MX Chip Exposure Confusion

[Dominik Muench]

Hi Guys,

I know there is an innate danger that this will make me sound like a total noob but I cant figure out for the life of me what happened here. I had my first shoot with my RED after the MX upgrade and for some reason the footage in RED Alert is hopelessly overexposed.

I shot at ISO 800...had my zebras set as usual (been shooting red for the last few years so I'm used to the camera and its configuration of course) i tend to expose to the right side of the histogram a little bit but i always keep an eye on my highlights and shadows, histogram and false color meter all looked ok on the red LCD.
Anyway, when I imported the footage into red alert...on the ISO 800 setting (which was the rating I shot at) the footage is blown out pretty extreme even though it looked fine on the RED LCD while shooting.

Only when I change the ISO in RED alert from 800 to 320 I am getting a "normal" exposure even though the footage was shoot on 800.
What am I missing here ? The base rating of the MX chip is 800 right ? I m using RED alert version 21.0.0, could it be that red alert is having issues reading the metadata from my camera files ?


attached are two screenshots, one with the original settings from the camera and how red alert sees it at ISO 800 (myra1) and one corrected version after i set the footage to ISO 320 (myra2) which looks closer to normal.

Any help greatly appreciated.

 

[Jason Beckwith]

Red Alert! only works through build 21 of the camera's firmware.

Switch to Redcine-X, and all should be well.

 

[Dominik Muench]

Hi Jason,

I have the newest version of the camera firmware installed. thanks i will take the footage through redcine X and see what happens.

it wasn't really a big issue to get around it but for a minute i was seriously doubting my lighting and metering skills there lol

 

[Jason Beckwith]

Yeah, it's just that Red Alert! is pretty much dead since it only supports cameras with firmware up to 21.

Your MXed RedOne is probably firmware build 30+

Redcine-X supports cameras with build 30.x.x, which is probably what's on your camera.

There have been advances in color science that you will be able to take advantage of with Redcine-X, as well.

Once you spend a little time in it, the look of your footage will drastically improve.

Try some older clips with earlier firmware builds in Redcine-X, and you'll be surprised to get a little more usable latitude out of older footage.

Happy shooting!

 

[Dominik Muench]

wicked, thanks for clearing that up

 

[Shane Betts]

Interesting. Stuff I've seen like this was as green as heck too. Redcine X is the G.O.

 

[Dominik Muench]

yes I set the white balance on these manually, still not perfect but you're right, the original footage has a crazy green color cast to it.

 

[Dominik Muench]

here is another still from that shoot exported from red alert uncorrected...as you can see...very green

 

[Dan Hudgins]

OLPF IR cut

OLPF IR cut

I think the M-X sensor board used a different OLPF filter so the IR cut is not the same, the IR filter can have a greenish cast, and when you change OLPF+IR cut filters you need to re-balance all the EI/ISO, K value, and white balance for the camera, which would seem to relate to the build numbers.

The software used needs to know the color bias of the sensor to get white balance, so you need to use the software build (REDINCE-X) that matches the version of the sensor board you are using (M-X).

I did a quick CC on the green version, hard to get things right from a jpg, anyway, if there mixed K light in that shot (in background)?

 

[Dominik Muench]

hmmm maybe its time to invest in an IR filter....I can hear my credit card crying already ^^

 

[D Fuller]

hmmm maybe its time to invest in an IR filter....I can hear my credit card crying already ^^

I think you'll find you need the IR filter less with the MX chip. But a white balance reference is a very valuable thing indeed.

 

[Dan Hudgins]

hmmm maybe its time to invest in an IR filter....I can hear my credit card crying already ^^

Only if you want it greener, no what I was saying is thet the M and M-X sensors OLPF's built in IR filter had somewhat different color, so the green cast does not match, so you need to use software (REDCINE-X) that matches the build number so that the software knows what the color bias of the data is to start with...

 

[Dominik Muench]

Only if you want it greener, no what I was saying is thet the M and M-X sensors OLPF's built in IR filter had somewhat different color, so the green cast does not match, so you need to use software (REDCINE-X) that matches the build number so that the software knows what the color bias of the data is to start with...

oh haha no there's more than enough green here thanks for that, i ll run the footage through redcineX instead tonight and have a look at the results. im pretty sure i tried it before but there was something that didn't quite work for me...is it possible that redcine X doesn't render sound when you are recording audio straight to camera ? I tried redcine X with my red rocket card on a pc system the other day and i could not get the audio to work.

 

[Gunleik Groven]

oh haha no there's more than enough green here thanks for that, i ll run the footage through redcineX instead tonight and have a look at the results. im pretty sure i tried it before but there was something that didn't quite work for me...is it possible that redcine X doesn't render sound when you are recording audio straight to camera ? I tried redcine X with my red rocket card on a pc system the other day and i could not get the audio to work.

If you still haven't run it through RCX (which is what it looks like), I guess that is a good plan before you start stretching your credit-cards

 

[Dominik Muench]

no i haven't yet, will give the red rocket a run for its money tonight ^^

 

[Gunleik Groven]

No Rocket needed to test this...

 

[Dominik Muench]

if i have the time tonight i might do two renders to compare, will render the same clip in cineX and in red alert and post some screenshots if anyone is interested, will be interesting to see the different results.

 

[Gunleik Groven]

The results WILL differ by a large margin.

Please post, but this is actually a known thing. It is also stated on the RED.com/support page.

I think you will enjoy your MX immensely once you start working with the material in Color (with the new plugin); CS 5, resolve, Storm, Clipfinder, RCX or any software that supports the MX sensor, the new color sciences and the new chip. You're in for a nice ride...

Cheers!

G

 

[Mark Toia]

if i have the time tonight i might do two renders to compare, will render the same clip in cineX and in red alert and post some screenshots if anyone is interested, will be interesting to see the different results.

Hey Dominik.
Drop in maybe next week, Im back in town. or give me a call.
I'll show you the light... (the fast easy way)

 

[Dominik Muench]

Hi Mark,

that would be fantastic, thanks heaps will do.