Originally Posted by cTLgo
I have some 3 megapixel pictures that I took with my Sony DSC-P100/P120. I was wondering, what is the largest I can print these without losing quality? 8x10 photo? Can I do a poster?
No offense, but I don't like your question.
A picture of the same size will be sharper if the original source has more megapixels. Likewise, for a particular image, the larger you print it, the less sharp it is. That's pretty much a fact of life.
The exception is if you print so small that the printer can't print at that high of density. But you see my point.
Let me rephrase your question to make it more useful:
"How big can I print a 3 meg jpeg, and still have people go say 'hey, great picture' versus 'wow, is that made out of legos?'
To give you some food for thought, I have three 8x10 pictures that I like to show people at work. Almost all the time, the reaction is, 'wow, great picture. What resolution is this camera? 5 MP? 6?'. I smirk and happily say - those were taken with my Olympus 2020 - a 2.2 meg camera.
So you can print much larger than you'd expect. I have a friend who has a couple of very nice 2 meg pictures blown up to 16x20. They are framed in her husband's office, next to a couple of 16x20 pictures shot with a 6 meg camera. I would bet money very few people realize they were shot with different cameras.
Keep these two things in mind:
1) The bigger the picture, the further back people will stand to look at it.
Imho, Most people rarely glance at a picture for more than a few seconds. They're not going to stand right next to it and pixel peep. So even though you blow something up large, and the pixels are bigger, people will generally stand further back anyway, which makes it less of a problem.
2) Certain pictures blow up better than others. Landscapes and single object pictures (like say, your dog, or a sunset), work well. Given a single object, people will generally stand far enough back to view the entire object. If it's a group photo of many people, you have slightly less leeway because they will start looking at each person, focusing on tighter area. One of my 8x10s is this one:
but people are still surprised when I tell them it's a digital picture.
So just print out one or two at different sizes, and see how you like them. I printed out my 8x10s as a joke - I was SO SURE they'd be crap. Instead, I was so happy with them I hang them up on my wall. Are they razor sharp? Of course not. Are they nice enough that everyone who sees it is happy with it? You bet.