ACR (adobe camera raw)/LR vs PS shadow/highlight adjustment?

[Hannibal Chang]

Just curious what the difference is between both. I see most photographers use Lightroom and a few use only Photoshop and know they use ACR within PS and also the shadow/highlight adjustment. What I find even more interesting is the fact that sometimes using PS shadow/highlight adjustment, you can squeeze more information from the shadows and then use curves increase contrast because the image becomes super flat afterwards. Is there any benefit/negative to using shadows/highlights adjustment in PS compared to using ACR?

[D Fosse]

I think it depends a lot on the camera sensor. Doing highlight recovery in ACR from a 14-year old Nikon D70, or a phone camera for that matter, might not yield very spectacular results.

My example above was shot with a Sony a7RII, which has a staggering 14-stop dynamic range. This means you can push exposure way beyond what you would normally even consider, and still effortlessly recover highlights that would appear totally blown out. I thought my Nikon D810 was good, but the Sony beats it hands down. It's just a newer sensor.

At the same time, Stephen is right that this is nowhere near as effective in the shadows. The linear TRC of a raw file means that the vast majority of the recorded levels are up there in the highlights.

But OTOH it does indirectly benefit the shadows - because you can give more overall exposure without blowing out the highlights. So taken as a whole production chain, the ACR highlight recovery also, as a side effect, gives you less noise and better separation in the shadows.

At the bottom of it all lies this: a rendered file uses only a subset of the data available in the raw file. It's a one way street.

[D Fosse]

BTW, to fully appreciate what a 14 stop dynamic range means, consider that transparency film had about 5 stops, and B&W negative film at most 10. Ansel Adams' famous zone system was based on a 10 stop range, and he used slow large format negatives.

[Hannibal Chang]

I see what you're saying with your A7RII. I have an A7ii and shooting with a sigma art, the combination itself gives me an incredible dynamic range but wish I had more, I'm always almost pushing highlights right before they blow out, nearly max out the shadows [to 95 in LR], then bringing the exposure down to 'normal'. However, for what I shoot, I don't expose for the overall photo, I expose based off of my subject (I'm an automotive photographer so I expose based on the vehicle).

[Hannibal Chang]

Hang on, how do you know how many stops of DR you have? People always tell me how many stops I have and I keep responding with I have no clue how to actually tell the difference when shooting. Only way I can is by looking at the light meter and adjusting in PP from there, so in a sense I can actually only tell how many stops I have based on my light meter haha.

[D Fosse]

https://forums.adobe.com/people/Hannibal+Chang  wrote

Hang on, how do you know how many stops of DR you have?

That's a property of the sensor, how many times you can go from threshold and double the amount of photons before the sensor reaches saturation point. Sony claims 14 stops, and I see no reason to doubt it. I'm duly impressed with this sensor. It clearly outperforms the Nikon D810.

BTW, the Sigma Art line is outstanding. I have the 24/1.4 and love it. In most lens tests these days, you'll find the 35/1.4 at the top of all rankings. It's considered the reference 35mm. As I wrote in another thread in the lounge, Sigma is about to become the Carl Zeiss of the East. They just need to up prices a bit and get rid of the old "knockoff" image - and I suspect that's what they're in the process of doing.

[Hannibal Chang]

how would I go about testing that though? Is there a way to tell how many stops I'm able to pull in correspondence to perhaps, how much shadow I can recover in Lightroom? Because I honestly cannot tell.

Yeah I have had my sigma ever since I was still a Canon shooter but after selling my Canon, got the A7ii then purchased a Zeiss 55mm 1.4. Both are incredible lenses. Just missing a 70-200 L lens from Canon now (Sony is just too expensive for what it is) as I currently have the F4 non L lens but I snatched it for $100 and given the right timing, still puts out incredibly sharp photos.