Friday, April 15, 2011

F550EXR – File Sizes — Review Part 35 ** Updated **

Bill sent an email this morning mentioning that he was getting half-sized RAF files sometimes when he shot M4:3 size, and I could swear I’ve seen that phenomenon myself.

I checked the firmware 1.10 to see what my file sizes were on the same set of shots and, well, all RAF files are 24MB, which by the way is exactly 1:1 compression with 12bit RAW.


File Size


L4:3 JPEG Fine



M4:3 JPEG Fine



L4:3 JPEG Normal



M4:3 JPEG Normal



RAF (all except SN)



RAF (SN and
sometimes P mode)



I went back and checked some of my test folders where I shot RAW+JPEG and the RAF files are 24MB as well. RAW means RAW … all data from both halves of the sensor no matter what JPEG settings are being applied. And since M4:3 is performing binning and not resizing, we should still see all the data in RAF files at that setting.

Update: In a surprise move, Fuji is binning pixels in hardware in SN mode. I.e. the RAF files are half the normal size. So shooting in SN mode in low light gives you this one very interesting advantage. It is time for a test of SN versus M4:3 in A-Prio or P mode …

Update 2: What is Fuji doing? I shot a quick test between SN and P mode DR400 and both came out at 12.4MB. WTF!!! The DR400 RAF file was far nicer in texture with finer grained noise (coming up in another article) … but how?

Note: If you shoot DR100 in M4:3 size, which does not need to bin, Fuji could have downsized the RAF files physically. I checked, it does not. And when you think about it, how would it do that? All of its interpolation algorithms are written against a demosaiced format to preserve the correct color data. The RAW format has no color data yet and without demosaicing the color info first, resizing the file would mangle it completely.

So … the universe is unfolding as it should … sort of.

A note on compression: I’ve mentioned this is the past, but I’ve seen discussions on certain web pages that compression at or below 10:1 is invisible to sharpening algorithms, which means that there are no visible artifacts at all. The file looks to our eyes essentially identical to the original if it had been saved as uncompressed TIFF.

So I am very happy to see such low compression on all of Fuji’s files. They seemed to be playing with higher compression with the F70 et al, but here we see ranges from 4:1 to 7:1 … that matches some dSLRs …

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