Very (VERY!) basic flash question

[jfeenin]

I use M as well and let the flash fill in the light needed to make it happen. It generally works pretty well unless I ask more of the flash than it can deliver.

[Girevik]

I've never messed around with using manual mode for flash - my flash instructions said to use program, so that's what I went with. Generally speaking, how do you determine your shutter speed and aprature? The light meter can't be much help, can it?

[jfrancho]

The meter is useful to determine ambient, or background exposure, which will be controlled by ISO/Av/Tv settings. The fact that P mode sets a standard exposure every time is why you want to use M. You want to control the ambient or background, not the camera. The TTL flash exposure (depends on brand) will determine the flash output, and can be adjusted using flash exposure compensation, FEC. When you bounce the flash, the light is scattered and diffused, and less intense. Some flashes will auto compensate for this, some won't, and I find that +2/3 FEC is what it takes to overcome it. What you have to realize is that shutter and aperture don't contribute as much to the subject exposure as it would be without a flash. Seperate the two functions in your head, and you'll be able to control your flash photography.

[degsy_safc]

Originally Posted by Girevik

I'm not sure what "FEC" stands for (I'm guessing something like "flash exposure compensation??")

Correct - its a Canon term, however to be honest with the Nikon CLS (Creative Lighting System) underexposure is not normally an issue - you can read about the differences between the 2 systems all over the web.

[Girevik]

Originally Posted by degsy_safc

Correct - its a Canon term, however to be honest with the Nikon CLS (Creative Lighting System) underexposure is not normally an issue - you can read about the differences between the 2 systems all over the web.

Hmmm - I wonder why I seem to be getting underexposed images then.

[jfeenin]

Some things I can think of are:

- The flash cannot put out enough light for the given situation. (Ceiling too high, room too large, walls or ceiling too dark to bounce effectively, distance to subject too long, focal length too long etc.)
- Some other light source in the scene or some other factor is confusing the camera''s metering of the flash.
- Flash is obstructed by something you don't notice at the time.

Some things I would try: (try to replicate a situation/scene for these tests that mimics one that normally underexposes).
- Increase the ISO, this will require less flash for a given shot and if there isn't enough flash power it will allow for it.
- Try manual mode f5.6 or lower at 1/125 or lower and take the same shots. Try to let the flash do all of the adjusting and force the camera to a fixed shutter and aperture. Try difference ones and see what the results are.

Remember in camera metering for exposure and flash is getting better and better. These days it is pretty good but there are still times it will fail. You may just be consistently taking photos in situations that don't lend themselves to that. A hand held meter would do wonders in diagnosing that if you can borrow one from someone near you to test.

[jfrancho]

I actually think it was easier with film. Film seemed to have more latitude with flash exposure. I guess the same is true with available light as well. But systems are definitely getting better.

[cyclohexane]

Film TTL was better. Besides the exposure latitude, the camera was able to measure the amount of light hitting the film when the shutter was open, and could adjust flash output accordingly to compensate. The coatings employed on the sensors in our digital cameras are too reflective, so now TTL metering is done through preflashes before the exposure is made.

[degsy_safc]

Originally Posted by jfeenin

Some things I can think of are:

- The flash cannot put out enough light for the given situation. (Ceiling too high, room too large, walls or ceiling too dark to bounce effectively, distance to subject too long, focal length too long etc.)
- Some other light source in the scene or some other factor is confusing the camera''s metering of the flash.
- Flash is obstructed by something you don't notice at the time.

Some things I would try: (try to replicate a situation/scene for these tests that mimics one that normally underexposes).
- Increase the ISO, this will require less flash for a given shot and if there isn't enough flash power it will allow for it.
- Try manual mode f5.6 or lower at 1/125 or lower and take the same shots. Try to let the flash do all of the adjusting and force the camera to a fixed shutter and aperture. Try difference ones and see what the results are.

Remember in camera metering for exposure and flash is getting better and better. These days it is pretty good but there are still times it will fail. You may just be consistently taking photos in situations that don't lend themselves to that. A hand held meter would do wonders in diagnosing that if you can borrow one from someone near you to test.

Excellent reply - very informative and accurate.....

As jfeenin said using a test subject and practising is the best way to understand a flash. A great subject to test your settings is a medium sized teddy bear propped on something approx 1 foot from a wall. This will give you plenty of details to test exposure, sharpness and shadows on the wall. Hope this helps.....

[ladonna]

Jfeenin,

Is FEC stands for flash exposure compensation? If so, great idea. I bumped my flash up a bit last night to shoot a large bridal party of 24 bridesmaids, etc. SB600 did an awesome job.
LaDonna

[ladonna]

Cyclo,
What's your settings for aperture and shutter in manual mode. Can you explain how you decide or a method you use in most situations. Thanks in advance for your help. I realize you posted the article over a year ago.

[physicsguy]

Originally Posted by Girevik

I think it's 1/60 - I set the camera to "program" mode when using the flash, but I'm pretty sure that's what it uses.

I have not used the D70 but with both the D50 and D200 cameras, Nikon does some peculiar things with flash when set to program mode, according to Thom Hogan. You might also want to try using one of the the other exposure modes.

[deluco]

Originally Posted by Girevik

I'm still trying to learn how to best use my flash (SB-600 with a Nikon D70), and it seems that most shots I take are pretty underexposed. I'm especially trying to learn how to bounce the flash off a celing and/or use a bounce card.

When bouncing the flash, should the flash output be bumped up or should the sensor pick that up by it's self?

By the book, if you are shooting with the strobe in TTL or Auto mode (I assume this is how you are shooting) and the camera in Manual mode, then the camera and/or strobe should compensate. However, what I've found is that alot depends on your camera and strobe combination and this may differ even between the same brand combinations (identical camera and strobes). You have to do your tests and adjust accordingly. Use the histogram.

Also, you can consider shooting with the strobe in Manual mode at a power setting in order to get the consistency that you want.

[after]

Girevik.

Also play around with the angle of the flash head (if it's straight up - and you are taking a picture of something that is a good distance away - then folding down the flash down a notch will change the angle of the light reflecting back (think of it in a billiard mindset :P). A lot of times you can't bounce flash if you are quite a distance away... you need to do direct flash (or at least with the wide fold down flash modifier in flash). I too have the SB-600... and it is adequate to me (but then my old flash that I was using was the SB-28dx - and the 600 is more powerful). A lot of times I find myself dragging the shutter some (setting shutter speed to 1/45 or so [1/30 if I am more desperate]). I use Fuji bodies, but they are based on Nikons thus fairly similar... I remember it took me some time to get used to what I needed to do in order to get good results consistantly... You may just need to keep plugging away and practice... I am not sure where you are located at, but feel free to PM me if you'd like some help over the phone or via live chat or something

[Girevik]

Thanks for the offer. What I've been doing is just taking a test shot or two and looking at the histogram. If needed I'll manually bump up the power on the flash. Wish I had an sb-800, though.