MX 2K more noisy than 4K?

[Jon B.]

Actually the only setting I changed was the 2k from 4k, both at 16:9. Same iso, same shutter. You described it correctly by saying 'cut out' of the sensor. At least that's what I expected. It seems to be processing differently for lack of better terminology on my part.

This is precisely what I did: exported the 4k and 2k tif of the same shot and cut out by zooming into 4k to match the 2k.

Getting some more examples under tungsten now. Will post compressed tifs later to get them on the site.

 

[David Battistella]

Jon,

A 2K cutout of material captured at 4K may ot macth well because you are using so much more resolution and the full resolving power of the sensor in 4K.

In 2K you are always compromised. I think Mike described it will in the 35mm and 16mm comparision. 16mm just will never be as sharp and has a different grain and noise characteristic.

My general rule is to shoot 3K at 48fps for slomo as going to 2K past about 72 can be very noisy unless you are outside or in some daylight condition.

I also highly reccomend "neatvideo" to clean up the shots. You will be amazed and what it can accomplish on grain.

David

 

[Uli Plank]

If you shoot 4K and scale down to 2K with any good scaling algorithm, there will be interpolation of neighbouring pixels. That is reducing noise as a side effect.

 

[Jon B.]

Here is the example,

I recorded a 4K shot, stopped recording, reconfigured to 2K and recorded again.

Afterward, brought the footage into rcx and exported both snapshots to tifs full res. Opened in preview and cropped the 4K to the 2048x1152 2K frame. I then exported both the original 2K tif and 4K cropped (2048x1152) tif to compressed jpegs to attach here.

This is the difference I was talking about between the cropped 4K and 2K... pretty significant in my opinion.

Now, this is my first shoot with my MX sensor outside of testing at home. My question is not what the best way to shoot 2K etc.. I wanted to know if anyone else has seen this on their MX sensors. I feel this is something wrong...

 

[Jon B.]

If you shoot 4K and scale down to 2K with any good scaling algorithm, there will be interpolation of neighbouring pixels. That is reducing noise as a side effect.

the r3d's look this way.

 

[Panos Bournias]

Here is the example,



This is the difference I was talking about between the cropped 4K and 2K... pretty significant in my opinion.

Yes pretty significant, I will check mine to see if it behaves the same...

 

[Jon B.]

Take a look at the images in post 24,

has anyone seen this on their MX sensors between 2K and 4K? I've only had the camera back a short while and am wondering if this is just my camera?

Before I get the 'why you shootin 2K?' comments please understand this is not about me shooting 2K all the time. I WANT TO KNOW IF THERE IS SOMETHING WRONG WITH MY CAMERA. Although, shooting in 2K for speed ramping the camera should not be looking this way. I do not remember dealing with this prior to the upgrade.

I want to see if there's some info out there before contacting Red about it.

Thanks!

 

[Stefan Auer]

have you compared all the metadata of those shots?
its hard to tell exactly with the jpg artifacts, but it doesn´t look like there is more noise but just different colorsettings. with gamma settings of R 0.92 G 0.94 B 0.8 on the 2k version it looks about the same to me.

 

[Jon B.]

No different settings. This was a test shot. I shot 4k, switched to 2K without changing any settings, and even the monitor lit up blue when I did so. Actually that's how I first noticed it.

Trust me when I say that these jpegs look exactly like the full res tifs exported from redcine X, which look exactly like the r3ds.

 

[Jordi Figueras]

Just thinking out loud here. Maybe I'm wrong but I have a theory about the noise in the Blue Channel with the M sensor and the build 30.5.

That build was released when the M-X sensor hit the street. I worked with it in a M-X camera and find no problem with the image, anyway, when in my (still) M sensor R1 the noise in the blue channel was huge. Then it hit me that the only people in he forum talking about that issue were people without the M-X sensor, so I think that the M-X sensor is far more better in it's blue channel. Hence the less noisy images you can get up 'till 1600 iso, so the 30.5 build was tried over the M-X sensor, so not having problems with the Blue Channel... but people with the M sensor got weird Blue Channel noise and RED helped us with an enhanced blue channel in build 30.6.

Don't know if this makes any sense to the rest of you, but maybe I'd try to do the test but with build 30.5, and see what happens...

Cheers!

 

[Jon B.]

Thanks for bringing this thread back up. I experienced this with my new MX sensor and build 30.6 BTW.

Went to shoot varispeed, reconfigured to 2K and the screen goes blueish. I think it's a problem with my camera. Waiting on Red to get back to me. If anyone experiences a shift in blue when changing image size please respond.

The difference is so noticeable in the thumbnails the images don't even need to be opened.

reposting...