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A900 ISO 320: Part II

From what I understand, it actually isn't about the amount of light, but, rather, how the ADCs respond to a bit more gain.
I understand that, what I mean is when you step back and look at the system as a whole -- a black box with dials and a lens on it -- this seems counterintuitive. :)
 

pegelli

Well-known member
Since the theory is that nothing changed in the raw processing with V2 can anyone give me some tips of how to reproduce the pink blotching in my test? Do I need to go even darker/more underexposed than -3EV or is there something else I'm missing?
 
T

Tony Beach

Guest
Since the theory is that nothing changed in the raw processing with V2 can anyone give me some tips of how to reproduce the pink blotching in my test? Do I need to go even darker/more underexposed than -3EV or is there something else I'm missing?
Replicate the same conditions that triggered it in the first place.
 

Lonnie Utah

New member
There is a difference between cRaw and plain Raw - cRaw is a lossy compression and I never use it simply because I don't want any additional processing steps in camera.
It's my understanding that sony cRaw is lossles.

Originally posted by http://support.sony-europe.com/


FAQ_47_5
Are there any differences in picture quality between cRAW and RAW?

No, there is no differences. Quality is not a problem even when compressed, but for those users who like uncompressed data, we left the uncompressed raw data support.

FAQ_48_5
What is the “cRAW (compressed RAW) format”?

The cRAW format has been developed using Sony’s unique compression technology. In that format, RAW files are compressed to 60 to 70 % of their original size, while maintaining the fine, detailed information, and rich tone information of RAW images.

FAQ_49_5
What is the benefit of using cRAW (compressed RAW)?

Since the image size is smaller, writing speed and number of images that can be recorded on memory cards will be improved.
http://www.kb.sony.com/selfservice/..._1_1&dialogID=218254316&stateId=1 0 218256768

As with any compression format, there are algorithms that can replace duplicated data without losing that data. This is what cRaw does. The trade off is processing speed in the camera to compress the files and expanding them again when opening the files. It should only really be noticeable if you are batch processing cRaw's vs Raw's.
 

pegelli

Well-known member
@ Lonnie Utah, general conclusion from these 7 pages of posts is that cRaw is lossy, but that the differences are really extremely minute. Note that Sony carefully avoids the terms lossless/lossy in their FAQ (for understandable reasons), and only talks about picture quality not being impacted.

Also realise that a cRaw file is only saved once, and doesn't have any risk of additional loss by opening and resaving (the reason to avoid repeated jpg lossy compression)
 

mazor

New member
wow, don't mind me saying, thats quite a bit of noise for iso 200 and 320 shots! Feels like it would be iso 6400 on a canon equalivalent. correct me if i am wrong of course ;)
 
Storage is cheap and I'd rather not use a lossy format until final JPEG output, besides batch processing runs quite a bit faster with RAW compared to cRAW since there is no "decompress" step. I batch process at both ends of my workflow, first when I import and render previews and then when I'm satisfied with my adjustments and export JPEG. Keep in mind that as you PP and push curves/WB/etc. around, minute differences may become less minute. :) I'm not going to criticize anyone for using cRAW if that suits their needs, it's just not for me.
 

pegelli

Well-known member
mazor, thanks for the invitation and I'll happily comply. All these pictures were heavily underexposed and then brought up with +3EV or more in the raw converter. That will make every 200 ISO picture look noisy.

Contrary to popular belief it's not ISO that sets the noise levels, but the amount of light hitting the sensor.
 
wow, don't mind me saying, thats quite a bit of noise for iso 200 and 320 shots! Feels like it would be iso 6400 on a canon equalivalent. correct me if i am wrong of course ;)
To make a fair assessment you would have to underexpose 3 stops on your Canon then push 3 stops in post. Anyway, when you consider we are looking at individual pixels from a 24MP sensor, the noise isn't a big deal at all unless you are making gigantic prints -- and even then the better color rendition makes it a worthwhile trade IMHO.
 

mazor

New member
ah, thx for clarifying that. but pushing 3 stops would make the iso 200 image essentially an iso1600 image equalivalent right?

Also based on what I see from the sample crops the iso320 shots actually seem crisper than the iso 200 shots which seem to to have a semi murky noise pattern.


mazor
 
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