Hi,
I have Lightspace Home Cinema Light and use it to generate full profiled 3D LUTs for a single chip DLP projector viewed in madvr. It works well and I appreciate the LUT manipulation tools that can also be used. I did have a few questions I hope you could answer.

I'm testing the ITU BT.1886 colorspace and have noticed that it seems to generate a LUT that is identical to a Rec709 colorspace with gamma 2.4. The 3D cube is visually the same and random color numbers have the same RGB values. I thought BT1886 would have different values since it is supposed to have variable gamma based on the characteristics of the display. I have also looked at low APL black level test patterns and it shows the same digital levels being crushed which is not what I would expect from BT1886. Is this a bug?

My other question relates to the i1 display probe settings for a single chip DLP projector. I am using an integration time of 2 seconds, Burst mode, low light averaging, and picking Projector for the display type. Is this correct for this type of display? Thanks.

Nope, that is exactly as BT1886 is, when used for display set-up. There will be change in colour values.
But, no material is mastered with BT1886, so it really is not a valid format to use - Rec709 is the industry standard for mastering.

I do not understand the 'digital levels being crushed' though.
There is no reason for any crushing, is the display is set-up correctly.
The best is to e-mail me the .bcs profile file to look at - I can check for issues.

The i1 Display pro setting are fine - no problem there.

Steve

Steve,
I've emailed the bcs profile. For digital levels being crushed, it is from the AVS HD 709 pattern disc.

With the black level pattern, I'm not able to see level 17 or 18 using BT1886 or 709 gamma 2.4. I was expecting 2.4 to behave this way based on the MLL and contrast ratio of the projector, but was expecting different results for 1886. It may be that the levels are actually visible if I get next to the screen instead of from my viewing position, though. However, I won't be able to check or perform further tests with the projector until next week or later. Thanks.

Profiles checked, and have replied directly.
All is as it should be, but a 'Relax Filter' of value 0.1 may help with possible small low-light errors, due to the projector and/or probe having slight inaccuracies.

Steve