WHAT IS THIS?

[scott pommier]

i shot a concrete drainage ditch (don't ask me why) and ended up with vertical bands of color. this was shot with my dragon using canon L glass and a spin-on variable ND filter. I also shot without the filter and got the same result. this coloration was not apparent in my LCD while i was shooting. i don't see it in the other shots from that day or any other. i am using the old OLPF. what am i looking at here?

(i increased the saturation on the second image to ensure that everyone would be able to see the banding, but it's quite noticeable on my computer monitor even before adjusting the saturation.)

scott

 

[Robert Ruffo New]

Looks like dirty OLPF (cleaned with some kind of cleaner ill advised cleaner that left residue). Causes steaks like this. Try cleaning it yourself or ask Red.

I've seen this a few times on rental cams that people tried to "clean" after some assumed mishap. Exposure to smoke machine smoke will do this if sensor left open too long during shoot.

Have you rented yours?

 

[Scott Crawley]

Could there be an oily residue of some kind on the lens?

 

[ericyoung]

Is your Dragon one of the batch with upside down OLPF maybe?

 

[Mark Toia]

I've seen it as well... and without a VND on... Not sure what it is.
Pushing a bit in low light really makes this stands out.
Try a black shade, thats my next move... and if not sucessefulI'll be sending ours back to Red for testing.

 

[scott pommier]

scott, no the lens was/is clean. eric, how would i check that?

 

[scott pommier]

mark, this was under the hot noon sun, and i had recently blackshaded.

 

[Stephen Williams]

mark, this was under the hot noon sun, and i had recently blackshaded.

Did you black shade with a lens on the camera? Or with the RED port cap & the camera in a darkish place.

 

[scott pommier]

stephen, with the cap on in a dark place, and i let the camera get good and warm. i shot using the same shutter-speed i used for the blackshading.

 

[Alan Gordon]

Was it rolling at all? Kind of kooks like bad florescent lighting interacting with a rolling shutter.

 

[Nick Fury]

i shot a concrete drainage ditch (don't ask me why) and ended up with vertical bands of color. this was shot with my dragon using canon L glass and a spin-on variable ND filter. I also shot without the filter and got the same result. this coloration was not apparent in my LCD while i was shooting. i don't see it in the other shots from that day or any other. i am using the old OLPF. what am i looking at here?

(i increased the saturation on the second image to ensure that everyone would be able to see the banding, but it's quite noticeable on my computer monitor even before adjusting the saturation.)

scott

Hi Scott,

I just got my Dragon back, with the new OLPF. I might have a bit of time later today. If so, any other particulars s o I can try to duplicate the shot? Then we'll see which ditch is which.

Thank you very much

fury

 

[Daniel Murphy]

Did you black shade with a lens on the camera? Or with the RED port cap & the camera in a darkish place.

Is darkish environment and capped lens ideal? Seems like this rarely is case unless night operation.

 

[Stephen Williams]

Is darkish environment and capped lens ideal? Seems like this rarely is case unless night operation.

Doing many incorrect black shades is a bad idea, just do 1 properly & your problems will probably vanish. I suspect the lens cap allowed IR light through.......The manual says use the Red mount cap for this very reason, a case of read the manual R.T.F.M.

 

[ericyoung]

scott, no the lens was/is clean. eric, how would i check that?

Close lens iris down to f11 - f22. Wave the camera at the sun to get bright flares. Look for the red dot grid pattern. If you see it, it's the old OLPF or the new OLPF is upside down.
http://www.reduser.net/forum/showth...ssed-by-Red)&p=1339708&viewfull=1#post1339708

 

[ericyoung]

Is darkish environment and capped lens ideal? Seems like this rarely is case unless night operation.

A metal body cap in a dark place is the best. If you're unavoidably in the sun, next best is a lens with closed down iris, and metal front cap, and some dark opaque material covering the lens. If the front cap/lens cap is plastic, it may not be opaque to infrared, so even more important to completely black out the lens and port area (without blocking the fan).

 

[Peter Arnold]

Did you shoot this under fluorescent light?

 

[scott pommier]

alan, this was shot on sticks, totally locked off.

nick, pretty basic setup...1/48th 23.976 timebase iso 250 5600k i shot with and without a variable ND and got the same result, one at f5.6 maybe, the other at f22

my guess is that you're not going to able to reproduce it. i might be in need of some kind of repair, not sure. it's a tough time for me to be without my camera unfortunately.

thanks to everyone contributing thoughts...

 

[scott pommier]

peter, no this is outdoors, at 11am, open sun. it was warm, not quite 80 degrees. but well within the range for my blackshading.

 

[Adam Johnson]

Anyone figure out what is causing this?

 

[Michael Romano]

Looks like maybe a form of aliasing artifact from a scaler? Try viewing it in 1:1 scale. I've never seen anything quite like it to be honest...