Metadata query

gus

I am entering a photo in a competition which requires a 5 meg min in size. Now the photo in question is a slight crop ..straighten...sharpen etc. Nothing huge done in photoshop other than the ordinary.

Now the metadata says its 2992 x 2156 so about 6.5 meg however when i download it my mac downloader (when i download it from my Smugmug page) says its 4.8 meg and it also says at the top of the metadata file that its 4.8 meg on disk (4,989,229 bytes) also.

Im no pixel peeper so have no idea whats what...any idea please.

Richard

gus wrote:

I am entering a photo in a competition which requires a 5 meg min in size. Now the photo in question is a slight crop ..straighten...sharpen etc. Nothing huge done in photoshop other than the ordinary.

Now the metadata says its 2992 x 2156 so about 6.5 meg however when i download it my mac downloader (when i download it from my Smugmug page) says its 4.8 meg and it also says at the top of the metadata file that its 4.8 meg on disk (4,989,229 bytes) also.

Im no pixel peeper so have no idea whats what...any idea please.

I'm guessing that it's a JPG and that the smaller size is because of JPG compression. What JPG quality level did you save the pic at? Anything less than 12 should result in a smaller file.

Manfr3d

You can increase the filesize by embedding a larger preview into it (if your software supports that) or by using less compression (i.e. 100% quality).

gus

Richard wrote:

I'm guessing that it's a JPG and that the smaller size is because of JPG compression. What JPG quality level did you save the pic at? Anything less than 12 should result in a smaller file.

ahh..i wonder if thats it. Tks i will check.

gus

So i go back & open the photo in RAW...save at max (10) to jpeg.

I open the jpeg in CS3 & look at the photos dimentions...3408 x 2292 = 7.81 meg. Thats cool.

However if i then open the file (im using leopard) with my browser, i see the thumbnail with 4.6 meg beside it...so i right click to see the meta-data & it too says the image is 4.6 meg

gus

Here is the data file...it does not work out to me ??

Richard

Gus,

At every quality level, JPG compresses image data, so you should not expect the number of bytes in the file to be the same as the number of pixels. The JPG will usually be smaller (though it can be larger in some cases). In reality, the amount of compression depends more on the complexity of the image than the number of pixels. A very large pic of a blue sky will produce a much smaller JPG than a small pic of a forest scene.

But don't panic. If you are saving directly from ACR, you can type 12 into the Quality field and get a larger file. In PS, the quality slider itself goes up to 12. I did an experiment just now that gave interesting results:

Original .CR2 file (8185344 pixels): 8.364 MB
JPG saved in ACR at quality 12: 5.071 MB
JPG saved in PS at quality 12: 5.096 MB
JPG saved in ACR at quality 10: 1.886 MB
JPG saved in PS at quality 10: 1.883 MB

So try saving it at 12 and see if that solves your problem. Your results may look quite different from this example since it always depends on the image, but I think you are close enough to 5MB at quality 10 that a higher quality should do the trick.