SB800 Manual leaves some questions unanswered

[work-page]

Although intimidating at first, I've made my way through the SB-800 manual

without ill effect. It did however leave a couple of things open, so I did a

bunch of indoor test shots (SB-800 + D50 + 50/1.8 AFD lens). That answered a

couple of questions, but raised a few others instead..

 

As far as I can see, there are two ways to set TTL. There's ordinary TTL, and

there's balanced TTL-BL. But on the camera I can also set normal sync and slow

sync. I always thought that slow sync was intended to give balanced results

between ambient and flash by floating the shutter speed, and indeed that works

as advertised. What's the added advantage of TTL-BL then? Or is it intended for

use in case of faster shutter speeds? How can it battle the dark side when the

ambient doesn't register? Its purpose just escapes me..

 

The other thing that baffles me is the Tupperware box. Alright, it's actually

called the 'Nikon Diffusion Dome'. The accompanying lighting suggestion booklet

suggests flipping down the wide angle adapter, mounting the dome, and tilting

the flash at 60degr to get the most diffused lighting. Am I doing something

wrong when that gives me the much worse shadows than no dome, no wide adapter

and bouncing straight up from a ceiling?

 

Answers and suggestions most welcome..

[BrettPrucha]

I think the difference between TTL and TTL-BL has to do with the way in which the flash meeters to determine how much light to output. My guess is that TTL-BL focuses more on the center of the frame to expose the subject to match the rest of the scene. Plain TTL uses more of a matrix type mettering. Your manual should explain the difference... The camera flash sync has to do with controlling the shutter speed and has no relation to the ammount of light outputed from the flash. A bit dated but none the less still good info on using flash photograpy is Moose Peterson's article, <a href="http://www.moosepeterson.com/techtips/flash.html">The TTL Flash System</a>.

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The diffusion dome provides better diffusion when bouncing the flash off the ceiling isn't a option. If you can bounce off of something than you are likely to get better results that way.

[paul_sokal___dallas__tx]

TTL exposes with subject priority where as TTL-BL goes for balanced exposure across the image so it's most useful as fill flash outdoors with bright sun. Indoors, as you suggest, using slow-sync and dragging the shutter is the way to go. When you use the diffuser dome, you do have a fraction of the light coming straingt at your subject and thus shadows. When you bouce, the shadows are minimal because the light is coming from the ceiling, wall etc.

 

Check out planetneil.com for good flash info.

 

And be thankful you survived reading a Nikon manual. Not everyone is so lucky.

 

Paul

[joseph_smith3]

Brett, the Moose Peterson link should explain the difference between Balanced TTL (balanced iTTL) and Standard TTl (staandard iTTL.) It is a major difference. In simple terms, with Standard TTL set, the two computers are delinked and do not work together. What you set on the camera and the flash happens. With balanced TTL they are linked and do work together. What you set on the camera and the flash can be modified by the computers. This link to an article by John Shaw might help you understand it better and explain the benefits of BL and its detriments: http://www.photosafaris.com/Articles/AShotInTheDark.asp

 

Remember when John wrote the article BL and iTTL did not exist. The matrix symbol or man sun symbol is the same thing for film flashes.

 

Regarding the synch settings on the camera, there are major differences among them. The choice of synch speed might affect whether you get preflashes, etc. Read your camera manual too.

 

Use of the dome softens the light.

 

Joe Smith

[frank_skomial]

"My guess is that TTL-BL focuses more on the center of the frame to expose the subject to match the rest of the scene. Plain TTL uses more of a matrix type mettering. Your manual should explain the difference..." - close, but not exactly.

 

BL is balanced, and required matrix metering to take on account all measuring points from entire field. BL is also the only flash mode that make use of the D information provided by D lenses, so the evaluation algorithm knows where the focus distance is (presumably the person in the center and in front), and what the backgroud needs for light are, and balances them all. (if balances with 1 flash only - then not much it can do anyhow - so you need multiple flash setup in CLS - where it "shines").

 

E.g. if you change focusing mode to a single central point, your BL will dissapear from the flash, not having enough information to balance from. I am not sure about non-D lenses, since all my lenses are D type. Someone could help here?

[work-page]

Many thanks to all!

 

It hadn't registered with me that the BL setting is essentially the same as the man and sun symbol on my old flash. I remember the manual calling it something like 'daylight balanced fill flash'. No wonder I got oddly overexposed results with TTL-BL indoors.. But now it starts to make sense again!