DNG has less detail than JPG for A4000 - page 2 - General Discussion and Assistance - CHDK Forum  

DNG has less detail than JPG for A4000

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Offline blackhole

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Re: DNG has less detail than JPG for A4000
« Reply #10 on: 15 / June / 2013, 16:14:31 »
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Re: DNG has less detail than JPG for A4000
« Reply #11 on: 15 / June / 2013, 16:15:20 »
IIRC, microfunguy has had an open challenge here for years asking anyone to post a jpg created from a RAW/DNG image that they feel is better than the JPG their camera created of the same original image.  I don't recall anybody taking him up on that.

The challenge still applies.

Generally speaking, I would say raw is not worth the effort.


Re: DNG has less detail than JPG for A4000
« Reply #12 on: 18 / June / 2013, 00:44:53 »
I've been playing around with RawTherapee, and although the new Amaze demosaicing algorithm is an improvement on the default AHD algorithm in ufraw/dcraw. I still wasn't able to get anything like the results I saw with the camera's JPG files.  The basic problem still seems to be the same: smoothing the noise also smooths out the details.  I suspect that there are more clever smoothing algorithms out there, just not in the open source projects.  Perhaps they depend on detailed knowledge of the noise characteristics, which Canon would know?  Anyway, I'm ruing deleting those JPGs and keeping the DNGs on all those pictures.

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Offline ahull

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Re: DNG has less detail than JPG for A4000
« Reply #13 on: 18 / June / 2013, 09:08:48 »
IIRC, microfunguy has had an open challenge here for years asking anyone to post a jpg created from a RAW/DNG image that they feel is better than the JPG their camera created of the same original image.  I don't recall anybody taking him up on that.

The challenge still applies.

Generally speaking, I would say raw is not worth the effort.

I can't say I have any examples from a Canon camera that would meet the challenge, but certainly from a Nikon D300 I have some. The trouble is that it takes a lot of time and effort to improve on the stock jpgs that you get from the camera, as generally speaking most cameras these days produce extremely good results, under most conditions, and furthermore, no amount of post processing will recover detail that isn't there in the first place, so to some extent I sympathise with Microfunguy's point.

The Nikon produces excellent results most of the time, but just occasionally it makes a mistake (or I do), and you end up with an image that is less sharp or colder, or has slightly less dynamic range than you could obtain, if you post-process the RAW image.

I also have a Ricoh CX-3 that goes everywhere in my pocket. It is inclined to produce images which have slightly more noise than I suspect I would get under  the same conditions with the SLR or from  a CHDK/Canon raw image.. I stick with the CX-3 because it is easy to use and built like a tank, so perfect for a life in my jacket pocket.

Like most of my cameras, I picked it up for next to nothing from ebay, and fixed it,  so it represents far less of a financial hit, if its tank like abilities are tested to destruction, than an SLR. Amongst the Ricoh's many other flaws is that it doesn't have raw, scripting abilities, and all the fun stuff that CHDK allows, so I invariably come back to CHDK and Canon's when the creative juices begin to flow.
« Last Edit: 19 / June / 2013, 12:32:21 by ahull »


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Offline PS

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Re: DNG has less detail than JPG for A4000
« Reply #14 on: 19 / June / 2013, 12:19:16 »
Concerning the challenge
People are better than algorithms at identifying artifacts, so manually you can selectively process different areas better using PC than camera's global (time and resource constrained) processing. Camera is a very limited PC with small range of adjustments to the output or imposed settings.
Any output though (in-camera / PC) is just temporary encoding for characteristics of particular display, so it's best to keep original data (raw) for encoding image to different displays.

Re: DNG has less detail than JPG for A4000
« Reply #15 on: 20 / June / 2013, 02:23:34 »
I could agree with all the logical reasons written above. But so far nobody has provided here any photos to proof that:)
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Offline ahull

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Re: DNG has less detail than JPG for A4000
« Reply #16 on: 20 / June / 2013, 05:21:57 »
I could agree with all the logical reasons written above. But so far nobody has provided here any photos to proof that:)

Define the problem and I might be up for the challenge, it it simply to improve on the .jpg produced by the camera, by starting with the raw file, or are you specifically talking about the level of detail available in the final .jpg?

What is the reward for accepting the challenge? I presume it is the usual collection of photos of fog, to be auctioned on ebay :P
« Last Edit: 20 / June / 2013, 05:24:50 by ahull »

Re: DNG has less detail than JPG for A4000
« Reply #17 on: 20 / June / 2013, 06:49:57 »

What is the reward for accepting the challenge?

A jpg allegedly "better" than the Canon and a passing of your time that takes you one step nearer to eternal oblivion  ....  that is all  :)


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Offline philmoz

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Re: DNG has less detail than JPG for A4000
« Reply #18 on: 20 / June / 2013, 07:54:28 »
I shoot RAW and have done so for many years.

For me, it's not about whether I can produce an image that is 'better' than the camera JPEG - after all who defines 'better'. It's all subjective.

My goal is to create an image according to my vision of the scene.

For me this is best achieved shooting RAW - this way I have 100% of the information that the camera captured.
If I want what the camera would have produced I can use DPP (Canon) to duplicate the camera processing.

But most of the time my vision is not that of the Canon engineers, clever as they are.

An example.

Heres an OOC JPEG taken earlier this year.


The koala was in the shade so I deliberately overexposed the image to capture the koalas details.
Notice how the sky behind is blown out top left and bottom right - to me this spoils the image because your eye is drawn to the bright areas and the koala gets lost.

Here's my rendition after processing the RAW file. Now the bright sky is no longer so distracting.


In case you're wondering the sky is not salvagable in the JPEG - any useful information is lost and can't be recovered. There's also a patch of fur on the forehead that can't be recovered in the JPEG; but contains more detail in the RAW conversion.


Here's a 100% crop of the face and eye - first the JPEG.


And the RAW conversion.


I think the RAW image allows for more detail to be extracted and it can be sharpened more without introducing haloes. As a result the final image, whether printed or on screen, has more impact.

But that's just my opinion - feel free to disagree :)

Phil.
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Re: DNG has less detail than JPG for A4000
« Reply #19 on: 20 / June / 2013, 08:19:23 »
I shoot RAW and have done so for many years.
...
But that's just my opinion - feel free to disagree :).
Nicely done - thanks for sharing!
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