Re: Default dpi

On 08/03/08, Henry G Belot wrote:

> Don:
>;
>>; The usual thing is no dpi information, not wrong information.
>
> My experience (Windows) is that some applications will strip off that
>; information if you edit them. I used to use a freebie version of
> PhotoShop and it did that. I think there was a way of changing that
>; behavior, but I wasn't aware it was happening until much later. These
> days I only keep that copy on the computer for cases where I have to
> deal with compressed TIFFs in its funky implementation. I'm sure there
> are other programs that also strip it out of the files. But with
>; digital photos, I would expect that it is in the original camera file,
> probably even in photos from your cell phone.
>
My images are mostly scans, not digital photos.

Regards
--
Don Cox
doncox%40enterprise.net">doncoxenterprise.net

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.

Don:

>> ...My experience (Windows) is that some applications will strip off that
>;> information if you edit them.... with
>;> digital photos, I would expect that it is in the original camera file,
>> probably even in photos from your cell phone.
>>
> My images are mostly scans, not digital photos.
>

My HP scanner embeds dpi in its scans, and PageStream treats them
accordingly. Don't recall just now if it's recorded as "EXIF" data per
se*, but it's there when I ask a program to show the file information.
Same with images off the web, at least in the ones I browsed the other day.

Incidentally, I asked a friend last night who has several Canon cameras,
including an SLR, what the default dpi was, and he said it was 72 dpi in
all of the cameras regardless of the size of the chip or the image size
set in the camera. So, it may not make any sense, but the Nikon images
(300 dpi) I have seem to be the exception rather than the rule for
digital cameras. And, yes, he has to deal with images that default to
40+ inches wide or tall in some application or other. Apparently, this
would be true of any application like PageStream that in some mode or
other tries to treat the embedded dpi as making some sort of sense. The
only way it seems to be useful is when a program reports back to you in
the title bar that you're looking at an image at x% of its original size.

HB
_____________________

*I'm definitely not up on this stuff, but file headers can carry all
kinds of information, some of it redundant. That's why I can give a
photo a new "file" name in my cataloging program and still have a record
of the original file name. I'm not up to looking, but the scanner may be
passing the dpi through another route such as the "system" header.

HB

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.

Howdy

dpi

Remember dpi only has to do with how your monitor displays the
picture and how your printer prints the picture
DPI has nothing to do with resolution...as resolution is the actual
pixel count that makes up the photo!

Most digital cameras use a dpi of 72 because that is the visual
capability of the display screen and
most computer monitors Macs use a dpi of 72, PC's use 96 DPI.

Therefore a dpi of 72 tells the graphics card to write 72 pixels
per inch to the display screen

When you print the picture you want to use a dpi of 300, in this case
300 dpi tells the printer to print 300 pixels per inch
The dpi of a camera is usually converted upon down load from the
camera. If you use Adobe's Camera Raw the DPI is set at 240 dpi.
Alll SLR manufacturers provide software that allows the easy control
of dpi, usually at download

We can thank an Apple engineer many years ago for equating dpi with
resolution... we have been paying for it ever since...

On Mar 10, 2008, at 4:39 PM, Henry G Belot wrote:

> Don:
>;
> >> ...My experience (Windows) is that some applications will strip
> off that
>; >> information if you edit them.... with
>; >> digital photos, I would expect that it is in the original camera
> file,
> >> probably even in photos from your cell phone.
> >>
> > My images are mostly scans, not digital photos.
> >
>;
> My HP scanner embeds dpi in its scans, and PageStream treats them
>; accordingly. Don't recall just now if it's recorded as "EXIF" data per
> se*, but it's there when I ask a program to show the file information.
> Same with images off the web, at least in the ones I browsed the
> other day.
>;
> Incidentally, I asked a friend last night who has several Canon
> cameras,
> including an SLR, what the default dpi was, and he said it was 72
> dpi in
> all of the cameras regardless of the size of the chip or the image
> size
>; set in the camera. So, it may not make any sense, but the Nikon images
> (300 dpi) I have seem to be the exception rather than the rule for
> digital cameras. And, yes, he has to deal with images that default to
> 40+ inches wide or tall in some application or other. Apparently, this
>; would be true of any application like PageStream that in some mode or
> other tries to treat the embedded dpi as making some sort of sense.
> The
> only way it seems to be useful is when a program reports back to
> you in
> the title bar that you're looking at an image at x% of its original
> size.
>
> HB
> _____________________
>
> *I'm definitely not up on this stuff, but file headers can carry all
> kinds of information, some of it redundant. That's why I can give a
> photo a new "file" name in my cataloging program and still have a
> record
> of the original file name. I'm not up to looking, but the scanner
> may be
> passing the dpi through another route such as the "system" header.
>
> HB
>
>

--
Mo Eb , Garry
----------------------------------------------------------
*
***
***********
*** *** http://home.comcast.net/~garrystasiuk/
* * Garry T. Stasiuk < GarryStasiuk%40comcast.net">GarryStasiukcomcast.net>

o "There are only 10 types of people in the world:
Those who understand binary, and those who don't";

[Non-text portions of this message have been removed]

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.