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Tuesday, December 8, 2009

What JPEG quality to use?

There is a never ending debate over the RAW vs JPEG in the web. For myself, I'm very lazy and always opt for the smallest file size to give biggest wow factor, so I always opt for the JPEG basic. Sometimes I will ask myself if I'm really taking up the correct JPEG quality setting, because professional always said, if you spent few thousands to buy the gear, why sacrifice the quality by choosing the lower quality photo?

Yeah, that confused me. But still, I'm very lazy and I hate managing too many photos that take me forever to sort out. Instead of listening to them, I did some test myself. Lets see.

Photo taken with Canon A570IS at 3072x2304 (Large) JPEG Fine and file size is 2,290KB. I cropped 100% and posted it here.

Photo taken with Canon A570IS at 3072x2304 (large) JPEG Basic and file size is 505KB. I cropped 100% and posted it here.

Can you see any difference? No? There is actually a major difference, which is the file size! If there is no difference in quality, then why bother taking JPEG in Fine format. Only wasting the file size, and I prefer to let my Canon A570IS or more intelligent Nikon D90 to compress it for me. The result is still satisfying. Sorry, testing it in the office, so only can do with A570IS.

I heard the difference will be more significant if shot is taken at night. Shall try again and post for your viewing. For now, I will stick to JPEG basic, maybe will try out RAW later when I have the free time to play with photoshop. Cheers.

Post Notes: Opps, forgotten to include the explanation on D90 settings. D90 photos quality basically divided into 2 category, as following:

Large (4288x2848)
Medium (3216x2136)
Small (2144x1424)

RAW (1:1 No compression)
Fine (1:4 compression)
Normal (1:8 compression)
Basic (1:16 compression)

In any circumstances, size shall not be sacrifice. The 12.3megapixels that is fitted onto CMOS sensor of D90 is incredible and everyone should make full use of every pixel. Each pixel is built-in with light sensor that detect primary colour of RGB, and the final result of the colour for that pixel is pick-up and recorded. By effectively reducing the size, the light sensor is shut-off to reduce the pixels count, why you would want that?

While jpeg compression is another story. By fully utilising the 12.3megapixels, the processor record every details but later it is converted into jpeg and apply compression accordingly. The compression process is similar to zip file, mp3 file or the TVB drama video compression that we watched. It effectively reduces the non-significant details that's not detectable by human eyes. If you are really picky, then you might be able to find some difference, but printing it out in 4"x3" photo frame, you will never notice the different. With example above, why bother doing fine?

I got a cheap computer and the processing of large amount of files is killing me. My joy still coming from shooting, viewing and sharing the photos in shortest time. So I am happy with the testing and will continue to stick to JPEG Large Basic setting for current time, until I'm ready to take up Photoshop for RAW.


Wai said...

Now is the world of PNGs!!!

PNG can be slightly bigger than jpeg but with the bandwidth on the net getting better today, people wouldnt mind having a slightly bigger file size for better image files. But PNGs are largely used on web files.

For pics, still jpeg is best :)

KVINLIM said...

PNG? that's for web only la. Photography still JPEG. What's the advantage of PNG? Smaller size?

Wai said...

yeah, PNG is slowly replacing gif and jpeg on the web edi. Unless animated gif la.

the compression of PNG is better thus clearer and sharper image with a slight difference (increase) in file size.

Photography still Jpeg la :D

KVINLIM said...

funny, just for own knowledge la ... if PNG is better, then why jpeg is still for photography?

Wai said...

no idea actually.

like gif file also. nowadays, rather than doing animated gif, some designers even used flash file (as in use flash to draw and animate) into a .swf file. and surprise suprise, the size is smaller/equal to gif file but at better quality!

no idea.. maybe its the way the image compression works.

But so far, still jpeg is being used in photography due to its compression. Rather than having .bmps all flying around

KVINLIM said...

bmp is some screw-up stuff la, the file is so big and I'm not sure what it compress! better off using RAW. anyway, jpeg is some file format that's proven and I can see it will still be in future. wouldn't want to keep some files that in future I will have no program to open it.

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