logarithmic cineon files

[edgar_njari]

Some time ago i downloaded some scans in DPX/cineon format.

cineon files are usually in 10-bit lograrithmic format.

 

The problem is that when i open the files they looked very low in

contrast. Is this how log images look before they are converted to

linear?

 

My question would be,how to convert them to normal gamma and

contrast? I got good results just by adjusting the curves,but

this really wont get me the original contrast of the negative.

There must be a simple way to convert log data to linear data.

 

Does anyone know any program or plugin that can do this?

 

thank you.

[k_sahai]

Hi Edgar,

 

Cineon files need to have the proper lookup table applied to them in order for you to work on them. I am not sure if thyere are 3rd party plugins for photoshop 7, but I know that photoshop CS has cineon support (at least reading in) built in. After Effects does come with a cineon converter in its pro edition. (In AE, you would inport the file normally place it in a comp and apply the cineon converter from the menu Channel->Cineon Converter). Other apps that read the cineon format on PC/MAc are Apple Shake, Discreet Combustion, Pinnacle Commotion. But if you have CS you might be home free.

 

The default standard settings to go from log to linear is 95 (for black point) and 685 (for white point). However, I have worked with DPX files which had their bk/white points set differently from the standard logLin defaults.

 

 

Hope that helps.

 

k.

[edgar_njari]

I have a small program,some image viewer,and it can open .cin and .dpx files,but they are not converted,they stay low in contrast

and washed out.

 

anyway,i am not in the position to purchase some of that software

just for opening some files,but i'm more interested in what you said

about adjusting black and white levels.

Can you tell me more about that? How do i do that,and where?

I use corel photopaint,it is similar in features to photoshop,

so you can just speak in photoshop words,and i'll understand.

 

thank you

[emre]

Use <A href="http://www.filtermeister.com/">FilterMeister</a> and write your own filter after reading <a href="http://www.filtermeister.com/docs/da.pdf">section 4.3 of the manual</a> [PDF], and use the logarithm function (<a href="http://www.filtermeister.com/docs/UserGuide.pdf">pg.27</a> [PDF])