SLOG ISO Ratings?

[Grug]

Hi guys,


I've just been going over Abelcine's ISO ratings for the F3 natively:


-3 db. = 500 ISO
0 db = 800 ISO
+3 db = 1000 ISO
+6 db = 1600 ISO
+9 db = 2000 ISO
+12 db = 3200 ISO
+18 db = 6400 ISO


And I'm wondering if anyone has confirmed ratings for the camera in SLOG? Is it simply +1 stop to all of the ratings (I.e. 0 DB = 1600 ISO, 18 DB = 12800 ISO)?


Cheers

 

[starcentral]

http://www.dvxuser.com/V6/showthread.php?262040-Slog-iso

http://philipbloom.net/2011/07/25/slogf3/

It doubles in the camera read-out, but not in "real life" from what I gather. It's still 800ISO. 42 foot candles at f4 @ 0db gain, 24fps, 180 degree shutter or 1/48th as I had measured once upon a time and written about in my bllaaahg

 

[bill totolo]

Hi guys,


I've just been going over Abelcine's ISO ratings for the F3 natively:


-3 db. = 500 ISO
0 db = 800 ISO
+3 db = 1000 ISO
+6 db = 1600 ISO
+9 db = 2000 ISO
+12 db = 3200 ISO
+18 db = 6400 ISO


And I'm wondering if anyone has confirmed ratings for the camera in SLOG? Is it simply +1 stop to all of the ratings (I.e. 0 DB = 1600 ISO, 18 DB = 12800 ISO)?


Cheers

I'll have to review my notes but I suspect these ratings are a "best case" scenario, depending on shutter angle and gamma selected.

 

[starcentral]

For the record I never see any change in exposure between rec709, cinegammas, or SLOG via picture profile. I don't have RGB slog so can not confirm that one.

 

[nsoltz]

And nothing that I can see either with RGB SLog.

Ned

 

[Douglas Villalba]

I can see a lot of difference on the monitor specially between S Log and non S Log.

 

[starcentral]

For the record I never see any change in exposure between rec709, cinegammas, or SLOG via picture profile. I don't have RGB slog so can not confirm that one.

Sorry poor choice of wording (two days of 14 hour long days shooting really get to you).

I really meant I don't see any change in ISO when I switch between the different picture profiles. I mean to say, the camera is always 800ISO.

Does anyone actually see 1 stop change when switching to RGB SLOG? ie. your middle grey would go up around 10% or 1 stop?

 

[Douglas Villalba]

My camera switches between 800 for S Log and 400 for non S Log and you can actually see the difference on the monitor when you do.

 

[starcentral]

ok I'm going to need to test this using a grey card not my eyes.. silly me.

 

[bill totolo]

Use the camera's reflective meter on a grey scale to set your f stop. Measure where you set it for S-Log, then check Rec709 with the various gammas.
Then turn shutter ON and set to 180º.

 

[starcentral]

Yep that's what I'll do.. but I really want someone to do it with RGB SLOG, I only have SLOG via PP.

Doug?

( and my shutter is always on )