[Prieni]

Legit question. Let's leave all of the rumours that in-camera DNG is better quality than PEF-converted-to-DNG aside (PEF Vs DNG... A Photographic Test - Digital Camera Forum), the simple and straightforward fact that PEF-to-DNG conversion is a one-way street is more than enough reason to stay well away from it - if the rumours ARE true, all the more so.

First time I came across that rumour and I have serious doubts about it being true. It's hard to believe that DNG should have not all the information in it (but that doesn't mean that it couldn't be the case). In the linked thread there are a few things that make me suspicious. "PEFs showed noticeably better AWB performance, color rendition, and noise patterns. The images from the converted PEFs appeared crisper, smoother, and over all just better looking." The AWB happens in camera, i.e. the camera is determining what the best colour temperature for the captured scene should be.
You should also keep in mind that this test was carried out with one rendering engine, namely the ACR one. I could well imagine that there are different settings for PEF and DNG's in ACR (there are different sets of colour settings you can select in SilkyPix, the raw converter I use). So these settings in the converter could make a difference in rendered colours.

Think it over: as long as I have PEFs and as long as there will be converters that either convert it to DNG or directly to a real image format like TIFF, PNG or JPEG, I will always be able to benefit from better conversion routines, improved demosaicing algorithms etc. Once I either shoot in-camera DNG or convert my PEFs to DNG, there's no going back. There is not now and will never be a program that converts DNG to PEF.

Isn't the above, all by itself, enough reason to stick with PEF? To me, it is, even more so if one reads the quality tests (pixel-peeping level) that show converted DNG's to be inferior to PEF.

The one-way conversion argument only holds true when information is lost during conversion.
And as you mention open source conversion routines from PEF to DNG I'm pretty sure that you could write a converter in the other direction. This open source also should be the proper place to find out if any information is lost in the conversion. If that could be shown then I would be switching to PEF without any hesitation.

Prieni

[newmikey]

First time I came across that rumour and I have serious doubts about it being true.

So have I, so have I, but they are doubts not certainty.

The one-way conversion argument only holds true when information is lost during conversion.
And as you mention open source conversion routines from PEF to DNG I'm pretty sure that you could write a converter in the other direction. This open source also should be the proper place to find out if any information is lost in the conversion. If that could be shown then I would be switching to PEF without any hesitation.
Prieni

Prieni, that's the strongest argument to date. Usually there are opensource efforts to solve file-conversion issues in abundance, yet here there are none. Now to be honest, that is probably more Pentax's fault than Adobe - they simply do not release the exact file specifications - bit by bloody bit. I do not doubt for one moment that the raw data is all there - Adobe would suffer a crippling blow if it would ever become known they messed with thàt. I am more worried about the little tweaks and bits of info that are added to the raw sensor data in order for a converter to interpret the file correctly.

If what you say is true, there still needs to be an advantage to DNG over PEF for anyone wanting to convert - what is that advantage? If the files are entirely equal, why convert in the first place? That's what I'm having trouble to understand. Looking back at what happened to PDF, is that so hard to understand? Yes, you have a gazillion of programs that can generate PDF's or convert office files to PDF but is there one single application not owned by Adobe that can do the reverse reliably?

An open standard is an open standard all ways around - the standard should guarantee hassle-free conversion both ways and not be owned by any one company. Is PEF an open standard? No, of course not, but it contains every single bit of information the camera engineers stuffed into the firmware and the sensor electronics. I'll be damned if I were to dump that in favor of a format that doesn't improve things one bit.

I'm not an evangelical though, whoever wants to shoot DNG should be entirely free to do so and be happy. The tone in these forums has changed a bit from that in that DNG is actually touted as an improvement on PEF. It simply is not and people should not be talked into believing it is any better just because the image editing and raw conversion software they use comes from the same company that set the DNG standard. It creates causality where there is none.

[Philoslothical]

The tone in these forums has changed a bit from that in that DNG is actually touted as an improvement on PEF.

DNG is supported by far more software, that IS an advantage. DNG shot with a current Pentax camera can be edited in software that existed before the camera - no waiting for Adobe to push out an update from the camera maker when a new camera is released, no selecting the ACR version required to support the camera you have - like you encounter with canikon formats.

To most people deciding which to shoot in the first place, these are reasons to shoot DNG over PEF. For you, already stuck in a proprietary format - which is EXACTLY what camera makers want - there probably is zero benefit to converting your collection. That doesn't mean it wouldn't be advantageous to switch for future work. But hey, nobody is telling you to do that either.

You came into this thread claiming DNG had disadvantages and throwing around strawmen about DRM. It simply isn't true. The image data between the two formats is equivalent, and given the choice between a widely supported open format, and a (let's be realistic, this is Pentax we're talking about) niche proprietary format like PEF, it's a no brainer which to select.

Now to be honest, that is probably more Pentax's fault than Adobe - they simply do not release the exact file specifications - bit by bloody bit.

And that right there, in your own words, is why PEF is the wrong choice. It is proprietary, software developers don't have access to the spec. Pentax can do with it what Nikon does with NEF, and add proprietary features crap that only works in their closed source software. That's a lot closer to DRM right there (although still not an exact analogy).

[Prieni]

Funnily enought, the first time that I used the DNG conversion was when my K20D files would not be converted by ACR anymore (since I'm still running the Photoshop CS, yes, the one without any number). It was either buying the expensive Photoshop upgrade or to go via the (free) DNG converter. The Adobe converter helped me to avoid the expensive Adobe Photoshop upgrade...

And this is an undeniable advantage of DNG, it works even with software that existed before the camera was even on the drawing board. I have moved away from the Adobe ACR converter meanwhile, but with the K5 DNG's that route would still be open to me. So to some people that is the distinct advantage.
Also Google's Picasa, which I use as a browser for my shots, does support DNG but doesn't support the K5 PEF's. That is an advantage that swings my preference to DNG rather than PEF.
The more widespread DNG becomes the more likely it is that software that I might use in ten years time will support DNG. But, of course, that is not an argument to use DNG right now, as long as you have a converter safely stowed away.

On balance for me DNG has more advantages than PEF and that's why I use it. Simple.

Prieni

[raider]

Oh, OK. That does it then. End of discussion. Let me get this straight though: so because 1) you said it and 2)the K-01 shoots only DNG I should stop shooting PEF with my K20D/K-5?

No need to get agitated. It is just my opinion for the Op. Like others have pointed out, DNG is more widely supported by other software. Also, the fact that the K-01 now only supports DNG could mean that Pentax feels that DNG would be their preferred format for the new upcoming DSLRs (of course i dont have proofs for this). If one prefers to shoot in PEF, please go ahead. I am just offering my 2 cents here. No need to get offended.

[Anvh]

Most if not all of the RAW formats are based on TIFF/EP, DNG is based so heavily on this that you can make DNG compatable with TIFF/EP.
Anyway since most RAW files are based on the same formatt the didffernces between eachother is probably smaller then you think

So yes i can see Pentax going to support only DNG since it has the most benefits for his users and it's a bit pointless to also have PEF when the quality of both is just as good.

[myrdinn]

I shoot in PEF as that gives smaller files than when I whoot in DNG. But as soon as the pics are transferred to my computer, I convert them to DNG as that gives smaller flies (smaller than the PEF's, and much smaller than the in-camera DNG's). I do that by using the DNG converter from Adobe.

But by doing that I see the new created DNG's are less sharp than the original PEF's. How is that possible? I see two possible reasons. 1: By convertering the PEF's tot DNG's we loose some information. 2: There is nothing to worry as even RAW photo's show a preliminary final editing, comparable to the editing that is done on the jpg's on my camera (with an adoption of the sharpness, contrast, white balance etc.). The only difference between the RAW's and the JPG's is that with the RAW's we can reverse and change the adaptatations, while in JPG we cannot - at least not without losing quality. When I convert the PEF's to DNG, I'm just loosing this additional and preliminary adaptations.

Does anybody know which of the two possibilities is right?

[Prieni]

myrdinn, how do you view the PEF and DNG to establish that the DNG is less sharp? Is that the developed images after conversion in your raw converter to, say, a 16-bit TIFF? Or are you just comparing the embedded previews?
I bet that there is no information lost in the raw data.And I guess even newmikey would agree.

Prieni

[newmikey]

myrdinn, how do you view the PEF and DNG to establish that the DNG is less sharp? Is that the developed images after conversion in your raw converter to, say, a 16-bit TIFF? Or are you just comparing the embedded previews?
I bet that there is no information lost in the raw data.And I guess even newmikey would agree.

Prieni

I think I do indeed agree Prieni. It might not be the actual raw data itself which after all adheres to the TIFF/EP standard - lossless for both formats. I've started to think there may be some hints contained besides the raw data that some raw developers read and others discard. Some raw developers might be "tuned" to DNG-type hinting, others to "PEF" hints. A bit like the kerning hints in AFP font files being misinterpreted by TTF-based layout programs and vice versa.

[Philoslothical]

I think it's more likely that the camera defaults that get passed to the editor (and applied to the raw representation you see and work with) are getting lost in the conversion process. Converting from PEF to DNG is just silly anyway. Cards and hard drives are both dirt cheap these days, and abundantly available (even despite Thailand being sunk for awhile). Worrying about cramming a few more shots on a card only to have the hassle of converting them after to save a little space on the hard drive? Seriously?

The real test is if PEF are somehow magically sharper than DNG shot in-camera, and we all know that isn't the case. Once you start playing around with converting proprietary formats, you're asking for problems.

/offtopic - curious, the forum adds an abbreviation for PEF but not DNG. Must have been overlooked, but it would be a good addition.

[Anvh]

Dng is better integrated when using lightroom and photoshop, no conversion is needed between the two. Not a plus for everyone but for my workflow it saves time and an extra file.

About the space it was quite a serious difference with the k10d so it did pay off quite a bit and we are talking about 5 years back now, my 8GB class6 card cost me more then 16GB uhs card I have now. With the current models the difference between the size is gone now but I still let lightroom convert the dng to dng, for one shoot it hardly makes a difference but for several thousands.
And we aren't talking about 1 disc or don't you backup?

[Philoslothical]

I do back things up. A 1.5 TB drive is under $100. I only have 20k raw files so far, totaling 220 GB per copy. That's about 1/6th of the capacity of one of these drives, actual space after formatting. So <$100 to store 120,000 raw files works out to what, ~0.08 cents per file? Twice that for a second copy. Right now I have enough space for a third copy, attached to a seldom used third computer. That's still only 660 GB total that is occupied by raws. Barring fire or theft, I'm in decent shape (and it's unlikely someone would walk off with all three aging towers). I intend to store an additional copy off-site eventually, but I'll probably wait until after my shooting frenzy this summer.

Buy more drives, compared to what we spend on lenses, it really is nothing.

[myrdinn]

I store my raws on two separate hard disks and on a dvd (I know I'm exagerating in making back ups but I don't want to loose them). So I try to have the files as compact as possible. But indeed on the K10 the differences in size between DNG and PEF were big, but that difference is smaller on the K5.

And yes I think I was comparing an embedded view (the PEF) with a non-embedded view (the converted DNG). But developed into a tif file I don't see any difference anymore.

So problem solved. Thanks a lot.