Scanning black and white

Discussion in 'Classic Manual Cameras' started by donald_miller|5, Oct 17, 2017.

  1. Wondering which seems to work best when scanning B&W, Scan in grey scale, scan RGB or scan RGB and convert to grey scale when finished with Photo Shop?
     
  2. Scanning in color, should generate proportional values in the three colors.
    You should, then, get the same result converting during or after scanning.

    I believe that JPG doesn't have a monochrome mode, such that it will generate three color values.

    I usually scan in B&W, and write JPGs. Scanning in RGB might generate some color that shouldn't be there.
     
  3. It can do that but you can then convert to black and white and/or change mode to grey scale later. I was wondering if some is any subtle or inherent loss of quality or detail depending on the scan mode. I started using tiff and raw recently and see a great benefit from it. Starting to read some tutorials on line. They have helped me alot and enlightened me alot about the featured I was afraid to try
     
  4. Since there is no colour information, there is no use (in my view) to scan to colour. So I scan to 16-bit monochrome TIFFs (actually saved as DNG files, since that fits my workflow better). I compared scanning to RGB, and haven't found any advantage to saving out RGB files from the scanner - files are 3 times as large.
    I'd never save directly to JPEG from a scanner program - it is a lossy compression and limited to 8-bits colour depth, meaning you start by throwing away data immediately; never a great idea.
     
  5. I just scan B&W negatives as B&W.

    Color negatives and color slides are done in full glorious color, and then converted to B&W with the appropriate tools.

    If I am shooting new film in old cameras, I almost always shoot color. It gives so many options in the conversion process with various Photoshop tools. My main exception is that lovely chromogenic Ilford film (XP2).
     
  6. Thanx, that answers my questions as far as am I losing anything. Wouter, you used the perfect term,. was I losing any data?
     
  7. The answer to your question is complicated. Firstly, if you're using a staining developer like Obsidian Aqua or other Pyro developers to develop your film, the black and white negatives have a color stain. As a consequence, there is significant difference in the color histograms when you scan the negative as color positive. Because the three channels don't have identical histograms, naive greyscale conversion doesn't make the best use of the information in those channels. Secondly, at least on some scanners, the green channel has been found to give the sharpest scan even when the negative has no stain. See Kenneth Lee Gallery - Scanning Tips with Epson and VueScan Software for a discussion. Scanning as color gives you more control over grey scale conversion.
     
    bertliang likes this.
  8. Raghu: So how would you suggest we should scan? In 16 bit color? And then only use the green channel? Can you extract that channel using Lightroom? Thnaks.
     
  9. Alan, I scan b&w negatives as 48 bit color positive at 3200 resolution on my Epson V600 using Epson's software with all corrections (including unsharp masking) unticked (ie no corrections). I basically do a linear scan with the scanner and all corrections later in LR/Photoshop.

    I've only LR V3.6 with me and it gives me no obvious ways of accessing the individual color channels. Photoshop is useful for this purpose and I guess some free image editing tools can also be useful.
     
  10. I use 16-bit grayscale for B&W negatives in my Epson V600, I use the Epson software that came with the scanner, and am happy with the results. It is important to adjust the scanner levels and gamma for best results; the auto settings are not optimum.
     
    Last edited: Oct 22, 2017
  11. Interesting, I do not know it this is relatred to what you described. This was ilford BW on Epsom V550 TIF raw RGB 2400. with Scanvue. All I did was invert with elements and got a green photo. It was shot in very heavy overcast. I wast on the Blue Ridge and felt compelled to take some pictures regardless and I have a green photo. green dye.jpg
     
  12. I tried a suggestion that I found on line and use it all the time now. Start with color settings on generic when I can and high low curves at 0.001. After preview do ALT/right click on darkest part of specimen. Then click "lock exposure". Then preview again and click "lock color base and preview again. The next part is my own thing, In elements I click auto color on the right on the quick screen and then do the other tweaks. It has given me what consider my best results so far.
     
  13. I scan with a Creo IQSmart3, and it produces what is basically a RAW scan. I can then open that RAW scan into whatever manner I want, however even when I know my ultimate goal is a B&W image I still output it as 16 bit RGB. This gives me the most useable information and bit depth. If I need to make drastic tone alterations instead of doing it to one Gray channel (if it were not an RGB file) and possibly getting tonal clipping, a "comb" effect on the histogram, I can make differing alterations to each RGB channel, and then when I do convert the file to appear monochrome ( appearance only, it's still an RGB file) those differing color channels are far less likely to produce a comb effect.
     
  14. Does your negative have a purple hue?
     
  15. So once you have the scanned file, what do you do in PS?
     
  16. Negatives that were souped in Obsidian Aqua (a Pyro staining developer) are generally quite sharp in all channels. The histograms are different because of the stain which acts as a color filter. I apply different gamma for each color channel in levels so that the histograms align the best possible extent (see attached pics for histograms before and after). Then convert to grayscale, process to my taste, downsize to 3000x2000 size (in case of 135 film) and sharpen minimally.

    Negatives that were souped in non-staining developers - use only the green channel as described here: Kenneth Lee Gallery - Scanning The Green Channel

    histo1.JPG

    hist2.JPG
     
  17. I develop my B&W film in D76. This is the only B&W developer I've ever used. My scanner is an Epson 4990 and I'm using Epson Scan software. I just leave my scanner set to RGB when I scan my B&W images and the reason why I do is that sometimes my scans will pick up some interesting slight color tinges. Sometimes these slight color tinges can be interesting. Often they're showing a gentle blue tint. And I've found that I can exaggerate this color during post processing if I deliberately concentrate the intensity during certain steps. So I just leave color active and just run with it. I can always easily convert to grayscale during processing if I feel the inclination.
     
  18. i was using D76 but switched to HC110. It is much more convenient as a liquid and I do not have to make large batches. It seems stable for a very long time and the results were much better than what I expected.
     
  19. Just now found this.Interesting and plausible. Anyone try this and have input?

    HC-110
     
  20. Which part of that article? Using the unofficial Dilution H (half Dil. B) ? I use that one structurally with HP5, as with Dil. B times would be very short. Works very well for me.
     

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