Wondering how large one can go without gross image degredation with a 16.1 MP camera like a Panasonic Lumix -- or sketchier, a Motorola Moto Droid cell phone.

I don't know about your cell phone, but I have gotten excellent results making 5 x 7 prints from my iPhone 6. 8 x 10 is okay. Anything larger - to me poor quality, but probably because in the film days I used a Hasselblad.

100 dpi is a rule for prints.

I like this one.

http://www.urban75.org/photos/print.html

I think 100 dpi is rather low for good quality.

If you have a good photo printer, that uses several inks, A4 is no problem at all.

There are so many variables involved in answering the question that even a "rule of thumb" would not be of much use, except to give a theoretical maximum. I have a poster-sized print taken with a 12 MP camera (Nikon D700) which looks great, exhibition quality.

What the camera/lens/processor creates in terms of quality is more important than the mere number of pixels, and then there is the printer, or print service, you use. And, small cameras and cell phones are hard to keep steady, meaning they won't look great no matter how many pixels if there is any camera movement. If I keep my 16MP Nikon Coolpix A pocket camera steady then an 16" X 20" print is no problem at all. But I have to do my part.

There are print services that specialize in iPhone source prints (like the free iPhone app Print Studio). Finding a good one will tend towards the best results and megapixels won't matter much.

If you don't want to make this a theoretical research project, go to the Photo Center at Walmart and get some prints made at various sizes of a good picture and judge for yourself what you find acceptable. You'll have "real world answers" with your own camera or cell phone. Feel free to share the results.

Thanks gents. I have managed a few images out of a very great many that by my low standards are halfway decent, and I was wondering if they had enough resolution to be blown up to 11 x 14 or larger. Guess Walmart will help solve the question.

Bill,

I have a terrible tendency to be too "edgy" in my posts when I think I'm right, and it's only after rereading them that I realize I could have been less direct and more "nudgy" than "pushy". But all the theoretical stuff is less helpful than the experience of doing it yourself with your equipment and in your environment. I really am interested in what you find out, with your camera and your printing service. It's so much more relevant than some optics/physics discusssion. And I hate "emojis" as a communication crutch.

And by the way, if you've got a digital image you think is good but could benefit from a little post-processing, don't hesitate to send it to me and I'll take a shot tweaking it.

I meant that to be taken as a minimum.

quote:

Originally posted by Saeed:
I think 100 dpi is rather low for good quality.

If you have a good photo printer, that uses several inks, A4 is no problem at all.