Broadcast G2 Dual ISO info

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

Javier Hernandez

  • Posts: 28
  • Joined: Thu Jun 19, 2014 8:02 pm

Broadcast G2 Dual ISO info

PostThu Feb 03, 2022 1:39 am

I am trying to figure out the different Iso settings since the URSA Broadcast G2 camera has only gain readout.

I assume 0db gain is the low end native. Is it 400 or 800 ISO?
Is +18 db the hi end native and is it 3200 ISO?

Also I would appreciate info regarding how to better set the exposure via waveform monitor while recording in BRAW. Many comments recommend over exposing 1.5 stops but I am in a broadcast environment and I don't know how that translates in the waveform.
Should I set the exposure as hi as posible as long as it does not reach 100% monitoring before a LUT, is a lower setting better or should I expose monitoring with the LUT. Consider that I am recording ISO for post but feeding live signals for broadcast. I do not record the lut to tape (aka SD CARD)

Thanks

J
Offline

wemrick1

  • Posts: 556
  • Joined: Sun Dec 05, 2021 12:47 pm
  • Location: United States
  • Real Name: Walter Emrick

Re: Broadcast G2 Dual ISO info

PostThu Feb 03, 2022 2:43 am

ISO 100 = -12db. ISO doubles every 6db and the highest ISO is 25600 @ 36db. Native ISO's are 400 primary and 3200 secondary. I am guessing the dynamic range distribution is similar to the BMPCC cameras. From videos I have watched it is debatable as to highest usable ISO being between 1600 and 3200 on the secondary native. 1000 ISO has been said to be iffy on the primary. Yes, 0db is at 400 ISO.

Look up the false color chart and it will show brackets in percentage of exposure for each color.
Offline

Ellory Yu

  • Posts: 3942
  • Joined: Wed Jul 30, 2014 5:25 pm

Re: Broadcast G2 Dual ISO info

PostThu Feb 03, 2022 5:49 am

Javier Hernandez wrote:Also I would appreciate info regarding how to better set the exposure via waveform monitor while recording in BRAW. Many comments recommend over exposing 1.5 stops but I am in a broadcast environment and I don't know how that translates in the waveform.

Exposing to the left (a.k.a ETTR) by 1.5 stops does not really apply to BRAW. That was more of a suggestion when recording with Prores 422 in Log (film mode).
URSA Mini Pro 4.6K G2, Blackmagic Design Pocket Cinema Camera 6K, Panasonic GH5
PC Workstation Core I7 64Gb, 2 x AMD R9 390X 8Gb, Blackmagic Design DeckLink 4K Mini Monitor, Windows 10 Pro 64-bit, Resolve Studio 18, BM Micro Panel & Speed Editor
Offline
User avatar

rick.lang

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

Re: Broadcast G2 Dual ISO info

PostThu Feb 03, 2022 12:00 pm

I’m not doing live broadcast but my understanding is that you need to properly expose the scene. Exposing to the right will make your live feed too bright. False Colour will guide you to a proper exposure.
Rick Lang
Offline

Javier Hernandez

  • Posts: 28
  • Joined: Thu Jun 19, 2014 8:02 pm

Re: Broadcast G2 Dual ISO info

PostThu Feb 03, 2022 3:49 pm

wemrick1 wrote:ISO 100 = -12db. ISO doubles every 6db and the highest ISO is 25600 @ 36db.


So:
db ISO
-12=100
-6=200
0=400
+6=800
+12=1600
+18=3200
+24=6400
+30=12800
+36=25600
Natives are 0db and +18db
Offline

Javier Hernandez

  • Posts: 28
  • Joined: Thu Jun 19, 2014 8:02 pm

Re: Broadcast G2 Dual ISO info

PostThu Feb 03, 2022 3:57 pm

Then, am I correct in assuming that (in theory) using +18db and closing my exposure should look cleaner than using +12db and opening the exposure, being 18db a native setting?
Offline
User avatar

rick.lang

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

Re: Broadcast G2 Dual ISO info

PostThu Feb 03, 2022 4:19 pm

Actually I would expect +12 (ISO 1600) to be a little cleaner than +18. The higher ISO range kicks in at ISO 1250 (on the Pocket cameras) which would be more than +9dB. ISO 3200 is the native speed of the upper range, but you can go lower. Assuming the Broadcast G2 works like the Pockets, I don’t recommend going over +18 if you can manage it. And you don’t want to go over ISO 400 either if you can avoid it. On the Pockets, ISO 1000 (in the lower range) is much noisier than 1250-3200 in the upper range.
Rick Lang
Offline

wemrick1

  • Posts: 556
  • Joined: Sun Dec 05, 2021 12:47 pm
  • Location: United States
  • Real Name: Walter Emrick

Re: Broadcast G2 Dual ISO info

PostThu Feb 03, 2022 4:25 pm

Javier Hernandez wrote:
wemrick1 wrote:ISO 100 = -12db. ISO doubles every 6db and the highest ISO is 25600 @ 36db.


So:
db ISO
-12=100
-6=200
0=400
+6=800
+12=1600
+18=3200
+24=6400
+30=12800
+36=25600
Natives are 0db and +18db


In theory yes but some reviewers are saying that 3200 is noisy. 1600 should be good. I believe the shift from primary to secondary ISO's happens between 1000 ISO and 1250 ISO.
Offline

Will Vazquez

  • Posts: 173
  • Joined: Thu Mar 30, 2017 7:40 pm

Re: Broadcast G2 Dual ISO info

PostMon May 02, 2022 7:39 pm

I want to provide some of my experience with 1600 and 3200 ISO. First time taking the Ursa Broadcast G2 out in the wild to film a dance musical theatre show. I was not sure what ISO to shoot at for this event, I've shot tons with the Pocket 6K, but never above the base native 400 ISO. So I went the day before during the tech rehearsal, and tested the different gain/settings on the new camera with the final lighting, and I'm glad I did. I wanted to keep the ISO low, but I had to shoot at least dB+12 gain (ISO 1600), for F/2.8 at 180° shutter, 29.97fps. I did tests at +12dB (1600ISO) and +18dB (3200 ISO). The higher +18 only had a tad more grain, but tons of more detail in the highlights. Because of the high contrast lighting for the dance stage, the lower +12dB resulted in blown highlights with no detail, but the +18dB was perfectly usable with nice detail in the highlights and more lifted mids. So I ended up shooting at +18dB and stopping the lens down to F/4.
Offline
User avatar

carlomacchiavello

  • Posts: 2584
  • Joined: Tue Aug 28, 2012 6:04 pm
  • Location: italy

Re: Broadcast G2 Dual ISO info

PostMon May 16, 2022 6:32 am

wemrick1 wrote:
Javier Hernandez wrote:
wemrick1 wrote:ISO 100 = -12db. ISO doubles every 6db and the highest ISO is 25600 @ 36db.


So:
db ISO
-12=100
-6=200
0=400
+6=800
+12=1600
+18=3200
+24=6400
+30=12800
+36=25600
Natives are 0db and +18db


In theory yes but some reviewers are saying that 3200 is noisy. 1600 should be good. I believe the shift from primary to secondary ISO's happens between 1000 ISO and 1250 ISO.
Some reviewer don’t know what are doing… :-P
Native iso / gain not mean miracle place where noise disappear, mean only analog gain applied. If you put 3200 iso with right light you not have noise, if you not give enough light you ever found noise, also in low light monster like Sony, disable noise reduction and you see everywhere noise.
Higher iso not mean more light mean more gain, low light mean low info, amplify low info mean you upper all info, noise for the first.
On every camera higher infos are when you cannot use / have more light, but not give you miracle. Miracle is from good denoise processor (in camera or in post). Blackmagic Design camera not have denoiser in camera (on broadcast should have it).


Inviato dal mio iPhone utilizzando Tapatalk

Return to Cinematography

Who is online

Users browsing this forum: No registered users and 83 guests