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  • 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 :)

Raven black hole sun issue

Alrighty everyone. Thanks for your patience. I just went out and shot towards the sun and at first I didn't get any results, but then I started tweaking things and I realized that the ISO setting matters. I started at 800 ISO with 6 stops of ND in and I couldn't recreate the black hole sun at any aperture. However, once I had the idea to lower the ISO below 400 I immediately saw it. I recorded the following video at ISO 250 with 4 stops of ND. In the video you can see me closing my lens down to T/22 and opening it up to T/1.5 and also moving the camera around so that you can watch what the actual lens flare is doing:

H.264 UHD Export (323MB):
https://we.tl/CdtmqKJBZp

R3D frame:
https://dl.dropboxusercontent.com/u/7361444/A003_C015_06074B.0000821F.R3D

Settings:
4.5K WS
24 FPS
Redcode 6:1
ISO 250
Aperture T/11
Shutter: 144 degrees
WB 5600K

The interesting thing is that the artifacts do not occur when the sensor is massively overexposed, but instead it happens at the moment just after the stop light lights up. As you continue to overexpose more and more the artifacts go away. So... there is a very particular range of overexposure that causes the issue. And it doesn't seem to happen if you are (correctly) shooting higher ISOs outside to gain latitude in the highlights. Still... there are times when you have to use the ISO differently out of necessity. And I shoot towards the sun a lot.

For those who were adament that I was wrong about this being a sensor issue, I'd challenge you to load up the R3D and mess around with it.
 
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Also, there is quite a bit of OLPF red dot pattern evident in the footage as well, but that's to be expected because I was shooting towards the sun and stopped down quite a bit.

Here is a closeup of the sun issue:
black_hole.png
 
Justin Litton said:
Also, there is quite a bit of OLPF red dot pattern evident in the footage as well, but that's to be expected because I was shooting towards the sun and stopped down quite a bit.

Here is a closeup of the sun issue:
black_hole.png
Click to expand...

I was just going to ask your f stop... That's expected above f11 and pointed at a hot source. (Exaggerated the curve to see the red dots). The center "hole" or "Spot" is not right and should not be there. I expect RED to fix this in a firmware update. But just to confirm this must be a Raven only issue because I've never seen that on any other RED cam.
A003_C015_06074B.0000821F.0000000.jpg
 
Yeah, I'm aware that's the case with the red dots. But what about the purple sun? Because I'm pretty sure that I could pop a few more stops of ND in and open up the aperture and still get the purple sun.
 
Justin, keep in mind that changing ISO doesn't change how light is slamming the sensor. Only changing the aperture can do that. High aperture will introduce artifacts including the red sensor pattern you are seeing. To avoid this, good ND and shooting with a wider aperture is the key. Also, what kind of ND are you using? Does this happen with other lenses?
 
Justin Litton said:
Yeah, I'm aware that's the case with the red dots. But what about the purple sun? Because I'm pretty sure that I could pop a few more stops of ND in and open up the aperture and still get the purple sun.
Click to expand...

It's not right and shouldn't be happening like I mentioned above. I'm confident its a firmware issue and can be resolved. I've literally shot with every RED cam but the Raven since 2007 and never have I seen that issue before. So it must be a Raven firmware thing.
 
Bob Gundu said:
Justin, keep in mind that changing ISO doesn't change how light is slamming the sensor. Only changing the aperture can do that. High aperture will introduce artifacts including the red sensor pattern you are seeing. To avoid this, good ND and shooting with a wider aperture is the key. Also, what kind of ND are you using? Does this happen with other lenses?
Click to expand...

What I'm saying is that my results don't agree with that, although I do know that what you are saying is correct. Before I shot this video I had my ISO set to 800 and I had two more stops of ND in and I was not able to see any hint of purple sun at T/11 or beyond. The aperture stayed the same. It's strange, but I promise you I'm not a camera newbie and it's true.
 
We are investigating this issue.
 
Justin, I've seen you fighting for traction on Facebook with this. I've seen you handle others dismissive and shortsighted comments with professionalism and respect. My hat is off to you.
Thank you for your Sherlock skills on this, man.
 
Brandon Shafto said:
Justin, I've seen you fighting for traction on Facebook with this. I've seen you handle others dismissive and shortsighted comments with professionalism and respect. My hat is off to you.
Thank you for your Sherlock skills on this, man.
Click to expand...

Haha. Cheers, man. I have a shorter fuse on Facebook sometimes but generally I try and stick to the golden rule. These professional forums should be a place of mutual respect. And I do wish people would sometimes be less knee-jerk with their comments that could potentially confuse someone who is new and has less experience to go on.
 
It's a very interesting issue. I constantly shoot into the sun, large HMI's and whatever can backlight my scene. Has never happened, but it's clear that in a perfect storm, it's happening with the Raven. I'm glad that RED is on it...
 
Going back to the very first RED One this actually was an issue. It was quickly squashed and only now has this version appear. The one with the original RED one was in the very first release, looked a lot like the bmd examples, and was solved. I'm sure it can be solved rather quickly.

david
 
Hey Justin,
I'm getting the same results on my Raven as well. I had another issue with the sensor and sent it to Red for repair. Hopefully, they will be able to address both issues at once - I'll update here when I hear from them.

Worth mentioning, though, is just how good Red's customer service is. As in, surprisingly good.
 
I have the same black hole shot with Sigma 50mm 1.4 A & canon 35mm f2 IS.
 

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We've tracked the issue down. This issue will be resolved in our next firmware release.
 
TheBied said:
We've tracked the issue down. This issue will be resolved in our next firmware release.
Click to expand...

Matthew, don't think the new firmware fix is what they had in mind and it's really not helping matters one bit.

fmmntw.jpg
 
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