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Gate shadow - On OLPF1 & 2?

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Paul J Steinberg

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The gate shadow is really driving me nuts. Directors are always asking for flares but my Dragon with OLPF2 has the habit of chopping them when you least expect it. It isn't just hard flares, blown out windows will do the same but the flare isn't as dramatic. On the wide lenses, sometimes jumping to 5K will get around it but that means reframing the shot. Longer lenses (50mm+) seem to get it even at 5K.

These examples are all PL mount, OLPF2. There was no mention of this when all the original footage was being shown, is this just an issue with the OLPF2 or is the OLPF1 seeing this as well?

Lots of R3D examples: https://www.dropbox.com/sh/4hab87i00wa8adl/AAD3vAisHwu27UbjlaHnxlN4a


GateShadow.jpg
 
What lens is used might have a lot to do with it, no? Like reflecting elements in the back of the lens or PL mount.
 
These were all with my Ultraprimes. The examples in that dropbox are with the 32mm and 50mm but I've seen this with my Alura zooms as well.

This isn't cutting the iris reflection, it's cutting the "bloom" flare. It is most obvious on source flares (the sun, a lamp) but you will see it on blown out windows as well.

See: https://www.dropbox.com/s/1j12qqdbm29kivl/A008_C011_0717XY.0000019F.R3D
You can see the cut just below the latches of the pelican case.

Bjorn, do you have both OLPF's at your shop? If so, can you test if they're both seeing this shadow?
 
I see this with the Nikon mount as well, so I do not think it is mount or lens specify, but probably in the the OLPF/sensor box design. It happens at very specific light angles as your shot here shows and it happens at a very specific tilt position as well, you could reframe that shot/angle to get rid of it pretty easily.

Take the lens off and the mount and shoot a light in there, you can create shadows. That is what you are seeing. A shadow area, where the "box" is flagging the light. the sensor is recessed a bit and that is how/why this occurs. It's not an easy "fix" because you can not just move the sensor forward as that affects flange focal distance. I think it is pretty much just something that is going to be there and you will have to work around by changing the angle etc.

Im not saying it is right or wrong, good or bad. It just there, I've had to deal with it and changing a few parameters can eliminate it fairly quickly. If I can't change the angle then cropping the top of the shot pretty much fixes it.

If this was 6KFF and you cropped it to an HD aspect ratio, I think it would be gone, need to chop off the top row of 200 pixels.

Battistella
 
All of these shots are with the bare lens? No matte box or anything?

I think it's kind of odd that, for the most part, the shadow edge generally lies on the border of 5k HD/1.85 Academy, which is what I thought UPs were supposed to cover. That said, A001_C003 has a double flare going on -- one that looks clipped, and one that looks full bloom.

Do you have another/similar camera you can test with? Something tells me this might not be RED specific (or, if it is, it's because of how much bigger the Dragon sensor is and how much bigger the housing has to be so as to cover said sensor).
 
Those shots were 6KHD and 5KHD croppings. The Ultraprimes are covering 6KHD but the 16mm does vignette just a bit.

With a locked off camera, these are two croppings of the same frame, same lens. These clips were shot with a bare lens but I did mount my MB-20II when the frame was locked to see if these flares were coming from an angle that the mattebox would cover, but not difference.

A001_C001: 32mm 6KHD - Shadow present
A001_C002: 32mm 5KHD - No Shadow (outside crop)

A001_C003: 50mm 6KHD - Shadow present
A001_C004: 50mm 5KHD - Shadow present

A001_C005 is the 50mm 5KHD with movement so you can see how it comes in/out.

You can shoot around it by adjusting the framing but the problem comes in when you're moving the camera (hand held/steadicam) and going in/out of the flares or working in front of a bright window. You can lose that magic subtle expression from the talent when the camera tilts just the wrong way and the shadow hits.

It does seem to be a mechanical rather than a software problem. There was no mention of this shadow with all that early footage with the OLPF1 so wondering if there was more than just the glass filter in front of the sensor that was swapped out.
 
Do you have another mount you can try? EF with some Stills glass just to see what happens?

I have not seen/heard of this before either (though I don't own a Dragon). I'm presuming it's an official RED PL mount and not a third party mount? Is it a motion mount by chance? Also wasn't there an issue with OLPFs going in backwards originally? Did this camera start as an OLPF1 that got sent back in?
 
Paul J Steinberg said:
Phil: Never saw this with MX and I'm not seeing it on the Alexa. Did this exist with the OLPF1 and wasn't mentioned or did the Dragon not have the problem with that OLPF?
Click to expand...

I've seen it on MX and Alexa and Film and everything. Format size holds relevance here. It happens on "some lenses". Not all. I think the example I posted in the other thread was Alexa or film. Can't remember.

Edit. I'll add, grab a flashlight you will noticed it frame top and bottom, but not left and right when inducing flare.
 
just to be sure / are we talking about the flare? - which as mentioned looks like an early epic "gate flare" or a 35mm 2-perf gate flare.

OR - are we talking about the awful shadow that cuts the flare in half? - because that looks horrible, and I have never seen that on MX, Alexa or film.
 
Right, to be clear I'm talking about the shadow that us cutting the flare.

I don't work at a rental house but I've never seen that with any camera or any lens that I've ever used in my lifetime. It's so prevalent I was just curious if it was evident when the very early adopters had the OLPF1.
 
Gate flare crop - I have been getting it too, on any nikon glass I have tried.

I have noticed some EXTREME flaring on Nikon glass - I have tried both Aluminium Nikon mount AND Titanium mount. Both give the most crazy flares even without bright light near frame.

Red has acknowledged that the Nikon mounts are too reflective inside, they specially made up a Nikon mount with a non reflective flocking material inside for me to test out. I have tested this new Nikon mount all week and I must say the Crazy Nikon flaring is a thing of the past.
Red sent me the mount to test as a proof of concept, but I think a more permanent solution will be in place soon.

I still get that horrible gate flare crop, it's not as bad as before though.
 
The gate shadow is also happening with the Canon mount. Seems to be a global issue.
 
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