DNG, Bridge, and ACR Preview Sharpening

[AlanDunne]

I have two related questions for the forum members, with hopefully easy answers.

1) If you are looking at a DNG image in Bridge (preview pane or slide show) is the preview based on the embedded preview in the DNG file, or some local Bridge preview save in cache?
2) When using ACR/Bridge, and having the setting for sharpening applied to the preview only, does the ACR sharpening get applied to the embedded DNG preview as well as the Bridge preview (assuming theyt are different)?

While the questions are simple, I will explain the context for the question (just to make sure I am asking the correct question).

When using Bridge you can set the ACR preferences, and one setting I have always used is the apply sharpening to preview images only. In Bruce Fraser's "Real World ACR" book he recommends applying sharpening to the preview only, and thus saving the real sharpening when the image is brought into Photoshop as a TIFF. Bruce's rationale was that sharpening could be controlled much better in PS than in ACR due to increased controls in USM and with sharpening layer masks.

I subscribed to Bruce's approach, however, the downside is that in order to get capture sharpening applied to you images, you need to have a vast amount of TIFF's with the capture sharpening applied. For 95% of my images, I was using default captured sharpening using batch automations driving the PKSharpener, with maybe 5% of images that required "custom" sharpening because of the importance of the image. For 95% of my images, this approach was way overkill, and was consuming huge disk space. Bruce's PKSharpener is a fantastic tool, but is overkill for the significance of most of my images and comes with a high penalty for memory consumption (RAM and disk).

Then along comes "The DAM Book" and Peter's concept of using the DNG preview as a "pretty good print". I really like this idea, and the pretty good print should be sufficient my 95% of images in various output forms (small proof, web galeries, etc) and I can automate these via Iview MediaPro. This will save huge amounts of TIFF files where the only difference between the DNG and the TIFF would have been the capture sharpening (tonal and colour adjustments being made in ACR, especiall now that ACR supports a curve and crop/straighten!). With this approach I only need TIFF masters for critical images, or those requiring special processing such as layer masks in PS, local colour on tone corrections, compositing, etc.

Also, Peter described the ACR sharpen as being deceptively sophisticated in spate of only having one control, as the sharpening algorithm was tailored to the camera body/resolution etc. Other books, including Bruce's, seemed to imply that ACR sharpening was pretty dumb. Peter "recommends" that ACR sharpening be applied to both the image and the preview, as a form of capture sharpening. This is a different recommendation than Bruce, and is based on a different set of assumptions.

Both Bruce's and Peter's recommendations make sense, even though they are contradictory. I think there is a way to marry the two recommendations as follows.

If the "sharpen preview only" setting is enabled in ACR preferences, and this gets applied to the embedded preview in the DNG (and not just a Bridge preview if it is different than the DNG embedded preview), then this is sufficent quality capture sharpening for my 95% of images. I do not need to make a TIFF master for these images. And since IVMP supports using the DNG preview to generate web galleries, contact sheets, proofs, etc, I can have these include the capture sharpening applied by ACR.

For the 5% of images where I want the higher control offered by PKSharpener, if I keep the "sharpen preview image only" setting applied, then when I bring that image into PS for further editing into a TIFF master, I can apply the capture sharpening in PS without ACR already having applied sharpening.

So I have married two contradicting recommendation for the setting of "apply sharpening to preview only". This works of course if the answer to my original question #2 above being YES.

Now, everyone start flamming away. I am used to being called a control freak!.

Cheers ... Alan

[peterkrogh]

Alan,
You get it exactly.

To answer your questions first:
1. When in Bridge, you are looking at the Bridge Cache, not the embedded preview.  This preview is held in the central cache, and, if you have "use distributed cache" checked in preferences, then it lives in the BCT document in the folder.  Currently Adobe does not make use of the DNG embedded preview in any way.

2. If you have sharpening in Camera Raw preferences set to preview only, it will not sharpen the embedded DNG preview.  This is why I suggest that you have CR apply sharpening to all files, and not just preview.

To expand a bit on your point.  Since Bruce does not use DAM software, he does not see things the same way I do.  The value of the embedded preview as a proof is most apparent once you try to integrate Bridge with DAM software.  If you like to concept of an embedded preview doing a lot of the proofing work for you, and you want to be able to use it without having to open in Photoshop and do a sharpening action, then I would suggest you use CR sharpening.  It is good sharpening - not the best you can possibly do, but certainly fine for proofing.

If you are going to make a master file, then you will generally do a critical evaluation as you open the file individually through Camera Raw into Photoshop.  In most cases you will want to tweak CR settings a bit when you open them to make master files, and sharpening is one of the settings you might want to tweak. (You might also want to tweak curves or shadows as well, since the settings that make a good proofing file - lots of punch - may not be right for a file where you will be carefully working on shadow detail to optimize it.)

As to workflow in bringing your images through, make sure to reset your sharpening preference after opening the file so that you don't forget and make a bunch of DNG files with no sharpening.
Peter

[AlanDunne]

Thanks Peter, this makes perfect sense. Armed with knowledge that the "apply sharpen to preview only" option does not include the embedded DNG preview, I will enable sharpening in ACR to apply to the image as well as preview and this will suffice for 95% of my images.

I have recently adopted a practice of using a Bridge label to indicate which of my images will be brought into PS for purther processing. I can use this label to find images and bulk set the ACR sharpening amount to 0% just before bringing into PS where I will perform a more critical sharpening as well as any other corrections or compositing.

For the remaining 95% of images, driving the processing from the DAM s/w (IVMP in my case) with the DNG preview image is a huge saving of time, effort, and disk space.

Thanks for taking the time to answer my question, and providing the enlightening concept of the "pretty good print".

Cheers ... Alan

[danaltick]

I have a follow-up question on this topic.  I haven't started working with DNG's yet, but is it possible to edit a DNG in ACR, making alterations to sharpening, shadows, etc., then open the file in PS, but not save the changes to the DNG; thereby, leaving it untouched for proofing?  Thanks.

Dan

[AlanDunne]

Dan,

once you "open" the DNG in PS it cannot be saved in DNG format. The image, further edited in PS, can be saved as a TIFF, PSD, etc. Thus the answer to your question is yes, the DNG remains untouched by the PS edits. I hope  I am interpreting your question correctly.

I figured that I owed you an answer here as you helped me greatly in the discussion on backups!

Cheers ... Alan

[peterkrogh]

Dan,
Unfortunately not so easily.  If you open a DNG and adjust the sharpening so that it opens into PS with less sharpening, you will change the embedded preview to have the lower sharpening setting.  I was thinking about this the other day, as I was answering the earlier questions in this thread.

What we would like, I think, is a way to open into PS, with custom adjustments, without altering the existing DNG.  This would entail a new button in Camera Raw.

I'll ask Thomas Knoll if he can do this.  It would not be for this version of Bridge, but possibly future versions.

At the moment, the work-arounds are probably:
1. Open into PS as desired, reopen into CR and reset the sharpening setting.
2. Duplicate the file, open into PS, trash the duplicated file.
3. Open into CR, Save as TIFF, change setting back, close and then open the TIFF file manually.

None of these are ideal.
Peter

[danaltick]

Thanks Alan for your answer; makes sense.  However, it appears that once you click on the "Open" button in ACR, your ACR changes get saved to the DNG before it gets loaded into PS.  Looks like Peter has addressed this problem from that perspective.

Peter, I hope you are successful at getting Thomas to make this modification.  In the meantime, I think I will go with option 2.  Seems the safest.  Thanks.

Dan

[AlanDunne]

Dan,

I did not get appreciate the intent of your original question, but having seen Peter's response, I now get it. I too would support the future feature of a new button as suggested by Peter. I have one follow up thought that may be useful for you. The type of sharpening that you would do in ACR is capture sharpening, which is a modest amount of sharpening to compensate for the lack of crispness in digitial capture. In general capture sharpening can be set to a default value that you can determine through some experimentation. Peter is currently using 50 (for a D2X I presume). I am using 40 (D2X) and 50 (D70).

For the "pretty good print" applications of the DNG embedded preview, a default capture sharpening value should suffice. Only for a small percentage of images youmay want a custom sharpening setting. For those you can use a label in Bridge to identify them, thus after you have brought those images into PS with custom values, you can find those images quicky to reset them back to the default. You can save an ACR setting subset for your default sharpening, and apply it from the Edit menu in Bridge without having to open up the images in ACR.

This isn't a perfect solution as the embedded preview has to be rebuilt every time the sharpening setting is changed, but it does help keep track of the images that deviate from the standard workflow.

What I am now doing is using ACR to set the capture sharpening to a default value for the DNG preview. This works for 95% of my images. I label special images and temporarily set the sharpening to 0 for those images before bringing into PS, then for those images I do a custom capture sharpening in PS and save these files as TIFF. I then find those DNG's via the label and set the ACR sharpening back to the default by applying the setting from the edit menu. It is usually these same images that also are targetted for high quality printing. These images thus receive custom output sharpening depending upon the image resolution and paper type. The custom output sharpening is saved as layers in the TIFF master. Contact prints, proofs, etc general do not receive special treatment and printing from the DNG preview in IView MediaPro does a sufficient job.

This is a workaround for the missing "button" described by Peter, but it does work. And the overhead is not too high as long as the number of images to receive custom sharpening is kept to a small percentage of images.

Hope that helps ... Alan

[danaltick]

Sounds like a good idea.  Thanks for filling me in.

Dan

[peterkrogh]

Alan,
One small quibble with the way you describe it.  I would say that what I will want to apply to the DNGs in general would be MORE than capture sharpening.  I will want to apply enough sharpening so that the proof generated by peeling off a JPEG from the DNG will not require extra sharpening. After some recent tests, I think I will be bumping it up from 50 to 75 or 100.

From a practical standpoint, the deciding factor in this is what the derivative created by iView looks like, since that is the only application I currently use that can access the preview directly.  In making this decision, I will have to balance between outputs that are at full-size and ones that are at reduced sizes.  Ideally you would have different sharpening values for each, but I'm going to split the difference and look for the value that is the best overall value.

Capture sharpening is a different beast, and is the amount of sharpening that you would want to apply when bringing the file into Photoshop, with the knowledge that you will be applying more sharpening later.

Peter

[AlanDunne]

Thanks Peter for the clarification. Your book seems to imply that you were limiting the sharpening in ACR to capture sharpening, but when you think about it, the whole notion of the "pretty good print" implies taking the sharpening beyond capture sharpening as you state in this thread. This is all starting to come together for me now. I will still use my label technique to identify images that will have a multi-stage sharpening workflow in PS and turn ACR sharpening off for those images.

I have been doing some testing with the ACR sharpening and it is much better than I was previously lead to believe. You can crank up the strength quite high before visible halos appear. Your new values of 75 to 100 do seem to be reasonable for the "pretty good print"

Cheers ... Alan

[peterkrogh]

Well,
As I was writing the book, all this was theoretical.  There was no application that could extract the embedded preview until iView 3.0 delivered in early November, so there was no way to get a good look at it.  And the effects of iView's extraction and resizing were unknown as well.

If you think that led to a few cold-sweat nights last spring as I was wondering if all the promised functionality would actually appear... well, you would be right.
Peter

[danaltick]

Peter,

I've been reading Bruce Fraser's new book "Real World Camera RAW" and he mentioned a way of opening a RAW file into Photoshop after making adjustments to it in ACR, and not have the adjustments saved back to the sidecar file.  I tested it and it worked.  Here's what you do:
    1) Open Camera RAW hosted by Photoshop
    2) Make ACR adjustments
    2) On the Mac hit Command-Option-O
    3) On the PC hit Ctlr-Alt-O
    4) Or hold down Option/Alt and click on "Open Copy"

Since I will be doing this primarly to make ACR adjustments (i.e. sharpening) to my DNG's prior to creating a master in Photoshop, opening ACR hosted by Photoshop rather than Bridge should not be an issue.

Dan

[peterkrogh]

Dan,
good find.  I was going to dig into that before making a feature request.  more than once I have asked Adobe for functionality that was already there...
Feel like writing up the issue and the solution as its own topic in the Bridge/camera Raw section?
Peter

[danaltick]

Sure, I'll try to get to that sometime this weekend.

Dan