increasing the dpi of a photo?

Question

I am making a business card and the photo that I have is 72 dpi and the company says that the pictures should be 300 dpi for best quality. I increased to 300 and the quality on my computer looks pretty bad. How can I be sure that these will print out okay?

here is what the website says...
Important Requirements:

1.The maximum graphic size that can be imported is 5 MB (5120 K).

2.We recommend the following graphic formats: .JPG, .TIF, .BMP.

3.You may upload black and white, grayscale and/or color images.

4.We suggest you make the image that you are importing the same size that you'll use on your design.

5.Low resolution images may print poorly especially when enlarged.
We recommend at least 300 dots per inch.

I understand now. Thanks for the advice. I went in and resized it. It was 1200 x 886 and I changed it to 300 x 222. Hopefully that will work out good.

Answer 1

you cant just change the number of the photo- you have to have an original higher resolution image to work with-

72dpi is a web image- if you increase the number it is still the same information in the picture you cant add more info (or more pixels) once it has been taken out-

the only way to work with a 72 dpi photo is to shrink it to 25% of its original size (figure 72 x 4= 288, thats close enough)
so either find a larger 72 dpi image to shrink down to a 1/4 of the size or find a new image at 300 dpi

Answer 2

There is always a lot of confusion between PPI and DPI and it has nothing to do with the resolution of your picture, only with how the printer will print them.

When you take a photo, the resolution of the image is given in # of pixels. When it is being printed, the standard printing setting will be to print 300 dots (or pixels) per inch. So if your camera happened to take pictures at 300 pixels wide x 300 pixels high (<1 megapixel), a 300 dpi printer would print this at 1in x 1in.

Let's say though that you are shooting a Nikon D70 6 megapixel camera. It shoots at 3008 pixels wide x 2000 pixels high. At 300 dpi, this would equal a picture roughly 10 inches wide x 6 2/3 inch high. Printing the same file at 200 dpi, the print would be about 15x10 inches. The source image doesn't change - it is always 3008x2000 pixels, but the printed resolution does because your are spreading the pixels out further when printing. Different cameras handle files differently than others, but a 6mp camera has the same resolution as any other 6mp camera, and is independent of the printed resolution or what the file's dpi is listed at.

So what does this mean? Many printers want you to specify the dpi setting and image size within the file itself. If you are using Photoshop and you want a 2 x 3 inch wide photo printed on your business card at 300dpi, the easiest thing to do is use the crop tool and specify a 2x3 crop at 300dpi and it will do all the work for you. Otherwise you will need to crop it to the correct 2x3 ratio and then specify the image to be 2in x 3in at 300dpi.

Answer 3

300 dpi is the standard resolution for printing - 72 is the standard for screen

Yes you should print the graphic at 300

You won't see the difference on the screen as the resolution of the screen is set at 72 dpi so each dot is 1/72 of an inch

As you have increased the number of dots to 300 per inch - one inch of photo is is now 4 inches

In other words it looks bgger not better. Printer dots are smaller and it should look better when printed

NOTE the maximum resolution you have is when you take the photograph / create the images everything else that you do detracts from this - if your image was poor to start with it will still be poor (actual poorer) when you increase the DPI