I wrote in my last post on working with raw files that I’d ordered an IT8 target for making an ICC profile. The target is pictured on the left. It doesn’t look like much for about £60.00, does it? Of course the expense comes from the precision needed when making it and then sampling the colours in order to make the reference file.
The way to use it is, you take a picture of the target and then use a piece of software to compare the colour values from the picture to the ones in the reference file in order to produce the profile. At least that’s what I think you’re supposed to do. I haven’t been able to make a decent profile yet, so I might be going about this the wrong way.
Anyway I had a Kodak target so I downloaded the reference file from their FTP server. I was using the Lprof program to generate the profile.
Here is the picture I was testing with. The one on the left is without any profile, while the one on the right is using the Nikon D80 profile and brightness correction.
I photographed the target and then loaded it into the Lprof program, along with the reference file. I then had to place marks at the corners of the colour grid. Lprof then put the green marks where it thought each colour square was. I then hit the create profile button and it started to do its stuff.
Each time I ran the program I got a warning saying there were inconcistences(sic) found and that I should check the target. Unfortunately it didn’t say what I should be checking for, nor was I able to find anything on the interweb.
This was the result of applying the profile. Not exactly an improvement. Of course I realised that this was due to brightness curve still being modified.
So I reset the brightness to the default value and got this. Better than the last one but still not what I want.
I read through any documentation I could find online and soon realised that I had placed the lower markers in the wrong place. I had thought they went on the small squares just below the colour block, when actually they went below the grey scale bar. I fix this and increased the quality of the picture and tried tweaking the settings but I wasn’t able to improve much on that last picture,
So it looks like I bought something of a white elephant. Hopefully as I improve in experience I’ll be able to make a profile which I can use to get good conversions. Ah well, there’s no sense crying over every mistake, you just keep on trying till you run out of cake.
Posted by msparshatt 
