Please tell me if I will have a problem printing an image with histogram

Discussion in 'Digital Darkroom' started by jammer_jammer, Aug 14, 2007.

  1. I accidently scanned about 20 photos in at 8 bits/channel as apposed to 16.
    When I'm done editing them, I'm getting a histograms like the one you see
    here. If the image looks fine on my screen, will it print OK or will there be
    problems on the print that I don't see on the screen?
  2. Here's the histogram.
  3. Jammer, how is this for a precise answer? It depends on the photo.

    The comb effect that you have in your histogram is displaying a loss of data, data that you lost in post processing.

    With some photos you might see a slight difference in the final print if it had been scanned as 16 bit as opposed to 8 bit, especially if you had scanned film. But since you scanned photos and not film, I'm guessing you're not going to print huge photos, and you will probably not see a difference.

    A printed image from a file will always have much more detail than your monitor does since you print at a much higher resolution than your monitor can display. So the only way to know if you've lost noticeable data is to rescan at least one image and print it out from both the 8 bit and 16 bit file and compare.
  4. Pure blacks and whites will go off scale on a histogram. So we need to know where the out of gamit areas are. If white borders or pure whites on a brides dress, and the blacks are very dark tones without detail in the print, you will be ok.

    If the print has no dark areas or pure whites, you need to rescan.

    It is not 8 or 16 bit, it`s the contrast that needs adjusting at scan stage. Unless you moved contrast around later and you did. That`s the white vertical lines on the histogram. I just can`t see the original. Recheck the histo on the original file.
  5. Thanks folks.
    I used the wrong terminology in my first post. It was actually 35 mm neg film that was scanned. Although it is just a family photo, it means a lot to me and I might want to go as large as 8x10 or 8x12 at some point so I guess I'm better off just rescanning the most important images from the group that got scanned at the wrong bit depth. : -(
    I've attached the photo. There a a few pure blacks and pure whites but not many. What would be your guess based on looking at the image?
    To you both,
    Just for my education, if there is too much data loss, what kind of problem does it cause to the print. In other words, in what way would it look bad?
  6. I just took notice of something else. The graph I showed you originally is the graph that shows up when I click to make a levels adjustment layer. When I click to show the actual histogram, it doesn't show the missing data. Which one of the two graphs should I be concerned with looking at in reference to whether there is too much missing data to make a decent print?
  7. gdw


    Before you rescan all the slides, pick out one that is important and print it in 8x10 or 8x12. If they look good on your screen they will probably print okay. The one you posted seems a little blue on my screen.
  8. I agree totally with Garry - print it and see.

    Here it is with some yellow (35) added.
  9. The image should look good, after some quick darkroom it should look even better : ) heres a quick version of it. As for the histogram, it look not that bad, and like others suggest, print it you should be happy.
  10. Print the image and see. The white lines are where there was no data in the original scan;
    when you increased the contrast of the shot, Photoshop sort of pulled the edges of the
    histogram out and left those blank spots.

    That will show up as poor tonal gradation in smooth areas, and maybe an enhancement of
    graininess or slightly harsher contrast. Generally, the effects of an overextended
    histogram like that will show up at any print size, so make a 5x7 and see if you like it. If
    it's decent, go with it. If not, rescan and retry -- can't take all that long.

    The final verdict on any photo is whether you think it looks good, not whether the
    histogram is continuous or any other scientific measure.
  11. It looks like the errors are spread out fairly evenly. I wouldn't worry about it. If there's huge gaps in part of the range like curves could create then it's really time to start worrying.
  12. Gary,<br>
    Thanks. Your right, it does look blue. This goes back to a previous problem that I tried to solve with the help of folks here. That being that when an image in CS2 looks correct to me, it ends up loosing a SUBSTANTIAL amount of yellow when looked at with a non-color managed browser. I use a i1Display2 for calibrating my monitor.
    Everyone here told me over and over and over that these color shifts are to be expected and to trust the calibrated image in CS2. I still can't believe that I should expect THAT much of a color shift. I KNOW something is wrong but everyone tried telling me otherwise. All I can think of is that my aging Trinitron is going bad and therefore isn't profiling correctly. I'm about to buy a new monitor so I guess we'll see if that fixes the problem. Actually, I'm REALLY glad that you brought this up because it just confirms what I had been saying all along. There is a MAJOR color shift away from yellow when I post things and vice versa. When I bring and image from the net, thats looks nice, into CS2, it immediately takes on too much yellow. What makes this even more mysterious is that I'm not even doing any complicated conversions. It's all strictly sRGB. It's driving me nuts but no body had an answer and kept trying to tell me that there was no problem. Argh!<p>

    Thanks man. Like I say, I'm not sure I can trust what I'm seeing on my screen any longer but your edit looks completely washed out and devoid of any contrast on my monitor.<p>

    Thanks, that's much closer to how I would have edited it.<p>

    Thanks for that explanation. That's what I was looking for.<p>

    Thanks for the reassurance. I guess I'll just have to break down and have one printed to be sure.<p>

    To everyone, thanks again and if you have any ideas about this color shift problem, PLEASE speak up.

Share This Page