PEF or DNG??

Ahh cheers for that.



With my K20D
PEF: 13.5Mb DNG:23.5MB ( roughly )

With my K10D

PEF: 8.7Mb DNG:16.5MB ( roughly )


Hmmmm - Huge disparity with the older crop of DSLRs. It seems if anything that since the K-7 the PEF isn't compressed. I would assume any compression lossless, but it does take time.

slight differences between K-5 PEF and DNG are probably due to header and containment code size rather than a difference in size due to compression method.

Must look into this.

When I get my K-5 I doubt I'll bother moving to PEF if the filesizes are pretty much the same. Wouldn't mind looking into it further though, even if it's purely for academic interest.

Hmm, thought the files were awfully large. I wonder if I should be re-compressing the DNGs on import.
If they are not compressed at all, I'd be quite disappointed in pentax again.
That is awfully wasteful, but I suppose it allows faster writes??? (of course that also depends if processor is fast enough to compress faster than writing full sized files. )
I may need to look into that wen I have some free time. That could be a good savings on disk space.

Yes, DNGs default to the "embedded" camera profile whilst PEFs default to "Adobe Standard".
This gives different results, though if you use the same camera profile you will get identical results from DNG or PEF

dave

I accidentally moved from PEF to DNG when resetting my k20... After 51 shots, I was quite surprised how my memory card was filling up.

After importing, I pushed the Pentax DNG's through Adobe DNG Converter. That reduced the images from the Pentax DNG's of around 21mb to the usual Adobe DNG's around 12 to 14mb each. The RAW compression is quite significant! I guess the K5 compresses the RAW files in the camera now since the PEF and DNG's appear similar in size.

Dick

I started off with PEF's on my K-x of 10-12MB each. Now save as DNG, no noticeable size difference

if the K-5 compressed the DNGs they would be much smaller than they currently are. i.e around 15 or 16Mb instead of the 25 to 31 amoringello states above.

I would say that if anything the K-5s PEGs aren't compressed. I wonder where's any official data on this. I'll try and have a look later

Well, I'll tell ya it is rather disappointing that Pentax does such a poor job at compressing their resulting files. Movie files are horribly large.
The DNG and PEFs appear to be compressed poorly (or perhaps not compressed).
Although honestly, they probably chinced out on the processor so saving full sized files is faster than compressing first. Although I'd argue that compressing in a good processor would alleviate some of the write time and allow longer high-speed bursts and faster recovery times. Argh!

Anyway,
Original photos
DNG: 30.6MB
PEF: 28.2MB

Imported to LR3 converted to DNG:
DNG now: 21.4MB
PEF now: 21MB

Looks like I'll be converting my old DNGs to DNGs.

I would probably use PEFs from now on except that I have a few other programs that use DNG but do not know how to handle K5 PEFs. So I'll be converting my DNGs to DNGs from here on out as well.
ARGH!!!

ARGH!! And of course LR3 will not batch convert existing DNGs to DNGs.
Makes sense but now I'm stuck being unable to reclaim that 30% of disk space!
WTF goes through Pentax's head!?!?!?
Rather upset with Adobe too, of course. They will convert on import but not after the fact. Argh!

It's all a bit annoying isn't it? - When I built my latest machine middle of last year I bought two 2TB HDDs. Mirror backups. They are both 60% full now.

I'm wondering if it's worth running a DNG to DNG conversion. I never thought of doing that in LR3. Can you just do a DNG to DNg swap in LR. i.e automatically delete the original, or is it a messy experience.

Answers my previous question.

You can convert DNG->DNG with the free Adobe_DNG_Converter with a big improvement in compression

Yeah, but I have dozens upon dozens of folders across disparate locations throughout the hierarchy.
I'd have to search out each folder by modification date of the files and process those individually.
Or just let it chug through the 60000+ photos, of which only about 10000 actually need to be re-converted. (of which many non-DNG files should NOT be modified)
I guess it simply a a lesson for me to keep in mind from this point forward.
Importing takes so darned long to begin with, I just hate to add time for redundant conversion on top of it all.
Have I said ARG! yet?


By the way... anyone have any idea why you might want to include the original RAW files within the DNG?
The comment says it is "just in case you need it later" or something to that effect.
If DNG is truly data-identical to the original RAW file, why have create a method of storing the original in addition the the DNG storage?
That tells me there is some conversion going on that makes the DNG data different and potentially degraded from the original RAW data.
Any ideas?

Thanks Dave.

I would very much doubt the data is downgraded. Any compression would be lossless.

I would never keep a 30mb DNG file AND it's more compressed 16Mbversion. point? none.

the other question I'd have on compressed DNG files ( or even compressed PEFs ), is would that add some overheard to proecsing times in Lightroom? Which isn't speedy at the best of times. Or is the WYSIWIG editing in Lightroom done on the previews it creates? Which would mean RAW compression would only affect exporting times. Which in my machine aren't too shabby

I don't mean because of compression but because of the conversion from RAW to DNG.
I cannot imagine any reason to keep both either... unless there was some modification and/or degradation that would warrant keeping the original data.

It just makes me wonder why that option is there in the first place.
Maybe just a hold-over from when it was needed to keep people happy who were afraid that DNG was going to be problematic? Perhaps it is an option like an appendix -- now something that just isn't necessary anymore and should be removed?