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Jeff, I have questions for you, if you don't mind...?
OK, I spent the last two days re-reading Bruce Fraser's wonderful book "Real World Image Sharpening" two more times (I am certified to teach it now!) in attempt to make sure I have every word of the book understood and mastered in my head and in practice (with a twist of my own here and there).
But after reading it, a general question seems to nag me. Since sharpening does not really add any true detail to a print, but instead, increases the perception or illusion of detail by artificially increasing contrast in the form of halos specifically at edges...
And because your general recommendation to sharpen at 100% view, just until the image looks "good" without doing any damage to the image, or over-sharpening...
(BTW, for some peoples info, I make large to very large, high end, high res, continuous tone, landscape gallery prints)...
I am having a hard time understanding the threshold of "damage" to do (or not to do) to an image file in ACR, by essentially increasing contrast halos, which in of themselves, it seems, are a sort of "damage" if you will?
Maybe there is a book(s) or article(s) or something out there that can help me figure out how to take "Capture Sharpening" right up to its limitation without going over??? I guess I'm needing more detailed explanation about how to figure out this threshold?
Can or does ACR sharpening (or is there a way in ACR sharpening) constrain the sharpening to specific tonal ranges (like when we use USM on a layer with the "blend if" sliders set to protect the top highlight and bottom shadow tones)?This allows the image to handle more sharpening with less damage.
The reason I ask, is because my main concern with "Capture Sharpening" is that I might take the haloing to a certain level, which may end up limiting the amount of additional sharpening I can do effectively (without damaging the image) in PS after up-sizing, because the halos have reached towards, or close to black and white... (hopefully I can find a better way to re-word that last sentence)...
Sorry if I am asking too many questions... But that is one reason for forums, right, to mull over and learn about issues? I admit, I am an obsessive quality freak with my prints (anyone hear of Christopher Berkett? - I consider myself, sort of, in the same vein as him in terms of the technical quality of prints he strives to make) and I am always on a constant search for as close to perfection as possible, even if it pains me (yet, it is a pleasure!). I know its a sickness, but an enjoyable one!
My general rule of thumb is that if you're seeing strong halos when viewing images at 100% then you're oversharpening. CR's sharpening does have built-in tonal protections as well as preventing color shifts; so you don't have to worry about those aspects.
>I am having a hard time understanding the threshold of "damage" to do (or not to do) to an image file in ACR
If you actually SEE halos, you've gone too far...you want it to look "sharp" but nothing more than that. If it looks "soft" it's not sharpened enough...if you are seeing halos, try reducing the Detail a bit while increasing Amount. Assuming you are in the ballpark with Radius. Lower radius (.5-.9) for high frequency data, higher (1-1.5) for low frequency data.
>Can or does ACR sharpening (or is there a way in ACR sharpening) constrain the sharpening to specific tonal ranges
Camera Raw already, by design, rolls off the highlights and shadows. It's in the pipeline with no user control. It also only sharpens the luminosity so it doesn't effect color at all.
Yes! That is what I want to hear!
I had read about the fact that ACR sharpening sharpens the detail minus the color (which makes me very happy) but I had not heard that there is a built in "roll off" of the shadows and highlights. That helps a lot!!!
Thank you (late, great) Bruce Fraser, Jeff Shewe, and whoever else is keeping ACR on the cutting edge!!!
Also thank you both Eric and Jeff very much for the feedback on the threshold I am talking about. Once I get the gallery rolling here in Vegas I'll invite you to see the results!
>and whoever else is keeping ACR on the cutting edge!!!
That would be Mark Hamburg and of course, Thomas Knoll. Both worked on the sharpening. Zalman Stern and new hire Eric Chan round out the Camera Raw team (although Mark has left Adobe) so it's down to 3 engineers, Thomas, Zalman and Eric. Plus some management and marketing (Tom Hogarty) and a few important QE people. Pretty amazing what a small team like this can accomplish, huh?
Yes, that is amazing that the team is so small. Hats off to you guys, and please keep on keepin' on top!
This may be totally out of line (by why the heck not have the audacity to try?) but would you allow me to send you a crop of an image (Tiff) of both unsharpened and ACR capture sharpened, to see if you think I am getting it down?
Post it somewhere online with links here in the forum...I really don't have the bandwidth (time) to engage in one-to-one communications...
I'm not sure how to post a tiff online? If I get that figured out, I'll let you know. And thanks again very much.
Jeff, I'll get to the examples soon (been overwhelmed with work).
So, I bought the updated ACR book, and am devouring it. I have read about the sharpening controls a few times now (while I was standing in the DMV line today). The "DETAIL" slider function, I'm having a hard time getting my brain around, and I am, so far, not finding enough "nitty gritty" information on how exactly it works. Of course I am using it, but I am not sure, exactly, what it is doing. I understand that it is a "halo dampening" effect, but isn't just turning down the amount halo dampening? So, what exactly is the difference? I understand the "masking" control (VERY COOL) and of course "Amount" and "Radius", but the "Detail" control is a curious "new tech" leaving me wanting to know more...
I just started a topic similar to this one without realizing that this one was already running. Sorry about that. Mark's questions are really zeroing in on the same areas that I am interested in. I too appreciate knowing that there is roll off in the shadows and highlights as that is consistent with the approach that Bruce Fraser presented in his book.
I have another question that is along the same lines as Mark's. Is the "capture sharpening" that compensates for the softness introduced by the camera sensor also happening in the background of Lightroom and ACR with no user intervention? If it were, then this whole thing would make a lot more sense to me because we would not be expecting one operation using the detail panel to accomplish what Bruce Fraser essentially described as two clearly discrete operations. One for capture and one for content. It seems to me that what most authors are recommending an approach with the detail panel that is more like content sharpening.
If you can shed any light on that I would appreciate it. I, like Mark, also would like a better understanding of the detail slider. Some have said that when set to 100% that it makes the detail slider act like the Unsharp Mask Filter in Photoshop. But that doesn't explain what halo suppression or "pinning the halo" means.
Thanks for all your sage advice on these forums.
Well, I'm at the Adobe CS4 announcement tonite then off to Adobe San Jose to meet with some of the Camera Raw team so it'll be a few days till I have an easy time to answer. But I will say that the Detail slider tweens between high and medium frequency textural detail while also acting as a halo suppression. Higher Detail = more high frequency, lower Detail = more medium fre frequency and more halo suppression. Complicated, I know...best bet is to do some visual tests and see what you get.
Thanks Jeff. When you do have time to answer can you shed a little light on my question regarding capture sharpening. Is there some behind the scenes optimizing taking place to compensate for the softness of the camera sensor? If not then I am confused about whether or not we are sharpening for capture or content.
Thanks JEFF for commenting, and taking precious time to keep us on the cutting edge.
"Detail slider tweens between high and medium frequency textural detail while also acting as a halo suppression. Higher Detail = more high frequency, lower Detail = more medium fre frequency and more halo suppression."
I read this statement about 5 times, and am having a hard time understanding it. Maybe because it is right before bedtime? I'll give it another try tomorrow tween students I am teaching Adobe Camera Raw! As I also keep playing with the control trying to analyze exactly what the allusive heck it is doing.
Move Detail to left: emphasizes wider edges / coarser detail.
Move Detail to right: emphasizes narrower edges/ finer detail.
Yeah...what Eric said!!!
Go to page 9 of this Camera Raw 4 pdf authored by Bruce Fraser and Jeff Schewe. It explains a bit more all the sliders in the sharpening panel:
"Move Detail to left: emphasizes wider edges / coarser detail.
Move Detail to right: emphasizes narrower edges/ finer detail."
OK so I took a high (and high/mid) frequency image and tried two semi extremes. I did a high Amount 150, 0.5 Radius, 5 detail, and 8 mask.
Then I tried to do an opposite approach to detail by having a 100 Detail and a 45 Amount (which basically looked to me, at 100%, to be close to the same amount of overall softness reduction. The Masking and Radius stayed the same.
Brought in PS as layers and toggling between the two images at 100% and 200% zoom, basically this is what I saw:
The image with the most halo dampening (Detail at 5) also lacked fine detail in the high frequency areas. The image with the halo dampening off (Detail at 100) had much more fine detail.
In the mid frequency areas, the difference was also there, but less.
Still a curious little slider in my mind...
Also, thanks Tim. That is actually the same wording as is in the new ACR book. I found this artical
There is some more description about the "detail" slider but still leaves me wanting. I'll just keep on with more tests I guess.
Eric Chan wrote:
> Move Detail to left: emphasizes wider edges/coarser detail.
> Move Detail to right: emphasizes narrower edges/finer detail.
Umm ... okay, but in which way is this different from Radius?
Olaf, radius is certainly related to detail, but behaves differently. The main thing you'll notice is that radius controls the overall width of the light/dark halos that are created around an edge. Move it to the right: wider halos; move it to the left; narrower halos. This is not quite the same as Detail, because Detail effects which frequencies in the image are to be sharpened in the first place, as opposed to how wide to make the halos.
It is often the case that you may want to use a lower radius (e.g., below 1) and higher detail (50 or higher) as well as a higher radius (e.g., 1 and up) with a lower detail (below 50).
Radius also affects the edge mask. Try this: set Radius to 0.5 and Masking to 40. Then option/alt-click on the Masking slider to see the on-the-fly mask preview. Remember what it looks like. Then set Radius to 3. Go back and option/alt-click on the Masking slider and check the mask preview. Looks different, right?
I've been following this thread with interest, and I have read the latest ACR book by Bruce and Jeff. Is it accurate to say that moving Detail to 100 and Masking to 0 results in function very similar to straight unsharp with a low threshold, except of course in the linear domain?
In other words with the above settings all edges, whether or not they are in a high or low frequency spatial pattern, are sharpened pretty much identically. I find it useful to start at Detail = 100, set the other sliders to somewhat over-sharpen, and then back off on the Detail to "clean up" the high frequency areas.
Similar, but not exact. There are still protections being applied, e.g., tonal ranges and other factors, so it's not quite the same as plain ol' USM.
Detail = 100 and Masking = 0 is a good choice when you want to emphasize texture (I use this often for rocks, mountains, sand, etc.).
I have taken Jeff Schewe's advice and have started really spending some time playing with the sliders just to see what happens. One interesting conclusion that I have come to is that using a very high amount with a very low detail setting can be useful in certain situations.
I took a photo of the side of a building that had lots of detail. There was a neon sign that was not lit because I took the photo in daylight. There was also a lot of high frequency architectural detail on the side of the building as well as a fire escape, windows, the works. So I had lots of hard high-contrast edges. The external surface of the building was a decorative stucco. So the picture had some textural detail as well.
What I did was set Amount to 134 and Detail to 5. The result was that I got really crisp edges on everything that had a hard edge because the halos on the edges were very intense due to the high amount setting. However, they were not really noticeable due to the halo suppression introduced by the low detail amount. They were just tight, crisp and hugged the edges very closely. The edges were sharp but the photo didn't look over-sharpened.
That was a real eye opener for me as I would normally never dream of using such a high amount. But with the right amount of detail it really looked better than anything else I tried.
If I went the other direction with a low amount of about 25 and high detail of 100, it didn't work nearly as well. None of the halos were very intense due to the low amount setting, so the hard edges didn't look nearly as crisp, and all it did was emphasize the texture in the stucco due to the high detail setting. That's not really what I was after.
For me these two examples are just the beginning of fooling with the sharpening in ACR. I am sure there is much more to learn. Nothing beats just taking the time to experiment.
>Nothing beats just taking the time to experiment.
The other thing I would point out is that all of the controls in Detail are interrelated. So, you really need to tune the sharpening _AND_ the noise reduction together. While many people feel that Camera Raw's noise reduction isn't very good, I would disagree...it's just not real strong (nor is it capable of being localized). Almost EVERY shot can use a small touch of noise reduction AFTER you've tuned the capture sharpening.
Also, you really need to understand how the masking comes into play. Even if you only use a small dose of masking, it will allow you to further refine the amount of sharpening as well as the detail settings.
The one area of Detail you can generally leave at default is color noise reduction. It may sometimes be useful to slightly increase or decrease the amount of color noise reduction but it's not nearly as setting sensitive as the other adjustments.
Once you find good base line settings for your camera/ISO/content, then you need to learn how to create Presets of just the detail settings for easy and quick applications of the gross numbers and then fine tune on an image by image basis.
If you find that you are often or always within a certain range of settings, you should consider creating custom default settings which can be tied to both the camera serial numbers as well as capture ISO.
Once you learn how to use the tools, learning how to use the tools efficiently then becomes important.
Thanks very much for your input on this topic. I am really beginning to gain a better appreciation for just how flexible and powerful the sharpening in ACR and Lightroom is. It's actually kind of exciting when you find a combination of settings that works way better than anything else you've tried.
Can you please elaborate on what you mean when you say "even if you only use a small dose of masking, it will allow you to further refine the amount of sharpening as well as the detail settings." I can see how it affects amount but I am not sure how it relates to the detail slider.
One of the things experiments that I did is I set the masking to about 50. Then I slid the detail slider to the two extremes of 0 and 100. When I viewed the mask, it appeared to look the same using both detail settings. I found that interesting but not sure how too interpret what's going on.
Thank you again for sharing your knowledge.
A mask at 50% would be too strong to show you the results of changing the Detail slider. Try more like 10-30 with a strong Amount setting...
Sorry to bug you on this one point buy I'm feeling a bit dense on this one. Can you please give me an example of the type of tweak you would be attemtping with the Amount or Detail setting that a small dose of masking in the 10 to 30 range would allow you to make?
Running Detail up high tends to hit a lot of high frequency texture...but if you have a high ISO it will also hit the noise. Since you really want to concentrate the sharpening generally on edges, increasing the mask would allow you to increase the detail and amount without having too much sharpening hit the noise. Then add a bit of luminance noise reduction as well.
Thanks Jeff. That makes a lot of sense. The only question that I have that's still rattling around in my brain is one that I first asked when I started participating in this thread. Here it is.
I read Bruce Fraser's sharpening book and while this is not a quote, I am pretty certain that he said that "capture" sharpening is primarily a matter of choosing a radius and amount that is appropriate for a specific camera and ISO. In addition I believe he said that it is done with the intent of eliminating the anti-aliasing introduced by the camera so that one could make a better mask for use in the subsequent sharpening passes. So it was treated as a separate pass from the "content" sharpening.
When he discussed content sharpening, that's when he emphasized the importance of choosing a radius, etc. that was appropriate to the subject matter. At least that's what I understood.
In ACR and Lightroom it appears that these two steps are now being handled in one sharpening pass that is approached more as content sharpening. Is that compromising the ultimate goal of achieving the optimum sharpening for the image?
The only thing I could think of is that maybe what Bruce defined as capture sharpening was straight forward enough to not require user intervention and is being handled by Lightroom and ACR behind the scenes once the camera involved is recognized by the software.
Ever since reading Bruce's book I have been an advocate of his methodology. But the only way I can think of to follow his method to the letter is to use Photoshop and treat the three passes independently. I would rather not do that unless it's really necessary.
So in a nutshell what I am asking is this. Is the default sharpening in ACR and Lightroom tuned to the camera and if not, how does one account for the capture sharpening as defined by Bruce, without treating it in a separate pass.
I hope I am note digging too deep into the inner workings of the software here. If so, just say so and I will just learn to live with this question unanswered. On the other hand, I figured it never hurts to ask:))
Thanks again for all your help.
>In ACR and Lightroom it appears that these two steps are now being handled in one sharpening pass that is approached more as content sharpening. Is that compromising the ultimate goal of achieving the optimum sharpening for the image?
Bruce, in the book was talking about separating source and content, yes as those are the two main factors of "Capture Sharpening"...but Camera Raw/Lightroom already does a sharpening scaling based upon the source of the image. ALL of Camera Raw's controls are source scaled based upon the camera. So, the primary goal of the capture sharpening is to set the parameters (frequency as determined by the radius) and then adjust the amount. The Detail slider and the Mask settings allow fine tuning the result.
So, rather than "compromising" the sharpening, it's actually exceeding the goals of Bruce's approach of Capture, Creative and Output Sharpening...
In other words, it's mo' better...
Thanks so much for your willingness to answer my barrage of questions. It has helped a lot and I have no more questions.
However, I would like to provide you with some feedback on a completely different note. I own the ACR for CS3 book that you authored with Bruce.
I really want to thank you for providing the downloaded example files. Seeing real life before and after examples totally opened my eyes to new possibilities. Especially the creative use that is made of the HSL/Saturation/Luminance sliders. When you referred to them in the book as the "scalpel" it clicked with me. I almost never used them before and now I use them to fine tune almost every image. I don't think the concept would have sunk in nearly so well though, if I hadn't been able to work on the files and compare my results with yours.
I have always appreciated the "Real World" series but felt that the lack of downloadable files was a weakness and that their inclusion would really enhance the usefullness of the material, especially because so many of the series example photos and screen shots have typically been fairly small. So for what it's worth, I would let your publisher know that it was well received, at least by me anyway, and I would love to see more of the same in future publications.
Thanks again for your helpful advice on all my sharpening questions.
>Thanks again for your helpful advice on all my sharpening questions.
You are welcome...and thanks for the kind words, I know Bruce would have appreciated them (as I do). Course, now I gotta get back to work on the NEXT version for Camera Raw 5!!!
(and yes, there will be a downloads for the next book too)
Jeff Schewe wrote:
>You are welcome...and thanks for the kind words, I know Bruce would have appreciated them (as I do). Course, now I gotta get back to work on the NEXT version for Camera Raw 5!!!
This thread has been very helpful with practical suggestions by Eric Chan and Jeff, who has been surprisingly humble and friendly. I've clashed with Jeff a few times online, but I do agree that his revision of the Real World ACR book was masterful--preserving Bruce's original material and adding content of his own for clarification and covering new features.
I too look forward to the ACR5 revision. I would also be interested in an update of Bruce's sharpening book. IMHO, Bruce was at his most creative in that area, but it is a ver 1.0 and things have changed since its publication.
>and Jeff, who has been surprisingly humble and friendly
Uh huh...well, that's a left-handed compliment if I've ever heard one. The participants (at least up till now) have been civil, so I've been civil. That can change in a New York Minute...
Steering somewhat clear of these last couple of posts, I was going to also add to my prior suggestion regarding the ACR5 revision.
It would not only be great to see downloadable file examples like the last book, but also, to the degree that it can be accomplished, it would be great to see new examples as well.
Not that the old ones weren't fine. It's just that I know for myself at least, that working through the examples is where a lot of my learning takes place and I would be much more apt to pay the $$$ for the new revised book if I could work through new examples as well.
>It would not only be great to see downloadable file examples like the last book, but also, to the degree that it can be accomplished, it would be great to see new examples as well.
Most all of the images in Chapter 5 (where the download examples came from) will be new images. Chapters 4 & 5, of course, need substantial revision because CR 5 will now have local tone & color corrections and other adjustments, and that massively changes the nature of Camera Raw 5's relationship to Photoshop. It doesn't mean you won't still need Photoshop for a lot of stuff, just maybe not so much.
"Steering somewhat clear of these last couple of posts, I was going to also add to my prior suggestion regarding the ACR5 revision."
My only suggestion so far is for someone to straighten the horizon on JEFF's "15-foot King penguin photo! LOL! Wonderful photo BTW Jeff.
But seriously, Real World Adobe Camera Raw With Photoshop CS3 is a kick tail must book for any serious photographer! (I read it about 6 times this week.) Now is time for a glass of wine.
New question about ACR sharpening??? And maybe it has been asked already... I have been at this capture sharpening thing full time for a couple weeks now, and am really happy about the results, and FINALLY get how all the sliders interact...
Would the developers of ACR please consider a "blend if" type of slider that would simply allow us FULL control of how ACR sharpening sharpens the tonal levels? This type of control at the Raw stage, according to Bruce, and I agree, is even more critical at the capture sharpen stage. I know it is sort of built in to ACR sharpening now, but I'd love, and I need the control. I would absolutely love this!
As well as being able to see the masks at all zoom levels...
Might as well ask...