I don’t have any experience with a film scanner. But I have done some editing with Photoshop CS, which does support 16-bit images. I haven’t been able to detect any difference in my 8×10 photographs. But then my originals were only 8-bit to begin with. Someone in the Photoshop forum indicated that he thought I might see some benefit if I had a lot of editing to do. But so far I haven’t seen any benefit. With Photoshop CS, you cannot save a 16-bit JPEG file; in fact, it is my understanding that JPEG is 8-bit only anyway. They have to be saved as tif images or psd images. And they can become huge in a hurry.
If you can start with 16 bit images in CS (I get mine from the RAW converter – I suspect that my camera produces less than 16, but more than 8!) then editing in 16 bit may help avoid posterisation if you need to really heavy exposure correction. I convert and save in 8 bit after the basic colour and exposure adjustments to save space. If your scanner talks 16 bit then the best strategy would be to do the colour and exposure adjustment in the scanner software to get advantage of the extra information and then do the rest of the eidting in eight bit in Elements.
Susan S
Susan, after you have corrected your images in RAW format in CS at 16 bit will it allow you to edit in PSCS in 16 bit?
Also, Jodi and others, be aware that 16-bit images can be truly humungous in size, especially after processing. I have an uncompressed 16-bit TIF image from my 5MP camera with two duplicated layers and seven adjustment layers that is 140 MB in size on my disk. (That’s not a mistype – it’s really one-hundred-and-forty-megabytes)
16 bit is only exactly twice as large as 8 bit 🙂
M
Jodi – in CS you can now do the basic editing, retouching and colour and exposure correction in 16 bit. Some of the filters are still 8 bit only – and things like the healing brush and large gaussian blurs are a bit slow on 16 bit. Going from jpg to 16 bit tiffs is definitely a shock to the disc drive – I usually flatten and save in 8 bit after I’ve edited. I imagine high resolution scans would produce some truly awesome file sizes!
Thanks Stu and Susan, I knew about the raw edit in 8 or 16 bit but curious as to what else you could do in CS with a 16 bit image. I really don’t think I will miss it at all….for what I do. Thanks.
Thank you all for taking the time to reply
Jay
Jay
I suspect if you had asked Minolta you would get a better answer. I suspect you would not notice any difference in the final image but you may loose a bit of flexibility in the file. Let face it up to just recently all work has been done with 8 bit and few people have notice a flaw in it. the average human eye can see about 8 million colours 8 bit delivers 16 million how much over kill do you need. While CS will accept 16 bit it will not with all its filters.
Grant
The issue, as I understand it (and my understanding is from Katrin Eismann’s book, which I’m fully capable of misunderstanding ;-)) is not in numbers of colors, but in levels of luminosity. 8 bits provide 256 levels; 14 bits (what you actually have to work with in 16-bit mode) provide 16,384. Eismann says that the extra levels can prevent banding and posterization in some situations where you would have them in 8-bit mode. She illustrates with two histograms of the same image, one 8-bit and one 16-bit, after tonal adjustment; the 8-bit shows banding (areas within the histogram with no information) and the 16-bit shows none.
interpolated banding ? 😉 😉
Even with eight bit editing you do need to have pretty big gaps between the "teeth" on the histogram for the posterisation to show up in the actual image. I’ve noticed it in jpegs from my camera only when I have had to adjust for underexposure and then also tried to increase the contrast in the region where I’ve brought up shadow detail. 16 bit is more forgiving. But if you get the exposure right to start with, then eight bit is fine – even if the histograms aren’t quite so pretty.
I would also guess that if you’re doing fine B&W photography and blending an everexposure against an underexposure it might be useful to have more granularity in luminosity levels. If, for example, you expose +2Ev and -2Ev and blend them, that would be nine stops you’re trying to compress into 256 levels. I have no idea whether today’s available output devices would recognize and be able to reproduce finer gradations than that, however.
Susan,
Somewhere I have seen a free plug in that provides a larger histogram … but I can’t remember where 🙁
Wendy
Wendy – I saw that too – but I have a sufficiently small screen that even the expanded view of the CS histogram is a bit in the way, so I didn’t bother to try it out..
Susan S
I was mystified by your msg at first, as my Epson 3200 can use 24 or 48 bit color. But then I realized that the 8 (16) bits you referred to meant color depth per channel (R or G or B). So 3×8 = 24.
Did you get mixed up as I did?
So PSE supports 24 bit color but not 48. Many scanners will go to 48. Similarly grayscale can only be 8 or 16 bit, and PSE uses maximum 8.
The fundamental problem with more than 24 bit (3×8 RGB) is that standard printers and monitor display drivers only accept 24 bit. So even if we can scan and edit at 48 bit, we have no final output device that can use it.
If there were, then there are many situations where the eye can perceive more dynamic range than 8 bit can do (8 bit is only 256 shades from black to white). It would not help colors dramatically, but it would help a lot not having so many washed out bright areas and blacked out dark areas. Move your info cursor around in an area where you know there were clouds and you find huge swaths of 255,255,255. Imagine if white was 4095,4095,4095 (12 bit per channel) or 65535,65535,65535 (16 bit).
Maybe someday there will be higher bit output devices (but I’m not holding my breath), so don’t toss the original slides or prints.
Carl
