image size so much smaller after editing?

[CompactRod]

I had edited an original jpg file 5.61mb without cropping, just change the brightness.
when I saved the image, it became 1.58mb.
Image was saved as 8 high quality jpg.
why such a big loss in size?
thanks

 

[ricleo]

compression in the JPEG.. i wld normally save with a minimum of quality 10 for JPEG haaha...but that's still compression too

 

[allenleonhart]

compression in the JPEG.. i wld normally save with a minimum of quality 10 for JPEG haaha...but that's still compression too

:bsmilie: i save as 12. baseline optimized

 

[catchlights]

compression as in discard data, higer the compression more data is discarded.
and if your image has very simple background, or not having lot of details, physical file size will be smaller, eg, a glass of water against plain color background vs night cityscape of Orchard Road.

 

[mayhemics]

yeah the file size diff betw 8 and 10, and 10 and 12, are not all that proportionate...

 

[CompactRod]

i normally shoot incamera highest jpg quality.
looks like cannot edit if need big file for printing
if i shoot in raw and convert to jpg, will it be just as small?

 

[giantcanopy]

Your brightening might have caused less details needed to be recorded, and the jpg compression is lossy.

But still quite a drop i must say

ryan

 

[jopel]

i normally shoot incamera highest jpg quality.
looks like cannot edit if need big file for printing
if i shoot in raw and convert to jpg, will it be just as small?

you should start shooting raw than jpg. Raw file give you more details for post processing. Upon converting to the highest quality jpg the file size will be reduced by 50% or so. File size is relative to the info (color, bit depth, saturation), dimension and resolution of the image.

 

[grantyale]

Photoshop Quality=8 drops a lot of information already.

 

[CompactRod]

even if we shoot at 21mp RAW after conversion to Jpg only get 50% left
any solution to capture 21mp and print in its full glory :think:

 

[jopel]

even if we shoot at 21mp RAW after conversion to Jpg only get 50% left
any solution to capture 21mp and print in its full glory :think:

save as tiff or psd file - it will be bigger than 21MB after all the post processing.