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Old Dec 31, 2005, 5:56 PM   #1
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I've been frustrated recently with this camera, and I read with interest the discussion about raw and ACR blowing out highlights. I noticed the same thing a few days ago, and today I decided to see what difference I could notice between the same thing in raw and fine jpg. It's not a scientific comparison. Both photos were hand held and I used the program setting for both. The weather was very cloudy and grey (it started raining about a half hour after I took them) so there's no chance of blown out highlights.

This is the full jpg version of the picture. The only thing I did was resize it.



Here's a 100% crop of the jpg version:



Here's a crop of the raw file. I used ACR to convert it but didn't change any of the settings, then just resized it in photoshop.



One of the things I noticed was that the raw version has more noise than the jpg one does. There are no highlights here to be blown out, so it didn't do that. It does seem to interpret the white balance and color saturation differently - is that more a matter of the in-camera jpg processing that lowers noise and tones down the colors? There isn't all that much difference between the two.

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Old Dec 31, 2005, 9:32 PM   #2
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I hope FZ30 Raw is more useful than FZ20 tiff.
I don't know if these raw issues may or may not depend on the converters.

Anyway one of the most important things in raws is the possibility to recover much data which jpg compression algorithms would tend to destroy, as details in HL and especially in the shadows.

┬žSo you may do a hard shot with large dynamic range (strong lights and deep shadows) and check which amount of details you can recover in the SAME ZONE of the image (shadows) with the same amount of LEVELs in the raw and jpg images.

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Old Jan 1, 2006, 1:09 AM   #3
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http://www.kenrockwell.com/tech/raw
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Old Jan 1, 2006, 2:44 AM   #4
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The camera does some noise reduction to the JPGs, so you're right about that.

On an SLR I believe that RAW can be quite useful for recovering details lost by underexposure or overexposure, but I don't believe it to be the case with this camera. So much of the detail in the shadows is lost to noise that there's really not much to recover. From what I've seen, you can do as good a job brightening shadows on the JPGs as you can on the RAW files.

The only advantage I see with the RAW is the ability to correct white balance after shooting. This is not nearly as easy or effective to do with a JPG, but since I rarely have any difficulty achieve accurate white balance with the camera, this kind or post processing is almost never necessary.

As for the highlight problem, I only got it using Adobe Camera Raw. Using UFRaw either alone or as a Gimp plugin did not produce the same problems. While the RAW converter was able to recover some detail in the highlights, I actually was able to do the same with the JPG by isolating the individual color channels. In other words, the RAW didn't have any significant data in the highlights that wasn't in the JPG as well.
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Old Jan 1, 2006, 11:45 AM   #5
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I had previously noticed that the jpg version of a purple flower lost it's brilliant color and turned it a bluish/grey, while the raw file had captured it correctly. I'll still probably use raw format mostly.

Can you answer a beginner's question - what is GIMP and where would I find UFRaw? I've been using Photoshop for a long time and am very comfortable with it, which is why I've been comfortable with Adobe Raw Converter, so I'm clueless when it comes to other options.

Thanks!
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Old Jan 1, 2006, 12:16 PM   #6
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If you type UFRaw or Gimp into Google you'll get the links immediately.

The RAW file itself doesn't really look noticeably different than the JPG. The differences you are seeing are the changes being made by ACR. By default all the settings in ACR are set to auto, which can radically alter the original image. This can be both a good thing and a bad thing. If you take a series of pictures of the same location or scene, your pictures may start out consistently white balanced and contrasted, but ACR will likely make different determinations about how each image should be interpreted and you won't get the consistency unless you manually synchronize the settings in Adobe Bridge.

Here's your first JPG with a single levels adjustment:
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Old Jan 1, 2006, 12:18 PM   #7
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Since it was just an adjustment layer, I simply dragged it onto the other image for an identical adjustment:


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Old Jan 1, 2006, 1:10 PM   #8
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Here's a quote from the dpreview of the FZ30 RAW

http://www.dpreview.com/reviews/pana...z30/page16.asp

"As you can see from the 100% crops below the Panasonic supplied RAW converter is basically using very heavy-handed processing to mask the inherently noisy results from this new sensor. Converting using Adobe Camera Raw plug-in (using the default settings) produces an image with significantly better detail and sharpness, but one that suffers from noticeable luminance noise (certainly higher than we'd like to be seeing from an ISO 80 image - look at the red patch). By increasing the Luminance smoothing option in ACR you can remove this whilst preserving more detail than you get from either JPEG or RAW files processed using the supplied converter."

Heres some articles on RAW vs Jpegs:
http://www.toddwalker.net/articles/rawvsjpg.html
http://www.luminous-landscape.com/reviews/raw_vs_jpg.shtm l
http://www.pixelpixel.org/helpinfo/35_rawor-1.stm

Also, you may want to look at this review of the LC1 by Sean Reid at Luminous Landscapes:

http://www.luminous-landscape.com/reviews/cameras/ leica-digilux2-part2.shtml



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Old Jan 1, 2006, 3:51 PM   #9
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Thanks both Corpsy and Harjtt - the articles were very interesting. I realize that I can always adjust the jpg file in Photoshop, but haven't had as much success as I have with raw. That's why I was so surprised to see how little difference there was between these 2 pictures taken back to back. Before I had thought there was quite a bit of difference, but except for the purple flowers I took early on, perhaps there's less than I thought. I think I'll continue to shoot raw files mostly because there does seem to be more dynamic range and some colors are interpreted better.

One thing I've noticed about noise reduction in general - I had a photo that I put through Neat Image (it was a night scene shot at 200 ISO and was quite noisy). The program changed the bright reds to a duller color, so I guess it's no surprise that the camera does something similar to some colors when it converts to jpg.
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