ISO rating

[alanfocus]

Just wondering how fast Red is?
Arri D20 is slow as hell whereas Panavision Genesis is about 800 ASA (I've shot under sodium vapour street lights with +.5 gain and it worked).
So where does RED come and how much control do we have.

[Ken Corben]

Howdy,

With over 25,000 posts on reduser since January - I'd recommend the search function for basic questions.

Here's one of several posts on the topic:

http://www.reduser.net/forum/showthread.php?t=442&highlight=iso+rating

Cheers

[Chris Gearhart]

Welcome to Reduser.net, Alan! Good to have you aboard.

The asa is still an unknown, really, and somewhat affected by the amount of noise visible at lower light levels. We'll know when we start seeing field tests. I expect Steve Gibby will be doing some comprehensive testings in a few weeks, as well as others.

For now, the collected wisdom is that you should count on 320 or higher, but with the potential for fantastic signal to noise ratio at lower levels.

[Rick Darge]

spoke to Jarred yesterday and he said around 320 ISO

He also said you can gain the camera up to 1600 ISO, this will improve with an upgrade possibly..

You can get up to 800 ISO with little grain

[Chris Gearhart]

Cool, Richard. I have utmost appreciation for our troops on the ground at NAB.

Shock and Awe. Shock and awe.

[Jarred Land]

we meter at 250 right now to protect for highlights... can push it almost two stops up. bumping to 800 is no problem.

[JD Holloway]

Hi Jarred,

How does metering at 250 protect for highlights given your under-rating the chips nascent ISO (given 320ish).

Sounds to me like your "Pulling" 1/2 stop or so IMHO?

J.

[Jarred Land]

the 320 never came from me.. i think richard got that number from someone else in the booth (it was a huge amount of info flying around in there.)

and we arn't pulling, we are pushing from the lows... we can reach really deep into the shadows.

[Rick Darge]

Damnit, I'm sorry.. didn't mean to misquote.. My brain is mushy. I know I'm not crazy though, I heard that 320 # a few times around nab yesterday

[steevo435]

the 320 never came from me.. i think richard got that number from someone else in the booth (it was a huge amount of info flying around in there.)

and we arn't pulling, we are pushing from the lows... we can reach really deep into the shadows.

OK, so regard of pushing or pulling what are you guys rating the camera at? It's a simple answer really, one that doesn't require pushing or pulling. Get a spot meter rating from a grey card, compare it to what the camera sees...
what do you have?

[Dave Cooper]

I thought 640 was said on DVXUser awhile back. Maybe that was on the pre-production model?

[Blair S. Paulsen]

Quick heads up: make sure your grey card is really 18%. Testing of several professionally sourced cards varied from 12.5 to over 30!

Keep in mind that while RED has working models of the RedOne at NAB and had protos for Peter Jackson to field test a couple weeks ago the top folks at RED are clear in stating that it is still in active development. A baseline ASA/ISO rating for the RedOne is still a ballpark figure. The other piece of this that has been stressed by several members of the Red Team is that the real issue is the noise floor.

With a film stock the actual physical size of the grain structure (and some other issues too involved for this discussion) provide a basis for determining a working baseline ISO rating. With an electronic system I think the crux of the issue is noise tolerance which is inherently subjective (not even taking into account creative appropriateness issues).

One thing that will be interesting to look at in testing is whether lower signal levels will show non-linear response curves in certain colors. CCDs tend to get muddy and shift warm in low light (DSPs in the newer cameras hide this quite well). Perhaps the Bayer tech is inherently immune to light level induced color temp shifts and this issue is moot. If I run across Graeme tomorrow I'll ask him.

[JD Holloway]

the 320 never came from me.. i think richard got that number from someone else in the booth (it was a huge amount of info flying around in there.)

and we arn't pulling, we are pushing from the lows... we can reach really deep into the shadows.

OK I get the picture,

Perhaps 320 is overrated; but with the camera able to dig seriously into zones 3-2-1-.05. The test charts shot earlier seemed to reveil this possibility. The colours looked decent to even three-four stops under exposed. I was very impressed. (great job Graeme?).

Interesting...I cant tell you how much I wish I was involved in testing. I'm no engineer, but I'm pretty used to working/sorting out cameras behaviour on the fly to determine baselines. This is the daddy of all projects.

I just wish I had a better idea of how many stops of usable lattitude above grey we have to work with.

As for noise...what noise? It seems to me that this chip can be pushed to the tits and dialed back into the zone in REDCINE (in emergencies or on budgets, read..no/limited gennies on location).

[Alvise Tedesco]

we meter at 250 right now to protect for highlights... can push it almost two stops up. bumping to 800 is no problem.

Sorry for my ignorance, but that means I can easily shoot around 5.6 (RED+Nikon) where I have to fully open using my M2 adapter (DVX+M2+Nikon)?

Asking myself if Nikkors are viable alternative to expensive HD lens+B4 mount for medium to deep dof

[JD Holloway]

Alvise...

sell the M2 while its worth something...

Nikkors will look terrific and the RED is more than fast enough for you.

Your DVX is not particularly sensitive by comparison.
It has a very high "noise floor".

CIAO!

[JD Holloway]

Quick heads up: make sure your grey card is really 18%. Testing of several professionally sourced cards varied from 12.5 to over 30!

A baseline ASA/ISO rating for the RedOne is still a ballpark figure. The other piece of this that has been stressed by several members of the Red Team is that the real issue is the noise floor.

Perhaps the Bayer tech is inherently immune to light level induced color temp shifts and this issue is moot. If I run across Graeme tomorrow I'll ask him.

1) Really!? Bugger... I will check soon! (I have, like...easily a half dozen)
2) HD cameras are often talked about as having a "floating ISO base" based on "lighting situations". Frankly, I think of it as a High Key/Low Key tolerance. In Low Key digital situations, you must pay attention to highlights, you will dig into the shadows...just watch the noise floor. With film, just dont underexpose or you have grey mush.
3) early tests looks like you might be right for most colours. I'd love to talk to Graeme when I'm in Ottawa again.