Discarding color information

[olivier_zee]

<p>Hi all,<br>

I'm scanning some black and white film (Ilford XP2 & HP5). I save the output as 24bit TIF files.<br>

I was wondering when you scan your BW negatives...do you keep the colour information or discard it in photoshop? I use film for my personal photography...so it's not like I am making money from it. I'm curious how you guys do it.<br>

<br />Kind regards,<br>

Olivier</p>

[hoshisato]

<p>I set my scanner software to save the files in 16bit B&W TIFF. Not that I'm worried about disk space, mainly because if have the images printed, they come back as proper B&W, without the dark purple colour cast .</p>

[mendel_leisk]

<p>When scanning my black and white negatives the initial file saved, and retained, was a 16 bit per channel tiff with the all 3 colour channels: red, green and blue. This was a Vuescan Raw file, gamma 1.0, for use in the Vuescan scan-from-disk process.</p>

<p>I did try saving a similar 16 bit greyscale file, and again using it for the scan-from-disk process. With both files I would produce a final greyscale jpeg, normal gamma, with some stretching of the histogram. The jpeg created from the greyscale raw file had noticeable degrading of detail.</p>

<p>I guess it depends on your workflow, but my hunch: the safest approach is to retain as much of the initial scan data as possible.</p>

<p>I asked Ed Hamrick (Vuescan author) and his response was: try both and compare.</p>

[thirteenthumbs]

<p>i scan at scanner optical limit as stated by the manufacturer in the highest bit RGB mode the scan software allows. this is my master file saved as uncompressed TIFF. Any other uses are copies from the master. the masters are burned to dvd.</p>

[alekos_elefteriadis]

<p>-No need to save in RGB, just 16bit crayscale, there isn't any color information.</p>

[lex_jenkins]

<p>I'll toss in another perspective...<br /> Scanners may vary in spectral integrity between models and over time. That may influence the integrity of the available data. The differences may be comparable to the subtle differences in spectral sensitivity between various panchromatic films. Spend an hour browsing various web forum debates over the qualities of various films and you know how important photographers regard those subtle differences.</p>

<p>And there is some color information. Look at the number of web forum discussions about the very slight color tints people have noticed in certain b&w films, particularly as iodide and sensitizing dyes became more of a factor.</p>

<p>Another consideration: If you scanned your carefully prepared optical enlargements on warmtone paper that was developed in warmtone developer and sepia toned, would you discard the color information as irrelevant?</p>

<p>Scanning and saving all available data makes the best sense.</p>

<p>Scanning takes the same amount of time overall, regardless of the type of scan selected, if you factor in the setup time, including dusting and other minutiae. Scanning at anything less than maximum available resolution and data is not only a waste of time, it may be a waste of opportunity that can never be recovered.</p>