Tuesday, August 12, 2008

14. Basics of Flash Brackets and Diffusers

I am often asked about diffusers and brackets. Photographers mostly want to know what they do and which ones are best.

Well, both the bracket and the diffuser were introduced into photography to solve the problems of the small flash.

The problems of a small flash, when used pointed directly at the subject, are that it makes harsh, flat light, that often causes 'Red-Eye', and, when turned to the vertical, casts a harsh shadow to the side of the subject.

HARSH LIGHT

In general, harsh light comes from a physically small 'apparent' source. An infinitely small source is called a 'point' source, because the light comes from a single point.

I use the word 'apparent' because the both the size of the source and its distance from the subject cause the apparent size to change from the perspective of the subject. For example, one of the harshest light sources is also one of the largest - the sun. It is huge - over 800,000 miles in diameter, but it is so far away 93,000,000 miles, that it acts as a point source to a subject here on earth. In other words, its apparent size is very tiny. This type of light casts very harsh shadows and makes facial features appear dull and lifeless.

The solution to harsh light is diffusion. Diffusion is the process of scattering the light from a point source so that it acts like a much bigger source. Think of the sun on an overcast day. The light still comes from the sun (effectively a point source), but the clouds scatter the light as it falls on the earth so that is becomes some of the softest light you can find. In effect, the clouds have changed the apparent size of the sun from a point source to a source the size of the entire sky. You can make extremely good portraits on an overcast day outdoors, where the facial features have nice texture and seem to come alive.

The shoe-mounted flash is also a very small physical size size (about 3 square inches) and is an effective point source beyond a foot or so. Consequently it makes extremely harsh light that is not suitable for portraits without modification (diffusion).

Now, some people think that simply putting a diffuser in front of the light will make it soft, but this is not the case, because that does nothing to increase the apparent size of the flash.

There are two ways to create diffusion when using a small flash. 1) utilize a physically large 'retransmission' system or 2) bounce off large surfaces. You can also use a combination of these two.

A 'retransmission' system is usually made from a large piece of translucent material that is lit by the flash that then retransmits the light evenly across its surface. The Gary Fong Light Sphere II is such a system. It looks like an inverted Tupperware bowl that is mounted on the flash. Then, the flash is pointed straight up and when it fires the whole translucent bowl lights up. In fact the cross section area of the bowl is about 16 square inches, or about five times larger than the flash itself. This softens the light so that portraits made within about five feet are noticeably softer than the bare flash.

Another even better 'retransmission' system is a soft box. If you get one that is 36 inches by 48 inches, that's 1728 square inches of area. This is 108 times larger than the Light Sphere, and creates light that just as soft as the light on an overcast day outside.

The problem is portability. How big is too big to carry mounted on your flash. My personal feeling is the the Light Sphere II is about as large as you can conveniently handle under normal circumstances.

As you probably know, the SB-800 flash comes with a small snap-on diffuser. If you own an SB-600, you can buy an after-market snap-on diffuser from companies like Sto-Fen. Just looking at this snap-on diffuser, you can see that it is physically very small and the question is: does it work? It is obviously not much bigger than the bare flash itself, so it cannot increase the apparent size of the flash directly. However, think of this small diffuser attached to the flash and the flash pointed straight up. Then when it flashes, the light scatters to the sides, up, back, and everywhere but down. This means some of it goes directly to the subject, but most of it goes towards walls and ceiling where it can bounce, sending some of the bounced light back at the subject. The key is that the bounced light hits the subject at a different angle than the direct light. This different angle is what makes the apparent size of the flash much larger. So, there is a small portion of the light which is still harsh that goes directly at the subject and the rest that bounces off walls and ceilings is soft. The small amount of harsh direct light is what makes the 'catch-light' reflection in the eye of the subject and is not objectionable.

The reason the Light Sphere II works so well is that it is large AND it scatters light in all directions. This makes it work extremely well indoors where the direct light is much softer than the small snap-on diffuser, and the walls and ceilings all increase the softening effect more than with the small snap-on diffuser.

Now, outdoors, all the light that scatters from a diffuser is lost forever. It never makes it back to the subject. This leaves the subject lighted entirely by direct light from the flash which is still harsh because the apparent size of the flash is still small. So, outdoors, the only thing that happens if you use a diffuser is that your flash batteries run down quicker, because the flash has to flash at a much higher power to light the subject than normal. The bottom line is that outdoors, never use a small diffuser; just use the flash direct. However, the Light Sphere II is useful outdoors due to its large size which softens the direct light out to about five feet.

SHADOWS AND RED-EYE CONTROL

Flash shadows are always objectionable and you should always strive to eliminate them.

Red-eye is also extremely objectionable. It is caused by the flash reflecting off the retina of the eye and back into the picture. Red-eye is best addressed while taking the picture, but can also be somewhat corrected during post-processing. I will discuss how to avoid causing it in the first place.

The solution to the red-eye and shadow problem is to raise the flash higher above the camera while keeping it directly above the lens axis. This can be achieved with either a flash bracket or a flash diffuser that sits high above the flash.

The flash bracket attaches to the tripod mounting hole on the bottom of the camera and the flash mounts on its top directly above the lens. It raises the flash several inches higher than when the flash is in the hot shoe. Then, there is a cable that attaches the hot shoe on the bracket to the hot shoe on the camera, so that the camera thinks the flash is still in the hot shoe.

The main reason for raising the flash higher above the camera is to force the flash shadow down behind the subject where it can't be seen. The LS-II diffuser also raises the flash high enough to fix the shadow problem when the camera is in the horizontal orientation.

Also, by raising the flash higher above the camera, the angle of the direct light causes the red-eye reflection to fall below the camera lens. This simple step elimintes 99% of the red-eye problems. It is important to note, however, that the farther you are from the subject, the higher the flash needs to be raised to avoid red-eye. For instance, if you are using a telephoto lens, and you zoom tightly onto a person's face from 30 or 40 feet away, you risk red-eye.

So, the solution to red-eye is also the bracket, although with a DSLR, the flash is already much higher above the camera than with a point-and-shoot, so red-eye problems are less of a problem.

There is another very important feature of a flash bracket - it fixes the dreaded 'side shadow'.

When you turn the camera to portrait orientation (vertical), and the flash is mounted in the hot shoe, you cast a shadow to the right of the subject on a wall. This shadow is very unprofessional and is to be avoided at all cost. With a flash bracket either the camera or the flash rotates so that the flash always remains directly above the camera. By locating the flash above the camera, the shadow will now fall behind the subject and out of sight.

This is a disadvantage of using the Light Sphere II diffuser. The LS-II still casts the side shadow, although it is less defined as with a bare flash. Often when I want vertical orientation while I am using the LS-II, I simply shoot horizontal and crop to vertical later in post processing.

Another important consideration with a flash bracket is the direction you rotate the camera when going to to vertical. Most professional photographers rotate the camera counterclockwise so that the alternate shutter release button is on top and useable. But some flash brackets for some unexplicable reason force you to rotate the camera clockwise, so you have to be careful when buying. I use a Custom Brackets 'CB Junior' with my D200 and SB-800. It is relatively inexpensive at about $110 and works well.

66 comments:

Anonymous said...

This is interesting post. I just recently realized this issue with the small snap-in diffuser of the SB800. Now you confirm it pretty useless outdoor. I only shoot direct with SB800 outdoor now.

Thanks again for the interesting post.

Russ MacDonald said...

Dundee,

Thanks for the feedback!

Russ

Raymond said...

I always wonder the usefulness of the small snap-in diffuser; but now I know more on how & when to use it more effectively. Thanks again for your great article!

Russ MacDonald said...

Hi Raymond,

You are most welcome! Please let me know if anything is not written clearly enough.

Thanks!

Russ

Anonymous said...

Exceptionally well explained and well written. Thank you.

Russ MacDonald said...

Fred,

Thanks for the kind feedback, and you are most welcome!

Russ

Russ MacDonald said...

z-vet,

Thank you!

Russ

Anonymous said...

Dear Mr. MacDonald,
I have learned a lot from your CLS articles. Your's is the best I have came across about the CLS. Hope Nikon listens to you. I have never used the Sb's in groups. If you have time can you please post an article on that.
Regards,
Rengarajan J

Russ MacDonald said...

Rengarajan J,

Thank you for the kind feedback on my blog articles.

I am working on a couple more articles and hope to complete them soon.

Based on your request, I will also write an article about how to use remote flashes in different groups.

Thanks again,

Russ

Unknown said...

Hi Russ,

Thank you for showing us the light! :) Your explanations are perfectly comprehensible.

One question, have you ever used the Gary Fong Whaletails? These are supposed to be a diffuser that allows us to not have to use brackets...

Thank you again.
Kim O'Neil

Russ MacDonald said...

Hi Kim,

Glad you can now see the light!

No, I have not used the Fong Whaletail. I thought about it, but it is considerably larger than the Light Sphere, and that is BIG enough.

Also, I don't know any experienced photographers who are using one. I may give it a try after I hear some good feedback from a few people.

Incidentally, I don't normally use a bracket when using the Light Sphere. I just watch the right side of my subject closely to make sure there is no wall there for when I go vertical. In fact, I shot a Wedding Rehearsal Dinner last weekend and only used the Light Sphere. Here are the pics:

http://russmacdonald.smugmug.com/gallery/6177522_6dnCP#389621489_ZwzPU

Thanks for the nice feedback,

Russ

Anonymous said...

Hi Russ,

Great Blog. Lots of helpful info for everyone out there who are interested in photography.

Was wondering do you use the Gary Fong Light Sphere 2 Cloud or Clear or both for your photos?

I strive to eventually take as great of photos as you do.

Russ MacDonald said...

To Anonymous,

Thank you for the nice compliments!

I have both the Clear and the Cloud versions of the Gary Fong Light Sphere II, but I use mostly the Cloud. The light from the Clear isn't as soft, and sometimes appears to make light patterns on the subject, especially if you are close. The Clear will give you a small amount of extra range, but I have rarely found that to be needed in the work I do.

Russ

Anonymous said...

After I have read all the topics of this very useful blog (many thanks for writing this all), I still have one question not answered.

Why the SB800 doesn't work properly in TTL remote.

If setting the D200 pop-up to commander and setting the SB800 to groep A Remote TTL on the SB800 and D200 (group A CH1 DLL FEC=0), the scene comes out underexposed by at least 1 full stop.
Even when using FV or setting the subject in the middle of the scene. It is getting worse if you use any light modifiers such as an shout trough or reflective umbrella or softbox.

Russ MacDonald said...

Hi Kurt,

Remote TTL is a very complex operation, and the system will tend to under rather than overexpose. This is because it has no idea how you have set up your flashes and whether or not there are places on the subject that will receive lighting from two or more remotes. It tries to protect you from blowing the highlights.

When using two Remotes in a 'standard' setup, where you have a main and fill that are on opposite sides and 45 degrees off the camera axis, the exposure turns out just about right.

If you use a single remote, you usually have to increase its power by +1.0 ev or slightly more. I just increase it before I ever take the first image.

I have also found that on the D200 that using FV Lock underexposes by about 1 stop regardless of the setup. When I use FV Lock, I just increase the flash by +1.0 ev higher than the correct setting without FV Lock. I think this may be an anomally with the D200, and I have heard of this problem with other Nikons.

Hope that helps,

Russ

Jim said...

Russ,

Thanks for the CLS Guide! I have never been happy with my flash photographs, and now see why. Your articles are clear and easy to understand.

Like other replies you received, I got very little from the Nikon manuals to help me.

Thanks again,
Jim

Russ MacDonald said...

Hi Jim,

Glad to hear you find my articles useful. Yhanks for the compliments.

Russ

Unknown said...

Hi Russ

I was at a fashion catwalk few days ago and the catwalk was terrible illuminated. Whoever looked after the light setup decided to position a number of spotlights on the floor illuminating the models from bellow. They all looked like in a spooky camp story (when we were holding a torch under our chins trying to scare our mates). Anyway..my question is how to deal with these situation when we use the flash but the model is strongly illuminated from bellow. What would you recommend?
I have attached an example here. Please note the shadows around her mouth.

http://photovidiu.smugmug.com/photos/452857090_cC59U-L.jpg

Many thanks

Ovidiu

Russ MacDonald said...

Hi Ovidiu,

Yes, I see the shadows. However, something else looks wrong as well. The colors don't seem right on her face. It's almost like her face is dirty.

Anyway, more fill flash should fix the shadows. I would probably use a Gary Fong LS II to soften the flash a bit and set the camera on ISO 200 1/60th and f/4.5.

Russ

Unknown said...

Hi Russ

Her face is not dirty. I have been studying all the photos I took at this event and most of the models there display the same problem. their face or their hands looks very "dirty". I got into a lot of suppositions thinking what could generate this effect until my wife came, she looked for a second at the screen and said "Yeah. Fake tan!". :) She was right. It was fake tan sprayed quickly and badly . Anyway. I fixed the shadow issue with the help of CaptureNX.

ozzy said...

great article. very informative. will leave diffuser off outdoors from now on. found that some daylight outdoor shots were washed out even when i used a sb800. was wondering if there was enough power or that i was too far from subject since i was using diffuser. thanks for your advice.

ozzy

Russ MacDonald said...

Ozzy,

Thanks for your nice feedback!

Russ

Unknown said...

Hi Russ

How is the Gary Fong LSII working on continuous shooting? Does it overheat?
Thank you

Ovidiu

Russ MacDonald said...

Hi Ovidiu,

I have never seen any difference in the heating of my SB-800 whether I use the LS II or not. I think a lot of the heating of the flash is due the heating of the batteries, and those are not enclosed when using the LS II.

Russ

Russ MacDonald said...

Gene,

I deleted your post by mistake.

I'm not sure what you mean that you are being 'short changed' in the strength of your SB600 flash.

The Guide numbers are different depending on the zoom position of the flash head.

The SB-600 is around 100 at 35mm.

The SB-800 is 125 at 35mm, and 184 at 105mm.

The Canon 580ex flash you mentioned is about 200 at 105mm, so it is slightly more powerfull than the SB-800.

Russ

Anonymous said...

Your articles are wonderfull, the Best online course of Nikon Speedlight. Thanks for your great work.
Kati

Russ MacDonald said...

Kati,

Thanks so much for your nice comment!

Let me know if there is anything you need more info about.

Russ

Golikov Andrey V. said...

Hi guys! Sorry English is not first my language. I hope you are understand my post:)
Thank you very much for this really useful blog. I find answer on many of my questions in work with CLS and TTL flash. Maybe I have one question how TTL work when flash direct to back of object, or on background, or when you shoot big object, when you use a few flash, not all of which direct on center of object. In this situation I think TTL work unpredictable, more accuracy in this situation use А/AA mode, when flash to measure own light.
I think about reason of preflash. I see a few reasons and write all my ideas, even those I consider incorrect, maybe it suggest you to correct answer:)
1. Construction reason. Flash need to correct impulse power regard to aperture value. Maybe while preflash happen, flash to measure impulse for 1 f/stop, and only after recalculate impulse power for given f/stop.
But in su-4 mode flash work without preflash, maybe it’s incorrect idea.
2. White balance, I'm sure what flash don't change color while change power of impulse (flash change power of impulse by impulse length). It's main reason of my friends pro photographers which use impulse light, instead halogen unit. They can change light power, without changing color balance and position of units. But SB800, SB900 can use colored filters, maybe it's important for camera, and camera need preflash to determine color of flash, to correct determine of WB.
3. In wireless mode, all group flashes one by one. Maybe preflash use like signal for next group, what they can make preflash, if it will in TTL mode, for example. But I don't know how work group in “off(--)” mode and M mode. Maybe group use time separate method for preflashes.
4.1 All new Nikon flashes can fire without waiting of full charge. Maybe preflash need to guaranty of enough of power for selected F/stop.
4.2 Flash have signal about not enough charge. How flash determine out of power, in preflash stage, or every times then it fire on full power. Maybe preflash need for determinate what power not enough?
5. FV Lock. You are use FV lock for reframing, but it's should work with change of shooting objects too. Then you press FV Lock, flash must make the same impulse regardless of changing of main object. So they make preflash, and remember flash power, and use this power value again and again for next shoot.
I make test, when flash in SU-4 mode and AA, we can't use FV Lock, maybe because flash don't make preflash.
:)So… When I write this big post, and on another language for me, I think I find answer:)
Main reason of preflash:
1. FV Lock function
2. Auto WB for working with Color filters.

I hope somebody can decode (understand) what I write:))) And sorry for this hard work:)))
Thank you again for really useful information about Flash working, and practice example. Bye Bye!

Russ MacDonald said...

Hi Golikov,

I am having trouble understanding your comments, but I will try to answer. Your questions don't appear to relate to the topic of the blog, "Basics of Flash Brackets and Diffusers".

Anyway, your comment about multiple flashes aimed at a large object "not all of which direct on the center" makes me think you are really replying to my other blog about A/AA modes.

I'm not sure I know what you mean by "impulse power". The word "impulse" is not normally used in flash system engineering. In engineering mathemetics, "impulse" means an infinitely short pulse of infinite power used to exciting a network and measuring its response. I think you are talking about the main flash pulse.

I think your numbered comments are your speculation about why there is a preflash pulse in AA mode (in response to my pondering in that article. It would have been better to put your comments after my A/AA blog article).

Then, I think at the end of your comments you have concluded that you know the reason for the preflash in AA mode: FV Lock function and Auto WB.

You may be right! If I get some time, I'll see if I can devise an experiment to prove it.

Thanks,

Russ

Anonymous said...

Russ: About the GP LS II - I use a D80 and an SB-600. How would you use the LS-II outside in sun? I tried it last week on the beach to add fill, but it didn't seem to do any good. Still got raccoon eyes.

Bright sun, around 1:30, Florida, LS-II pointed AT subject with dome on. Camera was on manual - I think - don't know SS or Ap.

Any help appreciated:

Richard

Russ MacDonald said...

Hi Richard,

When I shoot fill flash in bright sun, I do not use any diffuser. The diffuser weakens the flash so much, that there is often not enough power left to add the required fill.

You see, when shooting fill, the amount that the flash adds to your overall picture is fairly small, so you normally do not see any difference between using diffusion or not.

So, for fill, I recommend pointing the flash directly at the subject and using TTL-BL mode with matrix metering.

In addition, it also helps to use a flash bracket when shooting fill That will get the flash up higher, which will add some modeling to the shadow areas on the face, which will make the fill appear slightly less harsh.

Hope that helps,

Russ

Anonymous said...

Russ:
Very interesting. Thanks for the info. I DID forget to mention that I bumped the FV up to +3.0 on the 600, but that didn't help either.

The reason I used the LS was because I discovered it on a recent trip to Disney World in Fl. All the Disney photographers were using it and we were usually 15-20 feet away from them - HOWEVER - I noticed they only used it at Dawn and at Dusk - no other time.

Richard

Russ MacDonald said...

Hi again Richard,

If you increased the flash to +3.0 ev and that didn't help, that is a clear indication that the flash was already firing at maximum power. Also, if you look at the back of the flash right after firing, if it didn't have enough power, the 'ready' light will flash for a few seconds, and the display will show how many ev low you were; ie, it might say -2.0 ev to indicated the flash was too weak for that shot by 2 ev.

Russ

Russ MacDonald said...

Richard,

I forgot to address your other point.

Of course, when the light gets less like at dusk, then the flash becomes a much bigger part of the exposure, and at that time of day the light is dim enough that the LS works great. I always use the LS at dusk for the same reason.

Russ

Anonymous said...

Russ:

Wow! Thanks a million. I am now much more confident using the LS II outside and feel I would have done a much better job of those beach portraits had i knew all this before. Seriously, I am now a better photographer thanks to you.

Kudos!
Richard

Russ MacDonald said...

Richard,

You are most welcome!

I am always glad to make a better photographer! :)

Russ

John Meyer said...

Great blog!

steinv said...

Hi, Thanks for the nice CLS guide.
I need to shoot the Dance competition in the ballroom ( low light and High ceiling). If I'll use the sb-800 on the bracket with snap-in diffuser will the switch on the flash will disable the zoom feature of the flash and it will default to 24mm only? I will be using Nikkor 85mm/1.8 and would like to get as much power from from the flash as possible. What are my options? Thanks in Advance

Chris Fung said...

Hey Russ,

Thanks for all your hard work. Reading your articles has fortified my understanding as well as teach me things I've never considered.

I have a question about using the lightsphere and ceiling height. What would you consider a maximum ceiling height until it seems impractical to use a lightsphere? What alternatives do you recommend for high ceilings? Thanks for your time and reply!

Russ MacDonald said...

Hi Chris,

Thanks for the nice feedback!

If you are in a situation where there is a high ceiling, simply try the Light Sphere it to find out if it will work. Try it with and without the inverted dome to see which way gives better results.

If you leave the inverted dome off, then you will have much more flash power headed toward the ceiling for a bounce. I usually shoot without the inverted dome when I want a ceiling bounce. This greatly reduces the amount of direct flash in the image.

If you can't get a bounce, just leave the inverted dome on the LS and see how much it will soften the light. The LS will provide some softening out about 10 feet. Beyond that, it still gets the light higher above the flash than with the bare flash, so it is usually better than a bare flash out to about 20 feet.

However, beyond about 20 feet, I have found the bare flash is always better.

Hope that helps,

Russ

Chris Fung said...

Thanks Russ!

I feel much more confident now about using the lightsphere as a primary light source without bouncing it off a ceiling. Having a distance to gauge the effect of softening with the lightsphere on will definitely help!

I think you might of addressed this question in a previous reply; I hope you don't mind me asking if it has already been dealt with previously. When using bounce flash with the lightsphere, what is your usual working distance between yourself and the subject. What would you consider a maximum working distance. I know many of these things can be figured out by field testing, but it's always nice to hear it first hand by a professional :)

Thanks again Russ!

Russ MacDonald said...

Hi Chris,

I try to stay within 10 feet of my subjects when using the LS. That gives me very nice softening, especially when there is a good ceiling bounce.

Beyond 10 feet, you will sometimes run out of flash power, in addition to losing softening.

Some people point the LS directly at the subject when farther away, but I have tried that and I see very little benefit over a bare flash.

Russ

Unknown said...

Hi Russ and thank you for all your help. Do you, by any chance, have any experience with the Lastolite EZYBox? I contemplate getting a 60cm square and wonder if they are any good for weddings. Please note that I shoot without any assistant..so I dont know how am I going to manage to hold the camera and the soft box. Any tips?
Thank you
Ovidiu

Russ MacDonald said...

Hi Ovidiu,

I don't use soft boxes when I shoot on-location, for the very reason that they are hard to handle. I find that unbrellas work just as well, and they are easy to handle.

In fact, I often use just a Gary Fong Light Sphere II at weddings (when I am too short on time to set up the umbrtellas). It does a great job of softening the light for many situations.

Russ

Unknown said...

Russ.
Thank you for your answer and sorry to bother you again. Which LS would you recommend? The clear version or the Cloud one?
Many thanks again for all your help.

Russ MacDonald said...

Hi Ovidiu,

I like the Cloud LS better than the Clear, because it makes softer light and only reduces the flash distance a small amount.

Russ

R.Campbell said...

Absolutely outstanding your Blog Russ, i hope you don't mind i have printed your articles out into a book, very helpful and much appreciated.

I use a D90 as well as D300 and i'm starting to get into off camera flash. Had the SB-600 for quite sometime and added the SB-800 to my kit. I'm relatively new to Nikons CLS system so your Blog came in real handy for me.

Thanks again

Ross from Auckland, NZ.

Russ MacDonald said...

Hi Ross,

Thanks so much for the nice feedback. No, I don't mind you printing them out. Don't forget to read the Q&A after each blog. I've discussed many new points there that I have not had time to go back and add to the main bodies of the blogs.

Also, although I do use the flash off-camera quite often in my own work, I haven't talked much about it in my blogs. I plan to do that in the future, but so far, the on-camera issues have been enough to deal with.

Russ

Alexandra Holtzman said...

great blog! I was wondering what are your thoughts on this one?
http://photo-tips-online.com/review/lumiquest-softbox-iii-flash-diffuser/

You said big ones are better, this one's much bigger than Gary, does it mean it'll be better? I am just looking for a nice universal diffuser

Bipin Nair said...

Excellent and very informative.Thanks for sharing Russ.
After going through this post ,I have searched for Gary Fong Lightsphere and saw that there is a new collapsable version.It looks like Cloud ,but one of the demo video shows that it actually is see through ,but not Clear. Did you get a chance to use this? any comments ?
Also ,when you use lightsphere outdoors ,in a condition where you are only 15 feet (or less) away from subject and no walls or anything to bounce ,do you point it straight to the subject ? Also , do you use the Dome in such situations?

Thanks once again Russ.

Bipin

Russ MacDonald said...

Hi Bipin Nair,

No, I have not used the collapsable Light Sphere. However, the principle is the same. If it is the same size as the regular LS, and it is cloud colored, then it should work just as well.

At 15 feet outdoors, almost anything you do will still leave you with a near point source. I can see just a little softening with the LS vertical, but usually so little that it is not worth the power loss. So, just to avoid taking the LS off, I sometimes point it straight forward, not for diffusion, but to simple increase its power a little - and I am lazy!

When I am closer to the subject, and I want to make the background go dark, I sometimes point the LS straight forward, to kill the bounce. It still gives you pretty good softening of the direct light inside six feet, and it almost eliminates the bounce. In a small room, that can sometimes help to isolate the subject from the background.

Russ

Bipin Nair said...
This comment has been removed by the author.
Bipin Nair said...

Thank you so much for the answer Russ.

Just to clarify.Will it help using a lightsphere outdoors to soften the light ?

When using TTL-BL outdoors (as fill) , if there is no wall to bounce ,do you suggest pointing flash straight to the subject (with no diffuser) ?

Thanks,
Bipin

Russ MacDonald said...

Hi Bipin,

Yes, I recommend the Light Sphere pointed straight up with the inverted dome in place, if you are within 12 feet.

Farther than that, out to about 20 feet, you can point the LS directly at the subject, using the inverted dome. You will only get a small amount of softening.

Beyond 20 feet, take the inverted dome off, leaving the bare flash. This doesn't give any softening, but it saves you have to remove the LS from the flash.

Russ

Bipin Nair said...

Once again ,thank you so much for the advise.It helps a lot to learn.

The new lightsphere collapsable has an option to collapse it while it is stil on the flash (of course ,the dome has to be taken off) .

Probably you already know this, just sharing it for the benefit of other readers.

Thanks,
Bipin

Liju Augustine said...

Russ,

I have been reading your posts on CLS and I have to say, you have done a great job in persuading fence sitters like me to flash photography. I am staring to use flash more often and I recently bought a bracket. My question is about the flash angle when on a bracket. Would you recommend the flash to be angled 45 degree or straight on, when working with a flash bracket.

Thanks
Liju Augustine

Russ MacDonald said...

Hi Liju,

Yes, flash photography is lots of fun once you fully understand what your flash is doing. It can be very discouraging when you don't understand what it is doing.

For people photography, and assuming the ceiling isn't some weird color (orange or red are the worst) I usually use the small snap-on diffuser and angle the head up at about 60 degrees toward the ceiling. If the ceiling is low, I point it straight up. That will make softer light and better skin tones with more definition in the facial features.

I normally do not add a big diffuser like the Gary Fong Light Sphere on top of the bracket, because the whole rig gets top-heavy.

Russ

Liju Augustine said...

Thank you Russ, what if the ceiling is high or of a non-light color? Would you recommend pointing the flash straight on?

Russ MacDonald said...

Hi again Liju,

I take a test bounceshot and check the exposure in the histogram. If it's good, then I shoot bounce shots. If not, I usually get rid of the bracket and attach the Fong Light Sphere.

Russ

Honk said...

Hi Russ,

I've made a test and get unforeseen results with softener and TTL-BL.

Setup:
Cam in M (1/80, f4). Flash in TTL or TTL-BL (via Tipp #1, Matrix/Spot) & setup as shown below. Photo of a puppet, wall 4feet behind puppet. 5feet distance to puppet-Cam. Thin "Kleenex" (would learn how a very small softener without bouncing will work).

1) TTL + direct: As expected.
2) TTL + direct + Kleenex: Histogram "nearly" like (1).
3) TTL-BL + direct: As expected. Histogram "nearly" like (1).
4) TTL-BL + direct + Kleenex: Now I get underexposed pic like a direct TTL-BL flash an with FEC -1 (!).

I've tested Setup (4) in different conditions (in house) and I get always an pic like a -1 FEC. In regular TTL all will be fine. But TTL-BL...
First I think about reflections which irritate TTL-BL, but as well when I play around with the setup (greater room, distances), I get always a very dark result with TTL-BL and the direct "Kleenex". I expect, that (3) & (4) must be approximately the same (Histogram). But like approx. -1 FEC?

Do you have an explanation about this habit?
Maybe it's my old D200 (+SB-900), which result to this effect.

Regards,
Honk

Russ MacDonald said...

Hi Honk,

One thing that you have apparently missed is that TTL-BL should only be used when you want to add fill. If you use TTL-BL to try to make it primary, then you pictures will often come out dark as the BL function reduces the brightness of the subject to get it closer to the background.

Again: use regular TTL and camera Manual when you want the flash to be primary; ie, when in low ambient conditions (like in your suggested case). If you want the flash to add fill; ie, bright ambient conditions, use TTL-BL and the camera in P mode (or center the meter in Manual mode).

Lastly, don't use any diffusion with TTL-BL mode. You don't need diffusion when all you are adding to the picture is slight fill. The diffuser messes up the balancing algorythms.

Russ

Honk said...

Hi Russ,

but in the test-case the background remains unchanged. So I expected the same TTL-BL/Kleenex flash-result as TTL-BL without Kleenex ("diffusor").

I understand what is better to use in what case, especially with these results...

TTL-BL seems very unpredictable.
So, when I make a pic without diffusor and another with diffusor (without bouncing), than these parameters remain unchanged:
- distance
- backlight (unless I put the towel in front of the Lens)

What I now expect: Flash with towel (diffusor) = pre-flash should measure, that the main flash need much more power (like in regular TTL) due to passing the Kleenex.
What I get: A much darker pic (round -1). Doesn't make sense to me, due to non changed parameters for TTL-BL measurement (except pre-flash must go through a Kleenex).

Or short: Why powers the flash in TTL higher (balance the diffusor-light-loss), in TTL-BL not?

There must be a warning-sign on the flash: Use TTL-BL only direct, without diffusors/bouncing and never in dark conditions (just kidding).

Regards,
Honk

Russ MacDonald said...

Hi Honk,

TTL-BL mode uses lots of information to calculate the power of the flash. We already talked about the fact that it uses the information directly from the meter measuring circuit, and you have neutralized its effect.

However, when the flash head is pointed forward, TTL-BL uses the distance to the subject as the primary input to compare with the metering data to then calculate the required flash power. The preflash is also used, but it has only a secondary effect on flash power when the head is pointed forward. In fact, the main reason for the preflash when using TTL-BL with the head pointed forward, is so the system can calculate white balance.

So, when you placed the kleenex diffuser in front of the flash, it attenuated the flash power and the image became dark.

I should point out that when you use the diffuser that was supplied with the flash, it pushes a little switch and that tells TTL-BL to increase the flash power to compensate for losses in the diffuser.

This also explains why the images are dark when using a Gary Fong Light Sphere in TTL-BL mode. It turns out that that diffuser does not push the little switch on the flash head.

When you tilt the flash head up to bounce, distance is no longer used in the TTL-BL mode, and the primary input comes from the reflected preflash. Unfortunately, TTL-BL does not work as well when you bounce as when the head is pointed straight forward. In fact, TTL-BL becomes somewhat unpredictable when you bounce.

The bottom line is that for TTL-BL to work correctly, you should be in bright ambient conditions with no diffuser attached. Even the supplied diffuser that trips the switch on the flash is less predictable than regular TTL.

Russ

Honk said...

Hi Russ,

I don't catch on that a Kleenex neutralize the info from the meter measuring circuit ("mmc").
I think, the "mmc" was mainly for the background or at least less important to TTL-BL (uses mainly distance instead of "mmc")?

However, with your hint to "TTL-BL uses MAINLY the distance" (I know you have pointed out this before in your blogs so my question was redundant. Thanks again for your patience with your readers) the result (dark pic) is absolutely clear.
The distance tells the flash how strong it should power, not the preflash. The Kleenex spoilt this power.

PS: Very nice info about the Nikon-Diffusor and the little switch.

So TTL-BL IS unpredictable unless the user don't understand it all-embracing! But therefore we have you ;)

Regards,
Honk

Russ MacDonald said...

Hi again Honk,

No, the kleenex didn't neutralize the info from the meter. What I meant was that 'YOU' neutralized the meter information by making a controlled experiment. You made sure the info from the meter was the same for all shots. That removed that variable and the only problem was that you didn't understand the TTL-BL uses distance as primary when the head is pointed forward.

Russ

Honk said...

Hi Russ,

now I get it. The problem was my english-german translation/interpretation. You mean with "neutralization" something different than I understand.

And: It's impressing that in TTL-BL the preflash has nearly no effect to 'power-measuring' (I understand, but displaced it..).

Thanks for clarification.

Servus,
Honk