JPG file size after photoshop - ?? why does change so drastically

[sathni]

i have been using a 10d for a few years, and have always shot in the high-res jpg format...

when i use photoshop to clean things up, even if the clean up was minor, the new jpg file size is markedly different...

can anyone explain what is the best way to save post-processed files?...

or should i just shoot in RAW?...

or is there a difference between the different versions of photoshop?..

please advise - thx

[Pete]

It's probably because you're not saving in High Quality from Photoshop. You need to push the Quality slider all the way to the right (Quality 12).

[picturecrazy]

It's probably because you're not saving in High Quality from Photoshop. You need to push the Quality slider all the way to the right (Quality 12).

12 is a little high. If you know there will be NO more edits, then quality 10 does the job nicely and you likely will not be able to tell the difference between 10 and 12 in print.

[inthedeck]

Also, you should use RAW, in case you get that ONE picture, that makes the world stop. Otherwise, over the years, the jpegs will degrade, since JPEG's are a lossy format. RAW files will remain the same, like a 'negative' for years, no matter how many time you open/close/save/edit/etc. them.

[Bobster]

over the years, the jpegs will degrade, since JPEG's are a lossy format.
ROFLMAO!!!!!!!! thanks for that, made my Friday!!!! :D

[jonnythan]

He's not serious is he?

No, he's not serious.

Is he? LOL

[inthedeck]

ROFLMAO!!!!!!!! thanks for that, made my Friday!!!! :D

Not sure why you're laughing...but, mmmmkay. :confused:

[jonnythan]

You were kidding, right? JPGs do not degrade over time.

[dolfinack]

hehe. This is good.

[jonnythan]

I assume he's kidding, looking at his posts and photography, but don't you think that's kind of a mean thing to say to someone with 3 posts who doesn't quite understand and is liable to believe you?

[inthedeck]

I've read in many places, that the more you open, play with, and save jpegs, they degrade over time. I've never really used jpeg's, except when saving for the web...so for me, once those images are created, I hardly go back to them. As a result, they'll stay OK in jpeg format. However, if ALL you are shooting with, is JPEG, and you keep opening, fixing, closing those files, they have a slight chance of degrading over time. Look it up...there's people who agree, and people who don't. For me, it makes no difference, since I keep the RAW's that matter.

here's a link, too...should you like to read it. It'll explain more...but again, just another person giving his schpiel. Click Here. (http://www.michaelfurtman.com/jpeg_myths.htm)

"It is important that you preserve the integrity of your JPEG file. In addition to insuring that your retain the original file without over-writing it (make alterations to a copy), it is wise to turn off any in-camera processing, such as sharpening, contrast, and hue adjustments. Not only should you make these modifications in Photoshop, where you can do a more precise job, you want as "clean" a JPEG file as possible. Any processing done in-camera to a JPEG file can not be undone. Most dSLRs will allow you to turn off in-camera processing, although some point-and-shoot digital cameras will not."

Clean, the way I understood it, means don't open/close/open/close/work on/save/close open, etc, and try not to use in camera adjustments. You can take it for what it's worth...everyone has their opinion.

[jonnythan]

Every time you save a JPG, its quality degrades slightly.

Opening has no effect.

They don't "degrade over time." A JPG can sit there for 20 years through millions of views and not "degrade" at all. The quality only degrades slightly every time you save.

This isn't a matter of opinion. It's a matter of fact. Only the act of saving a JPG makes its quality degrade. This certainly means that if you open, change, and save a JPG file many times, the quality can degrade quite significantly. This is why many here recommend that you keep "the original" in RAW or TIF format, and only export to JPG when you are definitely done editing the file.

[inthedeck]

Every time you save a JPG, its quality degrades slightly.

Opening has no effect.

They don't "degrade over time." A JPG can sit there for 20 years through millions of views and not "degrade" at all. The quality only degrades slightly every time you save.

That was my point. Since jpeg's are all the OP shoots with...and edits. Thus, my suggestion for using RAW files...of course, RAW + Jpeg would be ideal too.

[AnthonyLin]

Haha, I understand your point inthedeck, but the way you phrased it on your post made it seem like JPG's will wither away with time. I seriously doubt anybody continuously edits their JPG's over the years.

[DAMphyne]

JPEG's will only degrade if you save over the original file.
This is why we "Save AS", this gives you a chance to determine the quality settings.
That is one true advantage of RAW, it's idiot-proof, you can't save over (change) the original file.