ASA Rating?

[Michael Totten]

I know this subject has been discussed ad naseum, but I have heard from a DIT friend of mine who owns several RED's that a couple big time DP's he's worked with have rated the RED at 250 ASA. He reported that anything above that is just too noisy.

I understand that acceptable noise is totally subjective. Those of you that shoot on RED often.. what say you ? For feature film theatrical work.

thanks .

 

[Kenn Michael]

the question is - Are they rating noise on the video tap? Are they going into RedCine and applying curves and quick grades? Are they doing Full demosaics, or just 1/2 Res (Standard).

I don't start to see any real noise until I get to 500. Even then, film grain is noisier.

I've heard a lot of people who don't quite understand the RAW concept look at the monitors from the HD-SDI outputs and base their opinions on that image without actually digging into the real data.

My DP friends rate it solidly at a 320 but have no problems pushing to 500 if need be. I can process very clean images from 500.

 

[Gunleik Groven]

Subjective observation here, but:

Red definitely loves blue light/daylight and is not too fond of tungsten. One could argument that the tungsten ASA vs the daylight ASA should/could be rated differently, that is, lowering the ASA settings in post when there's less blue in the light would equal a higher ASA rating for daylight shots.

When you lower the ASA/Exposure settings, you can get a lot less noisy image with the curves.

Graeme (or Stuart?) chopped me down on this once, and I guess they're right, but this is what I see so far.

That said: RED is generally extremely noisefree.

Gunleik

 

[NateWeaver]

I agree with everything Kenn is saying. You can't look at the monitor output to make any determinations. In fact, you have to know exactly what you're doing in Redcine/Alert to make correct noise determinations. De-Bayer quality has everything to do with it.

Also, rating the camera at anything less than 320, while helping the noise floor, is at the expense of your highlight latitude...so I never shoot at anything less than 320.

 

[Gunleik Groven]

I did purposely not throw ASA numbers, as I was thinking about matching shots.

 

[Warren Kommers]

In fact, you have to know exactly what you're doing in Redcine/Alert to make correct noise determinations. De-Bayer quality has everything to do with it.

Nate,

What are you finding as the optimal setting BTW for noise relief besides maximum full everything? For making pro res HQ masters for MV or commercial work. Or are you taking another route to master? Thanks.

 

[Kenn Michael]

320 ASA in RedCine or RedAlert (unless you have clipping artifacts at 320, then drop down to 250 to reveal more highight). Use curves to brighten, etc... Render at Full, not Standard or Half.

As full renders take awhile, that should be part of your online/conform process, not for all dailies.

Full is optimal as far is noise is concerned. In a Standard or Half render, sharp noise will almost disappear when rendered at Full.

Like Gunleik said, Red is pretty noise free. Even when it's a little noisy, it's still clean. Only in extreme circumstances can you push too hard and get the nasties. But at that point, your lighting on set should've been better!

On stuff that I've shot, I've gotten the semi-complaint that the images are TOO clean! "Can you grit it up a bit? Add some grain?"

All that said, I have had a few instances of weird compression artifacts - in the woods mid-day, doing very wide shots with many trees and leaves, I saw noise crawling up the tree bark. Too much detail? I think Redcode 36 would've helped there, but I haven't re-tested.

Build 16 should be pretty exciting.

 

[Gregor Hagey]

ISO rating not always necessary

ISO rating not always necessary

With Red it's not always necessary to 'rate' it with an ISO. Learn to use the histogram and try to expose to the right when you can. You'll get the cleanest picture possible this way. That being said I've 'rated' the camera at ISO 640 in low light Tungsten conditions and had good results comparable to film. For my taste I wouldn't want to rate it any higher though. When monitoring setting the Red to ISO 320 gives you the best view as to what is being captured on the sensor. In bright conditions resist the urge to monitor at lower ISOs. In low light conditions setting the ISO higher then 320 will still give accurate results.

 

[NateWeaver]

With Red it's not always necessary to 'rate' it with an ISO.

My gaffer appreciates estimations though. Hard to do a truck order without knowing a ballpark.

 

[Michael Ragen]

At the moment I like to shoot at 320 but process at 250 when going to REC709 with exposure adjusted with curves.
edit: of course it depends on the nature of the shot.

 

[Brent J. Craig]

...That being said I've 'rated' the camera at ISO 640 in low light Tungsten conditions and had good results comparable to film.

I have seen a projected 35mm film-output print of something Gregorios shot under these conditions and it was very very clean. Equal to or cleaner than any of the 200ASA film stocks. I have heard since that perhaps the lab didn't even use the full 4K resolution, in which case it is truly astounding.

 

[Barry Green]

the question is - Are they rating noise on the video tap?

That's indeed the big question. I wonder if Red hasn't done themselves a disservice by making the video tap look "too good". The live video tap doesn't represent what the footage is going to look like; it's a quick & dirty preview.

No self-respecting DP would make *any* decisions about a film camera based on what the video tap output looks like. But with Red, the preview out looks pretty good, so unless someone has really done their homework on the Red, there's no real reason for them to think that they're *not* seeing full quality, right?

The live video tap looks pretty good, we even have people asking if they can record it. Compared to the full potential of the Red, the 720P output is nowhere near representative of the final image. Maybe in build 16 they should change the live feed to black 'n' white and make it flicker, and that way shooters will know what they're dealing with and will then know what they've got to do in order to do proper tests...

I've heard a lot of people who don't quite understand the RAW concept look at the monitors from the HD-SDI outputs and base their opinions on that image without actually digging into the real data.

This is mandatory, of course. Any shooter needs to be told of this. If they're approaching the Red thinking it's like any "video" camera they've used, then they're starting with some pre-formed habits that are not applicable to the Red.

 

[Gunleik Groven]

Word
Gunleik

 

[Toby Oliver acs]

ASA rating

ASA rating

I am about to shoot an indie feature with RED and will 'rate' the camera at 500 ASA to help protect the highlights - effectively underexposing by about 2/3 of a stop. I would never set the ASA to anything less than the standard 320 ASA as you would be generally overexposing the image, not usually a good idea with a digital camera unless you are after that 'blown out' look.

 

[Bastiaan Houtkooper]

Don't forget that 'Film DOP's" are coming from a time where they focus on the dark areas. You were constantly checking your blacks and playing "safe" was always over exposing. Never come to a Lab with a 'thin negative". Highlights were almost never a problem. The people you worked with come from this (old) school system and will need to adept to the opposite. Protect your highlights as much as possible without loosing details in the blacks. It will take time and experience to change, but they became DOP's for a reason and after the first few shoots they will adept and know where to look. Indeed noise being the least of the problems. (unless shooting bluescreen).

Bastiaan Houtkooper NSC
showreel: www.zebrafilm.info

 

[PeterM]

Never mind about real ASA rating. For my view RED is a little bit to noisy compare with Sony F 900.
If you get Noise depends on what you shoot.
How we work
1. Treat the camera like a DSLR in RAW mode which simple shoot higher fps
2. use the false color mode
3. Use ASA 320 for gen view.
4 Push to 2000 than you will get an idea about the dark parts noise even on the RED LCD
5 push back to 320 ASA
6 Be aware you need an editional gamma, denoise and so on step (in our case in CineRED)
I honestly tell you when we first shoot I was really disapoited about RED.
After we understand the RED and its Sensor its turns to great.
And its only take us 2 days of learning by doing.

BTW In my view RED is sensitiv with its noise by temp.
After using the cam 2 ours in hot sun we got much higher noise in the footage.
Anybody else get this experiance?
So we try to keep the baby cool.
I would like to have more grip points in the cinered for nonlinear gammacorrection.