I need your confirmation!

[Ergin Ozturk]

Hi,

I know there are lots of forum for ISO setting for highlights. I read them all But i need to check myself that if i understand it correctly..

These are the facts that learned up to now;

Fact1:
If you are in the HIGHLIGHT conditions (with black areas) these are the steps to follow;

Step 1.Stay at 320ISO if possible.Because it is safe zone for RED
Step 2.If light is too much to stay at 320ISO then close the aperture step by step(f2.8 ->5.6->8->etc) to keep histogram in proper position (not full in right)
Step 3.If your histogram still in the right side and there is no more fstop the use ND filter to cut the light going into sensor.
Step 4:In post you can increase ISO up to 800 if there is no grain in picture.

Fact2:
While shooting increasing or decreasing ISO does not effect on the light amount going into sensor. In another words picture recorded RAW in RED is not depending on the ISO setting.

Do you confirm above facts?

Thank you.

ergin

 

[Hans von Sonntag]

Hi,

Fact2:
While shooting increasing or decreasing ISO does not effect on the light amount going into sensor. In another words picture recorded RAW in RED is not depending on the ISO setting. Is that right?


Thank you.

ergin

Yes.

Hans

 

[Adrian T.]

Step 2.If light is too much to stay at 320ISO then close the aperture step by step(f2.8 ->5.6->8->etc) to keep histogram in proper position (not full in right)
Step 3.If your histogram still in the right side and there is no more fstop the use ND filter to cut the light going into sensor.

You want to use NDs first in order to stay with the same DOF. Only when you run out of NDs or (on the other end) when you don't have enough exposure you want to change the aperture.

 

[Jonathan Smiles]

As you increase amount of ND then IR pollution is more evident so use IR NDs and/or hot mirror from Tiffen etc.

 

[Joel Kaye]

Step 2.If light is too much to stay at 320ISO then close the aperture step by step(f2.8 ->5.6->8->etc) to keep histogram in proper position (not full in right)
Step 3.If your histogram still in the right side and there is no more fstop the use ND filter to cut the light going into sensor.
Step 4:In post you can increase ISO up to 800 if there is no grain in picture.

If you're matching another shot you might ND first then change aperture. Just reduce exposure until highlights are no longer clipping then stop. You really want the histogram as far right as possible without clipping.

You're not going to need to boost anything to 800 in post on a shot you had to pull back exposure to start with unless it's for a very stylized look.

 

[Dylan Macleod CSC]

Hi Erin

Yes, changing the ISO is just "metadata". But If you set your ISO to 800 the histogram will now be giving you measurements based on this new ISO.

You will get "brighter" readings in your histogram and as a result may decide to stop down. When you stop down you are affecting the amount of light getting to the sensor. Because you stopped down based on 800ISO - if you try to "pull things back" to 320 later it will be underexposed.

ISO is metadata. Stopping down the lens is not.

 

[Ergin Ozturk]

Hi,

Am i digging to much but i have another question;

I thought RED is very similar to my Nikon D300 or any other DSLR. But i think use of ISO is not the same. Because -if i am not wrong- changing ISO make an effect in final picture in DSLR. For example in low light conditions, if you do not have more iris, you can increase ISO to higher settings (like 1200, 1600 etc) to get more sensivity and light. But in RED if you do not have more iris there is nothing to do other than putting more light to scene. Am i right?

ps: but while i am writing i though: For RED i can increase the ISO in POST by using RedCine, Red Alert. So;
changing the ISO in DSLR = changing the ISO in POST for RED?
What do you think?

ergin

 

[Dj Joofa]

Hi,
you can increase ISO to higher settings (like 1200, 1600 etc) to get more sensivity and light.

Typically the sensor itself does not become more sensitive. It is the analog amplifier gain after sensor but before ADC.

changing the ISO in DSLR = changing the ISO in POST for RED?
What do you think?

Nope. Red ISO gain is digital. Many DSLRs offer analog gain. There are certain advantages with both. Ideally, both should be used, in a meaningful way. To my knowledge, Red did not offer analog gain on the sensor, and I personally consider it a design flaw. I know Red differs with this opinion, but as I said before an ideal combination is the mix of both, that is also adaptive and situation dependent. I hope Red adds analog gain to their upcoming sensors.