Good morning,
So I have been sending out free prints to various groups over the last several months. Mainly healthcare workers. I am printing them at home and have been noticing that viewing distance is a question that needs to be asked. Some of the photos that I have are older so smaller sized and some have digital noise. If someone was viewing either of those pictures at really close they don’t look that great. However if there is an 8x10 print it is probably not going to be viewed at a few inches or even a foot. More likely it will be put on a wall or a shelf and not viewed from less than an arms length away (in my case that is about 2.5ft). At that distance minor noise will not be seen and a lower resolution image will look fine.
A common idea for printing images is 300 pixels per inch or PPI. So a 4x6 would need 1200x1800 pixels or a 2.16 megapixel image. A high definition TV is around the same 1980x1080 at 2.14 mp. We aren’t viewing it from inches away though it is across the room and it looks great.
I have printed 10mp images at 20x30 inches and they look great with 129 PPI and 16mp images at 24x36 inches at 136 PPI. Again they are not being looked at inches away and even if they were it would be a higher pixel density than a 40 inch HD TV.
Above is a picture I recently sent out it was printed at 13x19 inches at 276 PPI. The 4x6 print is a test at roughly full size. I took the pictures of the 4x6 with my cell phone. 1st is several inches away and the 2nd is about 2 ft. I cropped them to the same size so it is a mock of how a person would see the print at different distances. The most noticeable noise is on the black mountain. The 1st image it is speckled all over in the 2nd image a few are visible. Most people aren’t viewing a 13x19 inch print from 2 feet away it is from 4 or more feet away so this noise would even be less prominent than show above.
Viewing images 1 to 1 on your screen is a neat thing to be able to do, it is not often needed in my opinion. Also don’t be afraid of a little noise when printing.
~Scott