need help with jpeg compression

[steve.ledger]

One big difference I see is your tiff file while yours starts the same as mine when I save mine at 100% quality jpeg it is reduced to 500-600 k. I'll email you the original jpeg I exported from lightroom 1.4 before it crashed...Bob

I'm so confused with understanding your workflow Bob, sorry..

[robertj298]

Oh here is my exact work flow for the last image I emailed you. Imported the raw file into lightroom 1.4from camera. Tweeked the photo in lightroom 1.4. I exported the photo into psp9 as a high quality jpeg to get rid of some dark circles under the eyes. I did that with the smudge brush the saved. I ended up with the 4.68 meg file I emailed you. When I tried to duplicate this using lightroom 2.1 before recovering data from my hard ( I still had the photo on my memory card) I end up with a 700 kb file...Bob

[steve.ledger]

I think this is just a matter of getting ones head around what is happening under the hood..

This is how I understand it.

When you press SAVE in PSP you are using the default save settings for that file type, which is 25% compression / 75% quality.
25% compression setting does not mean the file will be just 25% smaller than the original, it means the file will show 75% of the ‘quality’ of the original file.

So your result of 700KB is really quite normal, I got pretty much the same result too (657KB in fact).

When you Export and use the JPG optimiser (with the compression to the lowest value of '1') - you end up with the 4.7MB JPG, as did I. This too is normal as you are compressing the file using the JPEG algorithm but set to retain 100% of the orginal 'quality' (even though it is still using lossy JPG.)

[robertj298]

Thanks steve your info finally hit me on what I was doing wrong. I thought when I set the jpeg optimizer from the file menu that was used for each photo I didn't realize I had to set it from the window after I click save as also....Bob

[steve.ledger]

No worries Bob, glad we got there in the end