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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 :)

Red Asa

studiodrome said:
any idea of what asa the mysterium sensor is? also will you allow the asa to be boosted to an asa of over 800 in camera?
Click to expand...

Hi,

From David's Stump's tests I would say 320asa.

Stephen
 
It's very difficult to "rate" a sensor in ASA terms. The last guess I heard was 160, but that's very approximate. I'm sure it can be pushed in camera.
 
Camera ASA

Camera ASA

The first estimate was 160, later revised to 320 based on David Stump's test.

To be honest, this is a difficult question to answer definitively for a digital sensor based camera. The ASA value is just a guideline.

The most important thing to bear in mind is that our real world testing has shown that the camera's output is extremely clean with very quiet blacks.

Which means that footage can be pushed pretty hard in post without any significant deteriation.
 
If we're talking about ASA for the chip, are we looking at it from the perspective of grain or of light-sensitivity? Because when I'm shopping around for ASA film I usually think of the amount of grain I'll be getting rather than the change in exposure time.

If the sensor is supposedly running at 320ASA, does that mean we're getting as much grain/noise as would be found in 320ASA film? Or are we getting 320ASA light sensitivity with grain/noise as would be found in 50ASA film?
 
Not comparable, in my mind. The footage I've seen projected from the camera is completely devoid of noise altogether... no gain or grain structure to be noted. Just a clean image.
 
But if you want to rate the camera at a higher sensitivity you are going to increase grain. Wether the difference in "grain" is dramatic or not (or even visible) depends on how much you're pushing it and what the s/n ratio of the sensor is. I bet you that if you rate it at say 6400ASA there is going to be some noise in the picture.
 
Well, it is a CMOS sensor, they tend to be slightly less sensitive and have more fixed pattern noise than CCDs but who knows, it's a new sensor so we'll have to see how it behaves. I'm optimistic.
 
if the ASA is rated 160, can it be boosted via gain ie +12?
 
Here, I grabbed one of David Stump's frames that was 5 stops under (at a rating of 200 ASA) and pushed it to a 3200ASA equivalent. The RED team had mentioned that they flubbed some settings during those tests so don't take this example too seriously.

Image is cropped from the original so the noise is much larger than in real life. I'd really like to see that noise signature in motion.

pushred.jpg
 
Sarmoti, is that a 100% crop?

you know, if that were exposed correctly I think that the noise level would be acceptable for filming a motion picture.
 
Looks like I'll have to plug away at an AI noise reduction program... after I'm done with my other ten programming projects.
 
Noise levels should look better in the finished camera though as we've made advancements since Dave took those shots.

Graeme
 
sorry guys, im confused.. someone please clarify the following..

1. there is no dial on the Red to boost gain for low light work? meaning one keeps recording underexposed.

2. hence the gain (ASA or ISO) boost is achieved in (raw) post production?

3 is the low light performance comparable to a Nikon DSLR?
 
to ad to akcelic's quesions: if we are recording in low light, will we be able to boost the gain in the lcd/viewfinder so we can see have in indication of how our final pic will look (especially for EFP work)
 
That's most probably how it will work.

Graeme
 
Graeme, wasn't David's shots processed without any static noise reduction and bad pixel mapping?
 
Justin Anderson said:
Sarmoti, is that a 100% crop?

you know, if that were exposed correctly I think that the noise level would be acceptable for filming a motion picture.
Click to expand...

No, it's more around 50% Still, it's like 1/10 of the total imaging area. Noise would be much less visible plus one of the byproducts of using REDCODE seems to be that it works as it's own little noise reduction algorithm.

Anders Holck said:
Graeme, wasn't David's shots processed without any static noise reduction and bad pixel mapping?
Click to expand...

Yeah, that's what I understand as well.

I wonder if results are any better amplifying directly on the sensor or wether that's even feasable. Also, can't fixed pattern noise be reduced by mapping it by shooting black and identifying it and then processing based on that map or does it change wth the sensor's temperature and therefore can't be properly mapped out? As I said, REDCODE seems to naturally act as a NR algorithm, you could also do some NR processing ontop of that and that image is zoomed in quite a bit.

Also, I want to state that the times where you would intentionally underexpose by 5 stops would probably fall in the very rarely to never category. When you underexpose film by 5 stops and push it to make up for it you certainly get more grain than what we're seeing from RED, especially on Fuji stocks. On the other hand film grain is more visually pleasing than video noise but we'll have to wait and see how RED's noise looks in motion.
 
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