Since we have been bombarded with a bit too much Pro ACR evangelism lately, I decided to write down my crude thoughts on some of the ACR peculiarities. These are meant as constructive criticism and thought provokers, not as pure critique or putting down of the product.
ACR 3 has introduced a new Curves tab. An interesting addition, because it gives us more control over the conversion process. But as it is implemented currently we first have to decide which Brightness & Contrast setting we desire, and then we get to fiddle with RGB curves...???
Whether this curve is combined with the conversion curve or simply a post-process is unclear to me, but if we are to believe Bruce Fraser, it helps recover highlights which is only possible during the actual conversion.
But that is not my point, I actually would love to be able to adjust the tonal reproduction curve with a curves tab, but I do not like to be confronted with two seemingly unrelated methods to do so. The Brightness & Contrast slider AND the curves tab. It should be either/or with the possible exception of a gamma slider if "linear" corrections are a bit too difficult to master.
The Brightness & Contrast sliders (or gamma slider) should simply be above the curves box, and adjust the curve accordingly.
And while we are at it. Introducing a reproduction curve would also be a great opportunity to add a Color-Cast correction slider option which is simply a (partial) correction to a complementary whitepoint. (Or even an arbitrary whitepoint if you want to introduce a colorcast).
Well, like I said, just some crude thoughts on the subject...
White Balance so easy, even our 5 year old can do it.- Melissa Strickland
A couple of points. The curve feature in ACR 3 is a luminence curve, not RGB. The adjust sliders and curve are both operating on linear data, with the curve making adjustments to what the adjust sliders have done. The sliders make relatively large moves and the curve is for fine-tuning and localizing these moves to a degree you can't do with the sliders. During conversion of the raw file, both slider and curve adjustments are applied, so ACR 3 offers more precise control on pre-gamma corrected data.
White Balance so easy, even our 5 year old can do it.- Melissa Strickland
Yes, I understand the separation between B&C sliders and the curve. But the question is: why do you want that?
I think I'm proposing a more logical grouping of controls. The curve tab should be the only thing operating on the reproduction curve. Move the relevant sliders to the curve tab.
But do we really need those sliders?
The whole problem with a Contrast slider is its lack of indication where the pivot point is. One should first move the image data within the correct range before a contrast slider makes a relevant change. Only experience will tell you what that range is, and afterwards you might need to bring the image data back to its original range.
If the curve is meant for fine-tuning, might as well fix the contrast all together. And simply do any contrast adjustments with the curve. In practice that means you could come by with a single contrast slider that changes the curve for adjusting an already fixed internal contrast, and most likely you only need some crude presets from the pop-up that is already there from which you customize, eliminating the necessity of the contrast slider...
Along the same lines you can dump the brightness slider by fixing some gamma.
White Balance so easy, even our 5 year old can do it.- Melissa Strickland
>The whole problem with a Contrast slider is its lack of indication where the pivot point is.<
The contrast slider always pivots at the midpoint (127/8)
In actual use I find the curve to be a specialized tool that many images don't require fiddling with, ie the default medium contrast works fine. So in practice you often don't have to go through a 2-tab editing process. IMHO the contrast slider is a byproduct of the fact that DSLR raw captures are linear and thus appear quite flat. Without the contrast slider everyone would have to make much bigger edits to the curve.
>Yes, I understand the separation between B&C sliders and the curve. But the question is: why do you want that?<
For me, the separation of the two saves time. On images destined for web previews, comps, or edit selection, I can get tones in the ballpark with a quick move of the sliders. For just the keepers, going to print, I can fine-tune with the curve if necessary.
I acknowledge that the decision by Adobe to have an ACR slider/curve methodology different than what we use in PS requires users to spend the time to adjust their concepts of using the tools. So I can see where you're coming from (I think). In this case though, I think the methodology is better suited to the type of capture, camera sensor vs scanned film.
White Balance so easy, even our 5 year old can do it.- Melissa Strickland
Linear Mode
