[wildman]

Normally I just shot in RAW.

However often I convert some of the Raw files to jpeg in PP.

I want to come as close as I can to the jpegs converted this way as to what the camera would produce if set to RAW+.

So whats the compression ratio of camera when set to highest quality jpeg setting?

Also in the manual (K20) there is the cryptic remark:
"JPEG Quality (Compression) **** (Premium) = 1/2.8"
How would you convert that to the conventional 0-100 scale used on most PP software when compressing a file?

BTW I did take test shot with camera set to RAW+. It gave me a RAW file of 23,509 KB and a JPEG of 9,532 KB. I than converted the RAW to JPEG using PP set at 100 compression ratio and it gave me a JPEG file of 9,370 KB. Does this sound about right?

I hope all this makes sense.

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Last edited by wildman; 05-19-2011 at 05:11 AM.

[Marc Sabatella]

If you're using any conversion software other than Pentax', JPEG compression is the least of the issues involved in matching the camera's rendition. Every processing engine is different. You'll see far greater differences comparing the results form two different RAW processors at the same compression setting than from one RAW processor at two different compression settings.

But yes, if you're getting about the same file sizes, then the compression levels are obvously similar. there's more to JPEG compression than a single "quality" number - good programs also provide control of other parameters of the compression. So it's possible you have a higher quality but different subsampling or whatever those other parameters are called. but in the end, does it really matter? Either you're getting a file size you like or you aren't. But you're never getting the same image.

[audiobomber]

Normally I just shot in RAW.

However often I convert some of the Raw files to jpeg in PP.

I want to come as close as I can to the jpegs converted this way as to what the camera would produce if set to RAW+.

Use Pentax Digital Camera Utility 4. Select the photo or photos you want to convert. Right click and select "Extract jpeg". The result is instantaneous and will look exactly the way Raw+ would have looked.

[Marc Sabatella]

Except at a much higher compression.

[wildman]

Ok thanks for that.

Anyone have any idea what the
"JPEG Quality (Compression) **** (Premium) = 1/2.8"
is about?

Never mind I think I got it figured out.
(1/2.8)x 23509 KB=8595 KB

9532 KB-8595 KB= 937 KB.
This difference could be accountant for by the thumbnail and the file header, EXIF data etc.

So for all practical purposes I will just set my PP conversion software at 100 and leave it at that.

[audiobomber]

Except at a much higher compression.

Holy crap, I never realized how compressed the extracted files were. I just did a test:
Raw DNG, 23.2MB
Plus JPEG (out of camera), 6.6MB
Extracted JPEG, 1.2MB
Converted DNG (Save As), 9.8MB

They all look the same on a computer screen.

[wildman]

Went a bit further.

The conversion software I have is sophisticated with many parameters to set if you want to.

Anyway had it strip out any EXIF data, thumbnails, etc etc and got a RAW file of 24509 KB down to 2676 KB converted to highest quality JPEG setting of 100.
I assume this is pretty close to a conversion of just the actual RAW data as created by the sensor with nothing much extra.

The file displays just fine. It shows me just how much bloat there is with a conventional JPEG conversion such as you get when the camera does this.

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Last edited by wildman; 05-19-2011 at 10:37 PM.

[Marc Sabatella]

Holy crap, I never realized how compressed the extracted files were. I just did a test:
Raw DNG, 23.2MB
Plus JPEG (out of camera), 6.6MB
Extracted JPEG, 1.2MB
Converted DNG (Save As), 9.8MB

They all look the same on a computer screen.

Which is one reason I was saying, the differences between RAW processing programs are *way* more significant than IQ differences due to JPEG compression. I've been using the 80% quality setting in ACDSee to render a 1200x1800 JPEG, which yields around 400-500K filesize. I can barely tell the difference between that at 100% and the original RAW file downsized to the same resolution.

[wombat2go]

It shows me just how much bloat there is with a conventional JPEG conversion such as you get when the camera does this.

Hi, wildman,
jpg file size also depends on the texture the image.
Camera jpg s of 3008 by 2000 = 6000 kPixels:
Pure foggy sky filesize was 1500 kB
Leafy tree filesize was 2700 kB
If the image is flat, the higher coefficients tend to zero even if you ask for high quality.
The Pentax exif data is only 0.01 MB (10 kB)
extract it by: >exiftool -a -u -g1 imgp0099.jpg > 0099_exif.

edit: the preview Image from camera for the above test shots is about 10 kB and the thumbnail is about 1.6 kB

[glee46]

Which is one reason I was saying, the differences between RAW processing programs are *way* more significant than IQ differences due to JPEG compression. I've been using the 80% quality setting in ACDSee to render a 1200x1800 JPEG, which yields around 400-500K filesize. I can barely tell the difference between that at 100% and the original RAW file downsized to the same resolution.

Being that RAW processing programs are more significant, which do you find better at the processing of RAW to JPEG?

I also find it interesting you use ACDSee. I loved that program years ago. Didn't know it was still good in modern photography.

My setup goes, Pentax DCU4 to convert to Tiff. Then over to PhotoPlus X4 for any major editing. Then to Picasa 3 to convert to Jpeg.

What would you recommend to OP as far as software in his case?

[wildman]

jpg file size also depends on the texture the image.

Yes I agree. I've seen this effect many times. A picture with, say, an Eagle in a clear blue sky is much smaller compressed then one sitting in a tree for instance.

However I controlled for that by using the same RAW file the camera used to generate a JPG in RAW+ and generated a JPG in PP. The difference in size between the two JPGs was significant once I got rid of all the extras even though I generated the file at the highest possible quality setting my software would allow -100.

Anyway the long and the short of it is that I'm satisfied that when the camera generates a JPG at it's highest quality setting that this is equivalent to the 100 setting on my conversion software in PP for all practical purposes. This what I was essentially asking in my original post.

[Marc Sabatella]

Being that RAW processing programs are more significant, which do you find better at the processing of RAW to JPEG?

I don't find any program "better" in terms of quality. They all produce slightly different results by default, but while one might look better to me for one picture, another might look better to me for another. As long as they give me controls to give me the results I want, I'm happy. The real differentiator isn't the quality of the output; it's the degree of control given and the ease of achieving that control.

I also find it interesting you use ACDSee. I loved that program years ago. Didn't know it was still good in modern photography.

ACDSee provides more control than some, less than others; it's more than sufficient for me and its Lighting tool is especially useful to me. Mostly, it really nails the usability well, I think. Note older versions of ACDSee don't provide RAW processing; only the Pro series from the last few years, and in particular, it's Pro 2 and later that provide the type of use model I find most natural. The current version Pro 4 really works well for me.

What would you recommend to OP as far as software in his case?

I don't have enough experience with other programs to make other recommendations.

[wildman]

ACDSee provides more control than some, less than others; it's more than sufficient for me and its Lighting tool is especially useful to me. Mostly, it really nails the usability well, I think.

I use ACDSee Pro ver 3 as well.

For me it rates very high for being intuitive to use and at the same time not being bloated with a lot of obscure technical features that I will never use and only distract from it's primary functions.

I have found nothing better for getting either raw or jpgs corrected for the basic properties of exposure, WB, color properties, tone etc.

[stormtech]

Nice to see some Acdsee users here -

I feel like the underdog as far as on the forums - like Pentax is to Canikon users.....

I'm using Pro v4 and love it - does everything I need to do and very intuitive.

Adobe is not the end-all when it comes to software!

[Marc Sabatella]

Yes, I agree that being an ACDSee user "feels" very much like being a Pentax user!

Note Pro 4 has a bug in its RAW processing for K20D only, where the WB info is not interpreted correctly when you go to make adjustments. I believe they have that under control in house, but I am not sure when they'll release a patch.