REsolution and dipi

On Wed, 03 Dec 2003 20:27:41 GMT, "Smurk" wrote:

Hi
I experience a situation I don’t quite understand with PS On my machine I set the resolution of my files at 300 dpi follwing the request of my printing services.
Then when they open the file on their machine, the resolution is back to 72 dpi but the dimension of the file has increased in pixels and they tell me that I have to provide my photo in 300 dpi again.
What can causes such a situation. Is that on my side or their side? Thanks for your advice on this.
Yves

Then the question is… when you "set the resolution of my files at 300 dpi" WHAT exactly are you doing?

Are you using the PS image size dialog box?

— JC

Yes I select image>image size> the set resolution to 300 dpi, check resample image and leave constraint proportion uncheck.
On the screen it shows the downsizing in pixels as the dpi increases. Then I click ok and save
As long as I use the file on my machine it stays at 300dpi, but when I pass it on to the print service and they open it on their machine it shows 72dpi but the number of pixels has increased. I did not calculate the proportion of increase as I was facing a situation where I did not understand what was happening.

"J C" wrote in message

On Wed, 03 Dec 2003 20:27:41 GMT, "Smurk" wrote:

Hi
I experience a situation I don’t quite understand with PS On my machine I set the resolution of my files at 300 dpi follwing the request of my printing services.
Then when they open the file on their machine, the resolution is back to

72

dpi but the dimension of the file has increased in pixels and they tell

me

that I have to provide my photo in 300 dpi again.
What can causes such a situation. Is that on my side or their side? Thanks for your advice on this.
Yves

Then the question is… when you "set the resolution of my files at 300 dpi" WHAT exactly are you doing?

Are you using the PS image size dialog box?

— JC

"Smurk" wrote in
news:5utzb.22649$:

Yes I select image>image size> the set resolution to 300 dpi, check resample image

Bad idea. Upsampling does nothing but degrade the image.

If you have too little resolution, it’s best to re-master the file (new scan, new digital shot, whatever). If you absolutely cannot, replace the image or run it as is.

and leave constraint proportion uncheck.

REALLY bad idea, unless you are distorting your picture for a good reason.

On the screen it shows the downsizing in pixels as the dpi increases. Then I click ok and save
As long as I use the file on my machine it stays at 300dpi, but when I pass it on to the print service and they open it on their machine it shows 72dpi but the number of pixels has increased.

You didn’t just happen to save in a format that doesn’t preserve image resolution information, such as JPEG, did you?

I did not
calculate the proportion of increase as I was facing a situation where I did not understand what was happening.

Okay. Please be more specific.

Exactly what kind of files did you send the printer, for starters.

I use the photoshop psd format as they use photoshop and request that they be provided with that format.
Regarding the resolution, my photos are native RAW that I export to TIFF. The size is about 20MB ea for 4000 pixels by 2800 pixels. But the resolution from the camera is 72 dpi. The print people asks for 300 dpi.. I remember many years ago I had to deal with that question but it was to print on an home printer. Now I am not sure as to how to proceed and the people at the printing company are not really helpful in that matter.

"Eric Gill" wrote in message

"Smurk" wrote in
news:5utzb.22649$:

Yes I select image>image size> the set resolution to 300 dpi, check resample image

Bad idea. Upsampling does nothing but degrade the image.
If you have too little resolution, it’s best to re-master the file (new scan, new digital shot, whatever). If you absolutely cannot, replace the image or run it as is.

and leave constraint proportion uncheck.

REALLY bad idea, unless you are distorting your picture for a good reason.

On the screen it shows the downsizing in pixels as the dpi increases. Then I click ok and save
As long as I use the file on my machine it stays at 300dpi, but when I pass it on to the print service and they open it on their machine it shows 72dpi but the number of pixels has increased.

You didn’t just happen to save in a format that doesn’t preserve image resolution information, such as JPEG, did you?

I did not
calculate the proportion of increase as I was facing a situation where I did not understand what was happening.

Okay. Please be more specific.

Exactly what kind of files did you send the printer, for starters.

"Smurk" wrote in
news:bGvzb.23921$:

I use the photoshop psd format as they use photoshop and request that they be provided with that format.
Regarding the resolution, my photos are native RAW that I export to TIFF. The size is about 20MB ea for 4000 pixels by 2800 pixels. But the resolution from the camera is 72 dpi. The print people asks for 300 dpi.. I remember many years ago I had to deal with that question but it was to print on an home printer. Now I am not sure as to how to proceed and the people at the printing company are not really helpful in that matter.

Yeah, it sounds like it. Let’s see if I can do better.

DPI is a target you have to hit to get sharp output at a given size. For example, on a printer that needs 300 dpi, to make a print 10 inches wide, you need at least 3000 pixels (300 x 10 inches). Your camera has more than that if you shot with the correct orientation.

As another example, you can divide the number of pixels in your file by 300 to see how large your print can be before you start getting soft prints. In your case, you’ve got enough for a print about 13 1/3 x 9 1/3 inches.

If that’s not clear enough, I can try again.

To fit your picture to the print, make a new PS document at the correct print size with a resolution of 300 dpi. Select and copy your original, then past it into the new document.

If your picture is smaller than the print you are trying to make there will now be white space around the edges and you should skip the rest of the message and I’ll talk about undersized pics.

Hopefully your image is larger than the print you are making. If so, select the layer your picture should now be on, then select the Scale tool (Edit-> Transform->Scale). Scale by grabbing one of the corners and holding down the <shift> key – this will allow you to fit the pic as close as possible to the print area. Double click to finish the scale (you can also drag the image around during that process to postion it properly.)

Now, this has resampled your image down, but *downsampling* doesn’t mangle your pics like upsampling does.

This is getting a bit long. Write back with anything that needs to be be clearer.

You are right I print 1 square foot tiles with my photos. So I am oversized even after dividing by 300.
Following your process I should be ok. I will apply the workflow you mention and see tomorrow if what I give them works this time. Thank you and I will let you know the results.
Thanks again you really helped.
Yves
"Eric Gill" wrote in message

"Smurk" wrote in
news:bGvzb.23921$:

I use the photoshop psd format as they use photoshop and request that they be provided with that format.
Regarding the resolution, my photos are native RAW that I export to TIFF. The size is about 20MB ea for 4000 pixels by 2800 pixels. But the resolution from the camera is 72 dpi. The print people asks for 300 dpi.. I remember many years ago I had to deal with that question but it was to print on an home printer. Now I am not sure as to how to proceed and the people at the printing company are not really helpful in that matter.

Yeah, it sounds like it. Let’s see if I can do better.

DPI is a target you have to hit to get sharp output at a given size. For example, on a printer that needs 300 dpi, to make a print 10 inches wide, you need at least 3000 pixels (300 x 10 inches). Your camera has more than that if you shot with the correct orientation.

As another example, you can divide the number of pixels in your file by

300

to see how large your print can be before you start getting soft prints.

In

your case, you’ve got enough for a print about 13 1/3 x 9 1/3 inches.
If that’s not clear enough, I can try again.

To fit your picture to the print, make a new PS document at the correct print size with a resolution of 300 dpi. Select and copy your original, then past it into the new document.

If your picture is smaller than the print you are trying to make there

will

now be white space around the edges and you should skip the rest of the message and I’ll talk about undersized pics.

Hopefully your image is larger than the print you are making. If so,

select

the layer your picture should now be on, then select the Scale tool

(Edit->

Transform->Scale). Scale by grabbing one of the corners and holding down the <shift> key – this will allow you to fit the pic as close as possible to the print area. Double click to finish the scale (you can also drag the image around during that process to postion it properly.)
Now, this has resampled your image down, but *downsampling* doesn’t mangle your pics like upsampling does.

This is getting a bit long. Write back with anything that needs to be be clearer.