How to Deal with Over Exposure in Natural Light Stills: Advice needed.

[lightdrunk]

I'll try it again with the curtains closed. The over exposure in the upper mid-left of the shell wipes out the detail. Any suggestions about high contrast in this photo?

[tbob]

You need the harsh, bright light to get the effect of the light shining through the shell. I am lousy at doing the post processing layers and HDR things, hopefully someone will step in for that part. (I use Aperture anyway so those things are not part of my post processing options anyway). You might be able to pull out some detail and lessen the blown out light in post processing, however most of it looks beyond simple manipulation repair.

However, for me the main thing is the bits of shell to the right of the large bright spot and left of the bright spot to the right. I would be tempted to compose this shot tight to those parts and just leave out the over exposed parts.

[lightdrunk]

Thanks, Tbob.

[Inkanyezi]

By decreasing ISO to 100 instead of 400, you gain two full steps of dynamic range, so I'd suggest exposing it almost three stops low, i.e. the same exposure data but with ISO 100 setting, which will call back some detail in the brightest part. Then you can tonemap it if needed or adjust the tone curve to cope with the contrast. A graduated filter could also be a great help, set by slanting and displacing to lower intensity slightly where it is at its sharpest.

[lightdrunk]

Thanks, Inkanyezi. Just learned something useful.

[Colin Southern]

Hi Doug,

There's 2 simple parts to the problem:

1. You need to get your exposure correct to start with, and that simply means choosing an exposure that doesn't blow the highlights (but put the exposure close to blowing them).

2. Next you need to use the "fill light" slider in your post-processing software to compress the dynamic range captured by your camera into something that can be displayed on your monitor (big fancy words for "reveal the shadow detail").

Some things that will help ...

1. If you have a tripod then use it, and shoot at 100 ISO to capture the best quality information.

2. If your camera has a highlight alert ("blinkies") then make sure that feature is turned on and watch for flashing pixels on the camera review screen when you take the shot.

3. Shoot RAW

4. Use a reflector (even just a sheet or two of white paper) to reflect a small portion of the light back into the shadow areas.

[lightdrunk]

Thanks, Colin: I've just got my new D800 and discovered that I can't load RAW files on CS4 from this camera. I'm upgrading to CS5 soon. My camera does have a highlight alert, which sometimes I have to ignore, unless I'm shooting between 5 and 7 in the AM, or 6 and 8 in the evening. I still don't know any thing about shooting still lifes but am happy to learn, as I am, here.

[Dave Humphries]

By decreasing ISO to 100 instead of 400, you gain two full steps of dynamic range, so I'd suggest exposing it almost three stops low, i.e. the same exposure data but with ISO 100 setting, which will call back some detail in the brightest part. Then you can tonemap it if needed or adjust the tone curve to cope with the contrast. A graduated filter could also be a great help, set by slanting and displacing to lower intensity slightly where it is at its sharpest.

Hi Urban,

Although most of your advice is valid, I'm not sure these iso figures add up, and we don't want to mis-inform, even if it is with the best of intent and trying to help.

The difference between 100 and 400 iso is exactly 2 stops, so that's how much the exposure will reduce by if all other settings are kept the same.

Changing from iso 400 to 100 won't gain 2 stops of "dynamic range" by the normal definition of that term - although I agree the exposure does need to be significantly reduced and two stops is a good place to start and yes, you could say you would be getting two stops more image information.

I'm just trying to clarify things for all, I hope you understand.

[Dave Humphries]

I've just got my new D800 and discovered that I can't load RAW files on CS4 from this camera. I'm upgrading to CS5 soon.

Hi Doug,

Adobe are currently saying this of the D800 and D800E; "These cameras are supported in Adobe Photoshop Lightroom 4.0, but not in Camera Raw 7.0. These cameras will be supported in the next dot release of Camera Raw 7." here, which is the current Camera model to ACR version look up.

My camera does have a highlight alert, which sometimes I have to ignore, unless I'm shooting between 5 and 7 in the AM, or 6 and 8 in the evening.

I don't understand Doug, surely it can't be so bright that at 100 iso and say 1/4000s, you can't get a usable aperture range without blowing highlights?

Colin's advice is good, so follow that as far as you can, given the current issue with getting at the RAW images.
Shoot jpg & RAW for now anyway and save the RAWs for when the converter is available - which will probably only be with ACR 7.1 in CS6 I'm afraid.

[lightdrunk]

Dave: I got things mixed up. I'm thinking of the red spots that come up on photoshop, and not a camera function. I don't know if my camera has a highlight alert. I'm going to reshoot this weekend and will document results.

[Colin Southern]

Thanks, Colin: I've just got my new D800 and discovered that I can't load RAW files on CS4 from this camera. I'm upgrading to CS5 soon. My camera does have a highlight alert, which sometimes I have to ignore, unless I'm shooting between 5 and 7 in the AM, or 6 and 8 in the evening. I still don't know any thing about shooting still lifes but am happy to learn, as I am, here.

Hi Doug,

You need to convert the files to Adobe's standardised DNG format first, using their free converter (I do this with all my files anyway). The current publicly released DNG converter doesn't handle the D800 yet, but if you send me a PM, I'll help you out with a non-public version

You shouldn't have to ignore highlight alerts; simply apply a little exposure compensation to make them go away.

[LeoLeo]

Hi Doug,

One small "trick" to avoid blown highlights in situations with high dinamic range is :
1. use spot mettering in manual mode.
2. do the mettering in the most brightest area that is going to be included in your frame, and consider that area to be +2 exposed (overexposed) ("marker" or whatever is called in your viewfinder scale).
3. frame your composition and shoot away

I don't know Nikon gear or D800, but if you have +3 on the scale, use +3 for that area instead of +2 (like on my 40D). This will guarantee detail in the most brightest part of your image. Don't be worried about darks, with a bit of post precessing, are quickly fixed.

If I have been confused, I will try to detail it.

Leo