Lightroom RAW->JPEG=Small files???

[jefftaz]

Hi,

I recently started using Lightroom and love it for processing my RAW files. However I am getting very small JPEG files when I convert. I am exporting to JPEG with 100% Quality, sRGB and 300dpi.

I shoot with a Canon 5D with nearly 13MP, however after the export my files range from 3-4MP - ?????

Please someone help me out - why are the JPEGs so small?

[jonnythan]

RAW files are naturally much, much larger than JPGs. JPGs are compressed, lossy files.

You say the files are "3-4 MP." I assume you mean 3-4 MB? MP is megapixels, it's a measure of resolution - not file size.

[jefftaz]

Opps my bad - yes it is 3-4MB, is that equivalent to a 12MP file size?

[jonnythan]

"12MP file size" doesn't mean anything.

I'm not sure what you're asking.

A RAW file is going to be a fair bit larger than a JPG file. The RAW file represents the information captured by the camera, before any processing. A JPG is processed - it has a color space applied, it is white balanced, sharpened, contrast enhanced, and saved to a lossy format.

RAW files give you much more flexibility in the processing of your image. They are much larger. JPGs are already processed and ready for viewing or sharing.

[davidcrebelxt]

Just to add:

For example, you could set your 5d to .jpg mode, and see what size file that gives you there.

They won't match size perfectly, because it all depends on .jpg compression rate camera is using compared to LR. (Camera usually compresses the .jpg more than even bundled software does when processing RAW.)

MP size doesn't really equate to file size. Camera manufacturer could employ lossless compression on their RAW to make files smaller... and the content of the image itself depends how much a .jpg is compressesd. In .jpg at least (not sure if this holds true for RAW) if is mostly a solid blue sky, the file size will be much smaller than if the image has vaired colors and shades throughout. Basically compression routine can say 'data for the next 50 pixels is exactly the same... here is the data, and repeat it 50 times when uncompressing.' {That's extremely simplified, I know, but that's one form compression can take.}

[lennythelens]

Jefftaz,

Jpeg always applies lossy compression, even at 100%. Yes your 5D files sizes produced from LR exported to Jpeg will be around the sizes you mention. 3-4Mb.

[cdifoto]

If you want big-ass files, export to TIF or PSD instead.

[jonnythan]

BMP all the way! :D