neilds37 Loc: Port Angeles, WA

Conversely, my camera has the same size sensor and I just printed an 11" x 14" that is just as sharp as the previous 8" x 10".

gvarner Loc: Central Oregon Coast

I think print viewing distance is the key. The closer you are for an 8x10, the sharper it has to be. Another factor is your sensor's resolution. Most are 300 or 250 PPI. For example, at 300 PPI, the dimension of a 1200x1800 pixel image would be 4"x6". So a 4x6 print would be at 100%, a bigger print would be a proportional increase or magnification of the image with associated magnified affects on defects.

wdross Loc: Castle Rock, Colorado

Not totally. It more dependent on the number of pixels recorded. 100 mp sensor records more data than a 50 mp sensor. A 50 mp records more than a 20 mp sensor. A 20 mp more than a 5 mp. Note that there is no indication of sensor size, only how many pixels. Then there is the displaying of that data in dpi (dots per inch). Most images are only printed at 250 dpi to 300 dpi since the eye, even inches away from the surface, cannot easily distinguish the individual dots. Then there is proper viewing distance. Anything closer is considered "pixel peeping". As you can see, sensor size is only one factor in the print. Sensor size usually limits the pixel size. Pixel size only determines how well the data is collected.

Now after stating all that, a properly shot 16 mp picture should make into a very nice 20X24 on your wall from a proper viewing distance. Larger sensors (e.g., more pixels) allow for larger sizes and pixel peeping.

via the lens Loc: Northern California, near Yosemite NP

Manufacturers make their camera so that at a set size a print can be made on a 1:1 ratio. You can however, often print much larger than that by using software to "upsize" the print with an algorithm (Lightroom does this automatically for you when you specify a specific size). To determine what size your camera can print on a 1:1 ratio at 300ppi (the resolution most often used for printing photographs) you divide the print pixel size (4608 in this case) by the desired print resolution (300 in this case). So, 4608/300 = 15.36. Then to find the other size for the print you do the same thing: 3456/300 = 11.52. So your Nikon P900 native 1:1 size for printing is a print size of 15 x 11. You can order digital mats to fit this size through many on line venders. The one I use is redimat.com. You may need to adjust the size a bit as a true digital size on a 3:2 camera is 10 x 15. (Sizes are figured by adding the same number to the ratio each time as you move up the size scale: so a 3:2 size with a 3 added to the 3 and a 2 added to the 2 is 6 x 4 and on up the scale.) You can figure out the size for the D200. In any case, most good quality sharp images can be printed quite large if you need that. The 1:1 ratio is a starting point for best quality image as determined by the camera manufacturer.

burkphoto Loc: High Point, NC

About 20x15 and 15x10, at roughly 240 PPI (minimum resolution where you spread ORIGINAL, uncropped, in-camera pixels over the surface of your paper, without being able to see them). Actual is 19.2x14.4, and 16.13x10.8 at exactly 240 PPI (common standard lab resolution).

BUT, you can double those dimensions for subjects viewed at a normal distance from the print --- 1x to 1.5x the diagonal dimension of the print. Just interpolate (enlarge) to the larger size in software or a RIP.

This assumes good light, base (normal low) ISO, and good techniques all around...

DMGill Loc: Colorado

If you have a photo printer, try my method...
Start with a copy of the image in Photoshop. Size that image to the largest image you would like to have and then crop down on an important part of the image to a size that you can print. Make a test print of the cropped image and see what it looks like at the distance you expect your photo to be viewed. This test method takes into account the many variables an individual image may present and lets you make the decision based on your own judgement.

wdross Loc: Castle Rock, Colorado

One more piece of food for thought. Your Nikon P900 will actually allow you to print a larger print "easier" (more data), but your D200 will capture the light "better", especially in low light levels (larger pixels). Both should easily print 11X14 and, with proper processing, as large as 20X30 or possibly slightly larger.

jack30000

DxOmark (https://www.dxomark.com/) rates camera and lens combinations using what they call perceptual megapixels (PMP). Many here will say don't get hung up on the numbers, but it does give a way to compare, for example, a 24 MP full frame with a "cheap" lens with a 16MP crop sensor and top quality lens.

Reinaldokool Loc: San Rafael, CA

Problem is the pixel size. The smaller pixels in a tiny sensor do not produce good 16x24s, in an aps-c sensor even 12mpxls do produce goo prints. It isn't the megapixels, it is the pixel size and therefore how many photons each can capture.

John_F Loc: Minneapolis, MN

When you see a sensor size given as 1/x where x is a single digit and one decimal digit you are being told the sensor diagonal dimension rounded off to one digit. The minimal error in such numbers numbers would be +/- 0.05. Quoting diagonals that way is a hold over from the optical format of television days. It was the tube diameter that had a sensor inside strapoed to the tube by a bracket of sorts. For camera sensors it is a very poor format to quote, when the exact width and height is known. One time I was going to buy a camera that had the sensor specified in optical format; my question to the manufacturer was not answered - needless to say I did not buy.

Whuff Loc: Marshalltown, Iowa

When you upload your photo to Mpix send the largest file size you possibly can, go to the print section and select the size you'd like to print, If the file size is too small for the print size you've selected it will tell you that you can't print that large or will not allow that selection. It's been a while since I ordered from them so I don't remember the exact sequence of what it tells you but I know I wasn't able to get as large a print as I wanted once for that exact reason and the site let me know. Also, you can call their customer service dept. or e-mail them and ask. They have great customer service.

Walt

a6k Loc: Detroit & Sanibel

I can't help you with print sizes, but here is one example of a graphic from the internet that shows sensor sizes. Your P900 has a 6.17 mm wide sensor. A "one inch" sensor has roughly double that width. A full frame sensor has about 36 mm width. This is only one of perhaps hundreds of good explanations out there.
http://photoseek.com/wp-content/uploads/Sensor-sizes_PhotoSeek.jpg

If you multiply the image's stated pixels width by the stated height in pixels you will get approximately the mega-pixels.

Note that the 16 MP P900 has (I'll let you do the math) much greater pixel density (or the inverse, much smaller pixel size) than, for example, an a6000/6300/6500 or a a7R2 (same for Canon, Nikon, etc. but examples that I know well). The size of the pixel on P900 is about 1.3 or 1.4 microns. The size of the pixel on an a7R2 is around 4.5 microns. Size matters. That is one reason, a major one, why the IQ on a 1" sensor is a lot better than a 1/2.3 sensor but that a FF sensor beats them both by a wide margin. Small sensor cameras are designed to have acceptable IQ and acceptable size, weight and convenience. The user self-defines "acceptable".

The sweet spot for enlargements is not where the P900 landed. View your pics on a computer at 100% to see what is really going on. I suggest using Imaging Resource's test shots for further comparisons.

Elsewhere on my posts you will find two pics of a squirrel, one shot with a Sony RX10 III and one with a P900. On a reasonable size monitor with perhaps less than 2000 pixels width, they both look good. If you blow them up to 100% the differences become easily seen.

Clear as mud, right?

MikieLBS Loc: "Southeast of Disorder"

You can get away with enlarging a medium quality photo too if you place it someplace where people will have to stand back a few feet to look at it.

wdross Loc: Castle Rock, Colorado

Your P900 16 mp sensor, the Olympus 16 mp 4/3rds sensor, and a Kodak 16 mp medium format sensor will all produce a similar resolution print. The computer does not care where or how it gets the 16 mp to generate a print. It will generate the same amount of resolution from any 16 mp file. The difference will come from the interpretation of the data collected by the pixel. Your P900 will have the highest signal to noise and the Kodak will have the least. The Kodak sensor will have the greatest native dynamic range and the P900 the least. The Kodak sensor will be able to produce the most color bit depth and the P900 will produce the least. And the Olympus sensor will be in the middle of it all.

Under the right conditions, all three sensors can produce a 20X24 print that from a proper viewing distance will be very difficult to tell one from the other. But the P900 will require more shooting skills and better lighting conditions than shooting with a medium format sensor to get the same amount of consistency.