I’ve been having an issue where my final recorded export is quite different in terms of color from what I see in my VDMX preview window. The recorded output is less saturated, and looks relatively washed out. I’m wondering if there’s some sort of color profiling issue going on?
This happens both when I record inside VDMX, as well as when I send the output to Syphon Recorder and record it there. Worth noting that when I use Apple’s OS-level “screen record” function, the colors appear to be accurate to what I see in my VDMX preview window.
(I’m recording in ProRes, so I don’t think it would be a compression issue or anything like that.)
I have seen this before as well… I would suggest the vidvox team take a close look at the issue, particularly around meta data tags written to the header of the QuickTime file regarding colorspace/gamma and the special REC-709A tag Apple recently introduced
Thanks for the replies @ProjectileObjects (and @bejohnny), much appreciated. I’ve uploaded a couple of videos — it’s kinda subtle, but you can see it pretty clearly in the tint/saturation of the pink + orange bits.
There’s actually a much starker difference between what I actually see on my screen in the VDMX preview window, and the final output from either recording.
VDMX recorded at 77.91 Mbit/s and OBS at 9.07 Mbit/s. VDMX captured at 8 times the ratem and twice the resolution as OBS.
It would make sense that the OBS video is compressing the overall color of the video in a way the increased the perceived saturation. I’m sure the VidVox gurus could chime in more about color theory, but I think this has more to do with data rates and methods of compression.
I’ve had issues in the past capturing syphon videos from madmapper, but it had to do with MM transmitting an alpha channel and the capture software not knowing how to interpret it.
There’s also a difference in what I see vs you, and everyone else without calibrated screens. If you’re curious, I keep mine in check for color correction using a Datacolor SpyderX.
All that being said, the difference in capture appears to be a subtle, less saturated. Is it possible that VDMX is capturing more accurate colors, but you prefer the higher saturation of OBS recordings?
Also, let me know if this helps. Maybe someone else will have the same issue in the future. Thanks
Thanks again for the helpful feedback! I think you may be right about the difference between those two videos, which is in fact pretty subtle. (Just to clarify, this was captured with the MacOS capture Command-Shift-5 function, not OBS.)
On further reflection, the real issue is that both captures are pretty radically different from the video feed I see in VDMX. I actually had similar color/saturation discrepancy issues using Premiere, which I was only able to resolve by switching over to FCP (i.e. what I see in my preview window in FCP is exactly what I get on export). I think this is a quite common issue with Premiere/AE, and I recently saw this explaining how to resolve it using an Adobe-provided LUT:
Wondering if maybe there’s something similar going on with VDMX?
Thanks very much for all the info, and sorry for my delay. That video was definitely helpful.
I guess I was hoping that since VDMX is Mac-only and I’m using my MBP’s built-in Apple display (i.e. a relatively fixed target), there might be a way around getting $10K monitor or other hardware to match my preview color to my output color. But yeah, color stuff
While it’s great to have a calibrated monitor (or a Flanders if you can afford it!) it has to nothing do with the issue here: the problem is showing on the same computer / display, between apps — not between systems.
There are well documented issues between the way apps handle gamma and colorspace tags. the alpha channel can also be a culprit (but not on an h264 which is a no-alpha codec)
It is might be a difference in gamma from 2.2 to 2.4
Thanks, Johnny! This is really helpful — I reckon it’s definitely a gamma/colorspace issue. Would the easiest way to deal with this be to use a custom VDMX-specific LUT? In my case I’m editing in FCP.
Just wanted to follow up on this thread with some learnings — I’ve found that if I re-encode the final output in Apple Compressor with a gamma correction of 1.66, I get roughly the colors the way they look in my project (vs. upon final output from VDMX Movie Recorder/Syphon Recorder). This is very much unscientific, but thought I’d share anyway.
Think I questioned this before but now just accept the differences. If its for something critical I do a little balancing in whatever editor I’m using to match a solid reference colour which gets me close. I might have a play with FFmpeg to test your findings. Cheers
late reply,
I’ve run into qt gamma issues outside of vdmx - from after effects exports… Check your recordings in vlc or something non adobe/qt. Sounds like it could be a qt encoding metadata flagging things as the wrong color space.
If it looks correct in vlc, you might be able to interpret footage in premiere to adjust the clip gamma with out re encoding. You would then need to have your proj/timeline color managed to export the correct color.
broad strokes - the gamma shift is subtle. its mostly noticeable in dark saturated colors. H264 also tends to desaturate things a bit (though its not really part of this discussion)
Thanks for the input here, @cmatts, super helpful. The videos do in fact look much closer to how they looked when monitoring in VDMX when I open them in VLC (vs. Quicktime Player). Your insight led me to try something I’m embarrassed for not thinking of sooner: in Compressor, changing the color space from “Automatic” to “Rec.2020.” This seems to give me the proper colors, without having to eyeball it with color or gamma sliders. Thanks again for the help.
