When do you lose Resolution?

I have a Nikon D70S. After I do a picture
taking session, I remove my memory card from
the camera. Insert it in my built in memory
card reader in the computer and burn the
pictures directly onto a CD-R.

Now as I understand it you can never change
the resolution of the pictures on the CD-R
( and please don't lets get into what will happen
20 or 50 years hence)
I read in this newsgroup that every time you open
a file and close it you lose resolution. I can
understand if you open and close a file from
a folder this can happen.

However you cannot alter a file burned to the CD-R.
Am I correct in what I state? If not please correct me.

Thanks in advance
Denny B.

Denny B wrote:
I read in this newsgroup that every time you open
a file and close it you lose resolution. I can
understand if you open and close a file from
a folder this can happen.


You only lose some quality when you re-save a file as a JPG since the
file is then re-compressed. And of course you couldn't do that to
files on a CD anyway.
And it isn't "resolution" that you are losing since resolution refers
to the pixel size of the photo, which doesn't change. Just opening a
file and closing it again without saving does nothing to the original
data in the file.

Denny B wrote:
I have a Nikon D70S. After I do a picture
taking session, I remove my memory card from
the camera. Insert it in my built in memory
card reader in the computer and burn the
pictures directly onto a CD-R.

Now as I understand it you can never change
the resolution of the pictures on the CD-R
( and please don't lets get into what will happen
20 or 50 years hence)
I read in this newsgroup that every time you open
a file and close it you lose resolution.

Not when you close it; it's when you *save* it. Technically, it's not
resolution that is lost, it's picture information. Oh, and this only
applies to lossy compression, such as .JPG. It doesn't happen with RAW
files.

However you cannot alter a file burned to the CD-R.
Am I correct in what I state? If not please correct me.

With a CD-RW you can open, save, and close (but I don't reccomend it
normally).

Austin

Denny B wrote:
I have a Nikon D70S. After I do a picture
taking session, I remove my memory card from
the camera. Insert it in my built in memory
card reader in the computer and burn the
pictures directly onto a CD-R.

Now as I understand it you can never change
the resolution of the pictures on the CD-R
( and please don't lets get into what will happen
20 or 50 years hence)
I read in this newsgroup that every time you open
a file and close it you lose resolution. I can
understand if you open and close a file from
a folder this can happen.

However you cannot alter a file burned to the CD-R.
Am I correct in what I state? If not please correct me.

Thanks in advance
Denny B.

A couple of things. First, it is only a JPEG that loses QUALITY with
successive saves. It does not lose resolution, it essentially loses
color accuracy and fidelity. The effect is similar to reducing bit
depth, although the 8 bit depth is not actually reduced. It is only
the SAVE function that does this. You can open and close the file as
many times as you like without changing the quality. Save is different
than Close.

Second, while you cannot alter the file ON THE CD, you can alter the
file in an editing program and save it as an altered file on your hard
drive, or burn it to a new CD.

"Don Stauffer in Minnesota" wrote in message
ups.com...

Denny B wrote:
I have a Nikon D70S. After I do a picture
taking session, I remove my memory card from
the camera. Insert it in my built in memory
card reader in the computer and burn the
pictures directly onto a CD-R.

Now as I understand it you can never change
the resolution of the pictures on the CD-R
( and please don't lets get into what will happen
20 or 50 years hence)
I read in this newsgroup that every time you open
a file and close it you lose resolution. I can
understand if you open and close a file from
a folder this can happen.

However you cannot alter a file burned to the CD-R.
Am I correct in what I state? If not please correct me.

Thanks in advance
Denny B.

A couple of things. First, it is only a JPEG that loses QUALITY with
successive saves. It does not lose resolution, it essentially loses
color accuracy and fidelity. The effect is similar to reducing bit
depth, although the 8 bit depth is not actually reduced. It is only
the SAVE function that does this. You can open and close the file as
many times as you like without changing the quality. Save is different
than Close.

Second, while you cannot alter the file ON THE CD, you can alter the
file in an editing program and save it as an altered file on your hard
drive, or burn it to a new CD.


Just one more note:

To ensure no loss of image data, files should not be edited as JPGs. Even
if one's camera or scanner outputs files as JPGs, the first step is to save
those files as TIFF, Photoshop, Paint Shop Pro or some other non-lossy
format. Do all editing in the non-lossy format. Convert back to JPG when
all editing is done, if you want to use JPG as your viewing format--which is
what it was really intended to be used as.

Also, editing software typically has a default compression for JPG files,
and the amount of compression can usually be changed by the user. I always
make it a point to use minimum compression as my default, just to ensure
that I don't accidentally lose data when saving a JPG. In PSP XI and
earlier versions, there is a feature called JPG Optimizer, where one can
determine in advance exactly how much compression should be applied to any
given file before it is saved, and it shows what the file will look like at
that resolution, before it is saved. I normally use that feature when
making my final saves in JPG formatted files.

The simplest rule that I use, with regard to JPG files, is to use them only
as final viewing format, never as a format to be used during editing.

jeremy wrote:
"Don Stauffer in Minnesota" wrote in message
ups.com...
Denny B wrote:
I have a Nikon D70S. After I do a picture
taking session, I remove my memory card from
the camera. Insert it in my built in memory
card reader in the computer and burn the
pictures directly onto a CD-R.

Now as I understand it you can never change
the resolution of the pictures on the CD-R
( and please don't lets get into what will happen
20 or 50 years hence)
I read in this newsgroup that every time you open
a file and close it you lose resolution. I can
understand if you open and close a file from
a folder this can happen.

However you cannot alter a file burned to the CD-R.
Am I correct in what I state? If not please correct me.

Thanks in advance
Denny B.
A couple of things. First, it is only a JPEG that loses QUALITY with
successive saves. It does not lose resolution, it essentially loses
color accuracy and fidelity. The effect is similar to reducing bit
depth, although the 8 bit depth is not actually reduced. It is only
the SAVE function that does this. You can open and close the file as
many times as you like without changing the quality. Save is different
than Close.

Second, while you cannot alter the file ON THE CD, you can alter the
file in an editing program and save it as an altered file on your hard
drive, or burn it to a new CD.


Just one more note:

To ensure no loss of image data, files should not be edited as JPGs. Even
if one's camera or scanner outputs files as JPGs, the first step is to save
those files as TIFF, Photoshop, Paint Shop Pro or some other non-lossy
format. Do all editing in the non-lossy format. Convert back to JPG when
all editing is done, if you want to use JPG as your viewing format--which is
what it was really intended to be used as.

Also, editing software typically has a default compression for JPG files,
and the amount of compression can usually be changed by the user. I always
make it a point to use minimum compression as my default, just to ensure
that I don't accidentally lose data when saving a JPG. In PSP XI and
earlier versions, there is a feature called JPG Optimizer, where one can
determine in advance exactly how much compression should be applied to any
given file before it is saved, and it shows what the file will look like at
that resolution, before it is saved. I normally use that feature when
making my final saves in JPG formatted files.

The simplest rule that I use, with regard to JPG files, is to use them only
as final viewing format, never as a format to be used during editing.


Thank you all regarding your input
into this matter. I have learned much
from your replies, particularly that
opening and closing a file is NOT saving it.

Thank you kindly.
Denny B

In fact, I strongly advise using the photo editor's native file format
for all saves while you are editing. No other format will retain ALL
of the editing info. So if you are editing in Photoshop, save as a .PS
file, .PSP for Paint Shop Pro, etc. Yeah, the files are large saved in
those formats, but you won't be editing that many images at one time.
When you are sure you are done editing, save as a jpeg or some other
compressed format, and delete the version in the editor's format.


jeremy wrote:


To ensure no loss of image data, files should not be edited as JPGs. Even
if one's camera or scanner outputs files as JPGs, the first step is to save
those files as TIFF, Photoshop, Paint Shop Pro or some other non-lossy
format. Do all editing in the non-lossy format. Convert back to JPG when
all editing is done, if you want to use JPG as your viewing format--which is
what it was really intended to be used as.

Also, editing software typically has a default compression for JPG files,
and the amount of compression can usually be changed by the user. I always
make it a point to use minimum compression as my default, just to ensure
that I don't accidentally lose data when saving a JPG. In PSP XI and
earlier versions, there is a feature called JPG Optimizer, where one can
determine in advance exactly how much compression should be applied to any
given file before it is saved, and it shows what the file will look like at
that resolution, before it is saved. I normally use that feature when
making my final saves in JPG formatted files.

The simplest rule that I use, with regard to JPG files, is to use them only
as final viewing format, never as a format to be used during editing.

Denny B wrote:
I have a Nikon D70S. After I do a picture
taking session, I remove my memory card from
the camera. Insert it in my built in memory
card reader in the computer and burn the
pictures directly onto a CD-R.

Now as I understand it you can never change
the resolution of the pictures on the CD-R
( and please don't lets get into what will happen
20 or 50 years hence)
I read in this newsgroup that every time you open
a file and close it you lose resolution. I can
understand if you open and close a file from
a folder this can happen.

However you cannot alter a file burned to the CD-R.
Am I correct in what I state? If not please correct me.

Thanks in advance
Denny B.

As everybody is saying, you can repeatedly view digital files without
wearing them out.

Still, I *do* still see value in storing backups on a read-only media,
just as you suggested. Otherwise, there is still some risk of
accidental deletion. Or perhaps even accidental modification. For
instance, I have accidentally destroyed filenames by copying the files
to old disks that could only handle filenames 8 characters in length.
Or, Windows Media Player has an option to automatically download track
info (like artist and title) and store it in your music files. It's
only trying to be helpful, but that would scare me if an image viewing
program did something like that to my pictures in order to implement
some value-added feature. Or maybe a virus will one day infect image
files and inject spam onto the pictures. Who knows?

So, periodically making a backup on read-only media is still a good idea.

"timeOday" wrote in message


So if I read it correctly the best thing to do is save as
jpeg direct from the camera/card but also save as tiff at the same time.
This should not be a problem with the state and price of hard drives.


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

Maurice Hood wrote:
"timeOday" wrote in message


So if I read it correctly the best thing to do is save as
jpeg direct from the camera/card but also save as tiff at the same time.
This should not be a problem with the state and price of hard drives.

The very best is to shoot in RAW format, convert to Photoshop files, and
make edits, resaving to PS format. The RAW file is the negative, so to
speak, and contains the most information.

OTOH, much paranoia is attached to the minute quality that is lost in
saving changes via JPEG. Tests have been done in the past that showed
that even after a half dozen or more resaves, the *apparent* quality
hadn't changed. Of course, mileage varies, and the worse quality you
start with, the more you have cause to be concerned about multiple edits
and resave via JPEG.

--
John McWilliams