I recall that less than a decade ago, a DSLR with 12 megapixels of resolution was regarded as an object of wonder. Today the highest megapixel resolution on a 35mm body has reached a staggering 50+ megapixels. Like a cult of lemmings, photography gear-geeks are already positioning the new number as the new objective their next camera should attain to, or overcome. Taking a virtual stroll on various online forums, I observe that it almost seems like the thirst for ever-higher MP numbers is unquenchable. Scores of amateurs and enthusiasts worship the resolution deity with an almost perverse fervour. Yes perverse I say, because one must be clinically unbalanced to unequivocally believe that added resolution above what modern DSLRs already deliver will give rise to any more improvements to image quality. Apple for their part, publicly demonstrated to the world that you could run a billboard campaign with a 8MP camera phone.
There is also the fact that social media platforms just serve a re-sized, re-sampled version of images we uploaded. These online services are not going to give your image a megabyte of bandwidth. A few dozen kilobytes for a mobile website, a couple of hundred kilobytes for a desktop website at most.
So is there any justification for all that additional resolution? Of course! Higher resolutions are useful for producing prints, allowing us to print large images with a high DPI. However, the resolution requirement for printing could be subjected to some level of variation. A viewer will stand further away when viewing large prints. Hence it may not matter that you are producing a large print at a lower resolution, since the audience will not be standing near enough to notice it. Remember what Apple managed to do with 8 MP and some good image enlargement software. Except for specific commercial uses, any modern entry-level DSLR should have sufficient sensor resolution to produce a satisfactory print for most requirements.
Another compelling reason for higher resolutions is that it offers us more cropping and post-processing freedom. Sometimes you just happened to have the wrong lens attached to the camera when you had to take that picture. Sometimes you realized after taking the picture that you would have preferred a tighter crop. Sometimes it is safer to take a wider picture, then crop out the unwanted elements rather than risk losing image elements that you can’t recover.
All good reasons. So how much resolution is enough? Let us take a look at the following un-cropped image produced by a 24 MP camera sensor:
Maybe a bit more resolution and it could be good enough to use as a photograph for a passport, never mind the awkward pose. Bear in mind this was shot by a cheap Nikon 50mm f/1.8G lens, stopped down to a well-behaved f/5.6 with a high 1/250 shutter speed, since I was holding the camera with only one hand while drinking soda with another. This crop also comes from the edge of the frame where the lens is supposed to perform at its weakest.
So here we have a demonstration of what 24 MP can do. We have so many megapixels now that sensor resolution has long ceased to be an encumbrance to good photography results for most users. We are more likely to produce good images with creativity, skill and good shooting discipline.
Understand that the treasured prints of the photography masters are just low-resolution smudge compared to what our digital cameras can produce today. But their work will continue to hang in museums, while our monster resolution images will just get a day or week of fame on Instagram or Flickr, then fade into obscurity. So go focus on the things that matter – the art itself. The great artists were known for their skills and creativity, not the brands, types, or quality of the paint brushes they used.