Noob question on ISO and exposure on Dragon sensor

[Kenny Shem]

Hi all. I know that exposure for Red dragon is unlike other digital cam such as C300, FS7 where you can simply dial in the ISO to make the sensor more sensitive and have brighter image. Changing the ISO values on the RED touch monitor has no actual effects on the raw image as it is only metadata and is only to assist in the viewing. However I keep hearing people say that ISO can be pushed to 1600 etc for Dragon and image will still be clean. Do they mean changing the ISO value in Redcine x pro and not the camera itself?

 

[Kalechi Noel]

ISO on Red works like it does on any camera. The higher you go, the more noise you can introduce . With the dragon sensor vs MX sensors.... You can go higher in ISO values with less noise than before . So yes the image can look "cleaner at 1600"

The advantage to shooting raw with RED is that the ISO value is NOt baked in. In post (redcineX, fcpx, premiere ) you can go in and change the ISO value to suit your needs if you are not happy with the image while editing. You can also adjust things like temperature , Tint, etc while editing as well.

 

[Michael Tiemann]

Hi all. I know that exposure for Red dragon is unlike other digital cam such as C300, FS7 where you can simply dial in the ISO to make the sensor more sensitive and have brighter image. Changing the ISO values on the RED touch monitor has no actual effects on the raw image as it is only metadata and is only to assist in the viewing. However I keep hearing people say that ISO can be pushed to 1600 etc for Dragon and image will still be clean. Do they mean changing the ISO value in Redcine x pro and not the camera itself?

You can change ISO in the camera or in RCX, and both are the same. One of the biggest effects of in-camera ISO is the effect it has on you: how you meter, how you interpret what you meter. Read Phil Hollands "Field Ops Guide" available as electronic media or physical book format at the RED store. After you read that, you won't be a RED noob much longer ;-)

 

[Daniel Stilling]

It's important to know that there are only 2 things that can physically alter how much light that hits the sensor: One is lenses and attachments, like ND's and other filters and its Iris setting, and the other is shutter speed. Those are the only limiting factors for light gathering. So I't very important that you optimize these 2 factors before you start jacking the ISO up.
I have seen DP's that set the camera to ISO 800 on a night shoot and thought the image was too bright and started closing down the Iris instead of lowering the ISO. This way you starve the sensor from light and induce noise. What you really should do is to lower the ISO (as long as your stoplights are not on). Getting a correct exposure on RED cameras is not as simple as picking one number. It's a combination of factors that need constantly analysis. Sometimes it's even counter intuitive.
It's similar to landing an Airplane: As you descend, if you get too low, you can't just pull on the yoke to arrest your descent, as you will lose speed and stall. you have to add power and then pull the yoke. If you get too fast, you don't drop power, you pull the yoke back. But I digress...
Point is: understand your camera intimately to get the best results...

 

[Kenny Shem]

Thanks all for the comments and info! I've just got Phil Hollands "Field Ops Guide". Won't be a noob for long!

 

[Matthew Quinn]

also Its worth mentioning you should be adjusting your OLPF for different situations. I was using the skintone OLPF at 800-1000 ISO for 90% of my last project. I felt comfortable pushing the Low Light OLPF up to 2000 ISO. But like others have said, Check off your aperture and filters before you mess with the ISO tooo much, it can be adjusted in post

 

[Terry VerHaar]

What everyone has said about ISO is true and good information. The one thing I'd add is that your ISO setting changes where middle gray falls; how many useable stops of latitude there are above and below. Here is a good discussion on the RED site:

http://www.red.com/learn/red-101/iso-speed-revisited

As an aside, I sometimes think people forget that there is some very good and fundamental information provided by RED on their site.

 

[Alberto Guglielmi]

Daniel's right on point.
It is a bit tricky with the ISO not being fixed. A huge advantage for post, but can easily translate in a mistake that you can't reverse in post. You might end up exposing for a higher ISO and then you have noise even if in post you go back to ISO250 because the sensor did not get enough light.

Basically for me it boils down to:
Expose for the light you want using the lowest ISO you can get to. That way you are never underexposing the sensor for light and you have some latitude in post. I might adjust as I learn more and more about the camera. But for now I had no issues with it.

It's important to know that there are only 2 things that can physically alter how much light that hits the sensor: One is lenses and attachments, like ND's and other filters and its Iris setting, and the other is shutter speed. Those are the only limiting factors for light gathering. So I't very important that you optimize these 2 factors before you start jacking the ISO up.
I have seen DP's that set the camera to ISO 800 on a night shoot and thought the image was too bright and started closing down the Iris instead of lowering the ISO. This way you starve the sensor from light and induce noise. What you really should do is to lower the ISO (as long as your stoplights are not on). Getting a correct exposure on RED cameras is not as simple as picking one number. It's a combination of factors that need constantly analysis. Sometimes it's even counter intuitive.
It's similar to landing an Airplane: As you descend, if you get too low, you can't just pull on the yoke to arrest your descent, as you will lose speed and stall. you have to add power and then pull the yoke. If you get too fast, you don't drop power, you pull the yoke back. But I digress...
Point is: understand your camera intimately to get the best results...

 

[Terry VerHaar]

Key point to remember... never, EVER set exposure based on what you see on the monitor. There are so many good tools built into RED cameras that will serve you so much better.

 

[Erick Liu]

Dragons have higher S/N Ratios so should be much better