Fine and Super Fine?

I have a 40D that I generally shoot in RAW or RAW + JPEG (fine). I also have a Powershot SX10 IS that can only shoot in JPEG.

Unlike the Adobe products I had been using more until recently where I find DPP to be better at a specific need, I noticed that DPP gives more specific info on images.

Playing around with DPP to get more familiar with it, the other day I noticed that when I opened a file from the SX10, the "image quality" showed as "Superfine". The Jpeg files from the 40D show as "Fine".

I had read on the "small compact digitals" section of POTN that the SX20 (and I guess now the newer SX30) don't have the "Superfine" setting - I never gave it much thought - some people seemed to say the SX10 has less compressed Jpegs...I don't know and I figured it was more likely just a label than a better quality (less "lossy") image.

Out of curiosity, I took two photos of identical objects without a lot of detail or color using the SX10 and the 40D both set to the highest JPEG quality available. (never really got why anyone would use a less than best setting - can always downsize afterward)

I thought that since both cameras have 10MP sensors (different size sensors, but still the image sizes would figure to be the same or very close), that if the Superfine and Fine really were different, then I'd have a larger file size with the SX10's "Superfine".

But according to DPP, the file size from the 40D was double the size - 2.5MP compared to 1.2MP. (Small for both, but again, very little detail and color).

Could it have been the lenses? I used a 300mm L prime lens on the 40D which with the crop factor gives me an effective 480mm - so I tried to get as close as I could with the SX10 which can go to an equivalent of 560mm (in full frame terms)...I also used the same ISO, shutter speed and aperture.

I was surprised that the file size from the 40D was twice the size but then thought maybe the better lens picked up more detail, but twice as much seemed unlikely.

Another thing that surprised me was the actual image sizes were different - not so much that they were different - (they were very close) but more that they seemed to be a very slight difference in the aspect ratio. The 40D file was about 150 pixels wider but the SX10 file was about 60 pixels taller

Totally confused

Any thoughts? (not that I'm concerned, just curious...Seems like an interesting result since I can't see the logic of it - I guess I should have tried some more photos - more detail, a more equivalent lens - except I don't have any for the 40D....I always knew I should have gotten at least one inexpensive plastic lens like the 18-55 but I'd expect even that to be optically far better than the lens on the SX - even though the SX does produce great looking images - but I don't think it's the optics, I think it's just magic!!!

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Thanks for any thoughts,
D.

Terms like fine and superfine are just qualitative descriptions of the quality level of the JPEG. The quality level is inversely related to the amount of compression (more compression - lower quality - smaller file). The only thing you know for sure is that a superfine level will use less compression than the fine setting - for a given camera. It's very possible that the fine setting on a 40D has less compression (higher quality) than the superfine on a compact camera.

For most cameras (especially DSLR's), even the lower quality settings result in image quality that is almost indistinguishable from the higher quality settings. Having said that, there's really no reason to save an image at a lower quality setting.

Steve-R wrote in post #11283544
Terms like fine and superfine are just qualitative descriptions of the quality level of the JPEG. The quality level is inversely related to the amount of compression (more compression - lower quality - smaller file). The only thing you know for sure is that a superfine level will use less compression than the fine setting - for a given camera. It's very possible that the fine setting on a 40D has less compression (higher quality) than the superfine on a compact camera.

For most cameras (especially DSLR's), even the lower quality settings result in image quality that is almost indistinguishable from the higher quality settings. Having said that, there's really no reason to save an image at a lower quality setting.

Yep, what you say makes perfect sense - I only really was curious because I remember (unless my memory is faulty) when I did take some "super fine" Jpegs with the SX10 when it was new and I was comparing the images to a Fuji of similar design = the file sizes were surprisingly large (the images did have a lot of detail and color - flower gardens, stuff like that).

I wouldn't have given it any thought if I had not read about the ongoing "debate" between "superfine" and "fine" on the small camera forum, and also that it's been mentioned that with CHKD, "superfine" can be attained with the SX20 (otherwise I'd have assumed there was no difference other than a label).

I STRONGLY agree that there's no reason I can think of that would justify using any camera at anything less than it's highest quality setting. Even if the image is meant for a small email. It's so fast and easy to resize and you can never get back what you didn't have in the first place. I always shoot in RAW plus (fine) JPEG - I may not do a thing to the majority of images, but there have been plenty of instances where having a RAW file of a badly exposed image made it come to life - Had a portrait like that the other day - I had just gone from inside to outside, my white balance was all wrong, my exposure was all wrong (i was too distracted to think about even looking at my settings and had the camera set to high speed so I got a half dozen images with one press of the shutter button...those picture looked beyond hope but out of 77 clicks, the very best was one of the first two or three that looked hopeless.

Peace,
D.