I'm pretty sure that ALL RAW formats use a sidecar file for metadata. I know the Canon CR2's and the Nikon NEF's and the Panasonic RW2's do...

Dick

I shoot PEF's. I import via Idimager. This program has many import options, one of which is to call Adobe DNG Converter after importing each PEF from the camera. At the same time, or shortly after I set up Idimager to copy the original PEF from the camera to a backup folder. After all this, I have ADC DNG's stored in my library, and original PEF's in my backup folder. Every month or so, I burn the original PEF's to DVD's and clean out the backup folder.

My main reason for the DNG conversion was to eliminate the need for metadata sidecar files. I tag, copyright and describe my images on import, so every PEF had to have it's own metadata (xmp) file. DNG files provide room to store that information, whereas PEF files do not. I was always concerned about a metadata file being separated somehow from the image file, and having to reenter all the metadata.

Dick

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 ran into this issue when I installed a Katzeye screen. The Katzeye focus screen was ever so slightly thicker than the standard Pentax focus screen on my k20d. As a result, I needed to adjust focusing for my manual lenses also.

Adjusting the auto focus using this method:

http://pentaxdslrs.blogspot.com/2008/06/part-1-autofocus-adjustment-for-pentax.h...

got me perfect focus with auto focus lenses. But I noticed after the auto focus system set focus, the image appeared slightly out of focus in the viewfinder screen. The split image finder of the Katzeye is most critical in displaying focus. Discussing this with Rachel at Katzeye led me to changing a shim above the viewfinder screen. Pentax shims are readily available cheaply. Now manually focusing an image displayed in the viewfinder matches exactly the focus as determined by the camera's auto focus system.

Of course, this process calibrated focus for all my manual focus lenses at the same time.

Dick

Hi Stefan,

By the term "calibrate the autofocus lens" in my reply, I meant the process of shooting a target and changing the focus settings until all manner of front focus and back focus were removed. I used Yvon Bourque's target to accomplish that.

http://pentaxdslrs.blogspot.com/2008/06/part-1-autofocus-adjustment-for-pentax.h...

Once I was satisfied that the auto focus system was focusing correctly, I noticed that the sharp focus point set by the calibrated auto focus left the image on the focus screen slightly out of focus.

I then began a new set of tests using manual focus lenses, ignoring the green hexagon and focusing using the focus screen. The Katz eye makes this very precise with it's split image focus feature. That was when it became clear that the focus screen was not properly positioned under the pentaprism - ie a smaller shim was necessary.

When using manual focus lenses, I prefer to focus on my chosen target via the split image on the focus screen. After replacing the shim, this focus point matches the green hexagon perfectly.

Hope this clears the matter up...

Dick

I'm afraid I have to disagree with your disagreement...

Focus adjustments apply small corrections to the autofocus system. A manual focus lens does not make use of the autofocus mechanism.

After installing a Katz eye and calibrating the autofocus for my autofocus lenses, I found that the correct focus point for my autofocus lenses were ever so slightly off (ie the green hexagon did not match the sharp focus point on the focus screen). In conversation with Katz eye, I was informed about focus screen shims and bought a few from Pentax. I found my Pentax k20d required a slighly smaller shim than the one that was shipped. Actually the real reason was that the Katz eye screen was slightly thicker than the standard Pentax focus screen. After changing the shim, the correct focus point as seen on the focus screen now matches exactly with the autofocus settings. And my manual focus lenses now match exactly with the appearance of the green hexagon.

Hope this helps,

Dick

This was the first place I learned about ettr, and it is still the best explanation I have encountered:

http://www.luminous-landscape.com/tutorials/expose-right.shtml

Dick

Thanks Martin!

What an interesting revelation!.

It never occurred to me that the histogram shown on the back of the camera would be affected by the settings when shooting in RAW mode. Obvious I guess, but just never thought of it.

I always shoot for ETTR in RAW mode and use the luminance histogram to warn me of clipping. But I have always noticed that the default matrix metering always shows an unexposed image on the histogram, and I tend to shoot again increasing exposure.

Clearly it's time to do some testing!

Thanks again!

Dick

Yes indeed. But the shim does not drop out with the focus screen. You have to lift a little 'tab' (don't know the correct term) to allow it to fall out. It sits between the focus screen and the pentaprism. I used a wooden toothpick to avoid scratching the pentaprism.

My Katz Eye was originally installed in a K10d, and no shim adjustment was necessary. But when I moved the screen to my k20d, and adjusting the auto focus to correct for a little front focus on my DA16-45, I noticed that the Katz Eye showed slightly out of focus after auto focusing. Since the focus tests clearly showed the auto focus was bang on, it was obvious that the focus screen had to be off.

So I ran focus tests with a 50mm 1.7 manual focus lens with a target and confirmed that using the Katz Eye prism to focus, my M50 was indeed front focusing.

I emailed Katz Eye, and they confirmed the problem. After changing the shim, and testing again, I was able to remove the manual front focus problem.

Now manual focus, and auto focus match perfectly using the center prism focus of the Katz Eye.

Dick

Hi Tim, Pete

That has not been my experience.

Rachel at Katz Eye sent me this information when I installed my screen in my k20d:

My camera had a 0.30mm installed, I found the 0.20mm did a better job in the focus tests. Now my manual focus and autofocus are exactly at the same point.

Dick