Please help with some basic questions

I recently met with some people about school picture days and they provided me with a sheet about how they do their set-up. For instance, on sunny days, their flash setting is at AA with an ISO at 100. If you go "below" 5.6, use ISO 400. This wording confuses me a bit. Are they saying that rather than going with a wider aperture and getting too shallow a dof, up your ISO instead? That would make sense to me.

They also say for cloudy days, their flash setting is TTL-BL with an ISO at 400. Ok, so less sun, higher film speed. Then it says at F16 or higher, use an ISO at 100 (f/stops are not rounded up to avoid dark backgrounds). Does this mean they'd rather you use ISO 100 than go beyond F16 (say F22, or do they mean f8, etc.?). I get confused when it says "higher" as I think more in terms of wider or stopped down.

It also says when exposing for the subject, expose him/her to match the background (so we're metering for the background no matter what the conditions?). With a bright background, hold meter in the sun facing the camera and for a dark background, hold the meter under shade facing camera. Got to learn more about metering with a light meter!!

If anyone can help me a bit with this wording, I'd really appreciate it. I think once I see what they are doing in person, it will make more sense than when it's written on paper. At least I have found this to be true in most situations regarding photography.

They also always use manual instead of Av or Tv, so I'm going to do some serious practicing with manual again. Although I would be going by their fixed settings, I want to get more of a feel for why they are doing what they are doing, which is obviously very important.

Thanks much.

(I'm no expert, but nobody else has answered yet…)

Gah. First off, you've been given instructions written in Nikon. "AA" is "auto aperture" flash mode, which you don't have. It is a thyristor autoflash mode. You can probably get close by using Average flash metering in the "E-TTL II" menu item.

"TTL-BL" is Through The Lens, Balanced fill flash mode, which you also don't have. It is (duh!) a fill flash mode. You might try Av mode on your camera, along with Evaluative flash metering in the "E-TTL II" menu item.

Yes to your guesses on the ISO and aperture situation. ISO and aperture both control maximum flash range, and also both control minimum shutter speed to keep from overexposing on ambient. Remember that your 40D can't use a shutter speed faster than 1/250 unless you have High Speed Sync turned on (Nikons can typically go to 1/500). If your ISO and aperture call for a shutter speed faster than that, you'll overexpose on ambient lighting—very easy to do in bright daylight.

By the way, are those aperture limits (f/5.6 and f/16) for an APS-C DSLR, or for 35mm film? If for 35mm film, you need to divide them by 1.6 (f/3.5 and f/10) to get the same sharpness results—depth of field and diffraction. This will, of course, affect your exposure calculations.

Yes to your guess on metering for the background. The idea is to expose the background using ambient lighting. The camera will automatically control the flash to expose the subject. However, the flash can't throw any "dark" on your subject so be cautious about overexposing the subject on the ambient when you have a dark background.

I would suggest that you do some experimentation with flash photography in daylight conditions, to get a feel for what your Canon rig does.

Thanks so much for all that info. I had a funny feeling about that "AA". Anyway, I guess I have a lot to learn. Not sure why Nikon is such a hit to be honest, but whatever. They also shoot in manual. I definitely need some practice using my flash. Wish I hadn't sold the 430EX, but I felt I had to at the time even though it wasn't worth a million bucks. They said they have one I could borrow. I'm pretty sure this is all dslr and not 35mm calculations. I think it's unusual that they would automatically put Nikon settings on their instructions? Wouldn't you think everyone would have their own gear and their own various settings? It's not like Canon is uncommon, right?

Doug Pardee wrote in post #5698368
Remember that your 40D can't use a shutter speed faster than 1/250 unless you have High Speed Sync turned on (Nikons can typically go to 1/500).

Just to prevent the OP from feeling uncomfortable with Canon now:

Current top models from Nikon (D3, D300) provide 1/250s X-sync speed. I know there were some old CCD models with partially electronic shutter that could do 1/500s (D70 for example), but this is history, as is the original Canon 1D with 1/16000 shutter speed and 1/500 X-sync...

Performa01 wrote in post #5699091
Just to prevent the OP from feeling uncomfortable with Canon now:

Current top models from Nikon (D3, D300) provide 1/250s X-sync speed. I know there were some old CCD models with partially electronic shutter that could do 1/500s (D70 for example), but this is history, as is the original Canon 1D with 1/16000 shutter speed and 1/500 X-sync...

No worries. I have no intentions of returning to Nikon for my personal gear at this point. I would need some serious convincing having been there and back. Is Nikon common for studio shooters due to better flash units or something? Otherwise, I don't understand the trend. Of course, my issue was always trouble with noise at low ISOs. I suppose if you're using lights anyway, it's not as big of a worry.

I'm sure it's been done to death, but if someone can direct me toward a thread either here, or in the flash forum regarding the benefits of the 580 over the 430EX, I'd appreciate it. I'd like to know if the differences would be worthwhile for me. I know it obviously is more powerful, but what else? Thank you. Hang on, it can be a master or slave, right? Forgive me. I've been entertaining the kids the entire day and at 100 degrees, it can be exhausting! I'm just about brain dead, so I'm going to bed now...

Mum2J&M wrote in post #5699127
No worries. I have no intentions of returning to Nikon for my personal gear at this point. I would need some serious convincing having been there and back. Is Nikon common for studio shooters due to better flash units or something? Otherwise, I don't understand the trend. Of course, my issue was always trouble with noise at low ISOs. I suppose if you're using lights anyway, it's not as big of a worry.

I’m not too familiar with Nikon – I’m a Canon shooter almost from the beginning when they invented the EOS, that made the competition suddenly look rather old. It was in the days when Nikon still was the undisputed market leader…

But no, their flash system isn’t superior, they are on par with Canon and better than the rest of the competition. The only real advantage is, that their bodies can take wireless control over their flashes, without the need of a master unit such as Speedlite 580EX or Speedlite Transmitter ST-E2 being attached to the camera.

The “trend” might result from the fact, that Nikon now finally has caught up and even surpassed in some areas with their new top line bodies, and are also busy working to make their lens line-up more attractive – this one leaves them a lot of work to do though. This has created much of a hype recently…
But this is really no reason to go back anytime soon, because strong competition is good for the market and Canon will strike back eventually, I’m sure

Yes, although it seems there are studios and companies (at least the two I've dealt with) who continue to have a soft spot for Nikon. This would have been prior to the D300 I believe. I find, for portrait at least, Nikon makes skin tones ruddy, but is good for landscape use.