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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 :)

Issues

I have a feeling you will not get less then 1/24 shutter because the artifact of CMOS skew will come back and bite you. I am sure they are running the sensor at a high mhz to kill the rolling shutter artifact - this in turn does not allow for a really slow shutter speed I think.
 
Been seeing this "noise" from the beginning but the team has been working on improving these issues and I am expecting that's what Jim has been referring to when he said they have been able to improve the performance without the daughter board. Perhaps they can jump in and give further details.

Steve
 
obin said:
I have a feeling you will not get less then 1/24 shutter because the artifact of CMOS skew will come back and bite you. I am sure they are running the sensor at a high mhz to kill the rolling shutter artifact - this in turn does not allow for a really slow shutter speed I think.
Click to expand...
Sorry that is incorrect. There is no relationship between the speed of the readout (which could cause skew) and the shutter speed. The shutter speed is simply the duration between readouts, the readout itself is a fixed time depending on the windowing of the sensor.

Brook, I also remmember reading that the shutter angle was just mislabeled when undercranking. Someone should do an exposure test and see if exposure comes up a stop from 24fps at 1/24th to 12fps at "1/24th".

Anders, I agree that the blue channel is not as nice as the others but those offhollywood images have been graded and I don't think they are good for testing. Is it possible that redcode compresses Red Green and Blue, different amounts? I didn't think that was how it worked.

MacGregor, how was Spain? I'm interested to hear more of your thoughts about the camera.

IBloom
 
I think I made too great of an assumption with my previous post - the camera doesn't currently scale the labels for shutter speeds at faster frame rates [a 180 degree or 1/48th shutter will still be labeled as 1/48th at 120fps], but your point that shutter speeds don't go longer than 1/24th may be accurate.
 
Is there a way to change the gain on the sensor? Perhaps doing that would be more favorable than bringing up the levels in post, if it's possible.

Are the dark areas fine if you don't bring up the levels? For example stuff in the 10-20 IRE range?
 
RED Team, can someone please respond to macgregors noise issue.
 
The blue channels is always going to be about 2 stops darker than the green channel due to filtration.

The blue channel is half sampled.

Wavelet compression does very good on clean noise free images but requires a significant increase in bandwidth to handle noisy images.

10:1 compression is pretty strong compression.

(Decides he's getting precariously close to breaking the LART NDA and shuts up.)
 
Busy working. Yes.

Graeme
 
i noticed with the .r3d footage that was upped by jim and co. that when 4k footage is played at 2k high res on redcine... it looks very very very grainy... the ugly stuff. but once i eport it to .mov... 2k... it looks fabulous... though i havent tried exporting to 4k.

but i am pretty sure that stuff look much less grainy when are brought of redcode raw. and i beleive that is normal. if you grab ureself some raw shots off of a canon dslr, especially a 400d or the rebel series so to speak... you will notice a less grainy outcome when you take ure raw shots and convert them to jpeg, you will notice that the jpeg stuff are smoother... less grainy. I have seen the very same with red raw.

when i first saw the footage... i said to myself... i aint never shooting at iso 320... that looks grainy to me, but i was pretty sure that iso 100 would be like grainless... and i usually shoot at asa 100... even with my canons... and if i aint satisfied with canons iso 400 or 200... but only 100... red's 320 aint gonna cut it either... unless im doing stuff shot at 4k for 2k and <2k out.... for that ... i beleive id litterally go for asa 1000... ive done tests... 4k down to 2k looks very usable.
________
XR80
 
The issues you guys are describing sound very, very similar to what you get with a DLSR sensor over 300-400 ISO.

I have said all along, since the very beginning, that there is no way in hell that RED footage is going to hold up at 4K. It must be downsampled to 2K or 1080 to hide the noise you are going to get. Same thing with DLSRs with CMOS chips similar to RED.
 
Blue noise

Blue noise

Just wanted to chime in and say that we reported this blue channel noise to the RED swat team a few weeks ago and sent along example images and firmware versions to further identify the problem.

When it happens it's quite a mess, but even so the users have commented on the image quality as amazing. Even when it's broken, it's awesome.


--
Rune Hansen
Reds #84, #85
Simplemente, Mexico City
 
Tom said:
The issues you guys are describing sound very, very similar to what you get with a DLSR sensor over 300-400 ISO.

I have said all along, since the very beginning, that there is no way in hell that RED footage is going to hold up at 4K. It must be downsampled to 2K or 1080 to hide the noise you are going to get. Same thing with DLSRs with CMOS chips similar to RED.
Click to expand...

Tom, I am confused by your post. What do you mean by Red footage won't hold up at 4K? Am I missing something here?

Jim has said for quite a while that this is the cleanest digital cinema camera available, virtually noise free when properly exposed. There have been some issues for sure based on some of the footage that has been posted, but I've always assumed these issues were related to compression after the fact.

I believe they must have had a breakthrough with the newest incarnations of the camera because no longer is the daughterboard needed and everyone seems very confident that some of the issues present in footage up until this point will no longer be an issue.

I am looking forward to the LART tests.

Steve
 
Steve, not even DLSR single frame exposures hold up at their full resolution. If you are looking at them pixel for pixel, they are terribly noisy and ugly to look at. Anyone who has viewed large DLSR jpgs knows this to be true. Once you downsample a typical DLSR image from roughly 4K to 2K, the image looks much cleaner and nicer and much of the noise is lost. If you downsample it even further, the image will continue to improve.

I think with a 4K sensor like RED's, people should shoot 4K and finish at 2K, and the results will be impressive.
 
We've projected 4k as 4k and it looked great (and that had gone through a much earlier REDCODE). I view DLSR images pixel for pixel all the time and they're generally fine. REDCODE is improving all the time.

Graeme
 
Tom, I get where you are going with this but you know that what you are saying is a bit controversial because that calls into question the whole 4K revolution. Sure, most of us won't be finishing much in 4K, most likely 2K or 1080P but for the feature film world I would think clean 4K would be essential for finishing.

What are you basing your fndings on, other than DSLR sensors? Do you have first hand info? I'm not trying to call you out, just want to make sure I am understanding your position well. It flys in the face of everything I have come to expect from this camera and without one in my hands and ready to test, I can't confidently say you are right or wrong. Please elaborate if you can.

Thanks,
Steve
 
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