If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Question about colour depth for scanner
Another newbie question.
My slide scanner (PF3650Pro3) can scan at 8 or 16 bit colour depth. However, if I manipulate an image scanned at 16 bit depth, on saving it is changed to 8 bit by the software. I have tried Photoshop element, Paintshop Pro & Gimp - all change the colour depth to 8 bit. Is there any benefit of scanning at 16 bit colour depth as almost all scanned images need some sort of manipulation. Scanning at 16 bit takes significantly longer than at 8 bit. -- Gautam Majumdar Please send e-mails to |
#2
|
|||
|
|||
Gautam Majumdar wrote:
Another newbie question. My slide scanner (PF3650Pro3) can scan at 8 or 16 bit colour depth. However, if I manipulate an image scanned at 16 bit depth, on saving it is changed to 8 bit by the software. I have tried Photoshop element, Paintshop Pro & Gimp - all change the colour depth to 8 bit. Is there any benefit of scanning at 16 bit colour depth as almost all scanned images need some sort of manipulation. Scanning at 16 bit takes significantly longer than at 8 bit. I assume you mean 8 bits per color. Paint Shop Pro, and perhaps the other programs you mention, only work with images having 8 bits/color or less. In any case, if you are scanning photographic prints, the color range of the print is less than 8 bits/color. That is true also for most negatives. Scanning with more color depth only lets you be less careful about setting scanning parameters, |
#3
|
|||
|
|||
"Gautam Majumdar" wrote in message k... Another newbie question. My slide scanner (PF3650Pro3) can scan at 8 or 16 bit colour depth. However, if I manipulate an image scanned at 16 bit depth, on saving it is changed to 8 bit by the software. I have tried Photoshop element, Paintshop Pro & Gimp - all change the colour depth to 8 bit. Is there any benefit of scanning at 16 bit colour depth as almost all scanned images need some sort of manipulation. Scanning at 16 bit takes significantly longer than at 8 bit. Well, Photoshop doesn't change from 16 bit to 8 bit all by itself. Eventually, however, you might as well change to 8 bits because the printers expect 8 bit depth. Jim |
#4
|
|||
|
|||
Photoshop CS can handle many (not all) processes in 16 bit.
Ideally 16 bit offers a wider color gamut. Reality is somewhat different. It is not clear that your monitor can reproduce the entire 16 bit gamut or that most people can actually discriminate that tonal range. Then there is the problem of printing. Printers operate in an 8 bit world. Printer gamuts do not coincide with the entire 8 bit gamut anyway. Then there are the issues of paper surface, reflectivity, ambient lighting, etc. At some point your 16 bit masterpiece will be truncated to 8 bits anyway using an immutable algorithm in an unadjustable driver. As a result when printing a 16 bit image color matching may be more prone to distortion than if the image is always 8 bit (Epson has educational materials discussing this). 16 bit color is an acquired skill and unless you have Photoshop CS is not available to you anyway. You are not really missing anything important to most people. |
#5
|
|||
|
|||
"Gautam Majumdar" posted:
"... I have tried Photoshop element, Paintshop Pro & Gimp - ...." None of those programs work in the "16-bit" color space. Use a program that can ... such as PhotoShop CS Picture Window (Pro) CinePaint "Gautam Majumdar" wrote in message k... Another newbie question. My slide scanner (PF3650Pro3) can scan at 8 or 16 bit colour depth. However, if I manipulate an image scanned at 16 bit depth, on saving it is changed to 8 bit by the software. I have tried Photoshop element, Paintshop Pro & Gimp - all change the colour depth to 8 bit. Is there any benefit of scanning at 16 bit colour depth as almost all scanned images need some sort of manipulation. Scanning at 16 bit takes significantly longer than at 8 bit. -- Gautam Majumdar Please send e-mails to |
#6
|
|||
|
|||
"Gautam Majumdar" posted:
"... I have tried Photoshop element, Paintshop Pro & Gimp - ...." None of those programs work in the "16-bit" color space. Use a program that can ... such as PhotoShop CS Picture Window (Pro) CinePaint "Gautam Majumdar" wrote in message k... Another newbie question. My slide scanner (PF3650Pro3) can scan at 8 or 16 bit colour depth. However, if I manipulate an image scanned at 16 bit depth, on saving it is changed to 8 bit by the software. I have tried Photoshop element, Paintshop Pro & Gimp - all change the colour depth to 8 bit. Is there any benefit of scanning at 16 bit colour depth as almost all scanned images need some sort of manipulation. Scanning at 16 bit takes significantly longer than at 8 bit. -- Gautam Majumdar Please send e-mails to |
#7
|
|||
|
|||
Gautam Majumdar wrote:
Another newbie question. My slide scanner (PF3650Pro3) can scan at 8 or 16 bit colour depth. However, if I manipulate an image scanned at 16 bit depth, on saving it is changed to 8 bit by the software. I have tried Photoshop element, Paintshop Pro & Gimp - all change the colour depth to 8 bit. Is there any benefit of scanning at 16 bit colour depth as almost all scanned images need some sort of manipulation. Scanning at 16 bit takes significantly longer than at 8 bit. You need a photo editor that has full 16-bit support, like photoshop CS. The is a definite improvement in image quality to film scanned with 12-bits/channel (16-bit/channel) output. The main benefits are the ability to pull more detail out of the shadows and highlights. In fact, I reduced my use of split density filters when I switched to 16-bit scanning as I found I could pull detail out of very bright clouds that with 8-bit scans appeared essentially white. Example: The 4x5 image was done on fuji velvia with no split density filter: http://www.clarkvision.com/galleries...a+b.c-700.html yet detail in the clouds is quite clear. On the film, they were quite bright, almost all white when looking at the slide on the light table. Previous to 16-bit scanning, I would have used a split density filter to reduce the cloud brightness. Roger Clark http://www.clarkvision.com |
#8
|
|||
|
|||
There is usually normalization going on that alters the level of the
8-bit per color image file based on info from all 16 bits. This is very much like what happens in most cameras when file is not saved as RAW file. So you do gain, just not as much as if the final output file had all 16 bits (so you could alter brightness/contrast yourself). |
#9
|
|||
|
|||
There is usually normalization going on that alters the level of the
8-bit per color image file based on info from all 16 bits. This is very much like what happens in most cameras when file is not saved as RAW file. So you do gain, just not as much as if the final output file had all 16 bits (so you could alter brightness/contrast yourself). |
#10
|
|||
|
|||
There is usually normalization going on that alters the level of the
8-bit per color image file based on info from all 16 bits. This is very much like what happens in most cameras when file is not saved as RAW file. So you do gain, just not as much as if the final output file had all 16 bits (so you could alter brightness/contrast yourself). |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Sad news for film-based photography | Ronald Shu | 35mm Photo Equipment | 200 | October 6th 04 12:07 AM |
places to take photos near Toronto | Apkesh | Digital Photography | 8 | September 30th 04 09:03 AM |
roll-film back: DOF question | RSD99 | Large Format Photography Equipment | 41 | July 30th 04 03:12 AM |
Review of two new digital backs for medium format | Bill Hilton | Medium Format Photography Equipment | 64 | July 21st 04 09:51 PM |
Depth of Field Preview Question: | Michael P Gabriel | Digital Photography | 6 | June 25th 04 11:29 PM |