Adobe DNG Converter misreading OLY 17/2.8 pancake?

[borrel]

Does anyone else have a problem converting ORF files taken with the 17/2.8 pancake on an E-P2 through DNG Converter 5.6.0.148 under Mac OS X 10.6.2? The ORF files are 13.4Mb large on average. When using LTM lenses on the E-P2 with an adapter, the DNG files that come out of Adobe DNG Converter are very slightly smaller - about 13.1Mb. But when the 17/2.8 pancake is mounted, DNG Converter spits out files in the 46 to 78Mb range with no JPEG thumbnails viewable in the Finder! I don't see any obvious differences in the EXIF and my version of Adobe Camera RAW is also 5.6.0.148. Example listing:

13234998 Feb 2 20:03 P2020389.ORF
13143488 Feb 2 21:07 P2020389.dng
13211503 Feb 2 20:05 P2020390.ORF
45991880 Feb 2 21:08 P2020390.dng

First image from a ZM 28/2.8 and the second from the pancake.

- Børre

 

[sper]

I shot with that lens for a while and I still can't process the files. I borrowed the camera so I don't have the Olympus software. I just have a bunch of useless RAWs. Somebody once told me that you need the Oly software because the camera corrects for distortion so much on that lens that nothing other than their proprietary software will work.

Uh...and on that note. I have RAW files I can't process because I don't have the right program. What's gonna happen in 10+ years when CR2s and NEFs are a thing of the past? I gotta start converting everything to DNG soon.

Oh hey...look...a film camera!

 

[sebastel]

the size difference (as far as i can remember) is due to the way the raw data is stored. with the 17mm lens, the ORF file stores the distortion and CA data, which leads to ACR to preprocess the three colours differently. in order to keep this process reversible, each colour is kept in a seperate part of the RAW file. so finally your DNG files will be about 3 times the size (more technically: the demosaicing can not be completed).
this should happen with all µ4/3 lens, but not with adapted ones, as no lens specific preprocessing data is known.

if someone with deeper knowlege in raw file processing would please shed a clearer light?

 

[borrel]

I really don't mind the file size if it's for a good cause. What I dislike is the absence of an embedded JPEG visible in the OS X Finder. It forces us to manage two images for every picture. One DNG and one JPEG to identify the shot.

- Børre