dpi?

Sorry if this is a dumb question but this magazine I want to submit to only accepts pictures at 300dpi. All of the pictures from my camera say 72 and I'm pretty sure that can't be changed.

So do you just change the dpi while editing in photoshop? or...?

ShaneKPhotography wrote in post #12366451
So do you just change the dpi while editing in photoshop?

Yes, just change the number when you output it, don't resample the image, and the image file will be completely unchanged apart from reading 300dpi in the metadata. That should keep them happy.

It's not a dumb question, it's the people at the magazine that are dumb.

DPI is meaningless until an image is printed, and then it's really the number of pixels width divided by the width of the print in inches. That's all.

Anyway, it's PPI (pixels per inch).

The 72 DPI in the EXIF field is required to be there by the EXIF standard if the device (your camera) doesn't specify DPI. 72 is specified as the default because some software crashes if there's nothing in that field. So it really means nothing.

You can change the DPI in the EXIF if you use DPP to process your raw images. Just put the 300 in the box when doing the "convert and save". It doesn't change the image in the least, but it makes ignorant picture editors happy.

You can do the same in Photoshop, but I don't know where the setting is found.

-js

When you open a RAW image into ACR set the Resolution in the Work Flow Options. Otherwise in Photoshop under "Image / Image Size" you can change the Resolution.
If you do it in Photoshop and don't want to change the pixel dimensions make sure you uncheck "Resample Image".
If you do want to resize the pixels dimensions make sure you change your resolution first.

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DPI (dots per inch) and PPI (pixels per inch) are mixed up by publishers, even though the two are not related to one another. Blame the lack of understanding by publishers, and/or blame the stupid software writers who mix up the two concepts by labeling 'DPI' when they really mean 'PPI', or vice versa!

• A print from a shot on film has no pixels. But when printed on a page by an offset printer (in a newspaper vs. in a high quality glossy magazine like National Geographic) using a 'screen' or matrix of dots on the page, the output quality is set by the 'screen' DPI.
  
• A print from a shot on digital has pixels. When printed on a page by an offset printer (in a newspaper vs. in a high quality glossy magazine like National Geographic) using a 'screen' or matrix of dots on the page, the output quality is set by the 'screen' DPI.
  

So basically what you all are saying is that by changing the number (dpi) it is just telling their printer how to print it?

Thanks everyone. This has been helpful.

ShaneKPhotography wrote in post #12377858
So basically what you all are saying is that by changing the number (dpi) it is just telling their printer how to print it?

Thanks everyone. This has been helpful.

The "DPI" number embedded in the image file by the camera is totally useless and, unfortunately, is totally misunderstood by many people who really should know better.

When I print an image file, I tell the software what physical size that I want the image to be. All of the pixels in the image file wind up being printed to that size.

If you need to change the "72" to "300" for some stupid publishers to be happy, that's fine. Just don't allow that change to affect the pixel count in the image file.

It amazes me just how many people involved in the printing profession are dead wrong about this.

JoYork wrote in post #12381764
It amazes me just how many people involved in the printing profession are dead wrong about this.

Unfortunately there are no laws against stupidity :rolleyesor laziness in finding it out)

number six wrote in post #12366647
It's not a dumb question, it's the people at the magazine that are dumb.

DPI is meaningless until an image is printed, and then it's really the number of pixels width divided by the width of the print in inches. That's all.

Anyway, it's PPI (pixels per inch).

The 72 DPI in the EXIF field is required to be there by the EXIF standard if the device (your camera) doesn't specify DPI. 72 is specified as the default because some software crashes if there's nothing in that field. So it really means nothing.

You can change the DPI in the EXIF if you use DPP to process your raw images. Just put the 300 in the box when doing the "convert and save". It doesn't change the image in the least, but it makes ignorant picture editors happy.

You can do the same in Photoshop, but I don't know where the setting is found.

-js

A lot of times people at the magazine get photographs that have cropped and resized to say 2X3 at 72PPI. Try and get a sharp 4X6 image in a magazine from a 2X3 72PPI source. It aint gonna happen. Folks at the magazines get all kinds of submissions from all kinds of sources. The usually prefer a 300 PPI image to whatever size the will be using in the publication. If its a 4X6 image they would like to get a 4X6 at 300PPI though in reality a 4X6 at 240PPI would work just fine. But to make life easier for everyone make sure the image you send is 300PPI at whatever size they need or larger. Don't take a small image like a 2X3 at 72 PPI thats been resampled and saved smaller and try and upsize it by just changing the PPI.

Sorry but I also wanted to add that many publications are now getting adds designed by office managers and other folks that don't understand all of this. Say an office manager gets a small image thats been reduced in size to 72PPI for a website or a powerpoint and they grab that reduced image thinking because it looks great on the screen its gonna be great in the ad.

Magazines get images even from some photographer that are just to small to reproduce in their publications. They're usually very busy and to just tell folks to send everything at least sized at 300 PPI to the size the image is going to be in the article or ad is the easiest way to insure getting image large enough to appropriately reproduce .

airfrogusmc wrote in post #12381970
Sorry but I also wanted to add that many publications are now getting adds designed by office managers and other folks that don't understand all of this. Say an office manager gets a small image thats been reduced in size to 72PPI for a website or a powerpoint and they grab that reduced image thinking because it looks great on the screen its gonna be great in the ad.

Magazines get images even from some photographer that are just to small to reproduce in their publications. They're usually very busy and to just tell folks to send everything at least sized at 300 PPI to the size the image is going to be in the article or ad is the easiest way to insure getting image large enough to appropriately reproduce .

The problem is that they don't say "4x6 @ 300 dpi" or 5x7 @ 300 dpi", they say only "300 dpi", period. If they were to specify a print size, it would be easy to calculate the number of pixels needed, but they don't, they just chant the magic mantra "300 dpi". As if a 400 x 600 pixel image can be printed at any size as long as it's labelled "300 dpi".

Dots, pixels its all the same. Just a different name.

300DPI = 300PPI @ final print size.

If you want a print at 4in x 6in @ 300 DPI you need an image at 1200px x 1800px.

Now LPI is a different story. That is what the press resolution is. Most 4 color offset presses print around 120-150LPI. You need double the LPI in DPI to achieve optimal clarity on the final printing.

TheReal7 wrote in post #12382747
Dots, pixels its all the same. Just a different name.

300DPI = 300PPI @ final print size..

And this illustrates perfectly the confusion which abounds, the wrong information which is stated over and over.

If you re-read post #5, you will appreciate the actual difference between 'dpi' and 'ppi'.

Wilt wrote in post #12385425
And this illustrates perfectly the confusion which abounds, the wrong information which is stated over and over.

If you re-read post #5, you will appreciate the actual difference between 'dpi' and 'ppi'.

My statement is 100% accurate when it refers to images and the off-set printing world in which the OP talked about. No one uses PPI in the print industry.


You confusing LPI with DPI in your post.
http://web.sos.com.au/​index.php/dpi-vs-lpi.html