Opticallimits

Full Version: ... and at last we're going to have uncompressed RAW from Sony
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
dpreview is an excellent site... for what concerns the tests and the reviews (with the unavoidable limits). I had a terrible experience in the forums, that I definitely left. They are so full of morons that they bring out the moron in you.

 

One of the most absurd discussion was about the lossy compression of Sony RAW files. No doubts that the issue probably doesn't matter for most people, but after some clear sample photos and the technical explanations of the people at RawDigger there were still fanboys who denied the very existence of the problem.

 

Now in a few days the thing has been "officially" picked up by DP staff, and after a short time Sony officially announced that they are going to offer the option of lossy compressed/uncompressed. It seems they have some problem with the most useful thing, that is lossless compression, but this is at least a starting point.

The issue is that they have had lossless compression in the past. They decided to make it lossy, and made a big error in their algorithm, which produces rather nasty artefacts in contrasty edges (if the conditions are "right").

 

What you now will get, in for now 2 models (A7S II and A7R II) is uncompressed RAW, apparently. This will mean huge files.

Canon offers since as long as I can remember lossless compressed RAW. Nikon offers, if I am not mistaken, lossy compressed RAW without errors, uncompressed RAW, and a choice between 12 and 14 bits format.

 

That Sony is starting to offer uncompressed RAW is not because of DPReview, it was announced they (Sony) were looking into it finally when the A7R II was announced. I hope for all those different model Sony owners that they will not limit the error free RAW to these two models (maybe the older BIONZ processors have hardcoded RAW handling, lets hope not).

And I hope that they will come up with a lossless and error free compressed RAW format like Canon. It is not that hard to do it right. But yes, provided that their Bionz processors/architecture are able bypass hardcoded algorithms, 

 

To give an idea: the 50mp Canon EOS 5DS® files are around 60MB on average (detailed and less detailed images), The uncompressed 40mp Sony A7R II files are all 81.4MB.

I recall this path with Nikon a few years ago (circa D5000): they didn't offer lossless compression at a certain point, but after a few complains they did with new models. For what I recall - which might be wrong - the kind of loss was different, the kind that eventually introduces banding, not those of strange artefacts in high-contrasted areas.

 

For what I've read, it really sounds as Sony has problems in implementing lossless compression in their older BIONZ... which it's rather silly, and suggests that they deliberately went for lossy compression, clearly erroneously predicting the results and the reaction of customers.

Some Nikons offer(ed) lossless compressed 14 bits, lossless compressed 12 bits, lossy compressed 14 bits, lossy compressed 12 bits and uncompressed 12 and 14 bits. That is a bit over the top, in my opinion Wink

Sure, but unless you have to pay that with something else... better more options than less options.  Wink

Quote:Some Nikons offer(ed) lossless compressed 14 bits, lossless compressed 12 bits, lossy compressed 14 bits, lossy compressed 12 bits and uncompressed 12 and 14 bits. That is a bit over the top, in my opinion Wink
 I'm not sure of the initial reasons for Nikon's lossless compressed/compressed..12bit/14 bit options, but I may hazard a guess it was to do with sports shooting and buffer depth or at least in came in handy for a higher buffer rate. I (re)joined Nikon with the D7100 which as we know is renowned for it's paltry buffer;

 

   14 bits lossless compression 5 shots @5fps.

   12 bits compressed             9 shots  @6fps

    Crop mode 1.3                  9 shots  @7fps.

 

 

  The D750

 

    14 bits lossless compression  14 shots @6.5fps

    12 bits compressed                19 shots @ 6.5 fps.

 

  

 

 It's a shame Nikon seems to struggle to offer a generous buffer, the D7200 is a big improvement but none of these three cameras can match Pentax who  must be doing something in the way of compression with their RAW files.

  At launch the K5 could shoot 8 shots @7fps, not much later they released a firmware which gave 23 shots at 7fps. That upgrade didn't seem to affect the file quality. The K3 achieves a classy 8.3 fps for 23 shots. 

I doubt that the improvement of number of shots with the K5 has much to do with RAW file size. The K5's file size was just a bit bigger than that of the D7000 and 60D, and they could never have cut that by a factor 3. There is only so much you can save (size wise) with lossless compression.

Quote:I doubt that the improvement of number of shots with the K5 has much to do with RAW file size. The K5's file size was just a bit bigger than that of the D7000 and 60D, and they could never have cut that by a factor 3. There is only so much you can save (size wise) with lossless compression.
 The file size of the Nikon's 12 bit compressed isn't that much smaller than the 14 bit, 20Mb vs 27Mb, yet give 80% more frames. 

  Something had to have changed on the K5 however, I never did check out the file sizes because the very first thing I did was to put in the new firmware.  More to the point is that Pentax achieves 23 shots at 8.3 fps at 24Mps the same Mps as both the D7200/7100 and the D750, and they can only make it to 14 shots.

   The difference in quality  from what I can see is marginal when shooting sports/birding as images tend to be less demanding than say trying to bring up shadows in night scenes and high dynamic landscape shots. The problem with the Nikon D7100 and it's banding issues prevented you from forcing shadows too much anyway.

   Am loving the D750 and no banding!