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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 :)

Epic STREAK FLARING

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What I see are lens flares, and they are a result of the larger Epic sensor.

If you look at your lens while taking ... a lot of sources can be seen reflected in the glass without flaring.

The Epic's larger sensor is making more of these sources that are hitting the lens create flares.

To say that differently, a greater range of light sources hitting the lens from a greater range of angles will cause flaring in Epic. In particular this will affect light sources just off frame much more.

There is nothing for it but to flag the lens a bit more aggressively than you are used to with S35 and R1 cameras.

Just a note, I'm ignoring the sun in the vimeo clip and just considering the flare from the water in that clip, plus the flares in the circus clip.

Now ... if I was 100% correct, then cropping the sensor would make the Epic behave more like Red One MX. I read here that cropping the sensor has not impacted these flares.

If that is correct, that means there are at least two factors at play here ... and I have no experience with the second one.

One hypothesis I have is that its an internal reflection. One thing that surprised me about the Epic M was how much shiny there was around the lens mount compared to R1. I frankly discount this, because I think if this were an issue it would affect more footage more often.
 
Guys I have been shooting for 20 years, I know how to use a matt box! There is a definate problem with the sensor bouncing light around something. David Wakely who is one of the founders of the Australian Cinematographers society first noticed this on my camera when he rented it.

I had my Red ONE MX right beside my EPIC last night and it didn't do it.

I had bottom, top, left and right flags on and it didn't make a difference. You cannot move flags mid shot.

The lens mount is definately different on the epic and seems shinier, so i masked the sensor with camera tape and that made no difference. I am sure light is bouncing between the sensor and the OLPF.

I would really appreciate if someone at RED like DEANAN could look into this please
 
ericyoung said:
Adam, did you have a bottom flag on the mattebox - as the flare is coming from bottom of frame?
Click to expand...

If you look at the whole shot the flares come from the top and bottom. The opening first few frames are very noticeable
 
Adam Eden said:
Guys I have been shooting for 20 years, I know how to use a matt box! There is a definate problem with the sensor bouncing light around something. David Wakely who is one of the founders of the Australian Cinematographers society first noticed this on my camera when he rented it.

I had my Red ONE MX right beside my EPIC last night and it didn't do it.

I had bottom, top, left and right flags on and it didn't make a difference. You cannot move flags mid shot.

The lens mount is definately different on the epic and seems shinier, so i masked the sensor with camera tape and that made no difference. I am sure light is bouncing between the sensor and the OLPF.

I would really appreciate if someone at RED like DEANAN could look into this please
Click to expand...

Sure, I can look into it.
 
David Battistella said:
Even on the R1 you could get light bouncing off the OLFP back onto the back of the lens and then back into the sensor. What happens if you used a net on the back of the lens? I wonder if that flare would still be there. It's the same principle as light bouncing off a filter in the mattebox back into the front of the lens.

The flange distance is the same in the EPIC and the R1 so the internal PL area has to be the same "volume", so that is kinda rulled out.

Maybe it's the difference in mounts.


Just tossing stuff out there.

David
Click to expand...

I recently shot a TV commercial with my EPIC and a net stuck in front of the sensor, I was shooting steadicam and the flares were still there.. I managed to move the lights around and put on all of my side / top and bottom flags for my matt box and avoid the flaring.. But at the circus with small lights everywhere, I could not avoid them.
 
Deanan said:
Sure, I can look into it.
Click to expand...

Thank you Deanan. I remember that someone was saying the OLPF filter is removable so I was wondering would this make a difference? I am reluctant to do this myself for fear of scratching the sensor, but if that is the problem, then i could go somewhere like LEMAC for them to perform the operation once in a while.
 
I am having these same vertical streak flares... was wondering if it was just me, until I saw this thread. NEVER had them on the MX before. I have been using ultra primes recently. I'll try my RPP's out here soon to see if I see the same.
 
Adam Eden said:
I had bottom, top, left and right flags on and it didn't make a difference.
Click to expand...
From what you're saying it's definitely a 'sensor based' flare, as opposed to a lens flare (in all fairness, just from how it looks and moves it clearly isn't a lens flare) - I still stand by my original guess that it's a gate flare or some other case of light flying around inside the mount/sensor enclosure, but it could also be related to the OLPF, perhaps. I've not had the pleasure of shooting on an Epic yet (first shoot will be early next month) - is there anything shiny on the edge of the sensor mount or within the enclosure? Could it be light refracting off of the edges of the OLPF glass if they're not blacked down? Has anyone ever seen them horizontally? That would help define the issue, I would guess...

Interesting, interesting!...

Cheers,
Dom.
 
OK, watching the clip again, it's certainly interesting that it happens only when the light source is just outside of the frame - not when it's in shot. Again, I think it's reflecting off something outside of the sensor - some edge or other within the image circle but outside of the actual imaging area. If someone were feeling brave, it would be interesting to see what happened if you blacked off the sensor a mil or two from the top and bottom edges. Maybe that's a test best left to Red, though!...

Be very interested to hear what the problem ends up being...
 
I have the exact same flares across all my lenses: Ultraprime, superspeed, Masterprime, Alura and Angenieux zooms.
I thought it was the black paint running up to the glass, and thought about taping it down with camera tape, but that doesnt work then.....
 
light bends and bounces... optical systems flare and glare. however, if a mustache (bottom flag) didn't help you out, and you can't grow a bigger mustache... it would be nice to at least know where it's coming from. true, some people like it, and i don't see much wrong with it, but there are situations where you have to capture clean images.
 
New theory...
Between the OPLF and the lens mount is a rectangular, soft, rubbery part (OPLF mount?) that is very SHINY.
...flares in images I have don't make it quite to the top of the FF image - the flare is shadowed.
Right behind this rubbery "mount" is a metal plate about 1mm smaller than the shiny rubber, and would cut a reflection off the rubber, maybe, just on the edge of the active sensor area...

No mattebox was used on this one.

attachment.php
 
A possible test might be to get in a dark room and record some flare tests to find out what angle the flares occur in relation to the lens.

From reading through this this could be done with a flashlight.

It would also be interesting to see (with the turned off and no lens in place) whatkind of reflections you get by shooting light at the open gate while looking at the sensor and olfp area.
 
Yes.

I have no big problem with them, but I think Mark is also asking why on the R1 and the EPIC. It's a bit of a curiosity thing, just to know and see the characteristics of s new tool.

I like the look of these flares too. You see them with 35mm glass, less likely to see this with smaller chips or 3CCD camera's.

David
 
Here you go, I dug through some archives...

Lets put this to bed... It all comes down to some lenses. reflecting internally and bouncing that light onto the film surface or chip plane.
This is not a RED problem, I'ts just simple old internal light bounce and some camera and lens combinations get it more than others.
To avoid it... use your matt boxes more efficiently. :) to keep it (like I do) then don't worry about it.

flare.jpg
 
Just to be absolutely clear.

I was not calling this a RED PROBLEM.

I do not see this as a problem, I see it as a creative choice. As I think you do.

David
 
Mark i am sorry but you are wrong.

This has nothing to do with lenses. It is a problem with the sensor. I have spoken to a few ACS cinematographers in Australia that agree with me.

This is a real problem as i cannot use the camera in the Circus scenario shoot, and i will now have to reshoot the entire sequence on the RED ONE MX.

For me this is far from being "Put to bed"
 
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