All too often, I see professional photographers on forums saying, “You don’t need more megapixels, 12MP is enough to print large photos with.” – and they are right, up to a point, but that is not the big picture (pun intended).
These pros are the same people who tell you that a used D700 (12MP) is just as good of a purchase as a new D600. I’m here to tell you that they are wrong, for 2 reasons.
The first is the image quality. The fact is that the D600 has a lot more dynamic range capability than the old D700. There is not question about this, and no debate. The D700 has a 12.2 EV range and 23.5 bits of color depth, while the D600 has 14.2 EV of range with 25.1 bits of color depth. It’s just a newer better sensor because technology has advanced over the last 4 years. For that reason alone, you should already choose a D600 over a D700.
The second reason is that 24MP is better than 12MP. And the D800’s 36MP is even better. And more MP’s than the D800’s is still better. Why, you ask? The answer is simple and obvious – you will spend less money on glass, and get more photos out of your camera with less lens changes.
A 36MP sensor allows you to use a shorter focal length, and crop in post-processing to get the same size photos that a lower MP camera produces at its best. Quite simply, you can use a much cheaper 70-200mm f/2.8 on a D800 instead of spending a lot more for a 400mm f/2.8 to put on a D700.
For anyone shooting hand-held, not a on tripod or secure base, you have to consider the possibility that you cannot hold the camera perfectly for every shots exact composition, and may need to crop in post. Again, having those extra megapixels is advantageous.
A regular print resolution is 300 pixels-per-inch (ppi) You can print in higher resolution if people are going to be looking very closely at the print, or you can print at a lower resolution if you plan for people to be viewing the photo at a distance, but for the sake of comparison, let’s look at controlling that variable, and assume that you want to make a print that will be viewed from 8-10 feet away, and that you want a 300 ppi resolution.
12MP is around 4,000 x 3,000. You could print your 12MP image up to 13″ x 10″, if it was not cropped.
24MP is around 5,656 x 4,240. You could print your 24MP image up to 18″ x 14″, if it was not cropped.
36MP is around 6,920 x 5,200. You could print your 36MP image up to 23″ x 17″, if it was not cropped.
Obviously, the statement that you can print large from a D700 is relative to what someone thinks is “large”. If you wish to print high quality, high resolution 16″ x 20″, you need the right camera for the job.
I know that this goes against the grain of some professional photographer’s recommendations, but the reality is that physics always trumps opinion.