Strange color cast Sony PMW-200

[Mark Sudfeldt]

Had this camera for about 9 months and never seen this issue before but when filming some Medieval fighting the other day I got this strange red or green color cast in some of the clips.

Seems to last for at least a second then just comes right. As I was on and off the tripod all day I forgot sometimes to turn off the image stabilizer when it went back on the tripod. Not sure if these shots had the stabilizer on. All the shots that had this problem were on the tripod except for one handheld shot. Sun was behind the camera. What is likely to be the problem here as I have never seen this before on this camera or my previous EX1.

Sony PMW200
Pal HD422 50/720/50p
0 gain, no shutter, 6100wb, manual aperture and focus.

YouTube clip of the problem clips here:

bad color cast - YouTube

[Chris Medico]

I think you are getting a stray reflection off something out there that is causing a flare. That has the feel of a flare.

[Mark Sudfeldt]

Not sure about that Chris. Thought it may be to start with but like no flare I have seen before and in some clips its like all the grass as a red tinge for a few seconds. Sun was behind me so it would have to be a reflected glare and not sure those helmets and swords are a big enough source for the effect.

Mark

[Wacharapong Chiowanich]

Can't really say what caused this strange effect but I'm absolutely certain it's NOT:

- Flare. The red and green cast always occurred separately and never in conjunction with the usual flaring effects like rainbow stream spreading radially from the probable strong light sources, sudden change in contrast, out-of-focus ghost images of the open iris (6-blades in case of the PMW200) etc.
- Malfunctions in the lens, prisms or the stabilization unit (for the same reasons above plus the images showed NO unusual stuttering, warping or other forms of distortion aside from the color cast).

That leaves the camera's IP, including the sensor readout or somewhere in the recording pipeline as the probable culprit. I suggest you skim the raw footage frame by frame and save the defective frames in TIFF or DNG and send your camera along with these including the raw footage itself in for Sony repair to have a look. I wish I could help you more but hope this helps.

[Dave Sperling]

Not at all sure but... Looks to me like it's possible that some light made it into the camera itself, not through the lens - maybe through some sort of multiple bounce reflection through a cooling vent or empty screw hole or other opening? individual color(s) would come from random light hitting that specific sensor. This might be a semi-logical explanation if the color pollution is happening when the camera is at a very specific angle to the sun. The diffuse nature of the pattern reminds me of the look from a film camera light leak.

[Cliff Totten]

Does your camera feel hot?

Could be that the sensors are overheating? (Or just one overheating)

Not sure but it could be an artifact from that?

[Mark Sudfeldt]

Thank you guys for your suggestions. Guess the only way to figure this one out is to send the camera back to Sony Servicing. It does look a lot like a light leak. If you look at the attached pic you can see that the green color cast seems to be through the whole frame including the trees at the top right taking on a washed out green compared with the unaffected frame. I don't think temperature was an issue as it is late winter here in New Zealand and the temperature only got to 12C that day.

[Warren Kawamoto]

It looks like some kind of internal light leak in your lens. See if you can duplicate it by putting your camera on a tripod in a dark room, then shine a bright light at your camera (focusing mainly at the side of your lens and the lens mounting area.) Move slowly from side to side and up and down. Watch a monitor to see if you can make the anomaly show up. If you can duplicate your zoom and f stop setting with the shots you showed us, it might help a bit to find the problem.

[Leonard Levy]

Definitely looks like something is wrong but I don't know what. I would try to replicate it before sending it to Sony. The more you know about the problem the better before sending to the repair shop because if they can't make it happen they may say nothing is wrong.

[Alister Chapman]

Almost certainly a light leak. It has been discovered that some early PMW-200's are prone to light entering the optical block via the cooling vents on the camera body. There is a fix for this if you send the camera back to Sony they will sort it out. Later cameras have revised internal light shielding.

If you need the camera for a shoot in the mean time, black tape over the vents just above and behind the ND filter switch and along the vents on the top of the camera will prevent the light from getting in. The camera should not overheat unless in a very hot environment when taped up like this, if it does get too hot it will flash up an error message before any lasting damage is done.

[Mark Sudfeldt]

Thanks all for your ideas. It has been sent to Sony and is now fixed.

Explanation from Sony Service:

"the brief colour casts on the footage as the camera was moved, this would be the result of light leakage finding its way into the rear of the imaging block through vents in the camera body. The light only reaches the sensor when the sun is at specific angles with respect the camcorder, hence the issue appeared briefly several times as you were panning the camcorder. Covers have been placed over these vents to eliminate this"

[James Kuhn]

Mark Sudfeldt...is there a serial number range associated with this issue? You say you purchased your camera approximately 9-months ago, correct?

So far, the notoriously bright and hot Florida Sun hasn't shown up in any footage. It would be nice to know if the 'light-shields' have been fitted in a subsequent serial number runs? I purchased my PMW-200 about 5-months ago.

Regards,

J.

[Mark Sudfeldt]

Yes, purchased camera back in early November 2012. Don't know what the serial number range would be but as Alister Chapman noted it was in "early" runs of the camera. Must take note not to buy early production runs of new cameras as I also had an issue with my Sony EX1 that had its lens replaced by Sony even though it was outside the warranty period as it was a known early production problem.