Mat Maessen wrote: > On 2/6/07, David Weiss <[EMAIL PROTECTED]> wrote: >> Is Photoshop, Elements or otherwise, a 16-bit editior? I seem to >> remember that some features are and some features are not? Please >> clarify. If not, is your work around to shoot in raw and use raw >> editors and then save in what format? Are there 16 bit jpegs? > > I cannot speak for Elements, but both Photoshop CS and CS2 have > extensive 16-bit support. Not all functions are 16-bit ready, but a > very useful subset of them are.
Do you know if this subset includes sharpening, curves and levels? Those and cropping is what I use normally. > JPEGs are 8-bit only. However, the advantage of 16-bit image > manipulation is not in the end product. It's what happens in between. Okay. Let's say I edit a RAW file in Lightrooom to may satisfaction, save it for the purposes of printing. I save it in adobe colorspace, and in what? If then I decide to smartsharpen the image in Gimp, save as jpeg, then print, how would this differ from smartsharpening in PS CS2, save as jpeg and print? I am thinking of purchasing lightroom, and am wondering if it is worth it to also buy PS CS2. I was going to wait to see what Gimp 2.4 offers, and also, I am not sure anymore that I will be doing much editing outside of Lightroom. > My workflow is follows: > > 12-bit PEF raw file from camera->16-bit native Photoshop file, Pro > Photo RGB colorspace->edits, adjustments, etc.->conversion to output > form/profile (sRGB jpeg 8-bit for web, other formats/colorspaces as > necessary for printing) > >> Secondly, is the difference between 8 and 16 bit editing likely to be >> seen in 4x6 prints? > > In a word, possibly. It all depends on a lot of factors. In my example > above, I have a 12-bit raw file, being converted to a 16-bit image > file in a VERY large colorspace. If I were to make that an 8-bit file, > there is a good chance that any adjustments like curves/levels/etc. > could cause posterization. If you look at the histogram of a "normal" > image, and it looks like the teeth of a comb, this is what you're > seeing. It's usually most noticeable in either shadow or highlight > areas, but sometimes it can be seen as an overall degradation of > tonality in the image. So it's not a question of large vs. small > prints, it's a question of adjustments and tonality. In general, the > wider the color space you're working in (sRGB being the narrowest, and > the default for web images. Adobe RGB is wider, Pro Photo RGB is wider > still), the more you're going to want to have the higher > bits-per-pixel. > > As I indicated above, what I'll do once I have the image in the form I > want it, is to convert it back to an 8-bit image, in the correct color > space (another thing that the Gimp cannot do, without going to a beta > at this point). Photoshop does this all very close to seamlessly. I > wish there were an OSS solution that would come close. I would look at > it in a heartbeat. Maybe in the 2.4.x version of Gimp, that will get > better. > > -Mat > -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
