Varicam LT IR pollution - Clean Blacks.

Looks very, very similar to what happens when I shoot with the blackmagic pocket under tungsten lights.

CaptainHook made a lut to help deal with IR contamination after the fact. Much better to prevent at from the get go, but I have found it handy.
Not sure if it'd translate to the varicam as it was designed for blackmagic cameras.

http://www.captainhook.co.nz/blackmagic-cinema-camera-lut/
 
Hey team,

First post on DVXuser here - I finally got approved, but I've been reading this forum for the past few months and I'm glad that this discussion has come up.

I tested the LT and was impressed with the build, IQ, motion cadence but not so much the reboots, poor slow mo IQ and the IR POLLUTION!

Mind you I only had half a day playing with it at a rental house (demo unit). Shot indoors and outdoors with a cooke s4 mini set.

Everything outdoors in full sunlight was just red/magenta/brown/purple lookin'. The subject's black shirt was purple. Skin tones very red. Mind you, I shot everything wide open using the heaviest internal nd density.


LT_V709.jpg
This is just with the vlog lut.

LT_V709_BALANCED.jpg
vlog lut with green correction. To me the background and skin are kind of acceptable, but his shirt is not.

LT_709_FLUOROS.jpg
This is indoors under a daylight fluorescent light. More true colours here. (how intense are those blues in the BG though!?)

I'd buy this camera, to me its image texture, cadence and dynamic range is very arri (organic and filmic as opposed to digital like) - but panasonic needs to look into possibly providing a better IR cut filter. I'm going to do some testing in the next couple weeks with an external IR cut filter because I want this camera to succeed.

Al
 
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I encountered an issue with IR while shooting in sunlight today. I guess I need to buy an IR cut filter, but would prefer if Panasonic could make one that could be placed internally.
 
I've just ordered a Zeiss LWZ2 15.5-45 zoom lens and will get a mattebox for it. Probably something light, like a BT Misfit Atom 2 or similar. I'll need to get an IR-cut filter too. Any recommendations?
 
I can't recommend any matte box filters, I'm still using the screw-on Hoya that I mentioned earlier in the thread. I use it all the time now...I *think* it's causing a bit of a green tint in some outdoor situations, but other then that seems to be working fine. Haven't noticed any weird skin tone issues. I should really test it under various ND strengths but I've been traveling a ton and haven't had a day to just sit and study it with a color chart/model.

We haven't heard back from Mitch/Panasonic on this yet, have we? They were looking into it, but never came back with any kind of information on what we're dealing with and if there's a potential internal solution in the works. Would love to get an update, if possible.
 
Not as far as I know. I agree, it would be nice to hear if there's an internal IR-filter solution planned. I'd much rather have that than a filter glass in the matte box.
 
Our tests found that 99% of the color shifts could be addressed in modest color correction, including basic CDL painting in the camera. Additional IR blocking would alter skin tones. With our testing it was determined that the current IR filtration remains our standard.
 
A good old manual white balance in every scene combined with Vlook1 have given us beautiful results every time so far.
 
Im going to add this note here again. I did a whole range of tests with the LT and IR pollution. I found that only certain materials displayed it and only those that were a Red / Black base dye. Duvetyn for example never has it under any conditions. I've found it easier to change shirts wherever possible as it's usually the only time it shows up, and in the one instance I couldn't because shirt had a logo I was able to grade it out with a colour picker using luminance (was pretty static shot), which on test was pretty straight forward in FCPX and resolve.
 
Hey Milan!


I have a 680 4x4 which does the trick, but you might want to try the Hoya 680. I think the SO is a touch more greenish compared to Hoya's.
But if you like the SO look then 680 is the way to go.

If you need a 4x4 and your in the US, I can sell you mine at a good discount. Ive only used it a few times.
 
Thanks Alex! I'm in Sweden. :)

No, I'm not specifically after a Schneider-filter, just one that is good and neutral in colour. I need to use it on a wide zoom, so I guess 4x4" won't work. I need a 4x5.65" filter.
 
Yea ok! In my experience the Hoya is more neutral.

Check this out:
http://www.hoyafilter.com/hoya/products/generalfilters/uvircut/

The site says the largest size is 82mm, but I wonder if that cover your lens' outer diameter?
I believe you have a Zeiss Zoom? Im not sure if you kept it or sent it back because of some glass issues. Please forgive I haven't been keeping up with all the posts.

I did a quick check online and didnt see if they had any square filters. You might want to send them an email to confirm what options are available.

Cheers!
 
I have the Hoya UVIR and it definitely adds a green tint with the LT. It does the job though IR cutting wise. By the way, different IR filters behave very differently with different sensors. For instance the Formatt Hightech Firecrest was very ineffective with the LT though Red owners swear that it is the best in cutting IR.
If you are shooting Tungsten Milan, my advice is to use an 80D or 80C filter instead of an IR cutting one. You'll lose half a stop but you'll get a cleaner image with less noise, better colors overall (from Tungsten), it will tame those exaggerated reds that the LT tend to render with purely red subjects and it will cut IR as well. It works really well with the LT and Tungsten light.
 
Thanks RayZan!

When I rented the IR-filter the glass looked a bit greenish, but I still managed to get the image to look as I wanted (although it's a bit exaggerated and not a natural look, but that was the purpose). The blacks look black. It was a Tiffen filter.

I also need to get a filter that I can use in sunlight with ND's. I was thinking about the Firecrest, because I've read so many good things about it, but now it gets even more difficult. It would be nice if someone from Panasonic (yes, I'm talking to you Mitch ;) ) could be of some help here. Please... :)

I understand that Panasonic have decided not to do anything about the internal filters, but I'd rather buy a filter than try to solve the IR-issues in post.
So if there is a filter (or several, but under different lighting) that works well, please let me know.
 
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I agree.

Subtle color issues either in video or stills in mixed light are tricky to diagnose ... especially difficult for male camera operators.

It is often overlooked that 40% of men are color impaired and most of those are unaware of the disability. 4% are stone color blind. Men over 60 can add crystalline lens yellowing to the color-warping mix. The UV damaged human eye lens "cuts" the blue end of the spectrum. Replace that aging lens and implant recipients are shocked at what they've been missing.

Mixed lighting will cause problems ... but in those cases where the IR cut filter's spectral boundary slopes aren't carefully manufactured, simple change them and test–or better yet, change your light. Here's the accepted stills UV-IR cut leader at (gulp) high prices:

https://www.bhphotovideo.com/c/buy/heliopan_digital/Ntt/heliopan+digital/N/0

Indeed Fuji, a firm noted for its color film and digital color fidelity, only uses young women to set all color profiles–it seems to be their secret weapon.
 
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