Exposure Compensations - DPChallenge Forums

Nikon AF-S Nikkor 70-200mm f/2.8G ED VR II

08/04/2008 02:55:34 PM · #1

I rarely shoot anything other than manual mode these days. But occasionally I switch to av or tv when I am hard pressed for time. When I do shoot in those modes, I rarely use exposure compensation, though sometimes I use flash exposure comp on my external speedlite.

Let's say that I am shooting an indoor party (low ambient light).
I have my ISO up around 800/1600
I am in av mode
The aperture is wide open on a 28-75 f/2.8
I have my camera's exposure comp set to +1
I have my external speedlight(s) flash exposure comp to -1

I assume that the camera exposure comp of +1 is going to give me a little more shadow detail in the bg and the -1 on the flash is going to slightly reduce the amount of flash exposing the subjects. Does that sound about right?

MattO

Nikon D4

08/04/2008 05:38:37 PM · #2

It sounds to me like you are going to really be killing your shutter speed and having some crappy photos because of overexposure. In AV mode the flash is only used for fill. The camera will already be setting your shutter speed for what is needed to get correct exposure based on the metering mode that you have set, and using flash just to fill.

In your setup you will be overexposing your photos by 1 stop and have less fill then you would expect. But really it wont matter because you are already overexposed and likely have such low shutter speeds that not only are your shots overexposed but they have a ton of motion blur in them. Unless you are shooting still life.

Matt

Message edited by author 2008-08-04 17:39:07.

soup

Canon EOS-30D

Canon EF 17-40mm f/4.0L USM

08/04/2008 06:22:12 PM · #3

yeah what he said. if you're shooting with a flash you should really be in M mode.

shutter speed controls ambient light

aperture controls flash exposure

and flash EC should work as expected.

Message edited by author 2008-08-04 18:23:00.

08/05/2008 07:59:55 AM · #4

Would anyone care to debate the posted replies?

Take a look at //makelightreal.com/photographic-lighting/two-flash/

Personally I have very little experience shooting indoor events (the only indoor shooting I do is studio and I'm always in manual). But I am interested in learning about the possibilities of using av inside. And whatever else he is, Neil Cowley is no idiot when it comes to indoor strobe lighting.

Edit to insert a small portion (but do see full context):
You have to know how your TTL metering and flash system will react for the camera youâ��re using. For instance, when Iâ��m using my Canon 1dM2, I generally have the TTL exposure compensation set to +1/3 and the ETTL(flash exposure compensation) set to -1/3. I also use two 550ex flashes, one on camera and one in my left hand. Both heads are zoomed to 50-70mm to keep the light from spilling onto foreground objects such as arms. Also make sure your focus point is on your subject for good TTL readings. When I was using the Canon 10D I had to use a little more compensation, about +1TTL and -1Flash Compensation - so feel it out for the model or body that you are using and the contrast you want in your images.

Message edited by author 2008-08-05 08:01:22.

08/05/2008 08:10:29 AM · #5

What's to debate? I didn't read the whole thing... but I don't think that he's using anything other than Manual exposure.

If you set your camera to Av mode, the camera is going to try to expose for ambient light ... which means even the backgrounds will be bright (ambient light will be exposed for 18% gray). If you want dark backgrounds (like what you saw in his pictures), then set the camera to manual mode, take a couple of shots to see what your ambient light is looking like, adjust the shutter speed accordingly, and adjust your flash compensation to get the amount of light you want on your subjects.

08/05/2008 08:14:54 AM · #6

I guess I misunderstood (still misunderstand) his post. When he says "I generally have the TTL exposure compensation set to +1/3" isn't he talking about in-camera exposure compensation? You can't set in-camera exposure compensation when in manual mode. I thought he was shooting av.

08/05/2008 08:27:01 AM · #7

And here is an example where he is in P mode (though he is outside).

To set my exposure I used program mode with an exposure compensation of -2 and a flash exposure compensation of +2 to get an extreme level of contrast between the dancer and the background.

//www.flickr.com/photos/makelovereal/154020838/

Again, I admittedly don't understand how the non-manual modes work with flash.

08/05/2008 08:54:38 AM · #8

Originally posted by Bernard_Marx:

TTL is referring to his flash metering. Has nothing to do with shutter or aperture, it only refers to how the flash is metering the scene.

08/05/2008 08:56:17 AM · #9

Originally posted by Bernard_Marx:

Okay, I don't know what "program mode" he is in there... but I would stick to manual and meter the scene yourself at -2. Av mode just really sucks indoors because the camera is metering ambient light which will change as you move around from hot spot to shadow and back. You want to control it.

Canon EF-S 18-55mm f/3.5-5.6 II

08/05/2008 09:25:53 AM · #10

Originally posted by dwterry:

Originally posted by Bernard_Marx:
I guess I misunderstood (still misunderstand) his post. When he says "I generally have the TTL exposure compensation set to +1/3" isn't he talking about in-camera exposure compensation? You can't set in-camera exposure compensation when in manual mode. I thought he was shooting av.

TTL is referring to his flash metering. Has nothing to do with shutter or aperture, it only refers to how the flash is metering the scene.

I will stick to manual. And I completely trust your knowledge and experience. But I am still a bit fuzzy on what Neil says he is doing. Here is his full sentence:

I generally have the TTL exposure compensation set to +1/3 and the ETTL(flash exposure compensation) set to -1/3.

What TWO things is he setting? It sounds to me like he is setting his external flash to -1/3... what is he setting at +1/3 there?

surfdabbler

Canon EOS-5D

08/05/2008 09:58:53 AM · #11

On the 400D, when I do shoot to use the flash as a main light, like indoor parties (where the ambient is generally bright enough to shoot without flash if you use ISO 1600 wide open and a tripod), I have to set the flash EV to at least +1, sometimes +2, or it underexposes. My camera thinks flash is ONLY for fill, and generally underestimates the overall exposure when the flash is used. If you actually want it to make a difference in your photo, and maybe duh...actually LIGHT something, then you have to bump up the flash EV big-time.

Once your flash is lighting the subject sufficiently, the ambient exposure is up to you what you want to do with it, but generally if you use much ambient exposure, you will get motion blur, so you probably actually want to underexpose the ambient light with EV set to -1. You'll also want to be shooting at least ISO 400, more if you can live with the noise.

This seems to be the reverse of what everyone else is recommending, but I've tried the other way, and I get underexposed blurry shots. But, the poor exposure, particularly with flash photography, has been one of my biggest frustrations with this camera. Can you tell? :)

surfdabbler

Canon EOS-5D

Canon EF-S 18-55mm f/3.5-5.6 II

08/05/2008 10:05:56 AM · #12

Originally posted by Bernard_Marx:

I generally have the TTL exposure compensation set to +1/3 and the ETTL(flash exposure compensation) set to -1/3.

What TWO things is he setting? It sounds to me like he is setting his external flash to -1/3... what is he setting at +1/3 there?

The second setting is the non-flash EV, which in Av mode determines shutter speed. So there are 2 EV settings. The flash EV, or FEV obviously controls the exposure of the flash-lit bits in the photo. The normal EV will control the exposure of the ambient lit bits in the photo. By setting the 2 appropriately, you can set the balance of flash-to-ambient light in your shot.

This is a little confusing calling it TTL EV, because stricly speaking, TTL is a flash exposure mechanism, but I think he is simply using the term incorrectly to refer to the normal EV setting.

Message edited by author 2008-08-05 10:10:01.

Canon EF 17-40mm f/4.0L USM

08/05/2008 10:15:25 AM · #13

Originally posted by surfdabbler:

Originally posted by Bernard_Marx:
I generally have the TTL exposure compensation set to +1/3 and the ETTL(flash exposure compensation) set to -1/3.

What TWO things is he setting? It sounds to me like he is setting his external flash to -1/3... what is he setting at +1/3 there?

The second setting is the non-flash EV, which in Av mode determines shutter speed. So there are 2 EV settings. The flash EV, or FEV obviously controls the exposure of the flash-lit bits in the photo. The normal EV will control the exposure of the ambient lit bits in the photo. By setting the 2 appropriately, you can set the balance of flash-to-ambient light in your shot.

This is a little confusing calling it TTL EV, because stricly speaking, TTL is a flash exposure mechanism, but I think he is incorrectly using the term to refer to the normal EV setting.

Yup, that sounds right. It sounds like he is setting the camera's exposure compensation to +1/3 or +1 (which means he is not in manual mode), and he is setting his flash to -1/3 or -1 compensation. And it sounds like everyone agrees that this should result in crap. Yet his examples are pretty nice and he does sound well versed.

No biggie though - like I said... I never really do that sort of photography anyway...I was trying to learn a little somethings.

soup

Canon EOS-30D

08/05/2008 10:22:27 AM · #14

you can do the same thing with manual mode. it's just you're manually setting the exposure compensation of the camera by slowing the shutter according to what the camera meters as correct. which will get you a brighter ambient exposure if there is enough light available.

i typically find i do this even if i'm not using a flash.

Message edited by author 2008-08-05 10:23:10.

Bear_Music

Samsung Galaxy S24 Ultra

Sony 24-70mm F4 Vario-Tessar T* FE OSS

08/05/2008 10:28:33 AM · #15

"TTL" stands for Through the lens and, strictly speaking, all modern SLRs use TTL metering. "ETTL" refers to flash metering that takes place in real time, through the lens. This is as opposed to the older sort of flash metering, where there actually was a sensor on the flash unit itself that read light bounced back from the subject. This was pretty half-baked flash metering, real hard to work with.

So the guy's using his terminology correctly, even if it seems confusing to some of y'all :-)

R.

Message edited by author 2008-08-05 10:28:57.