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?

[Lumigraphics]

Highlights and shadows in ACR covers a specific tonal band which cannot be adjusted. If you put your cursor in the histogram area and move it across, you'll see what tonal range the adjustments cover. All you can change is the level of that tonal band.

In Photoshop, you can use masks, complex selections, you can change the highlight/shadow parameters, you can Fade the effect after you apply it, you can apply it to a single layer (I often use it on a duplicate layer which I blend in.)

Other than the name, these are really two different things.

[D Fosse]

Doing this in Photoshop, you're working with rendered RGB data, a very limited subset of the original raw sensor data. You may be able to get the effect you're after, but at the price of grain and artifacts, simply because you're stretching limited original data.

Doing it in ACR, you have the full sensor data at your disposal. That means you can make much more extreme adjustments without noticeable image degradation. Shadows and highlight adjustments in ACR are image adaptive. It's not a "fixed band", the effect and depth depends on image content.

In short, you should absolutely do this in ACR if you want the best quality.

There is a golden rule for all of these things, which applies to the whole chain from original scene to final output: Do everything as early as possible in the process. Do as much as you can in ACR, then move to Photoshop when ACR adjustments are exhausted.

[Lumigraphics]

Sorry but I disagree with most of this.

Highlight/shadow in Photoshop is more like a filter. In ACR, it absolutely is a tonal range. Move your mouse across the histogram and it shows you what brightness level of the image will be affected.

As for applying adjustments early as possible, that’s is NOT a rule. Apply them in the order that you need. Altering shadow level in ACR is global while in Photoshop you can select a particular area to adjust.

[D Fosse]

I think you'll find that the consensus is clear about this. You have much more editing latitude with the raw data, than you have with RGB data. There is no point in arguing about that.

[Lumigraphics]

Working in ACR doesn’t let you make complex selections or apply an effect to a blended layer.

in addition, there may be other editing that you don’t want to redo. even things like dust spotting or stray hair removal are one time only for me. It would be foolish to go back to ACR and start over because I didn’t get a global adjustment correct.

One of the most important things you gain with experience is knowing how to avoid costly rework.

[Hannibal Chang]

yep, been there done that numerous times haha

[D Fosse]

Lumigraphics  wrote

Working in ACR doesn’t let you make complex selections or apply an effect to a blended layer.

We're probably talking about two different things here. Obviously you move to Photoshop when there's something you can't do in ACR. That was in fact exactly my point - you move on when you need to. If you can't do it in ACR, do it in Photoshop.

But in terms of the original question, where is it "best" to make shadow/highlight recovery - then the answer is ACR if you're just concerned with data preservation and integrity.

Of course there's nothing wrong with doing the adjustment in ACR and masking it later in Photoshop.

[Hannibal Chang]

Yeah I actually now shoot over exposed right before the point of where highlights become blown out so I squeeze as much data as I can from the get go, so essentially I guess I can still play with RGB data, but still would have more wiggle room playing with a raw file in ACR.

[Hannibal Chang]

essentially what you're saying is, I should only selectively mask something off and apply highlights/shadows to that specific area compared to adjusting in ACR for the overall photo?

[davescm]

Lumigraphics  wrote

Sorry but I disagree with most of this.

As for applying adjustments early as possible, that’s is NOT a rule. Apply them in the order that you need. Altering shadow level in ACR is global while in Photoshop you can select a particular area to adjust.

I'm with D.Fosse on this one - provided you are working on raw files. With jpegs it makes no difference.  You can apply both global and local adjustments in ACR/Lightroom and, if you take the result into Photoshop as a smart object, can quickly go back and adjust them further if required. It is not a question of when in terms of timeline but where in terms of what kind of data. In that respect adjusting shadows and highlights at the raw conversion stage wins.

Dave

[Lumigraphics]

You guys are missing the point. These are not the same things. The adjustments in ACR are NOT the same as in Photoshop. They do different things.

[davescm]

Of course they are different, and I stand by the practice of carrying out shadow and highlight adjustment on the raw file in Lightroom/ACR.

Dave

[Lumigraphics]

You aren't addressing the OP which was asking about the difference. My first reply did just that.

[Lumigraphics]

OP- just take this away. These are different adjustments that do different things. Its not a choice of using one or the other, its picking the right tool for the job.

[D Fosse]

Lumigraphics  wrote

These are different adjustments that do different things. Its not a choice of using one or the other.

Of course they are different adjustments, one works on raw sensor data and the other on rendered RGB data. Those are very different things. But they both attempt to accomplish the same thing: highlight and shadow recovery. Which is what the OP was asking about.

The original point still stands - highlight and shadow recovery are both more effective and less damaging, executed on raw data in ACR. That is so well established by now as to be almost an axiom. You're the only one disputing it that I've heard of in recent times.

Of course nobody's stopping you from masking the result in Photoshop, if that's what you were concerned about.

[Lumigraphics]

ACR does coarse global adjustments. And it’s not recovery, it’s setting the level of a tonal range.

The Photoshop effect is different. Not the same thing. It doesn’t work the same way or yield the same results.

If you want a coarse global adjustment, you do that in ACR. If you want targeted recovery with more settings to adjust, you use Photoshop.

I’m not sure why you are putting words in my mouth and being combative but please stop. You are claiming that I’m “disputing” something which I never said.

Oh and you can’t mask a global adjustment that you made before you opened a file in Photoshop, so I’m not sure where that comes from.

So, OP... it’s not either or. im not sure why some commenters are posing it as such but you use the programs at different times in the process for different things and you will get different results.

[D Fosse]

I can only urge people to read the whole thread, do some more research if they're interested, and make up their own minds. A lot has been written about this, and it's not particularly hard to find.

[D Fosse]

I decided to leave this thread alone - but as it happened I did a series of shots taken in very harsh afternoon sunlight only yesterday. It's too good an actual demonstration to pass up. I almost thought I blew the highlights out of existence here. This is exactly how it came out of the camera:

Not much point in running a shadows/highlights adjustment in Photoshop here. There's nothing to work with. This is cranking the slider all the way to 100%:

But - look what happens when I have the full dynamic range of the camera sensor data to work with. This is the ACR highlights slider at around -65. There's more to go on:

And with that, I think we can conclude this discussion.

[Lumigraphics]

:sigh:

Lets not miss my ORIGINAL point which is that its NOT either/or. These are different tools, they do NOT do the same thing, they do NOT have the same usage, and fighting a straw man is not helpful.

OP, both ACR and Photoshop have useful tools. Don't let anyone try to distract you by veering off into nonsense arguments.

[D Fosse]

From the original post:

Is there any benefit/negative to using shadows/highlights adjustment in PS compared to using ACR?

That question has been answered.

[Lumigraphics]

i answered in the first reply.

This has turned into someone asking if it better to eat using a fork or a knife and you claiming that a fork is always the right answer.

You can ignore my point if you have to be “right” but your answer is incomplete. Now let’s quit clogging the dead horse shall we?

[Hannibal Chang]

but in a sense, which one would give you more of a dynamic range without killing color? based on D Fosse's example, using highlights/shadows adjust to kill highlights literally desaturated the highlights and ACR retained color but the few times I used solely highlights/shadows adjustment, I didn't notice a difference. In D Fosse's example, it does look as if the picture's rendered data was modified and not the raw data itself.

[davescm]

Raw data is never modified - the rendering from that data is modified.

ACR/Lightroom can do genuine highlight recovery by taking data from a single raw channel and recovering luminosity from that one channel. This would put detail into a blown sky, for example, as grey detail.  Working with rendered RGB data cannot do the same.

Dave

[Stephen Marsh]

These old white papers from Adobe provide a fundamental background to some parts of this discussion:

https://www.adobe.com/digitalimag/pdfs/understanding_digitalrawcapture.pdf

https://wwwimages2.adobe.com/content/dam/acom/en/products/photoshop/pdfs/linear_gamma.pdf

https://www.adobe.com/digitalimag/pdfs/highlight_recovery.pdf

Raw sensor data has the obvious advantage in highlights, with an equally obvious disadvantage in the shadows. With the ability to render the raw data into a standard RGB gamma colour space, raw data has great benefit for exposure challenged images. It is also possible to make a secondary render into a non-standard RGB gamma that may provide more latitude for working the shadows using the Shadow/Highlight tool.

I agree with “both sides” – that not all tools are equal and that there are different places and different tools that perform similar but differently. The right tool for the right job at the right place and the right time!