recovering shadows

[cjgo87]

Hello,

I'd like to know roughly how many stops of shadow you can recover before you lose quality. I suppose it depends on factors such as what ISO you're shooting at. I'm currently shadowing a wedding photographer and he told me to expose for the skin. At first I was exposing for the highlights to protect them and thought I could edit the shadows in post. Appreciate the help and advice.

Thanks,

Chris

[danardeng]

Dynamic range and digital noise (the two factor that impact on shadow recover) is more complex than it appear.

You can find online some instruments to compare and evaluate the noise level and dynamic range (usually I use dxomark compare tool), but it works only as a compare from a sensor to another.

In the real world the quality of light impact on the quality of the photo more than we can image.

An example:

 - 1600 iso, daylight, correct exposition. In almost all modern fullframe cameras you have very little noise, and you can easily recover shadow

 - 1600 iso, artificial light (bad fluorescence lamps with 2800K), correct exposition. Probably you find more noise than you image. It's because of the limited light spectre you have to light the scene, so when you have to recover dominants and WB, you ask more from some type of pixel (usually blue) and the result is more (blue) noise.

So, my answer is

           I DON'T KNOW

and aside

           WITH WHAT CAMERA?

At the end, you should define an objective level of noise to define a "good quality image" to find an answer to how you can push iso

[IamNic]

Hi @cjgo87,

are you shooting in raw or just compressed in jpeg format?

- Nic

[cjgo87]

That's interesting. Does flash photography or regular tungsten light also have adverse effects on noise compared to natural light? 

I'm shooting on a Sony A7rii. 

I'm not sure how to define 'good quality' objectively.  I was thinking that I could only change the exposure a few stops before there is a noticeable change in the quality. I don't really know how to define noticeable objectively either though. Ideally trying to maintain the image quality as close to a well exposed image.

[cjgo87]

I'm shooting raw. I shoot both raw and jpeg.

[danardeng]

Flash light is comparable to natural light. It's really good.

If you are shooting an eventi with flash, you'll have strong shadow area, where flash is not hitting, and here the quality of light will different from flash (the one that come from the ambient).

Tungsten light is a wide range of possibilitys. I have in garage some old school Philips bulb specialized for photography and video with declared K°. Those are really good (not as flash and natural light, but good). Other cheaper can be worst, anyway good.

The worst bulbs are the one based on gas (fluorescent and discharge), with bad dominant. Also some cheap LED bulb can be really problematic.

In general all the situation where you have to spend a lot of time to regulate WB are bad also for noise in shadows.

The sensor of A7rii is still on the top of quality for dynamic range. For sure analog and digital signal processors are way better in newer models, and you find difference on color coherence expecially at high iso.

[HannahEd01]

Hey cjgo87, it's usually easier to recover details from shadow than from blown highlights, so I'd expose for the highlights (or a little under).

I also found out that your camera has setting that might be useful: https://helpguide.sony.net/ilc/1520/v1/en/contents/TP0001087237.html 
 

[cjgo87]

thanks danardeng for this info!

[cjgo87]

Thanks Hannah. Yes thats what I was trying to do but maybe I need to underexpose even more to avoid highlights and add more fill. Thanks for the link!