Gamma space...linear?

[Luca Immesi]

I usually use redlog or redspace but I've read this interesting article
http://www.computer-darkroom.com/d30-profiling/d30_profile.htm
and I've tried it in redalert (redcine doesn't have the linear light gamma option) with pretty good result (the grab is heavy compressed). Any thoughts?

 

[Vico Martin]

yeah! it works Luca, linear light recover lots of info in highlights and performing a logaritmic like curve fix the darks. Wish Redteam include Linear in Redcine.
Thanks a lot.

 

[Vico Martin]

...this girl´s eyes are my kind of linearlight... wow :blink:

 

[Ramesh Jai]

...this girl´s eyes are my kind of linearlight... wow :blink:

Don't know if it's her, her eyes or the fact that it's shot on RED that has my heart beating a little bit faster

 

[Luca Immesi]

...this girl´s eyes are my kind of linearlight... wow :blink:

Thanks
I'd like to know from Graeme and from some other developer of redalert if it's ok doing this or there is some downside or misconception.

 

[Peace Villow]

Hey Luca, can you make a comparison with redlog with the same shot.

Thanks.

 

[Luca Immesi]

Hey Luca, can you make a comparison with redlog with the same shot.

Thanks.

 

[Graeme Nattress]

It's fine to grade that way if you want. Set custom gamma to 1 in REDCine to linear light too.

Just don't set it to linear light, leave the image looking really dark and export 10bit DPXs - you'll loose two stops of DR.

Graeme

 

[Luca Immesi]

Just don't set it to linear light, leave the image looking really dark and export 10bit DPXs - you'll loose two stops of DR.

Graeme

Thanks Graeme for the answer but I didn't understand. Where? Redalert or Redcine?

 

[Peace Villow]

Thanks Graeme for the answer but I didn't understand. Where? Redalert or Redcine?

I think what Graeme talking about is, you can use linear light if you grade the R3D files directly in RA/RC/Scratch.
But when you use linear light then export to 10bit DPX and start grading the DPX, you will loose information in shadow area.

Right???

 

[Graeme Nattress]

Yes, right.

 

[Vico Martin]

or you can do two passes and masks, and let the colorist work a little for HDR. The recover of highs with linear is amazing. :innocent:

 

[Luca Immesi]

I see. Thanks.

 

[Antoine Fabi]

Er....well, i dont see...

Assuming you grade form a computer monitor with RA or RC, i thought the gamma space was just the first LUT conversion applied before CC...

The exported file, beeing DPX or QT contains the same info ? no ?

Why would we lose 2 stops of DR once it's been "crunched" in 10 bit file ?

Antoine

 

[Graeme Nattress]

If you apply linear light gamma and "do nothing", the max it can store is 10 stops. That means you'll notice posterization in the shadows because we have 12bits of data to begin with.

If however, you use linear light as a grade starting point, and grade from there, as long as you brighten the image up enough, you're not going to loose going to 10bits for DPX.

Graeme

 

[Antoine Fabi]

Ah!!!

OK!, if i "do nothing", then i lose 2 stops.
That...i understand.

Thanks Graeme.

Antoine

 

[Michael Cioni]

Here is another thread on the same subject.

http://reduser.net/forum/showthread.php?t=25779&highlight=log+lin&page=2

 

[Dan Hudgins]

TIF = 12bits?

TIF = 12bits?

If you apply linear light gamma and "do nothing", the max it can store is 10 stops. That means you'll notice posterization in the shadows because we have 12bits of data to begin with.

If however, you use linear light as a grade starting point, and grade from there, as long as you brighten the image up enough, you're not going to loose going to 10bits for DPX.

Graeme

If you output 48bpp TIF with gamma = 1 or linear sensor data, will a TIF frame hold all 12 camera bits? (or is the camera data always clipped to 10bits even in TIF files)

 

[Graeme Nattress]

16bit tiffs in linear light will fully contain the sensor data.

Graeme

 

[Jonas Rejman]

There it is...

The perfect digital intermediate, for apps, that do not support R3D:
16bit linear TIFF (with filetimecode).

Glad I have understood that right.

Thanks Greaeme!