Creating profile from target

[Lucas C Macedo]

To create noise profiles for my Minolta 7Hi I did:
1. Printed and fotographed the Target chart at ISO 100, 200, 400 and 800. For each ISO I shot in aperture priority at all apertures, 3.5, 4, 4.5, 5.6, 6.7, 8 and 9.5 - a total of 28 shots!
2. Analised the charts doing a rough analysis on the center square, then did a fine tune analysis on each small square ( 17 squares total ) for each aperture at ISO 800. ( each chart takes me around 15 minutes in my PC Athlon 1.3 MHz, 512 MB RAM ).
3. After doing all that for ISO 800, I decided to test the profiles on a photo I took at ISO 800 and although the result was excellent, I was surprised to see that it did not matter which aperture profile I used th result was the same!!
Obviously I only then analysed one aperture chart ( chose 5.6 ) for each other ISO !!
I went through all that explanation to make sure other usera don't make the same wrong assumption I did thinking Aperture would be impotrtant.

I guess the NI User's Manual shoud be more complete when explaining how to make calibration profiles which may have avoided me going through all that exercise!!

I'm wondering now if it's worth making profiles for each ISO at each shutter speed .... !!!! Anybody knows ??

[NITeam]

Thank you for posting your story. I guess we will have to add to the user guide what parameters are NOT important as well. Right now only important parameteres are explained there.

Regarding shutter speed and ISO. ISO certainly should be taken into account. Shutter speed is less important but I advise to build several profiles (btw, use auto fine-tuning after rough analysis; auto fine-tuning works very well with the calibration target) and compare their noise levels (use Profile Viewer, Ctrl+I). If the noise level do not significantly depend on shutter speed then don't take shutter into account.

Hope this helps.

Vlad

[Us 5 Camp]

Lucas,
I can certainly appreciate the amount of work you put into your profiles and would like to minimize my novice efforts as well.

Could you send me your 7Hi profiles so I could try them on my photos?

If so, please send me a PM and I'll exchange my email with you for the files.

Us 5 Camp