Jpeg and lossy format.

[Snappers]

Hi all,
I'm not sure if this has been placed in the right part on the forum so please feel free to move it if not admin.

I was going through the 2nd lesson today and came across this paragraph
"Even highest quality JPEG compression is a lossy format. Meaning, you will loose some of your image quality when you open it on your computer and save it back. More you re-save it, the more data will get lost."

I was not aware of this (and so I learnt something new today:):))
How many times would you have to open a jpeg file before you begin to notice deteriation with it? And does it only affect the file if you resave it. I.e. If you open it to look at it but close it without making any changes, does that affect the file?

I would like to start using Raw for my photos but that is a different topic which I will post soon.

[perfectoarts]

Snapper....I ALWAYS duplicate my images that I want to work on extensively. That way I still have the originals for later on. A safe guard really and I keep them on an external hard drive. Paranoia has set in as far as losing data.
Today I did a comparison. I took a photo in RAW format as well as JPEG.
When the raw was imported into Photoshop, it naturally was turned into a JPEG. It is still much clearer than the photo taken in JPEG.

[LensBaby]

I also use an external hard drive. I like the organization that I have with it.

[gjtoth]

I also use an external hard drive. I like the organization that I have with it.

Being in the IT industry for quite a number of years (more than I care to admit, actually), I've watched a lot of people make a lot of mistakes without backups and dearly regret it. I guess I've picked another hobby that requires extensive backups. I'm glad hard drive space is cheap! The online alternatives are getting better everyday, too.

[Snappers]

Garry you may well have a point there with online backup. My mum recently was backing up her hard drive to an external hard drive. All well and good, everything transfered over but then suddenly the external hard drive stopped working!

Morel of the story, if it is something important you are backing up, make sure you have two different forms of backup i.e. to dvd and external hard drive or even online storage.

[LensBaby]

Yes! I make sure that I have more than one source of backup. You never know when one of them are going to decide to be a pain. (my computer likes to do this sometimes it has a mind of its own)

[gjtoth]

Yes! I make sure that I have more than one source of backup. You never know when one of them are going to decide to be a pain. (my computer likes to do this sometimes it has a mind of its own)

Yes indeedy! They ALL die eventually. I cannot tell you the number of horror stories (including one of mine) I've heard about folks losing EVERYTHING... not just their photos. Years worth of geneology work, entire music collections, important personal and financial documentation... ad nauseum.

Here's a tip:

Make sure to get an OFF-SITE storage place (either physical or online) and make sure they BACK UP THEIR STUFF. Personally, I use 3. My MAIN storage facility is inbox.com. They offer 5 gigs free (no backup). However, for $5 a year... they'll back it up. For $30 a year, they offer 30 (thirty) gigs of space that's backed up. I use Flickr for my photos. I use Google for documents and spreadsheets because I have access to them from anywhere in the world and can work on them RIGHT ONLINE. Google is also good for photos.

If something is worth taking the time to create (whether it be a document, spreadsheet or a photo), it should be worth the time to back up.

<click> Soapbox mode off. ;)

[LensBaby]

Yes I agree. I have my photos backed up everywhere Even if I put them on CD I usually do two of them because you never know when one cd is not going to work. Oh yeah and I NEVER copy from one cd to the next. Thats just asking for it.

[Snappers]

Good Point Susan.

Garry, You know what I love about this forum so much, you never stop learning! I did not know that you could store documents via google although I use it as my search engine all the time. I also use Inbox but again just for email. So, I have some more info at my fingertips now thanks to you pointing me in the right direction.:)

[jerryph]

I find I can see the differences between a JPG file that was created from the original RAW file after saving it once. Let me explain... I will create a nice quality JPG file from a RAW file in CS3, then open up the JPG file in something like MSPAINT, add a tiny dot, something to change it and then save it under another name... now look at both JPGs and you will see that the one saved in MSPAINT seems less sharp compared to the original JPG. If you do this 3-4 times (as in you opened the file and saved it 3-4 times), and the results are even more pronounced.

Everytime you save a JPG file, some of the detail is lost.

This is why it is important to save the file in a lossless format like TIFF or RAW and work only with those formats. Use JPG as the final product for best results.