Originally Posted by damdy-cash
I have Problems to understand about my Gamma.
I have Calibrate my Toshiba MT700 with SpyderTV and Ursas Spreadsheet- for STV.
I put the Values in the HD-D Sheet and before I have a Gamma about 2,74. After I get a Gamma from 2,38 but when I look a Film the Picture looks very bright and overall not good.
Now I have take the Values in Raders Spreadsheet- Model and there a very different Gammas at all.
Rader Avia= 2,09 (confirm my impression from above)
Rader GetGray= 2,44
I think anything I haven't understood ore missing for me to see why there can so much differences between the Spreadsheet- Models. Have anyone a Answer for me, why this is so?
kindly Rgds Damdy
My method is, of course, correct!
I will say that there are definitely different ways of calculating gamma. I included two, and they should agree within about 0.05 of each other if the gamma is smooth. If it is not, then the point measurements will be off considerably versus the regression. Also, since my stuff is not going to be released, then maybe we should take this off-line.
On a more general note, you should check whether set-up is present. If you are using AVIA test patterns, then the IRE levels should match using the NTSC disc (I do not have the PAL disc to verify whether set-up is there or not) with set-up included. If you are using the PC patterns, then ignore IRE altogether and compre the digital values versus what you are measuring against. My guess is that this is the culprit. Rader's model needs quite a bit more work to be a generalized model (e.g., HD vs. SD, PAL vs. NTSC). It can be done manually, but you need to know what to change where.