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Comment by kalleboo | Hacker News Reader

ProRAW is definitely not RAW, the amount of white balance correction you can do is far more limited. It think it's closer to capturing the different HDR layers to allow the dynamic range to be tweaked more in post.

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ProRAW is just DNG with some additional metadata, and DNG can store actual raw sensor data, but Apple stores the semi-processed image after debayering and multi-exposure stacking yeah. The benefit is that it's 12-bit linear data so you get a decent amount to work with, and their automatic tonemapping is stored as metadata so it can be non-destructively tweaked or disabled in post.

Ex-Semi-Professional Photographer here...Yes, I think Apple is very misleading, if not being fraudulent, saying you can shoot in "RAW" format.

"RAW files contain uncompressed and unprocessed image data, allowing photographers to capture practically every detail they see in their viewfinder. The RAW file format stores the largest amount of detail out of any raster file type, which photographers can then edit, compress, and convert into other formats. Learn more about the benefits, drawbacks, and best ways to work with a RAW image."

If Apple is giving you JPEG-XL they are compressing the file, so it is not RAW.JPEG-XL is lossless compression.

As an ex-professional photographer , you should be very aware that RAW does not mean uncompressed or lossless.

Many professional cameras offer lossy and lossless compressed RAW, and have for over a decade now and most are processed to some degree before it’s even written.

RAW hasn’t meant literally raw in a very long time.

Even the regular lossless RAW setting can sometimes be "not quite RAW" when the camera dynamically lowers the bitrate it captures at. My camera does anywhere between 12 bits and 14 bits RAW depending on the shooting settings. Many newer cameras have baked-in NR that cannot be disabled (e.g. Canon R5), even on the lossless RAW setting

You can shoot real RAW with the iPhone hardware, just not with the system camera app. If you use something like Halide or Photon Camera, they have proper RAW options that give you a traditional noisy RAW.

“Noisy RAW”? What? It gives you a RAW file. Period. But this proves my point that Apple does not capture a RAW file, it is pretty highly processed. I want to do my editing, and I want to compress it my self if i want.

And I am talking about apple in this thread.

Apple does offer the ability to capture a lossless RAW file with raw sensor data, just not with their app. It’s exposed through their API for 3rd party apps to use. It’s harder to get a good result in low light or high contrast scenarios from a single exposure of such a small sensor, but many people prefer it to the processed ProRAW files.

The ProRAW format that the default app offers has a different use case: it combines the automatic advanced processing of multiple exposures into a file format that offers more flexibility for post processing than a standard photo does. With the new lossy compression option it gets more attractive for some users that are willing to trade in some quality for space. I don’t see the problem in offering that option next to the lossless compression.

Lossless compression is something I’m not going to argue about, as there is literally nothing lost by doing that and many professional cameras do the same thing, though with different algorithms. Well, unless your argument is that it’s not yet compatible with many photo editors, because that’s a fair point.

> If Apple is giving you JPEG-XL they are compressing the file, so it is not RAW.JPEG-XL is lossless compression.

Are you unaware that most DNG files are compressed using Lossless JPEG? Including ones that are storing raw sensor data rather than debayered data like ProRaw?

Most DNG files, not all DNG files. In the past DNG files were always raw uncompressed files.

Lossless compression shouldn't matter. That's why it's called lossless.

Lossless compression is still compressed. RAW photos are by definition not compressed. I do not care if you take out redundant bits, you are still taking them out.

"Lossless compression uses an algorithm to shrink the image without losing any IMPORTANT data." and the algorithm decides what is important.

>I do not care if you take out redundant bits, you are still taking them out.

Why does it matter? Why does that make Apple deceptive? Lossless compression is as good as no compression, the only difference is the decompression time.

You could store the uncompressed RAW file on a filesystem with built in (lossless) compression, or you could store the losslessly compressed RAW file on a filesystem with no compression. Once you have opened the image in your editor or photo viewer, the bits in that application's memory that you are editing or viewing are identical.

Moreover RAW does not mean 'uncompressed'. It doesn't even mean losslessly compressed. Often RAWs use lossy compression. Both Canon and Nikon RAWs can.

https://photographylife.com/compressed-vs-uncompressed-vs-lo...

I am confused. I assume you use camera that does not compress raw files. which vendor camera is that? Nikon compresses raws, Canon compresses raws, Sigma compresses raws, Sony compresses and processes (see "star eater") raws, most cameras process known defective pixels and subtract dark frame from long exposures before saving raw...

Is it some kind of industrial camera you are talking about maybe?

on Nikon cameras you can choose between compressed and uncompressed raw files. So I’m assuming you haven’t been around that many cameras.

https://www.dpreview.com/forums/thread/4635816

You just said yourself that raw files cannot be compressed... now you say that Nikon has your permission to compress raw files? What is the point you are trying to make?

(Also, try reading the thread you linked and reconcile it somehow with your previous claim that losless compression of raw files is unacceptable)

> RAW photos are by definition not compressed.

There is no such definition. Most cameras’ raw files nowadays are losslessly compressed. The compression being lossless means that the bits that were taken out can be reconstructed identically.

It seems you might be confused as to what lossless compression means?

No, lossless compression uses an algorithm to shrink a file without any loss. It can be restored to the same bitstream.

What you quoted is a confusing phrase: "visually lossless" which is in fact a lossy compression. It's like People's Republic which is neither a republic nor is it the People's, it's just a dictatorship.

Finally, JPEG-XL supports both lossy and lossless compression.

If you make a perfect physical copy of a picture, is it the same picture As the original?

You can not do that. It is literally impossible to make a perfect physical copy.

You can make a perfect copy of a file, however.

Have you ever zipped a file? Lossless does not mean data is lost. Lossless means data is not lost.

If it's lossless then there's zero loss and can be returned to 100% original file. However if algorithm decides what's important than it's by definition not lossless. Wouldn't be surprised to get something like that from Apple, they love to twist words into something they're not for marketing reasons. Like when they say that non-pro Iphone 15 has 2x telephoto while it does not have telephoto lens at all, it's just a digital zoom which all other phones have.

Lossless formats can compressed: take FLAC as an example.

Yeah, no, lossless compression is like zipping the file. The exact data can be reproduced by decoding.

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