Bit of a dumb question (exposing for snow)

Hi,
Bit of a dumb question ( I'm full of them ! )
I'm going on a trip to Japan to photograph the snow monkeys and cranes.
Bit of a novice with snow photography, what is confusing me is that I presume I have to over expose to get the snow white, but doesn't that overexpose my subject, as in a brown fur of a monkey against the white ??

If you are using your camera's auto exposure system, which it sounds like you are, then it will measure the brightness of different parts of the scene. Next, it'll figure out the average brightness of the parts it measures and set the exposure settings so that this average is about 3 stops below clipping. If your scene has a wide range between dark (fur) and light (snow) that is perhaps 7 stops of light difference, then the camera will clip the snow and you will lose all detail in it. If so, you'd need to dial in -EC to save the detail. If the difference is less, like 4 stops difference, you'd dial +EC to maximize the sensors recording ability (ETTR).

Personally, i want to see detail in the snow, so I might set -EC. You can manually set your exposure as well to get consistency in your photos.

frugivore wrote in post #18078872
If you are using your camera's auto exposure system, which it sounds like you are, then it will measure the brightness of different parts of the scene. Next, it'll figure out the average brightness of the parts it measures and set the exposure settings so that this average is about 3 stops below clipping. If your scene has a wide range between dark (fur) and light (snow) that is perhaps 7 stops of light difference, then the camera will clip the snow and you will lose all detail in it. If so, you'd need to dial in -EC to save the detail. If the difference is less, like 4 stops difference, you'd dial +-EC to maximize the sensors recording ability (ETTR).

Personally, i want to see detail in the snow, so I might set -EC. You can manually set your exposure as well to get consistency in your photos.

You seem to have managed to reverse the +/- for EC in your example. If the scene is brighter than average, the TTL metering system will make the exposure less, so that the bright white becomes dirty grey. So in this situation you would need to add some positive (+) EC. If it is really brightly lit snow, and you have a lot of it in the scene then maybe up to +2EV.

To the OP, since the exposure is being reduced because of the bright snow, that will also reduce the exposure of the darker subject too, so that can end up blocking up (the opposite to clipping). The additional exposure is given to all of the image, so that the darker colours also stay the correct brightness. Personally in a situation like this, where I don't have too much time to be chimping, I would also set Auto Exposure Bracket. I would set the AEB at +-2/3 stop, and would then set my EC to +1,1/3 stops. I would set the camera to burst mode, and in this configuration the camera will automatically shoot the the bracketed exposures around you EC offset, then stop. I also reset AEB in the custom functions menu so that it shoots -, 0, +, instead of the default 0, +, - order. That way when you are reviewing the images you see the darkest one first, and they then get progressively lighter. You should hopefully find the the + shot in the series is actually a good ETTR exposure, and if you have shot it in RAW you can then pull the highlights and midtones down in the RAW converter, while leaving the shadows unaffected. This process will allow you to bring out more details in the shadow areas, without introducing additional noise to the image. The middle exposure should then be normal. Having the three shot bracket though allows for the possibility that you got the initial guess at the correct amount of EC wrong. If you did not add enough then the + exposure becomes "normal" and you haven't really lost anything. If you overdid the initial EC, then the 0 becomes your ETTR shot, and the - is your "normal" exposure.

Alan

The problem isn't a dumb question, but a dumb metering system as has been said above. I try to take it out of the equation when I can with this: Need an exposure crutch?
If you have time before your trip, try it out.

What Alan said.

Or, if you're close enough to your subjects, you could just use spot metering, and exposure lock if you move off your subject.

Before heading out, try this:

Get a large white sheet, and then various objects to photograph. Something like a white shower curtain can be a little more in line with how light can play off snow than just fabric, but the key point is to get something that would be bright white in the shot.

Set these up in good light and practice photographing them while using your camera's meter. Try the various metering modes your camera offers with different items in the shot.

My personal favourite method has become spot metering off my highlights and shadows while setting things manually.

What Moose said. Expose for the monkey using spot metering and lock it in. Or shoot manual, take a test picture, review histogram and adjust accordingly.

BigAl007 wrote in post #18078886
You seem to have managed to reverse the +/- for EC in your example. If the scene is brighter than average, the TTL metering system will make the exposure less, so that the bright white becomes dirty grey. So in this situation you would need to add some positive (+) EC. If it is really brightly lit snow, and you have a lot of it in the scene then maybe up to +2EV.

Alan

Alan, I'm not assuming that the majority of the scene is brighter than average. If that were the case, then yes, I would advise some +EC. But if the scene is composed of bright and dark equally, and the difference between the two is wide (such as in bright sunlit scenes with deep shadows), I would dial in -EC since those highlights would get clipped. Of course, if you don't mind clipped highlights in some areas, let the meter pick the exposure. But I try to avoid clipping whenever possible and practical.

Luckless wrote in post #18078950
My personal favourite method has become spot metering off my highlights and shadows while setting things manually.

^

...this only does not work when the dynamic range in the scene is too wide to fit the capture media (B&W film vs. color neg vs. color transparency vs. digital Brand X sensor vs. digital Brand Y sensor) when you have to decide which portions of the dynamic range can be sacrificed in the shot.

A shortcoming of this technique is that it does not identify the exposure needed to render 'midtone' in the scene as 'midtone' in the exposure (the 0EV exposure). The shadow and highlght readings can cause bias in one direction or other, relative to that by some amount (e.g. -1.3EV, or +0.66EV), but it certainly allows you to assess the scene without squinting at a LCD histogram in bright sun!

Luckless wrote in post #18078950
Get a large white sheet, and then various objects to photograph. Something like a white shower curtain can be a little more in line with how light can play off snow than just fabric, but the key point is to get something that would be bright white in the shot.

Funny you should suggest this. I know 1% as much about light as many people here, and even so, while reading the replies above, I was thinking it'd be helpful to set up high-contrast scenes at home and practice with them. It just makes sense.

Styrofoam has some of the optical quality of snow, too.

Another idea, probably obvious: photograph the monkeys early and late in the day, when the light is gentler.

dregsey wrote in post #18078822
... I presume I have to over expose to get the snow white, but doesn't that overexpose my subject, as in a brown fur of a monkey against the white ??

In addition to some of the suggestions already posted, just to clarify, this part you have sort of reversed.

Since the snow is so much brighter than the Monkey, you may have to over expose the snow to get the monkey bright enough.

Short of blowing out all the snow, you want to get the subjects exposure right, and let the snow fall where it will.

As mentioned, usually when there is snow present, all that bright white forces the camera to drop it's exposure, making your subject too dark.

Faced with moving subjects and high contrast I don't spend time estimating EV plus or minus. Instead I always use AEB - why not? Then, since I shoot RAW and can easily make make further corrections, I am nearly always guaranteed a keeper as far as exposure is concerned.

OhLook wrote in post #18079013
Funny you should suggest this. I know 1% as much about light as many people here, and even so, while reading the replies above, I was thinking it'd be helpful to set up high-contrast scenes at home and practice with them. It just makes sense.

Styrofoam has some of the optical quality of snow, too.

Good idea.

THAT, + the angle of the light could bounce some fill into the monkey.
SO much to keep in mind, no? ; )

Maybe this is a stupid question, but when are you going? Usually there is no snow until January, sometimes later. Depending on when you are going, it might not be a problem.

I am of a different mind. Unless the snow is the subject of your image, expose for the subject and dont worry about the snow. If the landscape/snow is the subject of your image, then be concerned. Ideally if need be, its better have to fix snow rather than your subjects in post. Also, remember brightly lit snow under a clear BLUE sky may have. tinge of blue in it.

Shoot raw.