E-M5 or GH3? You tell me

Started 4 months ago | Discussions thread
Detail Man
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Re: Some Comments
In reply to texinwien, 4 months ago

texinwien wrote:

Since I've provided new images , I won't spend a whole lot of time answering your questions, but I'll hit them shortly.

Detail Man wrote:

texinwien wrote:

The E-M5 file is has noticeably finer definition than the GH3 file

This could be down to a focusing issue in the GH3 photo, but when I view at 100%, I'm unable to find any part of the GH3 photo that is as finely defined as most of the E-M5 file, and since both photos were made with the same lens at f/8.0, it may very well be that differences in fine definition are down to the cameras.

This assessment still stands. I looked at 100% magnification at both files at all stages throughout processing in RT, and the E-M5 file displayed finer detail at every step, both in fine fuzz of the model's sweater, and in the leaves of the synthetic plants. Nothing has changed about that, in my view.

OK. But the point of your posting is to show others - for them to observe the same, right ?

What does seem to have changed, slightly, are the color casts. they seem closer to one another now.

Your processed images have been re-encoded by the DPReview display system using 2x2 Chroma Sub-sampling and only a 90% Quality Factor. They may have also been down-sampled by the DPReview system (which, from my testing may be Lanczos-3) over an above any (possible) down-sampling that you may have previously performed using RAW Therapee (you must like the older version better, and not the more recently released Version 4.0.9.50 ?).

Fixed - I checked for a newer version of RT for my OS before preparing the first images, but somehow overlooked the one you mentioned. I've installed it and re-processed these.

Also, I have provided links (in both posts) to what should be the original JPEG files, hosted at PhotoBucket. Of course, the original RAW files are also available at imaging-resource.com for anyone who'd like to have a go at those

Those links do not work. After a few seconds of the web-page and a thumbnail being displayed, my browser-screen goes white, and no image is provided by the server (I am sure). Maybe they are too large (in pixel or byte size) for the Photobucket system ?

The DPReview Gallery ("Large") images are the same old 900x1200 re-encoded (and also down-sampled) images with degraded image-quality. You have to enable the downloading of "Originals" in you DPR Profile Settings if you don't want DPR to do a hack-job on the images.

Out of curiosity, which of the de-mosaicing options did you use (for both RAWs, I presume) ?

I used (both times) the default suggested by RT. The first time, that was 'amaze'. The second time, the newer version of RT suggested 'hphd'. I used the suggested default each time.

Right. I prefer AMAZE - but what is most important is that the algorithm is consistent for both.

I can see (at 700% view) that the first image displayed appears that it may well have more re-sampling artifacts than the second image displayed. Could this be related to your cropping of one of the images in order to try to disguise the differences in Field of View between the test-shots ?

Dunno, but I didn't do any cropping on the new images, nor any resizing, nor even stripping EXIF data from the files, so they should be as RAW as possible, hopefully.

Good to know. If we are able to then view them at the original pixel-size, things should be OK.

The first displayed image also had noticably lower amounts of Red relative to Green in the RGB histogram of your DPReview Gallery images provided (most prominent in the mid-tones comprising the bulk if the image-data). So (I suppose) that means that the first displayed image is the GH3 image ?

That is correct. Same order this second go-around, although the colors appear more even to me this time. Haven't measured them, however.

To make any kind of observations or resulting statements about "resolution", "definition", etc, you really should upload JPGs that have not been down-sampled at (or, if one of them has been re-sampled slightly to disguise differences in Field of View, consider that to be a source of distortions, particularly if down-sampling, as opposed to up-sampling, is performed) ...

Possible - as I mentioned above, I watched closely this time around, and my impression remains the same. The E-M5 file shows, to my eyes, a visibly and significantly finer resolution. I can't say with any certainty that this is due to either camera, of course. It could be down to error by IR or something strange happening during processing, but I do see a difference in resolution.

OK. But the point of your posting is to show others - for them to observe the same, right ?

... and enable the downloading of "Originals" from your DPReview Image Gallery (in DPReview profile Settings section).

I have linked to what should be the original files in both posts. If I could enable downloading of originals on a per-file basis in my DPReview gallery, I would, but I don't want to enable it on a global basis. I'll be happy to upload the originals elsewhere if photobucket is also doing any kind of optimization to the files. I'd like to make sure the original files are available for inspection.

It looks like the Photobucket approach has unworkable problems (of some particular sort) ...

Observations or judgements based upon DPReview display system degradations are questionable.

My judgments weren't made on that basis, but I do understand your point, and agree with it. That's why I provided links to the original files in both posts.

I was addressing the eyes of other observers only. Everybody's eyes (may) differ somewhat.

Such uploaded JPGs would likely exceed the 20 Mbyte limit (but if you use 2x2 Chroma Sub-sampling when encoding the JPGs, the file size can be brought under the 20 Mbyte limit).

The files were about 16MB, so they fit into my DPReview gallery.

But forever subject to the DPR trash-masher that re-encodes and down-samples as it stands ...

No particular investment in the outcome - but I think that the method of presentation is inadequate.

Understood - am willing to spend some time (but not an eternity) improving the method of presentation in order to make the comparison as valid as I can, within reason.

Let me know what you think...

No "dog" in this matter. Just interested in the technical aspects of presentation of results ...

Edited 4 months ago by Detail Man
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