Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Color shift without color temp change

S

Sean Sweeney

Well-known member
Joined
Jun 1, 2008
Messages
189
Reaction score
0
Points
0
Hi everyone - new to the forums. I've been looking around and I can't seem to find anyone with a similar problem to the one I've just encountered. I was working on a short film recently with the red-one, and during a scene the color started to change drastically, becoming very yellow. The actual numerical value of the color temperature on the display did not change, however.

We transferred the footage over to the computer to see if it was a red-lcd issue, but the color change was present in the footage as well. The room we were shooting in was warm, maybe 35 celcius, and the camera itself was rather hot to the touch. Might this have been a contributing factor? Have I overlooked something? Is this a glitch or something to do with user error?

Thanks in advance.
 
did you use fluorescent lights and a high shutter speed?
 
Perhaps let us know exactly what the settings were before and after the event occurred. That would help a lot.

I must say, this is a new one to me.

So what ended up normalising the camera?
Did you restart the camera?
Change the colour temperature around to see if that helped?
What was the colour temp in redcine?

Ivan
 
Some types of fluorescent bulbs shift color temperature at various phases of the AC waveform, and most any camera will see that color shift if the shutter speed is fast enough. Of course if you were using natural or tungsten light, etc. it would have to be something else.
 
The DP had swapped out fluorescent blulbs for kino bulbs in a standard office fixture, but that wasn't the only area where we had the problem.

The settings for most of the day were:

ISO: 320
Shutter: 1/60th
Redcode 36, 4K 2:1
23.98 fps
4700 kelvin

The effect wasn't only under the fluo's though, we brought the camera in front of a window and started to shift the color temperature manually and it went wild, at one point going ultra-saturated blue and black at about 5300 kelvin.

The problem was solved by resetting to a default camera color balance, tungsten or daylight seemed to work. But it slipped again a few times.
 
It's funny you should mention this because I've noticed over the past two days that one of our RED's has a faint yellowish bias to the image on the monitors compared to the other ones we are using, despite matching all the settings -- and it seems to be more obvious as the day goes on. Tonight we looked at the RAW files and noticed that the yellow-ish bias is in the original files.

So I'm wondering what the problem could be and what the solution could be.
 
Does the effect seem to be more pronounced as the camera heats up? After we cooled the camera down for a little while, the yellow bias didn't occur nearly as often.

Also, when you reset the color, how quickly did it go yellow again? We found it slipping after each take.
 
We tried the black shading, didn't help. The issue hasn't recurred since, even during a day of extremely hot weather here in Montreal.
 
I'm betting on bad floro or HMI ballasts.
 
We thought that too, but the problem was showing up in daylight situations as well.
 
I'm shooting with 3 Reds on a series for Sci Fi. My A body has been shifting yellow/green. Black shading hasn't helped and heat wise all 3 bodies suffer the same episodic conditions. We've shot about 1 1/2 hours of footage a day for 6 weeks and this condition just started. Suggestions?
 
Yellow hue too

Yellow hue too

I have been having the same problem where by skin tones to the naked eye look fine but on LCD and on the R3D file in Red Alert the skin tones look jaundiced / sickly yellow. We were shooting with Daylight Kenos and HMIs (we turned of the mixed tubes Tungsten and left only Daylight which made a slight difference) Camera settings where ASA 320 4K 2:1 25fps Daylight Balance. Schnider ND 0.3 was only filter, could this be caused by IR ?
 
had the same problem, but the camera recorded only red channel; I solved it by resetting factory settings then blackshading
 
You must log in or register to reply here.
Back
Top