overexpose or underexpose

Canon 7D

In a picture with white clouds in the sky and very dark shadowed areas is it better to meter the sky and bring up the darks in post, or meter the shadows and bring down the blown out sky in post? Which area may be unrecoverable, blown sky or black areas?

Anything over exposed is unrecoverable, especially when its blown. I would probably do either 3-7 shot AEB then do a Photomatix HDR or expose in the middle between the over exposed and under exposed and work on them in post. You can also use a GND filter as well.

Take Care,
Cheers, Patrick

Generally speaking, expose for the features of the frame that you're most concerned with.

You can pull down an overexposed image and show much less noise better than you can when trying to bring "up" an underexposed image.

The other options, when dealing with these problems for landscapes are:

1. Filters: A good system like Cokin or Lee, with a good circular polarizer and graduated neutral density filters will allow you to reduce light coming in from the sky so that you can balance the exposure out across the frame better.

2. Learn to blend exposures in post processing. This way you can take multiple shots to expose for both the highlights and shadows, then combine them for a better exposure in the final product.

Do you have an example photo for us to see and give more concrete suggestions?

Snydremark wrote in post #14953306
...Do you have an example photo for us to see and give more concrete suggestions?

Not really. I was walking the dog and brought along the camera. The sun was less than an hour from sunset and had nice color. The sky had distant huge clouds brightly lit by the sun. Rather than just shoot the shy I included treetops and that created the exposure difficulty.

The dog was yanking me around so most lack focus but the exposure problem is there.

Yeah; a situation like that either requires sacrificing the foreground (or using a flash to illuminate it), using a graduated filter or exposure blending.

Generally, in that situation, I'd likely just sacrifice the trees as shadows and expose for the sky.

Use the histogram(with picture style set to neutral) to set exposure so that the highlights almost(but not quite) reach the right side. This is the best that you can do with a single exposure and still may not match your vision of the scene if the DR is beyond the camera's capabilities...The suggestions about blending bracketed exposures or using GND above may be your only options in this case.

Such a situation in common in landscapes and architecture, ie the top of a skyscraper will be bright, where the street level will be in shadow.
It's far more easy to recover the shadows than the highlights, though there are limits.
Try a graduated neutral density filter, it will help avoid blowing out the sky in such shots.

Another trick to something like you describe, where a setting sun provides over exposure, is to move the camera about 45 deg away from the subject, lock exposure, then move back to the intended subject and shoot.

Your question points out why many shots could benefit from HDR. If you expose to keep detail in the sky, you lose detain in the shadows (or at the minimum you make the shadows quite a bit noiser, when you bring them up with post processing). If you expose for the shadow detail, you blow out the sky and lose details in the clouds. With a subject which does not move a lot, you can tripod mount the camera, take two photos and composite them together into a single shot.

when shooting RAW, you get a bit of the advantage of HDR via the Fill control and the Recover control, but not to the same extent as using HDR.

Wilt wrote in post #14956471
Your question points out why many shots could benefit from HDR. If you expose to keep detail in the sky, you lose detain in the shadows (or at the minimum you make the shadows quite a bit noiser, when you bring them up with post processing). If you expose for the shadow detail, you blow out the sky and lose details in the clouds. With a subject which does not move a lot, you can tripod mount the camera, take two photos and composite them together into a single shot.

when shooting RAW, you get a bit of the advantage of HDR via the Fill control and the Recover control, but not to the same extent as using HDR.

Going to Adobe's LR4/ACR7 and the new process 2012 Highlights and Shadows controls, gives even better results on pulling a wide dynamic range down to something that eventually will be displayable in only 8 bits. It's also surprising just how much highlight detail can be recovered from a RAW file when you really need to work an image.

Alan

If you shoot raw, but use the histogram on the 7D to decide if you are going to clip highlights, you have a good 1-2 stops extra headroom in the raw. You can send the exposure pretty far to the right and still be able to recover quite a bit of the image.

Tripod. Shoot raw. Bracket -3, 0, +3. You'll have all the data you need to use an exposure merging program like DPP, LR4.1, Elements. Good luck!

Even when shooting bracketed exposures, using ETTR will still maximize final image quality. See here http://oopoomoo.com …-free-natural-hdr-images/ for more.

TSchrief wrote in post #14958368
Tripod. Shoot raw. Bracket -3, 0, +3. You'll have all the data you need to use an exposure merging program like DPP, LR4.1, Elements. Good luck!

this.

to add, in my experience its very hard to recover a blown sky when exposing for shadows. however recovering shadow data is much easier when exposing for the sky. yes you will introduce noise, but you aren't getting back data that is lost. you usually get extreme banding and color gradation in the sky when you try to pull it down in post, shadow noise is much easier to deal with.

you really need to check your histogram after you shoot the image to see if you clipped blacks or whites and then adjust accordingly.

bracketing is however your best bet. if you can capture all the light range, do so.

mike_311 wrote in post #14959133
this.

to add, in my experience its very hard to recover a blown sky when exposing for shadows. however recovering shadow data is much easier when exposing for the sky. yes you will introduce noise, but you aren't getting back data that is lost. you usually get extreme banding and color gradation in the sky when you try to pull it down in post, shadow noise is much easier to deal with.

you really need to check your histogram after you shoot the image to see if you clipped blacks or whites and then adjust accordingly.

bracketing is however your best bet. if you can capture all the light range, do so.

Well "blown" certainly means your data is clipped and yes, you cannot bring detail back down from that. However remember that the histogram on the camera is not truly indicative of how much you have to work with, if you shoot raw. You do have more headroom at the top end in the raw.