacDonald said...

Hi Filipe,

You are exactly right, and you have caught an error that I made.
I will fix the wording in the blog to make it correct.

To restate all the cases:

In camera A and P modes you can select Slow without Rear, but if you select Rear it automatically adds Slow.

In camera M and S modes, you can select Rear without Slow, because Slow doesn't mean anything when you are setting the shutter speeds manually.

Thanks for catching that!

Russ

Russ MacDonald said...

Hi Filipe,

Well, it took me a while, but I found the comment that was in error. It was in one of my answers to a question on this blog.

What I meant to say was that in camera A and P modes, if you choose Rear sync, it will also put the camera into Slow Sync. Slow Sync will cause slow shutter speeds that will cause ghost trails. Then, Rear Sync will put the flash frozen image on the correct end of the motion blur.

Russ

Volker said...

Hi Russ,

many thanks for all the work you put into that site. It is fantastic!!!

Being a flash photography beginner I just realized that my D60 doesn't support FV lock (or am I just not seeing it?). Is there a way to work around?

Thanks and best regards
Volker

Russ MacDonald said...

Hi Volker,

Thanks for the nice feedback!

Unfortunately, you are right. As far as I know, there is no way to do FV Lock with the D60.

Sorry,

Russ

Kevin said...

Russ, hi (a previous anonymous poster again) added my name for brevity :)
I have read every one of your blog entries, and may have missed the obvious? Thanks for your faster than speedlite responses :)

I am unable to overpower the ambient (IOW, turn to black the backgrounds)
Setup:
Night time, indoors.
SB-600, correct exposure (camera meter) is 1/6 @ f/5.6 @ 200mm. ISO400.
Subject is about 8ft from lens, bkgd about 5ft from subject.
I crank the shutter up to 1/500s (D50 - nice to have that capability)and aperture to f/8, and the result is the same. Ambient is sill clearly visible, mbe a tad darker than exp.1.
I mean, that's 7 stops of adjustment, is the flash THAT powerful?
I tried TTL, BL, and FV lock.
Where am I going wrong pls?
---------------------------
Then, I was experimenting with the built in wide angle diffuser (14mm setting) on the SB-600 bounced off ceiling or wall, and noticed something very interesting. The fill in dark ambient from this is noticably better than a regular bounce with a homemade bouncecard. Where the card had left shadows in certain areas, the wide diffuser lifted all those easily.
Your experiences with using that diffuser if any pls?
Looking forward to your reply.

Russ MacDonald said...

Hi Kevin,

I think you are one of a few who have read all my blogs! Congratulations!

With an ambient of 1/5th, f/5.6, and ISO 400, you will definitely eliminate the ambient on the subject when increasing to 1/500th and f/8. You can prove this to yourself by taking a picture at those settings. It will be very dark.

Then, if you turn on your flash and the subject and the background are both bright, that's coming from the flash. this will happen when the subject is too close to the background.

To get good control of the background, the distance from the camera to the background needs to be more than twice the distance from the camera to the subject. The farther away the background, the more control you will have of background exposure.

It is in the distance behind the subject where the flash power dissipates. It does this according to the Inverse Square Law. In other words, if the distance from the camera to the subject is 5 feet and the distance from the camera to the background behind the subject is 10 feet, the flash power will be down to 1/4th the power it was at the subject. That's two stops, so the background will be two stops darker than the subject. Then, if the ambient was set to expose three stops dark by the camera, then the background will be down by 5 stops, and that is pretty dark.

If the background is 20 feet, the flash power will be down to 1/16th the power it was at the subject. That's four stops. By then the background will be almost completely black in the image.

However, this can be affected by a highly reflective room where a bounce will reflect strongly throughout the room creating a focus effect that doesn't follow the normal square-law falloff. Think of the zoom function on the flash. This is a special focusing mechanism that reduces the power dissipation to somewhat less than the normal inverse square-law function. Rooms with highly reflective walls can sometimes do this wich leaves the background brighter than it should be. The opposite also occurs in rooms with dark walls. In that case, the background will often end up darker than the inverse square law predicts.

To reduce the background brightness in a highly reflective room change the bounce direction. I often turn the flash head completely around so that it is aimed directly backwards and bounces off less reflective surfaces behind me.

Hope that helps,

Russ

Jeff said...

Hi Russ,

I'm starting to play with multiple off camera flashes. I'm going to be doing some wedding formals for a coworker next month. I'll be using 2 sb800s through 2 43" umbrellas for the group shots. I'll use my su800 of possibly a third sb800 as the commander. So here is the question. Does FV lock work with off camera flashes? I'm going to be using a tripod for the group formals and it would be really nice if the look of the shots was consistat and I didn't have to fix to much in post.
Thanks for your time

Jeff Maanum

Russ MacDonald said...

Hi Jeff,

Yes, FV Lock works great for off-camera flash. It definitely keeps all the shots looking the same.

However, it's important to know that FV Lock resets itself when the camera meter times out. You have to go into the camera menu and find the meter timeout and extend it to the maximum when shooting group shots. Otherwise it will time out and you won't notice it.

Also, I stopped using my SU-800 for portraits with my Remotes in umbrellas, because the SU-800 sends the commands forward and up, but not very strongly out to the sides. I was having cases where my flashes in the umbrellas to the sides or behind me weren't firing.

I also had no-fires when using the camera in vertical orientation. The camera sometimes blocks the Commander signals that fire the umbrellas on my right.

So, I went back to using an SB-800 on-camera as the Commander with a diffuser attached and pointing straight up to send the commands out in all directions. That is much more reliable.

Also, the preflashes won't make your subjects blink when using FV Lock!

Still, you have to remember to orient the flashes in each umbrella so the small round red IR window is pointed at the Commander.

Also, I usually use reflecting umbrellas, because the Remote is easier to 'hit' from the commander. In shoot-through mode, the umbrellas sometimes block the command signals. Sometimes they go right through, sometimes they don't.

Hope that helps,

Russ

Jeff said...

Thanks for the quick response Russ.
I did some portraits last weekend in a warehouse. The STU and sb800 was just to my right. I was having trouble getting the su800 to trigger the flash unless I was slightly behind the flash. Then I tried something different. I pointed the sensor away from me and at the model. Worked flawlessly for the rest of the shoot. Apparently the signal from the su800 bounced off the model and then back through the umbrella to the sensor. I was able to move around alot and could get shots close to the model with the umbrella and flash behind me and the camera.

Great blog, between you and Joe McNally I'm starting to figure this CLS stuff out.

Jeff

Russ MacDonald said...

Hi Jeff,

Yes, if the model has light colored skin and or is whearing light clothing this will work. But watch out - it won't work all the time.

Thanks for the nice comment, but I don't think I'm quite in the same league as Joe McNally. He does some of the most amazing work with speedlights! I love to watch his videos!

Russ

Peejay said...

Hi Sir,

I'm just wondering, in handling multiple flashes, and using the camera as commander, how will you do the FV lock? do i just need to point the camera at the subject, then press the FV button? or do i still need to put the AF point on the subject and hit half shutter as well?

In addition, since only the camera will be pointed to the subject, how will the other external flashes lock the exposure on the subject?

Appreciate your help on this :)

Russ MacDonald said...

Hi Peejay,

The Wireless CLS system is very sophistocated and it basically takes care of itself.

When using multiple flashes, all you do is aim at the subject and push the FV Lock button. The system automatically cycles through all the groups and sets the power of each group separately, and if there are multiple flashes in a single group they all get set to the same power, and together they will all add to the correct amount.

The system works best when each group hits the subject with its preflashes somewhere on the front so that a good return is reflected back through the lens. If a group is positioned so that it hits the subject directly from the side, then the power will sometimes be set too high as the system tries to get a standard power reflected off that group.

When you fire the FV Lock, all the calculated power settings are stored in the flashes themselves, and they are all sitting there ready to fire.

Then when you press the shutter, as soon as the shutter is open, the Commander sends the 'fire' command, and they all fire simultaneously.

This is why FV Lock stops the blinking problem. It is virtually impossible for anyone to blink fast enough after the fire command so that eyes will be closed. The only closed eyes you have are from chance blinks (or someone who is watching your finger and closes his eyes as he sees you push the shutter). That's why I always hide my shutter finger as I push the shutter.

Russ

peejay said...

Thanks Russ!! :) appreciate your thorough explanation on this :) Now, i'm really liking the CLS features of our nikons :)

peejay said...

Thanks Russ!! :) appreciate your thorough explanation on this :) Now, i'm really liking the CLS features of our nikons :)

Russ MacDonald said...

Hi Peejay,

You're most welcome!

Have fun with CLS!

Russ

JW Stephenson said...

Russ,

Just now playing with FV Lock on my D700 with SB600 mounted on-camera. As a test, I fired a normal shot at a subject. Then hit FV Lock and fired the exact same shot. The shot with FV Lock appears to be about 1 stop brighter even though the framing was exactly the same. Is this an expected behavior?

I shot totally Manual for ambient to eliminate any camera adjustments and ISO was fixed as well. Thoughts ...

Jeff

Russ MacDonald said...

Hi JW,

I have seen the same thing. It is definitely setting the power of the flash too high (or in many cases, too low). I believe it has to do with an adjustment on either the flash or camera. Since the flash power is consistantly too low or high, I just apply flash compensation whenever I use FV Lock.

My D200 is about one stop too dark, and my D3 is right on.

Nikon may be able to adjust this if you send them your camera and flash.

Regards,

Russ

nabil said...

Hi Russ,

I'm very new to this CLS and trying to absorb as many as i can.Your blog seems to be understandable compared to other websites and i thank you for that

From what your wrote:
"I first pointed my flash at the subjects and pushed the FV Lock button to fire the preflashes and lock in the correct flash power. Then, I recomposed the shot to place the subject on the left 1/3 line (rule of thirds), and released the shutter"

So from what i understand:
1. Aim at subject
2. Push FV lock for preflash
3. Half press shutter button after pressing FV(is that what you mean by "lock in the correct exposure", and do you have to hold half press for recomposing?)
4. Recompose picture (with the half press held from the previous step?)
5. Full press

Thanks

Russ MacDonald said...

Hi Nabil,

No, not quite.

When I pressed FV Lock, it fired the preflashes and the flash exposure system locked in the correct flash power automatically, based on the subjects in the center of the frame.

I didn't mention it, but after FV Lock, I half-pressed the shutter to lock focus on the subjects.

Then, I recomposed and completed the shutter push.

Nowhere did I lock exposure or say that I locked the exposure. The flash locked its own power, but the camera exposure was set manually with the shutter, aperture, and ISO that I chose.

Russ
Then, I recomposed to place the subjects at the edge of the frame

nabil said...

Thanks for the explanation Russ! much appreciated!

Anonymous said...

Hello Russ!
Congratulations for your blog, very helpful indeed!
I hv a D90 and a SB-600. I found very difficult to use TTL together with FV Lock for shooting indoor parties. I was like having to meter the flash almost in every shot, and I wasn't getting a constantly light. Plus I hd to advise the people that the first flash wasn't the "real" picture, that it was just for meterng the light.
Can I get the same results using the flash in manual mode and use the shutter to 1/15th?
Is there any tip you can give me for manual mode?

Newton said...

Sorry, my name is Newton..
Hello Russ!
Congratulations for your blog, very helpful indeed!
I hv a D90 and a SB-600. I found very difficult to use TTL together with FV Lock for shooting indoor parties. I was like having to meter the flash almost in every shot, and I wasn't getting a constantly light. Plus I hd to advise the people that the first flash wasn't the "real" picture, that it was just for meterng the light.
Can I get the same results using the flash in manual mode and use the shutter to 1/15th?
Is there any tip you can give me for manual mode?

Russ MacDonald said...

Hi Newton,

FV Lock is not for shooting parties. At a party your distance to your subjects is constantly changing. Once you lock in a flash value, you cannot change distance to your subject.FV Lock is for setting the flash power for an off-center subject or for controlling blinks. You have to make sure your distance doesn't change.

For shooting parties, let the Nikon TTL do its magic. Use regular TTL with -0.3 FEC, and put the camera in Manual mode at 1/80, f/4.5, and ISO 400.

You'll get great shots in most party lighting.

Russ

orim said...

just thought this article on fp high-speed sync mode is interesting
http://www.kenrockwell.com/tech/syncspeed.htm

Anonymous said...

Hi Russ,

I'm looking at D600 Manual, looks like for multiple flashes the CLS will count the entire frame instead of just the center frame ?.

John