how to set ppi settings on a digital camera NOT dpi

usignuolo

I have a couple of digital cameras I use to take photos, a Sony Cybershot and a Canon powershot. Recently a friend asked me if they could use a couple of photos I had taken to accompany a magazine article they had written.

So I emailed the images to the publisher. One image was 3.5mb in size and the other was 2.4mb. I normally take photos at quite a high resolution setting on my cameras and in this case I took one on the Canon on the largest setting available 2816x2112 and the other on the Sony which is a bit older at 2048X1536 (also largest setting available).

The publisher has sent back a message that the ppi of the images, as opposed to the dpi is too low for printing as it should be at least 300 ppi. I think the images concerned are 180ppi. I have tried resizing in Paint Shop Pro but it makes the images shrink, on screen at least.

Everything I look up says not to worry as you will be preparing images for a monitor but in this case I am not I am preparing them for printing. What am I doing wrong and can I change the setting on my cameras, and if so how ? Can anyone advise?

Scrilla

Yuk! A lot of people seem to confuse ppi and dpi. There are loads of sites that try to explain it such as here.

In short, you would need a camera with more megapixels to achieve 300ppi. Alternatively, the printed size (not screen size) of the image needs to shrink to achieve 300ppi. The third alternative is to have the image printed at the size wanted (doing some manipulation to compensate for the lower ppi), but it won't come very nicely in magazine print.

I'm not an expert by any means, but that is at least how I understand it without trying to go into jargon.

chrisbur

usignuolo wrote: »

I have a couple of digital cameras I use to take photos, a Sony Cybershot and a Canon powershot. Recently a friend asked me if they could use a couple of photos I had taken to accompany a magazine article they had written.

So I emailed the images to the publisher. One image was 3.5mb in size and the other was 2.4mb. I normally take photos at quite a high resolution setting on my cameras and in this case I took one on the Canon on the largest setting available 2816x2112 and the other on the Sony which is a bit older at 2048X1536 (also largest setting available).

The publisher has sent back a message that the ppi of the images, as opposed to the dpi is too low for printing as it should be at least 300 ppi. I think the images concerned are 180ppi. I have tried resizing in Paint Shop Pro but it makes the images shrink, on screen at least.

Everything I look up says not to worry as you will be preparing images for a monitor but in this case I am not I am preparing them for printing. What am I doing wrong and can I change the setting on my cameras, and if so how ? Can anyone advise?

Changing the ppi is no problem you have done it with Paint Shop Pro, as you say the picture became smaller on your screen. The ppi shows how big a picture will be when displayed or printed, so take the pixel size of your picture say the 2816x2112 as an example and divide be the ppi. This gives for 180ppi a size of 15.64 x 11.73 inches, but at 300 ppi it gives 9.38 x 7.04 inches.
300ppi is generally accepted as the standard for printing so in the example it would be considered okay for printing up to about 9 x 7 inches but if printed larger would not be a very good picture. Your smaller picture would come out at about 7 x 5 inches.
If the publishers are saying that they are going to use the pictures at or below these sizes then all that is needed is to change the ppi as you have done, but if that is the case I would have thought they would have done this themselves. If they want to use them bigger than these sizes then the only thing you could try is interpolating to a higher pixel count. How successful this would be would depend on the quality of the pictures and I would suggest asking the publishers if this would be acceptable.

JustPassingBy

usignuolo wrote: »

Everything I look up says not to worry as you will be preparing images for a monitor but in this case I am not I am preparing them for printing. What am I doing wrong and can I change the setting on my cameras, and if so how ? Can anyone advise?

Neither of the images are suitable for monitor display. My screen is 1280x1024; they will not fit on it (or anyone else's for that matter).

But you want them printed, which is a different matter from viewing on a display. It is critical to know the size of the image on the printed page. Suppose it is 8"x6".

ppi horizontally = 2816/8. Approximately 350 ppi.
ppi vertically = 2112/6. Approximately 350 ppi

If the publishers print at that physical size (or less. or a bit more) you have sent them the perfect picture and they are idiots to reject it.

dpi and ppi are the same.

JustPassingBy

It was only on my second, more careful reading of this post that I realised:

chrisbur wrote: »

Changing the ppi is no problem you have done it with Paint Shop Pro, as you say the picture became smaller on your screen.

The screen size is smaller because he has removed some pixels from the image - not because the ppi (dpi) has changed.

The ppi shows how big a picture will be when displayed or printed, . . . .

I'm afraid not. With printing, yes. The screen size on a particular display depends only on the pixel size of the image. ppi has nothing to do with image size on a screen.

so take the pixel size of your picture say the 2816x2112 as an example and divide be the ppi. This gives for 180ppi a size of 15.64 x 11.73 inches, but at 300 ppi it gives 9.38 x 7.04 inches.

300ppi is generally accepted as the standard for printing so in the example it would be considered okay for printing up to about 9 x 7 inches but if printed larger would not be a very good picture. Your smaller picture would come out at about 7 x 5 inches.

Ok. A good example.

If the publishers are saying that they are going to use the pictures at or below these sizes then all that is needed is to change the ppi as you have done, but if that is the case I would have thought they would have done this themselves.

Maybe they do not understand the significance of ppi. All usignuolo has do is change the ppi to 300 without altering the pixel dimensions; that is, without changing the onscreen size. In imagemagick it's a 10 second job. I do not know how it is done in Paint Shop Pro.

Mobeer

I think (and I am no expert here) that in Paint Shp Pro you go resize the image, change the Resolution to 300 (with units Pixels / Inch) and then change the Pixel Dimensions back to 100 Percent. This should change the Print Size to compensate for the changed Pixels per Inch.

Probably want to try this on a copy!

Are you getting paid for this? If not, why doesn't the magazine sort out its own images!

JoeA81

Yes in this scenario PPI and DPI are the same thing (Pixels Per Inch/Dots Per Inch - same)

DPI is not an inherant characteristic of a digital photo, it only comes into play when the photo is printed on paper.

For example if you had a photo that was 100x100 pixels/dots whatever, and it was printed on a page so that it was 2 inches x 2 inches in size, then it would have been printed at 50 DPI. However if it was printed so that it was 4 inches x 4 inches, then it would have been printed at 25 DPI. The photo itself has never changed from being 100x100 pixels, but that size to which it has been printed on the page has affected the size of the "dots" so a lower DPI looks worse.

There is nothing you can do to change these images to make them more or less acceptable to the publisher. All they need to do if they want them to be 300 DPI is to print the images smaller on the page! And if they want the images to be bigger they should have used a professional with a higher resolution camera!

mr_fishbulb

I'm very surprised that the publisher doesn't have the tools available to do this themselves.

JustPassingBy

mr_fishbulb wrote: »

I'm very surprised that the publisher doesn't have the tools available to do this themselves.

It's probably not the tools they lack.

chrisbur

JustPassingBy wrote: »

It was only on my second, more careful reading of this post that I realised:



The screen size is smaller because he has removed some pixels from the image - not because the ppi (dpi) has changed.

I'm afraid not. With printing, yes. The screen size on a particular display depends only on the pixel size of the image. ppi has nothing to do with image size on a screen.

Yes you are absolutely correct, I forgot that i have a habit of clicking on View Print Size in my Elements 8 to see the print size on the screen. If you do not do that then as you say the screen size will not alter just by changing ppi.

usignuolo

What I was really wondering is whether this is something I can set on as a setting on my camera, or do I need a larger camera? The printers by the way say they will not even open anything which is less than 300 ppi and 5mbs in size.