Then came the IT-8 with many many more patches for accuracy. TXT files which have the same number as the Target. These text files tweak the IT-8 for accuracy. Mike's latest batch of IT-8 targets are from a batch that carries the (R130730) Charge number. It naturally and usually comes with a TXT file with the same number that should show in the Profile Prism working window. Mike has a Spectrophotometer ( a big word for rectal thermometer) which adds perfection to the TXT file that comes with the target. This will be an file which he will supply with any target purchased from this batch and subsequent batches of targets. Just out of curiosity Mike, how much different were the values you read with your spectrophotometer versus the values supplied by Wolf-Faust? Do you think that a ColorMunki would be up to the task of spot-reading patches from an IT-8? My original from you is getting pretty old and scratched up, but I acquired a couple from stuff packaged with old AGFA flatbed scanners that are in near pristeen condition. Being at least 15 years old, (although stored in a cool, dark place) I question whether the data files for them are still accurate. The data files are comparable and they produce very similar profiles. Overall, mine reads a bit darker, perhaps because I used a darker backing when measuring. The ColorMunki is up to the task (accurate enough). The only problem with that device is the 8mm eye hole. #Eazydraw independent scale not available Patch#That's the same size as the color patches on the IT8 so each patch has to be measured with absolute precision. Even a half millimeter off and you're measuring part of a different patch than the one you intended. Title: Re: Profile Prism v8.I looked over the data file for the IT-8 target I have – remember this is a paper target, not a film target – and I did see the LAB data there.īut the problem is that I can’t easily identify which of the data are for the grayscale, and, even if I could, how would I take that data, and convert it to RGB? Conversions are easy for an image opened in Photoshop, but the only way I can get such an image is to scan the IT-8 target. Then of course, I’d have the scanner profile to contend with. Then if I printed that out, I’d have the printer profile to contend with.Įven though all my "stuff" is profiled, I’d still be off in what I’m looking for. I haev a goodly assortment of "test" image files, but what I’d like to get is a 10 step grayscale with RGB values defined in advance by the supplier. Taz Tally did refer to his 10 step target. But I searched high and low in Google, but couldn’t find it. I also wrote to Taz, and asked about it, but I"ve not heard back yet.īelow are the CIELab values for the bottom line grayscale in MY ACTUAL reference file. Note: these are not accurately gray (a=0, b=0) but the diffe- rences for a,b are not relevant in a photo. If you take a photo of this IT8-Scanner target then you KNOW the L values and you can ADJUST your photo by Curves in Lab mode for approximately the same results (theoretically …). You will easily find the relation between patch identifiers like GS0 in the target and in the reference file.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |