On sensors and megapixels…

In the days of film photography, things were easy: NO sensors, NO megapixels… Was it better back then?

Well, it doesn’t really matter. Film is gone and it is relevant only in the realm of cult and youngsters that want to get the feeling of old school shooting and even developing and printing. We are now faced with numerous options about sensors and megapixels. Countless combinations of them and thousands upon thousands of users either supporting their purchase after the fact or trying to make sense out of this mess.

Back then, the standard film was the 24×36 mm “carre” which is equivalent to today’s Full Frame sensors. In the days of film, this film was definitely not reserved for the “pro” cameras or the “good” cameras. Even small, run of the mill cameras had used this film. Actually, that film was the small format, compared to the likes of Medium Format cameras that used the 6×4.5, 6×6 or 6×7 films and of course the Large Format cameras. For the purposes of this article, we will not even get into the smaller films that the Agfa instamatics and their likes used. So, when you shot film, it was almost certain that it was the 135 or 35 mm film. Actually, even since Leica used that format, it legitimised it in the eyes of pros and the larger formats were left for studio work and niche photography.

The advent of digital photography changed things dramatically and it took the industry many years to arrive to a place where Full Frame sensors are beginning to become commercially appealing for larger target markets. Up until now, sensors on cameras that had the size of older compact and SLR’s carried much smaller sensors. The 1″ inch sensor became a selling tool for compact cameras which claimed that it was much larger than the ones found in “lesser” cameras. Four Thirds and Micro Four Thirds (M43) became the next big thing as they found their way into very capable cameras, especially Olympus which still uses this sensor on several great digital cameras. DSLR’s used what is called APS-C, a “crop sensor” that, while smaller than full frame, is “sufficiently” large for “serious work” (quotation marks are put on purpose). Of course “professional” cameras of today use (at least) full frame sensors and any DSLR or high end mirrorless is sporting one of those.

As megapixels began to increase in number from the 2.7 MP of Nikon’s 1999 D1 model to the staggering 61 MP of Sony’s current a7R IV, another conspiracy was brewing in the photography world. Companies like Fujifilm and Hasselblad would not stand and watch their bread and butter being taken away by the bandits, so they used their Medium Format experience from days past to develop and market cameras with 50 and 100 MP on Medium Format sensors! Where will it all end? Will it end rather?

So, let me try to make some sense out of the mess:

  1. Sensors – bigger is better. The bigger the sensor, compared to a smaller one with the same number of pixels, the better. Why? Because the pixels on the larger sensor will obviously be bigger, thus having the capacity to capture more information. Image Quality is indeed a function of sensor size and there are numerous comparisons on the net, showing side by side images shot with different camera / sensor combinations. It is, at the end of the day, a function of physics: bigger sensor equals more light.
  2. Megapixels – that’s a tough one… People seem to think that more pixels are always better than less. This is clearly not the case. There is such a thing as a sweet spot for megapixels for any type of sensor, balancing the number of pixels crammed into the sensor with their individual size (as we have established above that larger pixels are better than smaller ones). It is like horsepower on cars: sure it is great having more horsepower, but how much is enough and what happens above that point? Say we have a car with 2000 horsepower; sounds great but is it drivable? Anywhere? Probably not outside Bonneville Salt Flats… Same with megapixels: cramming more of the little suckers in the same sensor is not panacea. Files get larger and less manageable, the camera tends to be slower and at the end of the day, do you need all of them?
  3. Combo – the easy answer is this: ANY COMBO! Yes, this is an oversimplification of course but it is not entirely untrue either. Today’s digital cameras are extremely capable and, for the most part, affordable machines. There are definitely capable and extremely rewarding cameras in every single major manufacturer’s lineup. It all comes down to what each one of us wants to do with their camera. For several, if not most, uses the whole question of sensor size and megapixels is all but irrelevant! If camera size is of importance, chances are that you should end up with a smaller sensor as larger ones seem to find their way into well… larger cameras. As for megapixels, please keep in mind that, besides speed and large files that come with the high megapixel territory, professionals of 10-15 years ago worked with cameras having  5 megapixels or even less and PRINTED images for their work (newspapers, magazines etc). Today, most people do not print, they post on the web, which can certainly be achieved with any of today’s mass market cameras.
  4. A final word of caution – Do get the largest sensor and the highest megapixel count you can find if you can afford it. But please know that if your images are not up to par, it is certainly not the camera’s fault, if you catch my drift… Do not strip yourself of a nice alibi if you can avoid it;)