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How does lossless compression in Fuji RAF files work? (2020)

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Re: How does lossless compression in Fuji RAF files work? (2020)

#3

There are always these crazy discussions in photo forums where people are arguing that uncompressed RAW files are better than lossless compressed.

Glad to hear that audiophiles have some competition in who can invent the most pointless things to split hairs over.

The photo guys need to start taping magic rocks to their cameras to really keep up though.

Re: How does lossless compression in Fuji RAF files work? (2020)

#4

There are always these crazy discussions in photo forums where people are arguing that uncompressed RAW files are better than lossless compressed.

Those discussions I feel are fuelled by manufacturers like Sony saying [0] things like:

  Lossless compressed RAW:
  ...
  This is a popular format that occupies less space with minimal quality loss.
"minimal" "loss"? That's not "no loss", so what exactly is it?

[0] https://www.sony.co.uk/electronics/support/articles/00257081

Re: How does lossless compression in Fuji RAF files work? (2020)

#5
post #3

There are always these crazy discussions in photo forums where people are arguing that uncompressed RAW files are better than lossless compressed.

Glad to hear that audiophiles have some competition in who can invent the most pointless things to split hairs over. The photo guys need to start taping magic rocks to their cameras to really keep up though.

They weren't just rocks. They were brilliant pebbles.

https://web.archive.org/web/20150220012844/http://www.machin...

Re: How does lossless compression in Fuji RAF files work? (2020)

#7

There are always these crazy discussions in photo forums where people are arguing that uncompressed RAW files are better than lossless compressed.

It’s because manufacturers keep inventing their own formats instead of using plain DNG, and you can only figure out the difference reverse engineering the file. Even for the same manufacturer and file type, they may change encoding details between models or firmware revisions.

There are situations where they may decrease the bit depth of the final image if there’s not enough dynamic range, there are situations where even though the file is “uncompressed” the camera already does noise reduction and essentially compresses detail in the image, and so on…

Re: How does lossless compression in Fuji RAF files work? (2020)

#8
post #4

There are always these crazy discussions in photo forums where people are arguing that uncompressed RAW files are better than lossless compressed.

Those discussions I feel are fuelled by manufacturers like Sony saying [0] things like: Lossless compressed RAW: ... This is a popular format that occupies less space with minimal quality loss. "minimal" "loss"? That's not "no loss", so what exactly is it? [0] https://www.sony.co.uk/electronics/support/articles/00257081

I actually asked Sony Support about that. Their reply: "We can confirm that with Lossless compressed RAW there is a minimal quality loss. To have no impact on image quality I suggest using Uncompressed RAW files." Lossless isn't what it used to be.

Re: How does lossless compression in Fuji RAF files work? (2020)

#9
post #3

There are always these crazy discussions in photo forums where people are arguing that uncompressed RAW files are better than lossless compressed.

Glad to hear that audiophiles have some competition in who can invent the most pointless things to split hairs over. The photo guys need to start taping magic rocks to their cameras to really keep up though.

The worst part is its often in areas people improperly understand the benefits and downsides.

Biggest problem with good raw compression is you have a linear DNG, half processed essentially. Great, the file size is smaller, but now you miss data that processes like AI denoise can benefit from as the image is already debayered.

On the flip side, good compression like DNG 1.7 spec's jpeg-xl compression is borderline magic. Lossless is actually lossless. The lossy flavour is so good even at 105 megapixels in 16 bit (per color channel) I would challenge anyone to spot a noticeable difference compared to the original, a file possibly 20x it's size.

On a tangent, bits per channel is yet another part people split hairs over. 14 vs 16 has almost no difference, no the colours are not 'better' even in a full 16 bit workflow, the only real world perceivable difference is your darkest darks are more precise and under extreme editing conditions do look a little better if being raised extensibly in post. I digress 16 is bigger than 14 and yay marketing.

Looping back to compression, 14 bit raws without compression are padded to 16 bit lengths due to word sizes and file constraints. This bit throws off the less technically minded who make all sorts of assumptions about file sizes and being 'more lightweight to edit'.

Re: How does lossless compression in Fuji RAF files work? (2020)

#10
post #3

There are always these crazy discussions in photo forums where people are arguing that uncompressed RAW files are better than lossless compressed.

Glad to hear that audiophiles have some competition in who can invent the most pointless things to split hairs over. The photo guys need to start taping magic rocks to their cameras to really keep up though.

The problem is camera marketing makes it really unclear what you're actually getting. Really lossless? Does it trigger more on-body processing? Does it throw away bits to be "visually lossless"?

If you shoot a few thousand photos and then find you can't fix exposure as well as you'd hoped and the whole batch is worse, it's a pretty big disappointment, so it's smart to be risk adverse and skeptical.

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