Weapon/Helium Really Bad Noise

[Bradley Dunn]

I have the Weapon/Helium and I seem to always have a ton of noise in my image when I don't shoot full sensor. For example at 4K the image is horrible, and 3K and 2K is completely unusable. Not that I like to shoot at these resolutions all the time but 4K for 120fps for sure. (Noise is bad at 4K 24fps as well) I manually calibrate my sensor but at this point Im thinking I could be doing it wrong. Has anyone else ran into this issue?

 

[Michael Tiemann]

If you don't post an R3D image file there is no way to speak intelligently about what may be the problem.

 

[Karim D. Ghantous]

I don't own a Red camera, but when you say 'manually calibrate', I assume you mean blackshading. If so, I have heard that you should get the camera hot before doing that. You should also have a magazine loaded in the camera as well. This thread is helpful:

https://www.theblackandblue.com/2012/04/26/shooting-red-epic-1/

 

[Bradley Dunn]

https://www.dropbox.com/sh/v6wssnelbn30rne/AADbPGyGztAWXhpM38J6RIAfa?dl=0

 

[Bradley Dunn]

Ya in RED menu settings it's "Calibrate" and you can do Manual or Auto. Thanks for the article, I think the only thing I wasn't doing is waiting 15min for the camera to get to operating temp. I'll try that.

 

[Phil Holland]

Need an R3D snapshot to really dive in.

 

[Bradley Dunn]

Thanks just dropped one in that dropbox folder link above.

 

[Tom Gleeson]

Ya in RED menu settings it's "Calibrate" and you can do Manual or Auto. Thanks for the article, I think the only thing I wasn't doing is waiting 15min for the camera to get to operating temp. I'll try that.

Bradley,

Red themselves have posted a how to/instructional video on Black Shade calibration From your description the problem seems to be the black shading calibration being done at the wrong temperature. First check in Menu>Settings>Setup>Fan control and see what your target temperature is. By default I think it is 39C. Then leave the camera on until it reaches 39C. Only then go to MENU>Settings>Maintenance>calibrate>Sensor>Manual and do a calibration. As you are running a Helium sensor Red recommends a Manual Calibration. If you do a correct Calibration and the noise doesn't abate we can go to the next level. To mention the obvious as you window the sensor to smaller areas you will inevitably accentuate the noise floor but well exposed 4K Helium footage should look good. I also decrease the R3D compression ratios as I window down as well as decrease my ISO to control any noise.

 

[Phil Holland]

Had a look at the R3D snapshot. I wouldn't say it's too noisy, but there is image noise, but sort of what I'd expect in this condition. This is mostly due to the image background being on the cooler side and you're already at 3200K.

Things I would recommend overall. If this is a 2K finish, I don't see really any issues.

If you are finishing 4K for 4K, you'll want to likely favor a lower ISO Rating if this level of noise has a negative impact on what you desire.

Generally I would recommend filming 5K or 6K (or even higher resolution) for a 4K finish, sort of no matter the camera. Down-sampling does have it's benefits.

One other thing I think is worth recommending. In REDCINE-X PRO as well as in the SDK there is a feature under Image:Noise Reduction, X box Chroma Noise Reduction. This is proper chromatic color noise reduction algorithm. In particular for this shot, it will likely produce a more desirable image.

 

[Mike P.]

Yeah, I didn't think it was that noisy, and after you render out to a delivery codec/resolution, a lot of pixel dancing will get mitigated. Were you viewing in full-res?

There are a few tweaks that could make it better at acquisition though. 10:1 at 4k is a somewhat high compression ratio for non-daylight balanced sources, and shooting 4k for 4k isn't ideal. Conversely, from a noise perspective, I think you're better off going 6k 14:1 or 8k 18:1 and downscaling to 4k (those ratios are insanely high, but I *think* it'd clean up nicer than 10:1 4k for 4k).

For that .r3d you posted, going to 3500k/+5green (white balance off the Acura logo in the background), lowering to ISO500, and enabling Chroma Noise Reduction cleans it up nicely. Then use curves to get some contrast and brightness back to the mids.

 

[Les Hillis]

Looks underexposed to me, with the crop and RC compression exaggerating the noise a bit.

Based on metadata said 1/60th of a second shutter speed, 'metering' at ISO800, the lens stop required to get that depth of field, and with lighting that left a viewable picture on that TV on the wall...

I agree it's fixable though if you find the noise too much.

 

[Karim D. Ghantous]

It's worth repeating that chrominance NR is far more important and useful than luminance NR, all other things being equal. I always apply chroma NR to photos, but never lumi NR (with minor exceptions).