Actual RAW file size and recordable image number

[Matjazz]

I've noticed that K10D and K20D are doing some serious miscalculating when it comes to recordable image number (how much space is left on card). I've checked the manuals where estimated file size for K10D and K20D RAW is 16mb and 25mb respectively. In reality the file size is 10-11mb (K10D) and 12-13mb (K20D). I'm surprised that I can shoot 160 raw images on 2gb card which is 2 times more than recordable image number on K20D would suggest.

The counter on *Ist DS and K100Ds were quite accurate. Why is the difference on K10D so big and on K20D even bigger?

[hoghead]

My K20D raw file size is 25mb, not 12-13mb

[turbosaturn]

The file size of a raw saved in DNG is larger than that of a PEF. My guess is that when the K10d shoots in raw, it calculates the remaining shots based on a maximum possible DNG file size. Photos taken with a greater dynamic range tend to have a larger file size.

[Matjazz]

Just to be clear, DNG don't have larger dynamic range period. Acording to K20D manual PEF and DNG are equal in size - approx. 25mb.

However my K20D PEFs are 12-13mb. Here is proof.

[turbosaturn]

I was not suggesting that DNG has a higher dynamic range. What I meant about dynamic range is the amount of color information that is present in the photo. Taking a photo that is all black like leaving your lens cap on will result in a smaller file size than a photo taken of a garden on a sunny day because there's more dynamic range in the photo. Although the difference in file size between the two is roughtly about 7%.


Have you taken photos in both PEF and DNG to compare their file sizes yourself?

[Marc Sabatella]

Also, the amount of detail in the shot can affect file size, at least with JPEG. In fact, that's a moethd some people use to compare sharpness between lenses or focus settings - the sharper picture should in theory have a larger file size for the same amount of compression.

Anyhow, as to why the DS and K100D estimate remaining shots correctly: that's because they don't compress their RAW files, meaning they are always the same size. When using compressed RAW files, the camera gets very conservative and assuming it won't be able to compress much at all.

And whole an uncompressed PEF would indeed be abut the same size as an uncompressed DNG, the fact that the camera will compress PEF files where possible but will not compress DNG means that in practice, the PEF files will be much smaller.

[ryan s]

K10D in DNG = 16.x MB.

I've seen it vary from 16.1 to 16.7MB...this was also in Adobe Bridge...

[LeoTaylor]

Originally Posted by Marc Sabatella

Anyhow, as to why the DS and K100D estimate remaining shots correctly: that's because they don't compress their RAW files, meaning they are always the same size.

Not quite the same size. In fact I've used the rise in size of dark frames to indicate the thermal noise from the sensor....

I just checked a 4000+ files. My K110D RAW Astrophotos range from 9,247 KB to 11837 KB. The smallest ones are darks taken on cold nights (Telescope or lens capped). Not much compression, especially since the photos are mostly black sky.

The camera estimates 186 photos on a 2 GB memory card. That comes to 10,700 KB each which is close to my average size.

JPEG estimates are all over the range. The camera estimates 689 but I once stopped my K100D at over 900 and it had room for more. I was using Trap Focus and there was more activity at the bird feeder than expected.

[apeman]

The .PEF files out of my K100DSuper are pretty consistant at about 10MB in size each. My K20D on the other hand has files that range from 13MB to 20MB.

It looks like its the "lossless" compression of the .PEF files, but it seems to average out to around 160-169 images per 4GB CF card for me. It depends on what I am shooting, if I am shooting landscape, my images are larger as there are more colors, and things going on. If I am doing night shots, my filesizes are quite a bit smaller.

[benjikan]

My Raw DNG files are all around 23.2 MB per image. I shoot in Adobe & DNG format on my K20D. K10D's are 16.1 MB in RAW.

[Haakan]

I looked at different files from my K10D.

For me, the RAW images in DNG format were all about 16 MB, whereas the PEF format varied between 9-12 MB.

So it looks as if PEF has some lossless compression which saves space, but that the camera is conservative when calculating images and base that count on the size of the DNG format.

Best regards,
Haakan

[Matjazz]

Originally Posted by Haakan

So it looks as if PEF has some lossless compression which saves space, but that the camera is conservative when calculating images and base that count on the size of the DNG format.

So it seems. I just got a 18MB PEF. I believe it's just a matter of time when I get a 25MB PEF.

[Arpe]

I looked last time and my pefs range from 11mb to 19mb (K20D). But I can still fit way more on the card than the camera estimates.