ISO 250

[Aleksandr Frayman]

Hi all at us at the Russian forums the strange thought goes. Let's assume at the camera native ISO 800, the sensor can't use 250 differently badly. It is nonsense or the truth? In bad illumination I often shoot on ISO250 what problems MEANWHILE I don't notice

 

[Graeme Nattress]

All ISOs on REDs are "native" in the sense that they all share the very same dynamic range. Each ISO just distributes that dynamic range differently with higher ISOs putting more stops above mid grey (more highlight protection) and less below. Lower ISOs but more stops below mid grey (and lower noise) and less above. Picking the "best" ISO is scene dependent. We recommend ISO800 as a "good starting point" and that it is - but as every scene is different, using different ISOs is good. When you want low noise and don't need much highlight protection lower ISOs work great. When you have low light or need more highlight protection higher ISOs are great.

Graeme

 

[Shawn P]

Thank you for this answer. This helps clear up a lot of questions I had.

 

[Aleksandr Frayman]

All ISOs on REDs are "native" in the sense that they all share the very same dynamic range. Each ISO just distributes that dynamic range differently with higher ISOs putting more stops above mid grey (more highlight protection) and less below. Lower ISOs but more stops below mid grey (and lower noise) and less above. Picking the "best" ISO is scene dependent. We recommend ISO800 as a "good starting point" and that it is - but as every scene is different, using different ISOs is good. When you want low noise and don't need much highlight protection lower ISOs work great. When you have low light or need more highlight protection higher ISOs are great.

Graeme

Thanks for the reply of Graeme! I often shoot from 250 even at the fact that on 800 I see enough noise (it almost same as on my old BM Ursa mini 4.6). When I only bought the camera Epic w I made directly automatic calibration, dressed a cover on a lens and launched. I should make once again calibration or not?

 

[Les Hillis]

Phil has some pictures to help explain how the same dynamic range is re-distributed at different ISO settings -

http://artbyphil.com/phfx/red/dragon/images/phfx_redDragon_ISOFlutBreakdown.jpg

http://artbyphil.com/phfx/red/dragon/images/phfx_redDragon_ISOExamples.jpg

 

[Graeme Nattress]

Visibility of noise is almost always down to exposure. What good black calibration deals with is absolute black level and any pattern noise. If you're seeing any pattern noise then re-check the black calibration. If you want more feedback on noise, share an R3D and we can all take a look and advise accordingly.

Graeme

 

[Dan Kanes]

Rating at 250 ASA in a Dark scene that is supposed to look DARK is a great idea. Bright scenes - better rating at higher ISO to protect highlights. Hope that helps!

 

[David Battistella]

Keep an eye on the stoplights and the histogram.

David

 

[Björn Benckert]

As long as your goal posts are not raised. Its a bit like whst ever feels good... a lower iso will give you a cleaner image. Think of iso as nothing but digial gain... and how much digital gain do you have tolerance for.

 

[Marc Wielage]

Keep an eye on the stoplights and the histogram.

I think that's the best advice. I also tell my clients to avoid exposures greater than 1200. (You can push Helium a bit further.)

I don't think you necessarily have to rate the Red at 250, but I would go a little under 800 for the normal Epic/Dragon, and I also think all these cameras need more fill light than is obvious. You can always add contrast in post, but we can't grab more detail in the blacks if that area has no illumination.