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mag
07-07-2004, 08:19 AM
Hello. I'm new here. I'm having a bit of a problem with my pictures, and I was wondering if anybody here could help me out.

I have a Canon PowerShot A80. It's a 4 megapixel camera. I have it set to the highest quality settings it can go to--2272x1704 resolution, superfine compression. But I'm noticing some graininess in my pictures, especially when I print them out. I have also noticed when I look at the image properties that they only have 72 pixels per inch. I've been told that it should be 200-300 pixels per inch to get a quality image. But I don't know how to change that.

So I guess my question is what resolution/print size/whatever else should I use to get the best pictures from my camera?

Thanks.

mag

Nick
07-07-2004, 08:33 AM
Hi mag, you say grain noticed when printing. Grain can also be related to the ISO the image was taken at - do you know if you shoot in AUTO ISO, or do you set it yourself for various situations?

Also, what printer/paper/quality settings for it are you isng?

Now, a little about DPI :)

DPI stands for dots per inch, and states the number of dots that fall in a square inch, which makes up an image on a printed page. More dots, the smoother and the better an image. Low DPI, dots may be visible to the human eye rather easily, which of course isn't good.

Digital photos already contain a DPI when the picture is taken, and you can't further change it in photoshop or when creating a new file. The higher the quality of the in-camera settings, the higher the DPI. You can find out what DPI your image will print at by dividing the largers dimension of the image, by the largest dimension of the print.

If your image is, estimated at 2200x1700, and you wanted to make a 8x11 print, your DPI will be 200. 2200/11 is 200DPI, which will look very, very nice printed at that size. 300PDI is excellent quality, but you need a bigger image size. The bigger the image taken, the bigger the DPI you'll be able to get.

At least this is understanding, which is hopefully right :)

Ray Schnoor
07-07-2004, 08:51 AM
When a camera takes a photo, it is saved as pixels. When you print out the photo, the optimum setting is ~300 pixels/inch, although you should be able to get acceptable photos with 150-250 pixels/inch.

Printers, on the other hand, have dpi (droplets of ink per inch) in their specs. If you print a photo on high quality photo paper at the highest quality setting on, say, a Epson Photo Stylus at 2880 dpi, you will get several droplets of ink for every pixel in the photo.

In other words, pixels in a photo and dpi settings of a printer are not related to each other.

As to changing from your default of 72 pixels per inch, that would be for a printed photo of 31"x23" for your camera. I am guessing that if you set a print size of 4x6 or 8x10, the pixels would change proportionately.

As to the grainyness(?) of your printed photo, make sure that you are printing on photos paper at the highest "photo" quality setting of your printer.

Ray.