ETTR, how do you see anything on the screen?

The place for questions about shooting with Blackmagic Cameras.
  • Author
  • Message
Offline

greg fiske

  • Posts: 27
  • Joined: Wed Aug 22, 2012 5:31 am

ETTR, how do you see anything on the screen?

PostSat Feb 09, 2013 1:28 am

I'm having an issue where I'm exposing to the right on a black magic camera, but I can't see anything on the lcd screen. Is there a way to adjust the screen to compensate? Or can this only be done with an external monitor?
Offline

Darryl Gregory

  • Posts: 939
  • Joined: Sun Dec 16, 2012 2:49 am
  • Location: LA

Re: ETTR, how do you see anything on the screen?

PostSat Feb 09, 2013 1:34 am

Yes set display to video Not Film or whatever lol My camera is arriving today and I'm excited, anyway
there are some posts and I think even a video about it.

UPDATE: Here ya go
viewtopic.php?f=2&t=2233
Offline

greg fiske

  • Posts: 27
  • Joined: Wed Aug 22, 2012 5:31 am

Re: ETTR, how do you see anything on the screen?

PostSat Feb 09, 2013 1:38 am

That only corrects the image from being flat. To expose the cam properly, you need to over expose the image, and in that situation, you can't see.
Offline

Darryl Gregory

  • Posts: 939
  • Joined: Sun Dec 16, 2012 2:49 am
  • Location: LA

Re: ETTR, how do you see anything on the screen?

PostSat Feb 09, 2013 1:41 am

greg fiske wrote:That only corrects the image from being flat. To expose the cam properly, you need to over expose the image, and in that situation, you can't see.


read the link I posted.
Last edited by Darryl Gregory on Mon Feb 11, 2013 12:50 am, edited 1 time in total.
Offline

John Brawley

  • Posts: 4267
  • Joined: Tue Aug 21, 2012 7:57 am
  • Location: Los Angeles California

Re: ETTR, how do you see anything on the screen?

PostSat Feb 09, 2013 4:15 am

greg fiske wrote:I'm having an issue where I'm exposing to the right on a black magic camera, but I can't see anything on the lcd screen. Is there a way to adjust the screen to compensate? Or can this only be done with an external monitor?


When shooting RAW< you can easily set the ISO to 200 or 400 which should bring the range back into line. This won't change how the zebra's respond. (they are ISO independent)

jb
John Brawley ACS
Cinematographer
Currently - Los Angeles
Offline

CaptainHook

Blackmagic Design

  • Posts: 2054
  • Joined: Wed Aug 22, 2012 4:50 am
  • Location: Melbourne, Australia
  • Real Name: Hook

Re: ETTR, how do you see anything on the screen?

PostSat Feb 09, 2013 9:38 am

John Brawley wrote:When shooting RAW< you can easily set the ISO to 200 or 400 which should bring the range back into line. This won't change how the zebra's respond. (they are ISO independent)


Hey John, i'm curious what you do for Prores exposure? I haven't had a chance to test yet, but do you still ETTR and is it recoverable if so? I've been setting iso to 200 or 400 when testing in RAW which works well, but not sure the best method for Prores yet. Thanks! :)
**Any post by me prior to Aug 2014 was before i started working for Blackmagic**
Offline
User avatar

adamroberts

  • Posts: 4538
  • Joined: Wed Aug 22, 2012 5:27 am
  • Location: England, UK

Re: ETTR, how do you see anything on the screen?

PostSat Feb 09, 2013 12:18 pm

The incamera ProRes conversion appears to work something like this:
Takes the full 13 stops of RAW data, applies an exposure curve to the data that reflects your ISO settings and then compressed the outcome to a 10 bit ProRes file.

So if you set you zebras to clip at 100% you still get that data in the ProRes file.

So ETTR is still the way to go. Setting the ISO will help with seeing the image on screen and will retain the data in the final file.
Offline

CaptainHook

Blackmagic Design

  • Posts: 2054
  • Joined: Wed Aug 22, 2012 4:50 am
  • Location: Melbourne, Australia
  • Real Name: Hook

Re: ETTR, how do you see anything on the screen?

PostSun Feb 10, 2013 12:08 am

My understanding was that changing iso in prores will affect the dynamic range and noise depending which way from 800 you go?
**Any post by me prior to Aug 2014 was before i started working for Blackmagic**
Offline
User avatar

adamroberts

  • Posts: 4538
  • Joined: Wed Aug 22, 2012 5:27 am
  • Location: England, UK

Re: ETTR, how do you see anything on the screen?

PostSun Feb 10, 2013 9:01 am

It does affect the noise and the DR. It applies a curve to the RAW data. To lift the data from 800 to 1600 it lifts shadows and mids. That brings up the noise.

Going the other way compressed the highlights and mids toward the shadows.

Having shot the same scene in RAW and Prores and checked the files in Resolve you can see that the Prores file hold a lot of info.

Looking at the scopes in Resolve I'd say that in the Prores file you get about 10 stops of range from the original 13 RAW data.
Offline

CaptainHook

Blackmagic Design

  • Posts: 2054
  • Joined: Wed Aug 22, 2012 4:50 am
  • Location: Melbourne, Australia
  • Real Name: Hook

Re: ETTR, how do you see anything on the screen?

PostSun Feb 10, 2013 11:40 am

Yes, so with prores it seems you're better to shoot at iso800 to maintain DR since 400/200 clip at the same point, but you have to put up with potentially having the display too bright which is counter to what you said here.. ?
adamroberts wrote:So ETTR is still the way to go. Setting the ISO will help with seeing the image on screen and will retain the data in the final file.

I get that works with RAW, but it doesn't seem to be the best approach for Prores.. ?

I hope we get more viewing LUTs and even the ability to load our own for both RAW and Prores monitoring. :)
**Any post by me prior to Aug 2014 was before i started working for Blackmagic**
Offline

greg fiske

  • Posts: 27
  • Joined: Wed Aug 22, 2012 5:31 am

Re: ETTR, how do you see anything on the screen?

PostSat Feb 16, 2013 11:59 pm

John Brawley wrote:This won't change how the zebra's respond. (they are ISO independent)

jb


With my testing I did today, the zebras do respond differently (zebras set to 100%). It clips at 800 but not at 200. Should I have the zebras set to 95%. I expose for 200 iso, and see no zebras, but when I change it to 800, I see zebras??? Tells me something is changing and its not metadata?
Offline
User avatar

rick.lang

  • Posts: 17173
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: ETTR, how do you see anything on the screen?

PostSun Feb 17, 2013 5:08 am

greg fiske wrote:
John Brawley wrote:This won't change how the zebra's respond. (they are ISO independent)

jb


With my testing I did today, the zebras do respond differently (zebras set to 100%). It clips at 800 but not at 200. Should I have the zebras set to 95%. I expose for 200 iso, and see no zebras, but when I change it to 800, I see zebras??? Tells me something is changing and its not metadata?


Interesting Greg. Does this happen when you are using ProRes Film and ProRes Video settings?

When you have the ISO at 200 and have zebras at 100% and almost showing and then switch to ISO 800, do you have to close the iris 2 full stops to get back to the zebras almost showing?

Rick Lang
Sent from my iPad using Tapatalk HD
Rick Lang

Return to Cinematography

Who is online

Users browsing this forum: Digiimpact, vivoices and 96 guests