At what megapixel does a camera become the limiting factor when printing digital images?
I hope other users can understand the question. What I mean to say is if I were to use a 4800 dpi inkjet printer to print images from a 5 mp camera, would the printer or the camera be the one limiting the image quality? Should I substitute the printer with a 9600 dpi printer or the camera with a 10 mp camera? If I were to get a 9600 dpi printer, what would be the recommended mp camera? At what mp does it become overkill, assuming I don’t plan to do any cropping or resizing.
The number of DPI on a printer can be misleading. 4800 dpi doesn’t mean a printer can print 4800 pixels in one inch. It’s just the size of the ink droplets. When you print a picture the computer automatically resizes it to send it to the printer. This is more complicated than it appears, but thankfully it’s done automatically by the printer driver.
More megapixels is better, of course, but not as much as you might think. For instance, your camera might have more pixel resolution than your lens can resolve, in which case the lens is the determining factor. 5 MP. is plenty for an 8×10. More MP might give you better color saturation or better tones, but won’t make the picture any sharper.
Check out this article, ‘The Megapixel Myth’. It has actual samples to look at of different MP cameras printed the same size.
http://www.kenrockwell.com/tech/mpmyth.htm
Check with the maker of your printer. Some (most) will give you the settings for files to get the best resolution on the paper when printing on their printer, with their ink and their paper.
Some have set the target DPI settings at 280dpi .. go figure.
As others have pointed out, the dpi specification on printers can be misleading. For one thing, printer driver software does some interpolating on its own. This means that, for instance, if you have an image that is 8×10" and 240dpi (dots per inch), the printer may "fill in the gaps" by printing dots in between your actual pixel images. This helps a lot in giving the print a smoother look.
In general, you don’t want to be printing using an image with less than about 150 ppi (pixels per inch). Anything above that is nice to have, and you can get professional-looking images at 240ppi and above. I personally like to print at 360ppi if I have enough pixels in the image for the size of the print.
So, let’s take your camera and figure this out. A 5MP camera probably has and image sensor with something like 1,920x2560ppi. This means that the largest print you can do at 150dpi is 12.8×17.1. That’s actually pretty large. But if you would rather get a little better quality, you might want to print with 240. This would now limit your max print size to 8×12. Still pretty large, really.
But there is one thing related to sensor and image quality you should probably be aware of. The larger the sensor, the better the image quality, generally. This means that a digital SLR with 6MP will produce better images than a compact zoom camera with 10MP. What I’m saying is that the mega pixel war is largely dubious in terms of the actual resulting image. unfortunately, it confuses a lot of people…
In general now, as long as you are setting up your printer properly, it will be the camera and lens (not to mention photographer, lighting, subject, etc.) that will limit the quality of your prints.
At 8X10, I don’t think you’ll be able to tell the difference between a 5mp camera and a 10mp camera and a 4800dpi and a 9600dpi printer.
What you WILL notice is the difference between a crappy lens and a good lens, a noisy sensor and a clean one, and a good photographer and a bad one.