Pixels per inch?

I am a knifemaker who sells via the net. I have my third Canon, this one is an A3100. Been using it for years, has always done what I needed.
Until Now.
Spent most of a day getting a camera-ready ad together for a magazine.
Sent the copy in and it came back with a note saying the image must be at least 300 pixels per inch. Mine was 160.
So I reread the manual and nowhere does it mentions Pixels Per Inch.
I use Paint.net software and it has pixels per inch.
Is there a way to set the camera to use 300 pixels per inch?
Thanks!
Dave

WinDancerKnives wrote in post #17462870
I am a knifemaker who sells via the net. I have my third Canon, this one is an A3100. Been using it for years, has always done what I needed.
Until Now.
Spent most of a day getting a camera-ready ad together for a magazine.
Sent the copy in and it came back with a note saying the image must be at least 300 pixels per inch. Mine was 160.
So I reread the manual and nowhere does it mentions Pixels Per Inch.
I use Paint.net software and it has pixels per inch.
Is there a way to set the camera to use 300 pixels per inch?
Thanks!
Dave

Pixels per inch refers somewhat to the resolution. With a photo at 160 PPI, the photo will not print well and may be pixelated. You can change the PPI in programs like Photoshop where you can resize an image.

Or you can download Image Resizer for free. This is a windows 7 application.

Here is a link: https://imageresizer.c​odeplex.com/

What they need is an image that's at least 300 pixels for every inch the final ad will be, both wide and high. So for a quarter-page ad, they'll need something that's at least 1200x1500 pixels (4"x5"). Since you said you prepared "a camera-ready ad", I assume you'd edited a picture or pictures, using some program like Photoshop, Elements, Paint Shop Pro, Zoner Photo Studio or the like to add text and/or paste in several photos. If that's the case, you'd need to make sure your ad copy meets the minimum number of pixels for the size (in inches) it'll run. Then, you'd set the image properties for that image (in your editing program) to 300 dpi. Then when you saved the completed ad as a JPEG/TIFF or whatever format they need, it'd have their required "300 ppi" setting.

Incidentally, dealing with the publishing industry is probably one of the few instances where "pixels/dots per inch" actually matters as much as the absolute number of pixels in the image. You might also check with the publisher about what "color space" they need the file to be; common color spaces are "sRGB" and "Adobe RGB" (not exclusive to Adobe); they represent colours slightly differently, so using the wrong one can cause some colours to shift.

With any press printed pieces you need to deal with two parameters:
1. The DOT per inch, which is a characteristic embedded within the file, which tells the offset press the density of ink dots to print a photo. For your own experience with this parameter, think of your local newspaper vs.a copy of National Geographic...the local paper photos are very low quality while the National Geographic and Sports Illustrated ones are pretty high quality and fairly 'realistic'...that is entirely due to the number of inkdots that make up the photo, and NOT the PIXEL COUNT of the photo! You might have seen the swimsuit controversial pictures in the newspaper, which are very much lower in quality than the SI images in the magazine!
2. The PIXELS per inch defines the amount of detail within the photo and how 'sharp' the photo appears to the viewer, and also may exaggerate the 'stair step' rendition of any edges running not perfectly vertical or horizontal in the photo.

Unfortunately all too many press printers confuse the two parameters above. Their thinking for a very long time is about the 'screen' or the density of dots that make up the halftone dots of ink rendition of a photograph...low dot screen used for newsprint typically, high dot screen used for National Geographic and Sports Illustrated.

Was that the 'dpi' parameter within the embedded EXIF data, or was it lack of true image resolution? If your photo was only 1600 pixels tall and would print 10" tall on the final page of the brochure being printed, that is 160 PIXELS per inch (point #2 above), regardless of the inkDOT density value (point #1 above) buried within the EXIF of that file.

WOW!
Thank you for all the info! I really appreciate you all taking the time to explain this to me

So to be sure I understand:

I use Paint.net to work with all my pics and it has a PPI setting when you work on a photo.

So I don't NEED to change anything on my camera and can just reset the PPI in the software and that changes the actual image to the required 300 PPI? Does that work with any image that I can open in Paint.Net?

And 1 last question before I go modify my ad: Does converting a color photo to Black and white affect how the picture 'looks'?

An interesting thing I found when I bought this camera which was much higher pixel quality- The pictures with the new camera had 'scratches' in every shot. I finally sat down with a picture of a specific knife and the actual knife and looked them both over with a magnifier. That batch of knives actually DID contain those scratches. These old eyes could not see them on the knife. I immediately wondered how many knives I sold that had the scratches Now, before I consider a knife finished I go over it with the light and magnifier and if it looks good I take some pics and go over those, too. My dad drummed into e from the time I was a small boy that 'It is a poor workman who blames his tools'. In this case my unaided vision tool was actually at fault.

Thanks again for all the help.
Dave

That's right, changing the Paint.net ppi setting to 300 will do what you need.

As for converting colour to B&W, well, it depends. "To simplify somewhat, if two colours are both about the same "brightness" and you change the image to B&W, they may blend together, even if one's a bright red and the other's a blue or (more likely in your case I'd guess) one's the steel of the blade and the other's a tan of a bone or wood handle). So you might, in those cases, want to play around with your B&W conversion process.

Thank you all again. I was ready to tear out my hair [But that is figurative since I no longer have hair] combing the internet and the Canon site trying to find out how to reset the pixels in the camera
Your help is enabling me to get the ad published now instead of waiting three months.
Thank you!
Dave