Loosing DR with lossless Comp Raw (M)

Started 2 months ago | Discussions thread
SrMi
SrMi Veteran Member • Posts: 5,778
Re: lossless is lossless

Alantkh wrote:

SrMi wrote:

Alantkh wrote:

SrMi wrote:

Alantkh wrote:

Dave Oddie wrote:

chrisfisheye wrote:

Dave Oddie wrote:

The guy who made this video does not know what he is talking about and the testing is not scientific.

The number of people making YouTube videos who clearly have no idea what lossless compression is, is quite surprising. He's another.

Well my tests confirm his results..

You can do your own tests and it will confirm that there is a problem with the hightlights in supposed "lossless" compression.

If he had not made this video I could not imaginate there was a real problem.

So many thanks to this guy for his work !!!!

Hands up for him.

And hands down for Sony (on this specific topic, I like Sony otherwise).

I am not going to do my own tests because the second you touch the camera to change the settings you risk moving it, changing the focus and the exposure can change slightly. Neither you, I nor him are capable of conducting a scientific tests. If you think what he did is rigorous scientific testing then you don’t have a background in science.

As to lossless L being worse than uncompressed there is only one way would be possible and that is the compression is not lossless. For it to be worse it must throw something away.

As Sony say it is lossless then if it is worse they are lying because I am sure they understand the term lossless when used in the context of compressing data means it does not throw anything away. Anyone with a background in computing understands this.

His testing is a series of snapshots out in the open not a controlled laboratory test but testing if there is a difference between uncompressed and lossless L in the first place shows a fundamental misunderstanding of what lossless means.

Before Sony introduced the M and S sizes they only had one lossless compressed format which was just called “lossless compressed” and no one thought it was anything other than a lossless compressed raw file in the true meaning of the term. In fact for quite a while Sony only offered uncompressed and compressed (as in lossy compressed) so there were loud cheers when lossless compressed came along. It seems to me the introduction of the M and S sizes has done nothing but confuse people who now for some reason think that lossless L (which is what lossless compressed was renamed to) is for some reason actually lossy! This is nuts. if it delivers lower quality images than uncompressed then Sony does not in fact have any lossless compression option.

You are just adding “noise” to this discussion. I agree with the op that the YouTuber did something useful unlike of your posts…. We don’t have to get everything right to contribute something useful. Nobody gets everything right….

nobody cares about loseless compressed L vs uncompressed. Most of us knows that they should be roughly the same in terms of IQ.

There is clear difference in IQ, but it may not always be visible. With only small space savings, I cannot fathom why one would shoot with lossy compression.

The huge dr change with lossless compressed M is new to me and extremely useful. It’s very rare I learn anything useful in doreview forum these days…

I meant lossless compressed vs uncompressed. I don’t think there is any diff in iq.
people shoot lossy compressed to hit 10fps not for space savings.

I also meant lossless compressed vs uncompressed.

??? I assume u have data to back that as that is against what most people are saying here. I honestly have no idea why lossless compressed L will have any difference with uncompressed assuming it is just doing zip like compression.
Sorry for misunderstanding as the very next statement in your post was about lossy compression so I thought you meant lossy compression vs uncompressed

You are right! My mind was completely absent when writing that reply. I apologize!

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