At what megapixel does a camera become the limiting factor when printing digital images?

Question

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.

Answer 1

I'm just agreeing with the guys above me. My goal is 300 dpi, though. Funny thing... I don't really have any idea what resolution I am printing. I can not set this directly with my Epson Stylus Photo RX620 printer. I set the paper type and the image quality and hope for the best!

I'm looking at the upgrade model printer (RX580) on Epson's website now. They say that it has a "maximum resolution" of "5760 x 1440 optimized dpi." What does THAT mean? It says, "Hardware Resolution = 1200 x 2400 dpi," (which I believe refers to the flat-bed scanner) and, "Maximum Resolution = 9600 x 9600 dpi interpolated." (There's that "interpolated...")

All I know is, if I want the best quality, I use good paper, choose "Best Photo," turn off "High Speed" and "Edge smoothing," and go for it. If my image is 300 ppi in Photoshop, I can't see any improvement in print quality if I crop it and wind up with over 600 ppi, so I just resize to 300 ppi. If I have anything in the 200 ppi range, it is still fine, although I can see the difference. If I get down to the 150 or lower ppi, I amnot going to be satisfied with the print.

Clear as mud, I know.

I have an assortment of cameras. I do like working with the 10 MP images and, obviously, the DSLR is better than the P&S camera, but as long as I am using most of the original image size, I can't see the difference in an 8x10 from the D200 (10 MP) or D70s and D50 (6 MP), even with a magnifying glass. My RX620 claims 5760 x 1440 optimized dpi resolution and 9600 dpi optimized resolution, by the way.

Answer 2

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 8x10. 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

Answer 3

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 8x10" 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 12.8x17.1. 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 8x12. 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.

Answer 4

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.