When I am just messing around I normally take photos in the 1600X1200 setting. Is this the right thing to do?
If I think there is a chance of my making an 8 by 10 photo or an even bigger print from my picture should I raise my image size to 3264x2448?
Why would I have use the 4608x3456 ( 16m )?
Will my image quality be better if I crop an image depending on what image size I took the photo at originally? ( Say 1600x1200 compared to 3264x2448 )?
Thank you for your help!
For online or electronic display the image pixel dimensions are the image resolution, but also note that few web sites can display images at full resolution.
Cropping means discarding pixels. Fewer pixels means less image resolution. It is a good idea to avoid cropping whenever possible.
When you start referring to print sizes, like 8 inches x 10 inches you have to consider image pixel dimensions relative to resolution (as defined by pixels-per-inch or ppi) and the image aspect ratio.
Most DSLR cameras make images that have a 3:2 aspect ratio. An 8x10 print has a 5:4 aspect ratio. So some portion of a 3:2 image has to be cropped away to make an 8x10 print.
You have 1600 x 1200 pixel images, which is a 4:3 aspect ratio. 3264x2448 and 4608x3456 are also 4:3 aspect ratio pixel dimensions.
We can deduce that your 4:3 aspect ratio images have a long side that is 1.33333 times longer than the short side (4/3= 1.333), while 5:4 has a long side that is only 1.25 times longer than the short side (5/4=
1.25).
Using a 1600x1200 image as a start we can calculate how many pixels have to be cropped from the long side of a 4:3 to get to 5:4 - 1200 x
1.25 = 1500.
1600 px -1500 px = 100 pixels that have to be crop from the long side of a 1600x1200 image to print an 8x10.
Next we need some simple algebraic related math equations:
Pixels divided by pixels-per-inch = Inches
Inches divided by pixels = Pixels-per-inch
Inches times pixels-per-inch = Pixels
To print a 1500 x 1200 image as an 8x10 we use
Inches divided by pixels = Pixels-per-inch to get 1500 px/10" = 150 ppi. As a check we can do 1200 px/8" = 150 ppi to verify the resolution is the same for both sides of the image.
How much print resolution is needed (pixels-per-inch) relative to print quality is dependent on a number of factors - print size, image quality, viewing distance, etc.
Many online print labs have minimum ppi (resolution) requirements, usually at or near 100 ppi. No doubt, the higher the print resolution (ppi) the better.
