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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 Gradient

Rick Darge

Rick Darge

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So Epic users, let me throw it out there once again. Are you guys getting a weird light leak gradient on ISOs above 2000 whenever you turn the Epic on for the first time?
 
I use an M and an X and I regularly see the effect you describe after powering up both cameras. I don't know what causes it.
 
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How long does it take to diminish? I feel like I'm over-reacting because nobody else seems to care but why are we seeing this on the Epics? Is this something that can be fixed with a firmware update later down the line? Red, please let us do blackshades quicker than 25 minutes!!
 
do you absolutely need to black shade to get rid of it, or if you just leave it on for 15-20 minutes it's gone? because high end cameras need to reach optimal temperature before it hits peak performance. what you're seeing from a cold boot could be from that. all of it works in a sweet spot, temp is part of it. black shading is another part of the equation for optimization.
 
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Then why didn't the Red One ever display this issue? That camera is high end...
 
I've seen our MX units do this. I imagine it's a nominal temperature issue - i.e. black point is only correct at the nominal operation temp.

Alexa throws a temp warning for the first minute from a cold boot due to this.
 
This indeed has happened in my experience, but only once.

I was shooting with Ketch Rossi and Clay Haskell with EPIC-M #8 in NYC. It was bitter cold, and we were checking to see what the image would look like at high ISO's. At that time, the EPIC firmware was so much in its infancy that a Black Calibration was not an issue.

Since then, I've been with Ketch numerous times and since Black Calibrations are performed, we don't see this issue...
 
I can confirm this and it happens at room temperature.

The BSC needs to be done after the camera is "on temperature".
A cold camera then has the streak, till it is heated up.
What concerns me was the fact that this is no extreme condition.

On the other hand this might be only a big concern, when shooting very low ligh, with the intention to push the blacks up a lot.
 
@Jonas: How long until "on temperature"?
 
This sounds like another aspect of the half-hour-calibration-every-time-you-change-a-setting issue.

I wouldn't tolerate this kind of reliability issue from a plastic $900 DSLR. How are people taking it in stride from a camera that costs as much as a BMW!? It's insane!
 
I was trying to find my understanding on how much this is of an issue or not. These are my personal findings, through tests on 2 EPIC-X cameras.
I also add my personal conclusion about this issue, which may make some wrong assumptions. The explanations I offer are from my own limited understanding of technology, so I might be wrong at a lot of points. Please take everything with a grain of salt and test yourselves.



1. TO REPLICATE THE ISSUE

There is a very simple way on how to replicate this phenomenon. The noted times are exaggerated,
to make sure that it is reliably replicable.

1. Turn the epic on and let it run for minimum of 40 minutes.
2. Perform BSC.
3. Turn camera off, and let it cool for minimum of 60 minutes.
4. Turn the camera on, put the lens cap on and crank up the ISO to max and the WB to coldest.

=> This is essentially looking into the quality of the BSC.
=> You should see a gradient on either left or right of the image.

The gradient disappears slowly as the camera chip gets closer to the temperature of the BSC.
Once on temperature the noise is uniform.
You can speed this process up by manually putting the fans on 25%, as the camera heats up faster this way.



2. POSSIBLE MEANING OF THIS

The initial reaction is of course panic, as this might mean, that one needs to:
a) wait before BSC to get the chip on temperature (min 20 mins)
b) wat until BSC finishes (20 mins)

Combined with e.g. shooting timelapses, with variable shutters, these times might cause headaches during the shoot.



3. REALITY CHECK

1. Every high-tech equipment is sensitive to temperature. This "issue" shows how precise the EPIC is performing BSC.

2. The fact that this effect is not visible on RED ONE, or 5D or 1D does not mean those cameras are not sensitive to temperature - they may not have as sophisticated BSC as the EPIC. One person I contacted about this told me, that he has the same phenomenon when cranking up the ISO that high on his 5D.

(As an example, there has been a lot of talk about IR pollution on the RED ONE, I heard opinions such as "Alexa does not need hotmirrors" or "Phantom is ir pollution free". I tested those cameras myself, and found that they are prone to IR pollution under certain circumstances, same as a 5D and a 7D.)

3. Shooting on high ISO ratings (beyond 2000) will always push the limits to any sensor. Noise and temperature sensitivity will start to become more problematic. Problems on pushing so far beyond native limits will result in issues on any type of equipment. This should not come as a surprise.



4. MY PERSONAL CONCLUSION

Our cameras were on a high-end perfume commercial, that was a nightshoot with large temperature differences. We shot at 5K@96fps, at the limit of the camera.
The BSC was performed after cameras were on operational temperature, before the shoot every day. There were no issues with the image quality.

I was shooting on a glacier the whole winterbreak, every resolution, framespeed, shutter, highspeed and timelapses. No issues - if one respects the "limits" of the equipment.


I think it is very important to understand, that every piece of high-tech equipment has some sort of "bugs", that are there, because there are limits to physics. Every camera I worked with, Phantom, ispeed3, RED ONE, 5D, 1D, Weisscam and SI-2K has some sort of a "thing" that one had to understand and learn to work with or around it. People working in stereoscopic projects can surely sing an anthem on this... :-D :-D


BSC seems to be on the later builds more complex and sensitive, so it is more important to understand its working and perform it adaptively to the shooting environment.


I understand when people are disappointed with this behavior of the EPIC, as it seems unexpected and new, and something that "should not be there". For me, this is not a real world issue, but part of the learning curve.


There has been reports of issues with the gradient during production, which is of course a problem.
If the BSC was performed as prescribed and the issues were beyond the limits of what we can replicate, this might hint to hardware problem,
but I have not more information on that particular case.
 
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Jonas, thank you SO much for this post!
 
Jonas' comments mirror my experiences with my Epic M and X. I appreciate and support his "Reality Check". I did a quick test and found a distinct gradient at iso 3200 on a cold start. After five minutes, it was mostly gone. After ten minutes, no detectable gradient. This at room temp. Much of my shooting is at night, very dark scenes. I have never noticed a gradient issues in my real-world shooting. Of course, the camera has usually been running for at least ten minutes for setup purposes. It is just not an issue in my experience. Others may find this situation problematic.
 
Lee Saxon said:
This sounds like another aspect of the half-hour-calibration-every-time-you-change-a-setting issue.

I wouldn't tolerate this kind of reliability issue from a plastic $900 DSLR. How are people taking it in stride from a camera that costs as much as a BMW!? It's insane!
Click to expand...

Hi Lee,

With respect, companies such as Canon, Nikon, etc who make "plastic $900 DSLR" cameras, have had around 20 years experience making digital cameras. Red have only been around for 4 or 5 years now. Give them a chance.

Also, the Red Epic is still a "beta" camera. Not all its functionality is there yet. Wait another year (or hopefully less) and most of its features will have been enabled and bugs fixed.
 
I just tested mi Epic at room temperature ISO-2000 - 3200 - 6400 and 12800. No issues with gradient just an increment of hot pixels.
 
Christian, was your testing done immediately after camera startup or after some minutes of warmup time? What firmware version? What is your camera, M or X and serial number or date you received it? Just curious about potential differences in camera builds.
 
Yep, my Epic-X have a gradient left to right in frame clearly visible to about 10 min after camera start. Last time a did BSC the camera ran about 10 min in room temp also. But after camera have reached calibration temp there is no issue what I have seen.
 
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