slhunky Loc: Murfreesboro,Tn

I read on here a couple days ago that everytime you open a JPEG some of the quality is lost. So, to protect the quqlity of the images should they be saved to a disc as soon as they are downloaded to the computer. Or, do you have other suggestions?

ShakyShutter Loc: Arizona

If it was stated that "every time you OPEN a jpg you loose quality" that was wrong.

Each time you open a jpg and then SAVE it the quality is degraded slightly.

Viewing a jpg does not affect its quality otherwise all the web sites in the world would be full of really bad looking images.

slhunky Loc: Murfreesboro,Tn

Thanks for your response. I must have misunderstood.

liv2paddle Loc: Wall, NJ

False. Simply opening or displaying a JPEG image does not harm the image in any way. Saving a JPEG repeatedly during the same editing session (without ever closing the image) will not accumulate a loss in quality. Copying and renaming a JPEG will not introduce any loss, but some image editors do recompress JPEGs when the Save As command is used. To avoid more loss you should duplicate and rename JPEGs in a file manager rather than using "Save As JPEG" in an editing program

slhunky Loc: Murfreesboro,Tn

Thank you very much.

photocat Loc: Atlanta, Ga

Change your jpeg files to tiff before saving and you don't have to worry.

For instance with windows 7, if your viewing a photo and rotate it and then move on to the next , windows with save, that is a problem, or could be. However, if you rotate it back no problem.

As others have stated, it is the saving that creates a re-compression of the file and that action results in loss of information.

Once or twice you probably won't notice a change but it will start to break down if one continues to open and SAVE

slhunky Loc: Murfreesboro,Tn

Good Info, thanks

Jschneir Loc: Santa Monica, CA

Lots of bad info. Before you do any editing, serious editing, duplicate the image and work on the duplicate. Opening and closing WITHOUT SAVING OR SAVING AS will NOT degrade an image, but if you do the saving and savings as there will be some image degradation, but it takes more than 3 or 4 such cycles before you start introducing artifacts and loosing details. Each image editor does it differently. DO NOT SAVE TO CD OR DVD. They are cumbersome to use once you have a lot of images. You should have 2 or 3 external drives and backup to those drives. That way you can easily search if you have to find a misplaced image. CD/DVD have a limited lifespan, 10 years unless you are using gold plated stuff. How many of you still have 5.25 inch drives or 3.5 inch drives? Technology is rapidly changing and you could easily find yourself out there with real problems trying to find drives and software that will read those drives.

Unless you have a very large harddrive, saving images as TIFFS burns a lot of space, a tiff file can easily be 5-10 x larger than the original jpeg. There are some programs that have a no-loss rotation tool, but you do have to be careful. A free program with a no-loss tool is FastStone.

photocat Loc: Atlanta, Ga

well, for myself, i always save to TIff, shoot in RAW and don't use jpegs.

External storage is cheap these days and everyone has to make a judgement on how they are going to handle their files if they expect to have anything to leave to their children.

I thought it has been made very clear on this site, never, never , never work on an orginal image; always make a copy and then back up everything with more than 1 copy

Jschneir Loc: Santa Monica, CA

I've made this challenge to my students and the results are a bit surprising. My challenge. Shoot pictures using the option to shoot both jpeg and RAW at the same time. Process the RAW and color adjust the jpegs as needed. Relabel the images so you can't tell the
RAW processed jpg from the camera created jpeg. Trade images with a friend and see how many RAW prcoessed jpegs they can tell from just the jpeg images. If, you shot unique lighting it is one thing but just looking at either commonly lit picture, not side by side, most people, even those with fairly educated eyes, have a hard time knowing which image was originally shot as raw and then processed into a jpeg and which came out of the camera as a jpeg. Sometimes, even side by side image comparisons (RAW vs jpeg) are hard to distinguish.

The point I am making is that for most photographers, not working pros, jpeg is just fine. Shooting using both the RAW and jpeg allows you to bring out a bit more on those unique special photos, but most shots just don't warrant that much time and energy.

photocat Loc: Atlanta, Ga

I would agree in principal.

My response to my students is, when shooting my nehprews birthday party, jpeg, when making art RAW.

It boils down to intent. For me, making art, I want every bit of information available. This of course is based on my intention and needs which are probably much different than many on this site.

In no way am i suggesting all should be shooting raw. THe suggestion about changing jpeg to tiff was to give an option for reducing the possiblities of degrading an image.

marcomarks Loc: Ft. Myers, FL

You're halfway correct and the other half is backward. Opening and displaying a JPG does not harm it - that's true - as long as you don't SAVE it and only CLOSE it. It is uncompressed to view it or work on it. ANY time you re-save a JPG, whether you SAVE or SAVE AS, you are re-compressing the file to put it back onto the hard drive.

If you view a file, edit the file, and SAVE AS with another name, the original file remains unharmed. If you view a file, edit the file, and SAVE with the same original name, the original file is gone and never goes back to the original condition.

OPEN = uncompressing the file. CLOSE = nothing happens to the file on your storage media. SAVE OR UNSAVE = re-compression of the data with loss, either wiping out the original file with a deteriorated version of the same name, or creating a different new file with a different name that leaves the original alone.

slhunky Loc: Murfreesboro,Tn

Thanks for the info