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Author Topic: Sony Compression causes artifacts - orange peel and compression  (Read 5554 times)

Zeissgeist

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I think it's worse with the A7r than the NEX7. 

Anyone else seeing this ?   

 
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NancyP

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Re: Sony Compression causes artifacts - orange peel and compression
« Reply #1 on: December 16, 2013, 07:47:28 pm »

orange peel artifact????
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Bart_van_der_Wolf

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Paul2660

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Re: Sony Compression causes artifacts - orange peel and compression
« Reply #3 on: December 16, 2013, 08:22:40 pm »

Reports by Lloyd chambers on his pay site.  Many feel it's from the lossy compression of raws.  Seems  shutter vibrations are also an issue depending shooting style and lenses.  Too bad sony didn't put image stabilization on the sensor as on the Alpha line. 

Paul Caldwell
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Paul Caldwell
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MrSmith

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Re: Sony Compression causes artifacts - orange peel and compression
« Reply #4 on: December 17, 2013, 07:01:29 am »

seems like a storm in a tea-cup with lots of spurious opinion with 800% enlargements of badly processed jpegs.
anyone with any 'expert' view? are there less tonal values at 16bit from the sony raws than from the d800?
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ErikKaffehr

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Re: Sony Compression causes artifacts - orange peel and compression
« Reply #5 on: December 19, 2013, 02:18:30 pm »

Hi,

I don't have no doubts about the artefacts but I have doubts about compression causing them.

Best regards
Erik

http://www.fredmiranda.com/forum/topic/1260544/0#12002036

Cheers,
Bart
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Erik Kaffehr
 

Fine_Art

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Re: Sony Compression causes artifacts - orange peel and compression
« Reply #6 on: December 19, 2013, 03:05:13 pm »

Orange peel is from software smoothing points into lumps. You can create it in 16 bit with no compression.
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Bart_van_der_Wolf

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Re: Sony Compression causes artifacts - orange peel and compression
« Reply #7 on: December 20, 2013, 09:35:41 am »

I don't have no doubts about the artefacts but I have doubts about compression causing them.

Hi Erik,

Just to make sure, so do I. The type of compression used is more likely to produce overly smooth results without patterns in smooth gradients.

Cheers,
Bart
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== If you do what you did, you'll get what you got. ==

MrSmith

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Re: Sony Compression causes artifacts - orange peel and compression
« Reply #8 on: December 20, 2013, 11:18:55 am »

I'm still none the wiser  ??? 
Is it raw lossy compression that causes grain/orange peel or is that just caused by un optimised processing?
Are there really less levels of information effectively making the Raws only capable of 8bit images and having steps/gaps when you process them in 16bit?
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ErikKaffehr

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Re: Sony Compression causes artifacts - orange peel and compression
« Reply #9 on: December 25, 2013, 04:14:27 pm »

Hi,

The gaps are just BS. Let's assume that we have saturation at DN (Data Number 16000). Shot noise will have a standard of deviation of 126 DN. So the value will vary between 15872 and 16128 (if I recall it right 65% of the values will fit into this interval). If we would bin eight of those 256 values in a single bin it would represent the distribution exactly.  Exactly in the sense of the quantisation error being an order of magnitude or two less than statistical variation. Using a lot of bits for large values is just meaningless. There is a proverb for it: 'Measure with micrometer, mark witch chalk and cut with ace.'

The Sony cRAW format uses another form of compression. It uses 16 or 32 pixel samples, saves minimum and maximum values and uses 7 bit coding within that interval. That coding may have problems reproducing very steep gradients.

Best regards
Erik


I'm still none the wiser  ??? 
Is it raw lossy compression that causes grain/orange peel or is that just caused by un optimised processing?
Are there really less levels of information effectively making the Raws only capable of 8bit images and having steps/gaps when you process them in 16bit?
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Erik Kaffehr
 
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