resizing pictures in pixels

<p>What are the dimensions (in pixels) that I need to crop a senior wallet for printing? Also what are the dimensions for a 5x7 and 8x10 (in pixels) My original photo is 2560x1920. I am new to this so please no rude comments. Thanks</p>

<p>Ideally best photo quality is obtained when the image is printed at 300 pixels/inch.<br>

So: an 8x10 will print best at a size of 2400x3000 pixels.<br>

The 5x7 will be best printed at 1500x2100 pixels and so on.....<br>

Your original <em>can </em>be up-sized as needed with little visible quality loss,(up to a certain size), in an editing program....Regards, Robert</p>

<p>Sarah, sounds like you have an Olympus or other digital camera with a 4:3 aspect ratio (which includes the Micro 4:3 cameras by Panasonic and others). That aspect ratio may require some cropping to fit traditional print sizes, just as the more common 3:2 aspect ratio for many dSLRs (which derives from the familiar 35mm film aspect ratio) requires cropping to fit an 8x10 print.</p>

<p>At the 300 pixels per inch specification Robert mentioned that will give you a print 8.5 x 6.4 inches or 21.7 x 16.3 cm. Or, if you prefer a print closer to 8x10, that same 4:3 aspect ratio at 300 ppi will give you a 10 x 7.5 inch print. This will also require resampling the file to a slightly larger file size in order to maintain the other factors - aspect ratio, print dimensions and resolution in pixels per inch.</p>

<p>The alternative is to choose a lesser resolution while maintaining the original aspect ratio, print dimensions and overall file size. For example, a 200 ppi resolution while maintaining all other factors - pixel dimensions, aspect ratio and file size - would give you a print 12.8 x 9.6 inches. Depending on the image content and viewing distance this may be an acceptable ppi resolution.</p>

<p>Without knowing the specific dimensions (inches or centimeters) of the wallet sized print we'd only be guessing. However you can estimate this for yourself in almost any photo editing software. For example, I just used Irfanview to estimate the variations I mentioned above, using a hypothetical photo file measuring 2560x1920. I could have done the same thing in FastStone, my copies of Paint Shop Pro, Photo Paint or other editors that offer features for resizing/resampling and print output previews. It's easier done than described - just plug in the variations you want to experiment with, whether print size in inches or centimeters, file dimensions in pixel resolution, pixels per inch (some folks use dots per inch, which can be confusing), or even file sizes in kb or mb (usually not relevant unless you're dealing with enormous files).</p>

<p>You can also preview crops in various editors. Irfanview and FastStone (shareware with unlimited free trials) both offer this but for some folks Picasa is even easier to use for visualizing cropping - altho' it's not quite as handy for estimating other factors such as pixel dimensions. Using a crop preview in a photo editing program will give you an idea of which part of the original file may need to be sacrificed in order to accommodate a specific print size that doesn't match the aspect ratio of the original file.</p>

3 x 2 inch wallet size printed at 300 ppi/dpi = 3 times 300 x 2 times 300 = 900 x 600 pixels

 

7 x 5 inch size printed at 300 ppi/dpi = 7 times 300 x 5 times 300 = 2100 x 1500 pixels

 

10 x 8 inch size printed at 300 ppi/dpi = 10 times 300 x 8 times 300 = 3000 x 2400 pixels

 

From this, I'm sure you can see how to do the math for 200ppi/dpi, or any ppi/dpi. Just multiply the print size dimensions by 200 or the chosen ppi/dpi.

 

 

The different sizes will not be in the same aspect ratio as your camera and you will have to decide how much to crop off. Even in the days of film this was a problem. A film frame would enlarge to 8x12 inches. The photographer or lab had to decide which 2 inches to crop off to get the standard 8x10 inch photo. Many photographers would frame a shot very loosely to allow for that.

<p>When converting inches into pixels you have to take into account the resolution of the image. The web generally is 72 px/in whereas most prints are 300 px/in. This makes a BIG difference.</p>

<p>Most wallet size prints are 3x2 inches, though they can be smaller. If you are printing them at 300 px/in, the dimensions would be 900 px x 600 px. Likewise a 5x7 would therefore be 1500 px x 2100 px. </p>