Visit MPB Visit MPB Visit MPB

.PEF technical information

Posted 09/05/2012 - 20:32 Link
Hello my name is Chris and I am an aspiring Visual Effects artist. I came here because I was looking for some technical information regarding the .PEF format. Specifically how the set color space (Using AdobeRGB) affects your color when saved to the RAW format. I am mainly looking at spherical and lat-long HDR images for use in 3d applications. Any advice on where to look for this info or a lead in the right direction would be nice.
Edited by cleverchris: 09/05/2012 - 20:33
ChrisA
Posted 09/05/2012 - 22:32 Link
I'm not clever, but I am called Chris, so since we have something in common I thought I'd say hi.

Hi.

By the way, what is a lat-long HDR image? I know what lat-long is, and I know what HDR is. But together, no idea.

What has lat-long got to do with exposure?
.
Pentax K-3, DA18-135, DA35 F2.4, DA17-70, DA55-300, FA28-200, A50 F1.7, A100 F4 Macro, A400 F5.6, Sigma 10-20 EXDC, 50-500 F4.5-6.3 APO DG OS Samsung flash SEF-54PZF(x2)
.
Edited by ChrisA: 09/05/2012 - 22:35
JAK
Posted 10/05/2012 - 10:31 Link
Given the technical nature of your questions, while I am not saying no one here will know the answers, that would be too presumptuous, but the nature of your questions seem to be quite technical therefore have you tried asking Pentax directly?
To most users here the .PEF format is Pentax's propriety version of .DNG and Pentax may well be bound by commercial secrets. However have you seen this page here: link which seems to cover some of your queries and maybe someone from that site maybe able to help you further? (By the way I'm not endorsing the product in that link, if anything it seems to lack support for many recent cameras.)

John
John K
Edited by JAK: 10/05/2012 - 10:42
MattMatic
Posted 11/05/2012 - 13:08 - Helpful Comment Link
Chris,
The PEF format is not in AdobeRGB
All RAW formats (not just Pentax's PEF) are in a colour space of their own - the native space of the camera.
It is the RAW convertor that specifies the target colour space of any image, and you can choose what you like!

That said, there is also an embedded JPG within the PEF RAW file. The colour rendition is dictated by the choice within the camera (e.g. Vivid, Natural, Portrait etc), and the colour space is likewise specified in the camera (either sRGB or AdobeRGB).

But, most RAW Converters (like Lightroom, Adobe Camera RAW, Silkypix etc) ignore the embedded JPG completely and work just from the RAW data.

As to which colour space to use... a general rule of thumb:

* If you don't know much about colour spaces, or are using web graphics, or are giving stuff to others - use sRGB

* If you are primarily targeting print (and especially offset litho for press work), then AdobeRGB is a good choice.

* If you are going to throw the image around a lot in Photoshop, then ProPhoto with 16-bits per pixel is a better choice.

In the latter two cases, you will always need to flatten and convert to sRGB before outputting for web or online print services.

Hope that helps a bit
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)
Posted 16/05/2012 - 01:09 Link
Thank you for the info MattMatic. While I am just getting into the techy world behind DSLR's my background in computer science and visual effects sometimes makes me lean towards more verbose questions. I am not an expert by any means.

Add Comment

To leave a comment - Log in to Pentax User or create a new account.