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A JPEG image by nature is an 8-bit image. I do not know what the implications are of converting the 8-bit JPEG image to a 16-bit image. But I do it as part of my workflow. The big advantage of doing adjustments in ACR is that those adjustments are made nondestructively. My workflow is very similar to yours. I open my JPEG images in ACR and make adjustments to them. I then use an action to convert them to 16-bit tiff images that I review in Bridge and make any additional adjustments in Photoshop. Then I have another routine that flattens those images and converts them to 8-bit. The quality of my JPEG images has improved substantially, in my opinion.
But I wonder if ACR does it adjustment in 8 or 16 bits.
BTW you know you can automate ACR to process the jpg so that it's output is in 16 bits. That would save you the step of putting it through the first recorded action.
Or is that you were already doing? Can one create actions in ACR?
Yes, I understand that, but since you are starting with an 8-bit image just because it's a JPEG I wonder how much is gained by having ACR output 16-bit images. You cannot create the extra data, so I don't know how much is gained by doing that. But I do convert to 16-bit images.
After I have done my initial editing in ACR I simply click the Done button. Then I have an action that I run as a batch that creates the adjustment layers that I commonly use and then save those images as 16-bit tiff images. After I have made any additional adjustments in Photoshop, I have another action that flattens those images and converts them to 8-bit. You might not agree with that workflow, but it works for me. And it has really become quite fast with Photoshop CS3 and ACR 4.1.
You will not magically gain any non-existent information, but working in 16 bits does afford you much more latitude in manipulating the image, especially when doing gradients and the like; you'll avoid banding.
That's kind of what I suspected, but I wasn't sure. It's good to hear it from someone else.
What I am trying to understand is what is going on when one works on a Jpeg in ACR. Is it being manipulated in 16 bits? Or is it being worked on in 8 bits and THEN created into a 16 bit file AFTER the 8 bit manipulations?
With PS I can increase the file to 16 bits BEFORE I do and layered adjustments. Is this what is happening behind the scenes in ACR?
Unfortunately, once you return to 8 bits, like in printing, the banding returns. At least it does doing 16 to 8 in PS. I have an image of a reflection in water that changes over a wide value range. As an analog print it is continuous. As digital, it is discontinuous. No amount of dithering, noise etc can fix it.
As far as I understand it, ACR opens the JPEG image and allows you to edit the image as it is. Therefore, it would be an 8- bit image. That could very well be one of the reasons why it is not as easy to recover blown highlights in a JPEG as it is a raw image. Remember that the choice between 8-bit and 16-bit is one that is made when preparing to output an image from ACR. ACR is not going to create data that isn't there.
>ACR is not going to create data that isn't there.
Correct; but, then, neither will Photoshop. :)
As stated earlier in the thread, the benefits of working in 16 bits, if any, will come when manipulating the image in Photoshop.
Yes, I understand that. But the question was, is ACR editing JPEG images in 16-bit mode. And I was trying to answer that, no, ACR would edit in 8-bit mode because that's all there is in the JPEG image. It creates the 16-bit image when it outputs to Photoshop, I think.
Correct. I also think that is the case, Jim, since you can do all kinds of adjustments in ACR before committing to either 16 bits or 18 bits in the workflow options.
So, yes...if you open a JPEG (or 8 bit tiff) it is converted to 16 bit, linear Pro Photo RGB for editing. It's been shown (by Lightroom) that while limited in recovery (cause the original ain't linear) the fact that the totality of the edits in CR are in linear ProPhoto you could see a real benefit to processing camera JPEGs (as apposed to already edited JPEGS saved out of like Photoshop) over doing similar edits in Photoshop.
As long as we have your ear here
Just bought and watched the Camera to Print video tutorials. Most enjoyable and valuable; thank you. I put in a plug for them in a thread at the Photography forum .
Now, if you could talk Michael Reichmann into making his web site look a lot more like his physical gallery looks, you would be doing him a huge favor. :)
"...if you open a JPEG...it is converted to 16 bit, linear Pro Photo RGB for editing. It's been shown (by Lightroom) ...that the totality of the edits in CR are in linear ProPhoto you could see a real benefit to processing camera JPEGs (as apposed to already edited JPEGS saved out of like Photoshop) over doing similar edits in Photoshop."
This is interesting and good news! Now my grasp of all this technical talk is limited so bear with me if I am not up to speed. I just want to make sure I understand this.
ACR opens all 8 bit JPEGs automatically in 16 bit ProPhoto workspace BEFORE the actual editing is performed?
At the risk of hopelessly confusing myself even further, why would ACR be a better platform for JPEG processing with out of camera jpegs but not previously edited JPEGs?
Jeff, I know you've stated "it's beed shown by Lightroom" but can you show me this? Where has it been shown? A link, webpage? That way I can look at this myself, spare you trying to explain it to me and (yes this is pure self interest) hopefully free time up for you to work on the ACR 4.1 book I am looking forward to.
Thanks for the time you devote to helping us noobs pursue our passions!!