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Purple Specular Highlight Ring?

Paul E. McCarthy

Paul E. McCarthy

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I shot a table top gig last week and and when wide open on a Arri Zeiss 100mm Macro and Ultra primes I got this purple specular highlight ring. They disappear when closing down. I would like to know exactly what this is.

I also saw it on the new Martian trailer which a screen grab is attached.

Thank you
 

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Paul E. McCarthy said:
I shot a table top gig last week and and when wide open on a Arri Zeiss 100mm Macro and Ultra primes I got this purple specular highlight ring. They disappear when closing down. I would like to know exactly what this is.

I also saw it on the new Martian trailer which a screen grab is attached.

Thank you
Click to expand...


You don't get it if you shoot/develop with DragonColor I think...
Try it and tell me if you have better results.


Pat
 
I've seen it too on my footage where the contrast was high. At first I thought it was CA from my lens, but am now thinking it has something to do with the sensor as I've seen it brought up a couple of times with footage being shot on different lenses (same looking artifact).
 
You can see this on DragonColor2 in the deepest blues, reds, magentas and violet/purple. It's basically the very edge of the color saturation spectrum.

I think the best thing would be to follow the advice of people here and reprocess at regular DragonColor

Cheers
 
Send me an R3D to look at please.

Graeme
 
David Battistella said:
You can see this on DragonColor2 in the deepest blues, reds, magentas and violet/purple. It's basically the very edge of the color saturation spectrum.

I think the best thing would be to follow the advice of people here and reprocess at regular DragonColor

Cheers
Click to expand...

In my situation I was seeing it specular hightlights.
 
Purple around highlights like that when the lens is wide open is a form of chromatic aberration. The shot on the Martian trailer looks to be shot on a small camera, not a RED though.

Graeme
 
Strange. I've shot some jewelry and have not had this issue come up. I've seen it more in night scenes with really saturated colors. I don't think it's specular highlights or it would be visible on a lot of other footage (sun on the water, etc.) some of it might have to do with lenses and different coating as well. If it's still there when you switch to DC1 then it's probably CA.

http://www.reduser.net/forum/showth...hting-System&p=1440847&viewfull=1#post1440847
 
All blues are amped up when using Dragon Color 2 and exhibit extreme clipping in the blue channel. Nothing to do with lenses, CA doesn't show up like that or actually illuminate. We ran into a same problem when shooting some casino work. We ended up monitoring and giving the client everything in DragonColor 1, I'd say stick with that. I thought DC2 was also originally intended for underwater work, hence the amped up blue channel.
 
Charles Bergquist said:
All blues are amped up when using Dragon Color 2 and exhibit extreme clipping in the blue channel. Nothing to do with lenses, CA doesn't show up like that or actually illuminate. We ran into a same problem when shooting some casino work. We ended up monitoring and giving the client everything in DragonColor 1, I'd say stick with that. I thought DC2 was also originally intended for underwater work, hence the amped up blue channel.
Click to expand...


+1 Here is the R3D with the problem from this thread. DragonColor was the key to solve.

Pat

Ps: I think this happens more with LED light probably due to some high energy peaks not wisible to human eye but more prone to clipping with an electronic sensor. (?)
 
I've seen this on some colored blue lights, but it's a matter of color science, not a hardware error. Changing from Dragoncolor2 to Dragoncolor1 fixes it. If you know you got shots like that, just do that.

As for that shot in The Martian, it's obviously a GoPro.
 
Patrick Tresch said:
+1 Here is the R3D with the problem from this thread. DragonColor was the key to solve.

Pat

Ps: I think this happens more with LED light probably due to some high energy peaks not wisible to human eye but more prone to clipping with an electronic sensor. (?)
Click to expand...

Thank you for posting this, but what I experienced is a purple ring around a specular highlight that I could diminish and remove by stopping down. I did try adjusting the luts. I will try to have someone recreate it today
 
Paul E. McCarthy said:
Thank you for posting this, but what I experienced is a purple ring around a specular highlight that I could diminish and remove by stopping down. I did try adjusting the luts. I will try to have someone recreate it today
Click to expand...

Do you have a pict? So that we are looking at the same artefact? Thanks

Pat
 
What you're describing Paul is chromatic aberration from the lens. You will see it on practically every lens that has a wide enough aperture.

Graeme
 
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