Achieving the proper color balance and exposure for multicam video can be very challenging.

Professional broadcast cameras can be associated to a CCU for live adjustments but it is often reserved for high budget live productions.

A cheap but very efficient solution is to use "X-rite ColorChecker Video" in post-production associated to a supported NLE, like Resolve, FCPX, etc...
http://xritephoto.com/Filmmaking
http://www.xrite.com/cat...orchecker-passport-video

I have the feeling it wouldn't be really difficult to implement in vMix (it works a little bit like the auto white balance) and once set it doesn't require a lot of CPU power like LUTS for instance. It's very easy to use and provides good results. You simply shoot the color board and the RGB + HSL values are modified to match the reference colors.

It'd be great if it could be used for live video in vMix (which lacks solid features for color matching).

Thanks,
Guillaume

+ 1

I don't know what the best solution is but I agree there is a need within vMix to quickly and efficiently to balance multiple camera feeds.
I bring this up whenever I notice it, which most recently was on the January edition of the "vMix Fun Time Live Show". Although basically a 2 camera show (without counting the "desk cam"), Martin's camera was obviously flatter than the main camera, not by much, but enough that I noticed (which is an irritant to me).


Ice

+1

I think you mean the function like Newtek Connect Pro color adjustment. http://translate.newtek..../connect-screen-left.jpg

You can adjust one camera itself or set one to the master and the other three to slave.

It is actually not easy in moving sports production to use this function but it would be great when it will be integrate in vMix.

Those who want to try it. You can rent the Connect Pro app monthly.

Jan

Thanks for all the examples Guillaume.

It is also with CCU not easy to calibrate cameras. I worked also with Grass Valley LDX 80 system cameras with CCU. There are so many different settings (RGB in white areas and black areas, Skin tone, pedestal, color gammas etc.) The right light in the right situation is the key for good quality pictures. When you have a good light operator, use him. When the light in the production is manageable, the light operator can also change the RGB colors in light to help you. In fast changing situations, he is your ace.



I think with this x-Rite board it will make the adjustments faster. Also the skin tones are very interesting.

Jan

+1

vMix really needs RGB for black and RGB controls for whites. Having only one set isn't that useful as the blacks become painted very quickly.

A luminance gamma would help at lot too. A colour wheel instead of RGB faders would be more intuitive and I find the faders too coarse for fine tweaks. If these could be finer by default and hold down shift for faster changes.

An alternative would be applying a lut to the camera source, this could be generated as a global offset for each camera type. The free Resolve will create luts from live sdi and then all fundamental grading tools become available if only once prior to the show. A few different preset luts could be switchable for each camera.

+1

Same problem. It drives me insane trying to match colors.

Hi Dwan, Ittaidy,

I like the x-rite / colour match idea but it must be applying a grade or lut upstream in Resolve so a similar thing would be required in vMix.

I did some speed tests with Resolve rendering with no LUT at 93fps, then applied a lut and it's was around 92fps. I think that luts are a simple transform that would be well suited to gpu processing. I tried some more complex grades via the lut and no difference. It's amazing the subtle and radical colour grades that just a lut can achieve and you can still use Resolves colour match tool to automate the process for those new to grading.

Being realistic, implementing more powerful adjustable colour support could be a complex art and therefor not likely. Luts make use of Resolve and other dedicated tools already available with decades of experience in colour. Lumetri may export luts too. Sure this would be aimed at high end users with good hardware but it's really this level of production that see and need these tools.

Switching between a set of preset luts per camera in vMix could enable the following making them more suitable for live work eg various colour temps, +3,6,9 db of gain, gamma stretch and crush, highlight knee etc. These supplied presets could also be overridden by user luts. It could fun trading luts like football cards, a lut for an in set monitor feed in the studio - or getting arty - day for night ?

I don't think the correction we already have is done in the capture cards as it applies to file sources. I was thinking the same thing that the luts only need to run with the `air' cameras so should be possible with a decent system but I doubt luts are very computationally demanding unless Resolve is magic code.

There are few ccu capable cameras in the lower price range, BMD and JVC are the only ones I know of making such a feature more relevant. I'd happily pay $500 for lut support - now if your could `effects dissolve' between luts. It's easy being an armchair software engineer but I think this would be a killer feature for more high end work that vMix is proving it's capable of.

Peter

LUTs are great, but imagine this situation:

You're shooting an outdoor concert, which starts during the day, and ends at night.

You use all the same camera's, but also a few ptz and a gopro.

Once it becomes dark, you have the golden hour, before it's really dark.

During the golden hour, you have to tweak the cameras continiously with small incriments, and fix small color variations untill night falls for good. The LUT that seemed perfect in daylight, might make your cameras look totaly different during night.

In such situations either manual controls over color, or have some kind of accurate xrite kind of control to do it quickly.

If you don't have this, you will see, that you just can't have enough LUTs to keep color in balance all the time until it's completely dark.

Dwan, funny you mention Sony post luts as we were recently discussing this at work. I have found them pretty useless and usually just make a base grade myself. My colleague had similar issues when processing camera originals at a huge post facility in London. I initially thought this was just me.

Ittaidv, I agree this is far from the ideal live solution just a good start that may not be that hard to implement. It would allow you to correct fundamental colour differences between brands and then have a few warmer / cooler versions. The Sony ccu cameras allow you to link multiple ccus and then globally apply offset corrections since the lighting changes would affect all cameras equally. Dream on.

I have a few old JVC 251s that have ccu options but at $US 3800 per camera that wasn't happening. I've been able to hack the protocol and now have DMX lighting control of most parameters. They burn 16 channels per camera. It's cool being able transition between presets over time.
http://au.jvc.com/pro_ca...ohd_camcorders/rm_lp25u/

This looks ideal, check out remote camera control -
https://www.blackmagicde...s/blackmagicstudiocamera

RGB white and RGB black painting would also be very welcome.
There's so many good affordable cameras but no ccu options.