Archived posting to the Leica Users Group, 2006/11/28
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Len, as you know I sent you my attempt off list and a link to Julianne Kost at Adobeevangelists, where I learnt this approach. I'd like to add to the suggestions regarding setting the black and white points. I thought that this might be of interest to others and maybe promote some discussion. I know that there are some Photoshop gurus on the list. As was pointed out you can use thresholds to locate the darkest and lightest areas, then sample there. But unless those points are truly pure white and black (which your monitor and print won't reproduce anyway) you are losing some tonal information there. That becomes particularly important where the scan is only 8 bit (as in a jpeg). So you end up with gaps in your histogram, that is not a smooth range. So for a white, for example, firstly there has to be one in the image. Only a specular light source would truly be close. I'd suggest that you look at the sampled RGB values, find the lowest value and then adjust the other two channels to the same value. Use a levels adjustment layer. Now you've neutralised the highlight, Similar process for the darkest point. For the mid tones choose a point that you think should be a NEUTRAL grey. You may not necessarily have or want exactly a mid-tone. If you do set that point as say 133 and it wasn't close, you are altering the tonal range once again. It may not be bad, but it may not be what was there, either. The important point is to adjust the three channels at that point to be the same value. Use a curve adjustment layer. The other point I mentioned off list is that, once you have established a corrected version, you can drag the adjustment layer to other similar images where you have a number to correct. Well let's see what our knowledgeable LUG folk think of these suggestions Cheers Hoppy -----Original Message----- From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org [mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On Behalf Of Don Dory Sent: Tuesday, 28 November 2006 14:24 To: Leica Users Group Subject: Re: [Leica] IMG: Need help with C22 degs Len, You shouldn't panic, this is a relatively easy correction. If using PS then open an adjustment layer:levels. Use the white point eye dropper on something that should be white in the image; you can use the pointer to find something near 255,255,255. Then find something that should be black and do the same with the black point eyedropper. Most of the time the color gets really close at this point. This is your original: http://gallery.leica-users.org/v/DoryG/On-the-road/OrchidIsland_1.jpg.html and this is what happens after I did the above: http://gallery.leica-users.org/v/DoryG/On-the-road/OrchidIsland_1copy.jpg.html Possibly a little bit blue but pretty close to reality as seen by thirty year old print film. In actuality I would add another adjustment layer for color and tweak in a little bit of yellow back. Don don.dory@gmail.com On 11/27/06, Leonard Taupier <len-1@comcast.net> wrote: > > I have a large number of C22 color negatives from the 70's I'm trying > to scan. I find it impossible to get the color right. I have spent > hours with the following two images and they still aren't right. Does > anybody know of a profile for Nikon scanners what will handle C22 > processed negatives? > > Nearly all my old negatives were taken in the Far East in Taiwan, > Hong Kong, and off shore Islands. About two years worth. > > http://gallery.leica-users.org/v/LeonardT/Orchid+Island/ > OrchidIsland_1.jpg.html > > > http://gallery.leica-users.org/v/LeonardT/Orchid+Island/ > OrchidIsland_2.jpg.html > > Thanks, > Len >