Welcome to our community

Be a part of something great, join today!

Log in
  • 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 :)

320 or 800??

P

patrykrebisz

Member
Joined
Jan 3, 2008
Messages
10
Reaction score
0
Points
0
Website
www.patrykrebisz.com
Im getting ready for my first shoot with the Red camera and was wondering if u guys can shine some light on this issue. Normally with other cameras (CineALta, Varicam and whol bunch of other cameras) i try to get the image as close as possible to the properly exposed image as i know doing the post on it will bring significan amount of noize. Likewise with Red i assume u should aim for as properly exposed image as possible... Right? Im asking because someone told me to shoot at 320ISO instead of 800 and if its too dar to bring it back in the post as one way or another it will end up with more noize.

Your thoughts???
 
Shooting in ASA320 is the same thing as shooting in ASA800, the recorded data is the same. The only difference is that your monitor will show you a rough idea of what it would look like "pushed" to 800.

Red has only one native ASA (which is roughly 320), any other setting is simply changing the meta data.

That said, I find up to ASA1000 to be acceptable to me, depending on the nature of the shoot. Night and low light scenes can have a bit of grain. Build 16 is supposed to feature improvements in this area.
 
do some test with camera set to 320 ..640 ...1000 ...
when you bring them into RC ... in color correction (RC) set the ASA to 320 for all shots ... then use curves to bring up the dark images ...
 
i'm not sure i fully understand the concept just yet. I downloaded RedCine -- anyone knows where i could download sample footage so i could play with it...

Again the camera is going to be a rental so i don't have access to it to shoot the test.
 
patrykrebisz said:
i'm not sure i fully understand the concept just yet. I downloaded RedCine -- anyone knows where i could download sample footage so i could play with it...

Again the camera is going to be a rental so i don't have access to it to shoot the test.
Click to expand...



Just look in the Footage section of the forum.
 
Shawn Nelson said:
Shooting in ASA320 is the same thing as shooting in ASA800, the recorded data is the same.
Click to expand...

except....

Doesn't affect how you expose for a given iso setting ? Your iris / exposure determines how much light the sensor gets right ?

I think it's wrong to say that the iso settings don't affect the raw data, because it infers what the cinematographer was rating the camera at.

jb
 
Noise isn't quite the same thing as grain, nor does it behave in quite the same way (though noise reduction software and grain reduction software are more or less the same thing) -- faster film stocks are grainier though.

With a film image, the detail exists on the grains themselves (dye clouds, actually, not grains, to be more accurate when talking about color.)

Anyway, what people are trying to tell you is that the RED camera has a basic sensitivity and any changes to that are just done in post by pushing or squashing the signal levels, etc. So the ASA settings on the camera are just metadata settings and also affect the video output that goes to the monitors, but it doesn't affect the recording itself. However, how you expose the image of course affects what gets recorded.

Since the camera has a base sensitivity in the 320 ASA range (and nearly daylight in color balance) if you rate the camera at 640 ASA, for example, all you are really doing is underexposing what gets recorded -- or to think of it another way, what you are doing is biasing your exposure more for highlights and less for shadow detail compared to a lower rating. And if you correct this recording back "up" to a brighter look to compensate for the underexposure, you will probably see some noise, just as when you push the gain on a video camera. How objectionable that noise is is a matter of personal opinion and taste.

The camera also acts a little noisier in 3200K tungsten balance than in 5500K daylight balance, or at least, the blue channel is noisier in tungsten light, since you are essentially underexposing the blues.
 
John Brawley said:
I think it's wrong to say that the iso settings don't affect the raw data, because it infers what the cinematographer was rating the camera at.
Click to expand...
But it doesn't affect the raw data. Whether you rate the camera at 100 or at 2000, it will still take the identical same image.

The ISO rating is merely "advice" to the post-processing system as to what the cinematographer envisioned. But it does not fundamentally change the data that gets recorded at all. In post you can choose to take the cinematographer's advice, or ignore it, or re-rate the shot.
 
Barry Green said:
But it doesn't affect the raw data. Whether you rate the camera at 100 or at 2000, it will still take the identical same image.

The ISO rating is merely "advice" to the post-processing system as to what the cinematographer envisioned. But it does not fundamentally change the data that gets recorded at all. In post you can choose to take the cinematographer's advice, or ignore it, or re-rate the shot.
Click to expand...

Yes I know.

But it does determine how one chooses to expose the image. I have to type something into my lightmeter.

That affects where I set the iris on the lens.

Just like film, you can change it all in the grade later. But i still don't think it's correct to say the ISO is advice.

jb
 
However if the the DP is basing the exposure decisions he's making on the viewfinder image or the in camera meters he will choose differently depending on the ISO. Therefore it's important to understand that while the chosen ISO may not affect gain directly it may indeed have an effect on the final image in so much as the exposure (iris setting) once chosen cannot be undone.

Edit: John beat me to it.
 
Evin Grant said:
However if the the DP is basing the exposure decisions he's making on the viewfinder image or the in camera meters he will choose differently depending on the ISO.

.
Click to expand...

Once again i think this is a major trap. because the viewfinder exposure assistance, be it histo's or zebra's etc is based on what the ISO is. So you have *exposed* for that ISO even if you don't use the light meter way of exposing.

JB
 
I don't have my RED yet but by playing with other people's footage in REDCINE I came upon an observation. It appears that if you want to reduce noise- its better to reduce the ISO to 100 and use the curves and/or exposure to bring it up than to set the ISO to something higher (ie 320 or 400). It appears in scenes prone to noise like lowlit night scenes that this results in a much cleaner image with cleaner blacks. Having said this I guess the idea would be to shoot at the ASA that best matched your lighting level and the F-Stop you wanted to shoot at and then apply this technique in post.

One further observation I had was that the ISO levels of the camera don't seem to carry many of the other properties they might in film. For instance, I've noted that faster stocks tend to have a little less contrast and be a bit softer (especially in high key situations). This is probably due to the the difference between noise and grain. In film we always feel the grain a bit even if it is fully exposed. In video it appears they grain is mostly only felt when there is some lack of discernible information. Therefore if you want a fast stock feel in bright light the best option mightbe some sort of grain addition filter.

This is all a bit of conjecture so feel free to correct me.
 
You must log in or register to reply here.
Back
Top