copy or move? Is there any difference in quality if I copy or move a jpeg from an SD card to the computer? Or do I lose quality copying from the computer to a back up drive?

Npt Bob Loc: Newport, RI

Is there any difference in quality if I copy or move a jpeg from an SD card to the computer? Or do I lose quality copying from the computer to a back up drive?

EstherP

I have always thought that "moving" images from a card to the computer is the same as "copying" except that the software deletes the image at the same time from the card.

Personally, I always copy and paste the images from the card to the computer, using a card reader. Then when I am certain the images are all copied to the computer's hard drive as well as to one external drive, I put the card back into the camera and re-format it there.

I think I can say with certainty that there is no difference in quality whether you copy and paste (copy) or cut and paste (move) from the card to the computer.
The loss of quality comes in with compressed file formats such as .jpg, if you open the image, then save it.
Just opening, having a look at it, then closing without saving also makes no difference in the image quality.
EstherP

BermBuster Loc: Hi Desert S.Cal

Should be the sameyou can always check the "properties" of the jpg file, if one is 500kb and the 'copy' is 295kbit got compressed and you lost some quality.
But I have never had that happen. You usually lose quality on a jpg every time you "save" it..in your photo program.

And I agree with everything EstherP said.. :thumbup:

Eustace2 Loc: Cincinnati

Neither moving or copying should degrade the quality of the JPEG. I have seen some articles showing that opening and re-saving a JPEG (rather than just closing without saving) can cause the image to degrade from the multiple compressions and expansions. If you Google the question you will find some articles showing the result.

Npt Bob Loc: Newport, RI

thanks Ester - I have always used the same sequence to ensure I didn't do something stupid and lose a file. Didn't think about the fact that a move could actually be basically the same as a copy = therefore no difference in quality.

jerryc41 Loc: Catskill Mts of NY

Npt Bob wrote:

Is there any difference in quality if I copy or move a jpeg from an SD card to the computer? Or do I lose quality copying from the computer to a back up drive?

Same thing. In both cases, the computer makes a copy, since it isn't going to remove something physical that's on the card. It's all just software. It duplicates the 1's and 0's on the card and writes them onto your hard drive.

I always copy the images, just to play it safe. As long as they're still on the card, an accident in transferring them won't matter. If you do a Move, and something goes wrong, well, that would be bad.

Npt Bob Loc: Newport, RI

Thanks ALL,
As I stated above my concern was quality vs protecting from stupid mistakes causing loss of photos.
Looks like being "safe" is OK!

rook2c4 Loc: Philadelphia, PA USA

I always copy files from the card, never move. If something goes wrong with the transfer, at least I still have the original on the card for another attempt. Only after I'm certain the transfer was successful do I consider deleting the file on the card (usually by reformatting the card in the camera).

ziggykor Loc: East Texas

I will not even use "Move" when transferring files from one hard drive to another. It's just too easy for something to go wrong. I use copy and paste, verify they are all good and only then to I delete them from the source location. I download from the card the same way.

jerryc41 Loc: Catskill Mts of NY

ziggykor wrote:

I will not even use "Move" when transferring files from one hard drive to another. It's just too easy for something to go wrong. I use copy and paste, verify they are all good and only then to I delete them from the source location. I download from the card the same way.

:thumbup:

Bultaco Loc: Aiken, SC

ziggykor wrote:

I will not even use "Move" when transferring files from one hard drive to another. It's just too easy for something to go wrong. I use copy and paste, verify they are all good and only then to I delete them from the source location. I download from the card the same way.

Sound advice.

Papa Joe Loc: Midwest U.S.

EstherP wrote:

I have always thought that "moving" imag... (show quote)

I agree right down the line with Esther, except on one small point. I may be wrong, but I don't believe you lose anything by just opening and then saving a .jpg. It's my understanding that if you make any change to the picture and then save it, there can be a slight loss, but not just opening/closing it. Correct me if I'm wrong.

EstherP

Papa Joe wrote:

I agree right down the line with Esther, except on one small point. I may be wrong, but I don't believe you lose anything by just opening and then saving a .jpg. It's my understanding that if you make any change to the picture and then save it, there can be a slight loss, but not just opening/closing it. Correct me if I'm wrong.

You may well be right, Papa, I am only repeating what I was told and what I read.
The way I understand it, is that every time you save a .jpg image compression is applied again, regardless of whether you have a change to the image or not. And compression means loss.
One of these days I will do a test, and save a .jpg image a number of times and see what happens.
But in the end, why save an image when you have only opened it and made no changes?
EstherP

BboH Loc: s of 2/21, Ellicott City, MD

I use move all the time - from card to computer, from directory to directory. The only time I use copy is if I want the image in two or more files which, many times, I do. I have seen no degradation of image between the two commands

AzPicLady Loc: Behind the camera!

I had always used the "copy-paste" system. But a computer guru told me that occasionally when you do that the copy isn't a "real" file but a reference to the original, and should you then delete the original, the copy wouldn't be usable. I've never had that happen, but then I usually don't ever delete anything, either!