View Single Post
Old 13th October 2011, 08:01   #10083  |  Link
THX-UltraII
Registered User
 
Join Date: Aug 2008
Location: the Netherlands
Posts: 851
Quote:
Originally Posted by nand chan View Post
Yeah, that's fine. I would have assumed 2.2, but it makes sense to use 2.3 for projectors since that's what the BT.709 spec recommends due to the way movies are overencoded. Either way, the problem now is that madVR outputs a 2.2 PPC, and your projector assumes you input a 2.3 PPC.

Depending on your setup, this can either be a good thing or a bad thing:

1. If your ambient light conditions are perfectly normalized to an ICC reference encoding room setup, it's bad - in this case, you want a perfectly source-linear light level.
2. If your ambient light conditions are average or dimly lit, it's probably the perfect setting. Do you know if he measured your ambient light level during viewing?
3. If your ambient light conditions are very dark to pitch black, it's too low - in this setting you want a curve somewhere around 2.45 to 2.5.

Ideally, you want to perfectly recreate the Trimaster's reference CRT curve, but that's not as easily doable. It depends on your viewing conditions. If in doubt, you can leave his “imperfect” 2.2 -> 2.3 transition (which is actually better in this case, due to, again, overencoding of movies).

His lack of providing an ICC profile baffles me a bit though - they're just as important for video displays as they are for computer displays, since you're using a HTPC to drive your projector which technically makes it a computer display - and an ICC-calculated .3dlut is the only way to get the most out of your viewing experience, especially since it allows you to match gamuts such as xvYCC etc. as well if the need ever arises, without having to pay for an expensive re-calibration.

Ps. How often is he going to update the values? A calibration should be updated at least once a month.
I just had contact with the ISF professional again and he told me that a ICC profile is not made by with the standard calibration my JVC got. A ICC profile only is made when running content from a HTPC which is what I do of course

Will he need to do a re-calibration for my pj for the best result?



EDIT:
got a new reply from the IFS guy. I ll try to translate my best:

Quote:
Do you only play with rendering programs, video editing for BT605 and rec709bt?
If you ONLY play movies or games than the calibration as I did it is correct. For a ICC calibration you pay € 250,- extra, and again, this is only done for people who play with blackmagic or AJA cards.
For a HTPC it is normal to make a standard ICC profile and calibrate on that profile, otherwise every other source you will connect to your display device other than your HTPC will not be correct. A ICC profile is a extra profile and is only beeing used in systems with a ''locked'' hardware system. And again, only for special purposes, not for HTPC usage. I also will have to make the profile with two analysers, one for the ICC profile (auto process via HTPC) and after that a calibration with the spectrum analyser.


EDIT 2:
And again a reply:

Quote:
You have to read carefully. Do you have a blackmagic card or AJA? I gave you a perfect calibration, the signal that is send out by your PC is 100% according to the standard, gives you a D6500 greyscale with a 2.3 gamma (as close as possible) and a REC709 colorspace.
As I explained before a ICC profile if you run colormanaged software like a renderer, final cut pro in combination with a AJA or blackmagic card of if you use another very specific setup. For normal HT usage, as you do (watching movies) I gave you the correct calibration.


EDIT 3:

Another reply from him:

Quote:
ICC profiles are for HTPC usage in fact not needed. You just have to have a correct D6500, gamma 2.3 and REC709 calibration. You DO use a ICC profile by the way, but that s 'generic' standard ICC profile. Look in your projector settings and you will see this.
Let me be clear again:
If you use ICC we are talking about setups that work with AJA or blackmagic cards or a very specific colormanaged workflow where you convert from 1 colorspace to another, THERE IS NO HTPC SOLUTION THAT CAN DO THIS. What you do is just play a dvd or videofile and for this is absolutely no ICC profile needed

Last edited by THX-UltraII; 13th October 2011 at 10:42.
THX-UltraII is offline   Reply With Quote