Hi Mike,
I have a 1.78 screen and I am in the process of changing my masking settings to use top masking only for 2.35 and 2.40 content because it is a better viewing angle for my single row theater and also has the advantage of getting rid of letterboxing. I have been experimenting with the Vertical Shift setting that is available in the Lumagen Radiance Pro to shift the image for 2.35 and 2.40 content to the bottom of my screen, and from there closing the top mask.
Right on. This is
exactly what I do in my theater. FWIW, because 2.35 and 2.40 are almost identical in size on my 110" diagonal screen, I use a single setting in the Radiance Pro for both of these ratios. That setting is based on a 2.40 movie, so I end up clipping a very small amount of the 2.35 frame on movies that are truly 2.35, which are actually pretty rare.
To put hard numbers on it, 2.40 content is 40" tall on my screen. 2.35 is 40.85". So for true 2.35 content, by masking it to 2.40 I end up clipping 0.425" off the top and bottom of the image, which is negligible.
One setting you may wish to employ in addition to shift in the Radiance is the masking feature, on the top. This will ensure that if a movie is slightly taller than the preset that you're using, you don't end up projecting distracting light onto the top mask.
The first thing I did was to use the Kaleidescape Test Masking option to determine the proper Vertical Shift setting for 2.35 content. So far in my testing this is working fine with 2.35 titles.
I then put on some 2.40 titles so that I could use them to set the vertical shift value since Test Masking has no 2.40 option. This is where I started running into some unexpected problems because the vertical shift value I needed changed dramatically depending on the specific title I was playing. For example, A Few Good Men worked as expected because I needed a higher vertical shift value to move the image slightly lower on my screen than for 2.35 content. Ford v. Ferrari also worked with a higher vertical shift value than 2.35, although I did need to tweak it slightly. But when I tried Cloud Atlas or Bacurau the image was way too low on my screen and the bottom was cut off so I needed to set the vertical shift value to be exactly half of what worked for A Few Good Men in order to raise the image much higher than where I moved it for 2.35 content, which is counterintuitive. When I tried playing Cloud Atlas and Bacurau on my ATV the higher vertical shift setting for 2.40 worked exactly as expected.
That indeed does not make sense. I happen to have Cloud Atlas in my library (downloaded from our movie store) and so I just fired up my projector and played a couple of scenes. (I haven't seen the movie yet so I just picked a couple of scenes at random.) The movie comes up exactly as expected at 2.40, and my normal 2.40 masking preset is displaying it perfectly masked. I have buttons as part of my Control4 setup that let me manually select aspect ratios, so I can switch to 1.78 or 1.85, see what lies at the top and bottom of the film frame, and then switch back to my 2.40 preset and verify that I'm seeing the entire frame with nothing being clipped and with no extra black.
I would tend to suspect that maybe something is not quite set up right in the Radiance. It's easy to mess things up when setting up the various options for shift, mask, etc., and inadvertently introduce some image distortion that is really not obvious when you are looking at it. One thing you might try is to project the movie with the Radiance set for a 1.78 aspect ratio, and then use an actual physical tape measure to check the size of the black bars top & bottom, and the height of the active image area, to see whether the image is the size you expect, and that it's vertically centered.
Be extra sure that you're not inadvertently applying NLStretch or LBoxZoom settings, as those will mess things up. You only want to use vertical shift and input masking.
FYI, I am using Crestron as my control system, and I have scheduled time with my programmer on Monday to try to fix this.
Cool. I use Control4. Our Control4 driver actually doesn't distinguish between 2.35 and 2.40, which is one reason I have the one preset instead of two.
So here are my questions for you:
1) Is there a way to use Kaleidescape controls to work with top masking instead of relying on the Lumagen Vertical Shift setting?
No, not really, at least at present. The Lumagen approach is a good one.
I have quoted below from SJHT's post in this thread which would suggest that there is:
Normally, for 2.4 aspect ratio movies, my system (which reads the K control information to know the movie is 2.4) lowers the image to the bottom of my 16:9 screen and lowers top masking. Also, because K control system allows you to reframe things, you can instruct it to set screen masking on. This allows all of the on screen displays (menus, etc.) to be reframed to 2.4. Works slick. Also, when I go back to the movie covers screen, the system reverts back to 16:9 (e.g. raises masking, etc.).
What SJHT is referring to here is the setting where you tell your player that you are using screen masking. This ensures that the movie's subtitles(*) as well as the Kaleidescape system's playback menus and indications (the "Pause" message in the top right corner, the menu that lets you pick audio/subtitles/etc) are all displayed within the same part of the screen as the actual movie image. This ensures that none of that content is cut off when the letterboxed area is masked off.
I put an asterisk after subtitles because there are some rare movies where the subtitles are actually "burned in" on the image, as opposed to being displayed by the player. In those cases, obviously, we're not able to move them.
2) Can you also explain what SJHT means when he says the K control system "allows you to reframe things" so that the on screen menus are reframed to 2.40?
See above.
3) Is there a reason I am seeing such dramatically different results, only on Kaleidescape, with the same vertical shift setting for titles that are all described as 2.40?
Many thanks.
See above for some suggested troubleshooting. I'm not sure how you're routing signals. Do you have the Apple TV and the Kaleidescape player on different inputs? The Radiance has both per-input settings and per-source-resolution settings, so it's possible that something is configured subtly differently for the Apple TV and the Kaleidescape player. If you
are running different inputs, you could try swapping the devices to the other inputs to see what happens, just as a diagnostic step.