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12-01-2016, 09:14 PM   #16
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QuoteOriginally posted by clackers Quote
Alan, the RAW is the direct readings off the sensor.

The JPEG is a manipulated version with a set of assumptions including gamma, colour space and white balance.

So, the RAW numbers are the original data, the JPEG ones are derived quantities.

Honestly, that's two different concepts.

As for the histogram, I think you have a misunderstanding.

What you are seeing is not the RAW data, it's the result of the JPEG with a reduced bit count, so it is potentially misleading especially as far as clipping at either end is concerned.

Love all your work, BTW - I nearly bought a Voigtlander 58mm because of you!
My understanding is that RAW data isn't quite "straight off the sensor". If that were the case, I imagine all RAW files taken with the one camera would be of equal size. There is minimal processing done by the camera, to account for luminosity (in the case of the dominant Bayer filter array, using the "green" pixel data) and (I think) to unscramble/interpolate the colour filter. As each camera maker (even makers using the same sensor) uses their own RAW file format, I'm guessing that each does this minimal processing in a slightly different way. I tend to favour the Adobe DNG format with all my digital cameras.

I didn't buy my Voigtlander 58 because of Alan, but he did validate my purchase, albeit unbeknownst to him!

12-01-2016, 09:17 PM - 1 Like   #17
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QuoteOriginally posted by alan_smithee_photos Quote
Heh, thx!

My comment was more: they're both digital files. The data differs but in the end it's...data. Output, rendering, etc., differ. But it's 1s and 0s.
ASP, you and I are using the same 26 letters as Shakespeare, but the quality of results is quite different.

QuoteOriginally posted by alan_smithee_photos Quote
I am curious about your workflow, though, and how the in-camera stuff you use compares to what you do with RAWs in post.
The JPEG's almost irrelevant to me, Alan, because there really isn't a thing about the RAW I wouldn't hesitate to change in post. The top one is natural light inspired by some of your shots, but a vertical window rather than that horizontal strip you use often. The second is strobe and beauty dish.




Last edited by clackers; 12-01-2016 at 09:33 PM.
12-01-2016, 09:43 PM   #18
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QuoteOriginally posted by RobA_Oz Quote
My understanding is that RAW data isn't quite "straight off the sensor". If that were the case, I imagine all RAW files taken with the one camera would be of equal size.
This is controversial, Rob - to me at least, even if others go 'meh'.

I'd be happy if it was left up to the RAW developer software to do everything from the original captured data.

But my guess is every manufacturer alters the data and has some justification for it.

I would rather a camera didn't do distortion, noise reduction, sharpening, lightening the corners to offset vignetting, etc, because these are lossy procedures that restrict how much more you can do in Photoshop or whatever. m43 style lenses even have tables in them telling the camera what weaknesses the body will have to overcome.

I would rather the computer gave me optional lens profiles, rather than a camera spit out pre-cooked RAWs that are defacto JPEGs, but others will disagree.

It's hard to work out who does what, but some brands obviously do it more than others, and the Pentax lens designers have said they prefer not to go far down this modern road.
12-02-2016, 10:07 AM - 1 Like   #19
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QuoteOriginally posted by RobA_Oz Quote
My understanding is that RAW data isn't quite "straight off the sensor".
The data in RAW files are voltages as reported by the image processor. The data in image files (e.g. JPEG) are direct abstractions of pixel representation. A lot happens in between. The difference may appear to be academic, but from a programmatic perspective the difference is huge. The contents of an image file are explicit instructions on how to build an image. The contents of a RAW file are data and metadata and usually at least one preview JPEG thrown in for convenience. As for the size difference between different manufacturer's RAW files. It depends on the contents (some, such as Pentax, have multiple preview JPEG stuffed in along with the data) and how it is organized. At least one manufacturer (Sony, you know who you are) outputs compressed data in their RAW files, though that technically is a no-no.


Steve

(...I added significant additional text as an edit...sorry...)


Last edited by stevebrot; 12-02-2016 at 10:13 AM.
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