Megapixels for Print Vs. Megapixels for detail ( The Megapixel Blog)

Every year, new cameras are being released with more megapixels than the previous year, making your current camera seem outdated. Case in point, first we had the Nikon D800 at 36.3 MP, and now the new Canon 5Ds was just announced to be a whopping 50.6 MP. So, with a sensor of this size, will you get big beautiful prints full of detail? Yes and no.

Detail is entirely dependent on sensor size. Where as image size is dependent on pixels. I’ve worked with DSLR’s from both Nikon and Canon at all resolutions. In the following blog I will do my best to explain.
Let’s start with talking about what megapixels are. A single megapixel amounts to exactly one million pixels in an image. If you know the width and height in pixels of an image created by your camera, it’s easy to calculate how many megapixels your camera can produce. In the case of my first Nikon, the images were 3008 x 2000, so I simply multiply 3008 by 2000 to get 6,016,000 pixels total. So, my little Nikon DSLR was 6 MP, rounded off.

Now that we have figured out what megapixels are, how many megapixels does an image need to be to be viewed on your computer? We basically figure that out the same way. For example, my 2014 custom iMac is 2560 x 1440. So, to view an image on my current monitor at 100% resolution, the image has to be around 4 megapixels. Surprising, isn't it? So now that we covered the size an image has to be to be viewed on a screen, how many megapixels do we need for print? Below is helpful chart that explains the largest an image can be printed, based on megapixels and quality.
PRINT SIZE & QUALITY
Typical Sensor Size
|
Resolution
(WXH)
|
Excellent @300dpi
|
Good @200dpi
|
Poor @150dpi
|
3mp
|
2048 x 1536
|
7” x 5”
|
10” x 8”
|
14” x 11”
|
4mp
|
2464 x 1632
|
8” x 6”
|
12” x 8”
|
16” x 12”
|
6mp
|
3008 x 2000
|
10” x 8”
|
15” x 10”
|
19” x 13”
|
8mp
|
3264 x 2448
|
12” x 8”
|
16” x 12”
|
22” x 16”
|
10mp
|
3872 x 2592
|
13” x 9”
|
19 x 13”
|
26” x 17”
|
12mp
|
4290 x 2800
|
15” x 10”
|
21” x 14
|
28” x 18”
|
16mp
|
4920 x 3264
|
17” x 11”
|
24’ x 16”
|
32” x 22”
|
35mm Film (Scanned)
|
5380 x 3620
|
18” x 12”
|
27” x 18”
|
36” x 24”
|
36mp
|
7360 x 4912
|
24” x 16”
|
36” x 12”
|
48” x 32”
|
So now that we know what megapixels are and how they effect digital and print viewing lets dive a little deeper into how they affect detail. Higher MP DSLR sensors have been pushed on us the last few years by camera manufactures. First the D800 and D810 at 36mp and now Canon is coming out with a 50mp. So will a 36mp or 50mp capture as much detail as a 36mp or 50mp Medium format? The simple answer is no It will not because a medium format is able to capture a greater range of information due to a sensor that is twice the size along with having larger photosites. Larger photosites are able to capture more information along with having lower noise. An APS-C can’t capture as much detail as a 35mm sensor. In the same regard a 35mm sensor cannot capture as much detail as a medium format sensor. Yes, with higher megapixels on 35mm sensors you can get a little increase in detail but marginally. I believe we have already hit the ceiling on the detail we can get out of the current size 35mm sensors we have out right now.

So why do manufactures keep pushing higher megapixels DSLR’s on us every year? The answer is simple. They need a way to convince us that the next model we buy is a bigger upgrade than the last.
There is a lot of debate over megapixels, and even this blog post cannot possibly go over all the science. Ultimately, it depends on your uses. If you're not going any bigger than standard photographic prints, then 16-22 MP is more than enough. If you’re shooting anything bigger than that, say billboards, then renting or buying a medium format is probably your best bet for optimal quality. As always, the best camera for the job is the one you have. Happy Shooting!
As always, I would love to hear everyone's opinions on this.
*Photographs that appear in this blog are not property of Jonathan R photography. They are purely being used for illustration purposes and Jonathan R Photography claims no rights to them.