Over the last 20 years an ethos has been developing. The idea that larger sensors are better. They must be better. They are bigger.. bigger is better right? Right? Are you sure about that?
We need to dump the notion that bigger megapixels equals better images. We need faster focussing and faster speed. 20 Megapixels is plenty.Well the cameras are certainly bigger and the lenses are. And they look impressive don’t they. All those huge cameras and lenses. You must be professional to use something like that. Well looks can be deceiving can’t they. Bigger is definitely not always better as many tens of thousands of photographers have learned at (sometimes) great expense. Better to know something of the background perhaps before reaching for the purse.
The first digital cameras had small megapixel sensors. But while the concept of digital was new the camera was an old beast. Recognized as a camera and well developed, there was a common shape and size. There was also a well regarded means for viewing the scene through the lens and these cameras were called single lens reflex.
Thus the camera we see today in common use is a marriage between concepts based around film and the digital sensor. The space is filled with electronics and batteries of course but it is a recognizable shape. It is comfortable in size. Along with this came the concept of ‘full frame’ being basically a sensor equivalent in size to a piece of 35mm film. Essentially lenses were set up for 35mm film and so making sensors a different size would mean making different lenses. There is some room for smaller sensors using the same lenses but ‘full frame’ is an expression that it is hard to go past. The merits of full frame and medium format are widely commented on.
Full frame sensors allow you to shoot in reduced light with a lessor amount of noise at higher ISO levels. The images will be softer but perfectly usable.
Most images are shot at ISO levels between 50-1000 ISO
Images 2000mm high [2 metres] can be printed from well exposed images taken from a tiny sensor.
Image stabilization in cameras [best] or lenses [good] is allowing us to maintain low ISO ratings.
Heavy lenses are consistently left ‘on the shelf’ because photographers don’t want to carry them all day.
Colour Matched Images from different sensors printed at A3 give the same visible result whether the file size is 16 megapixels or 80 megapixels.If I printed 4 images [colour matched] at A3 with cameras from 16, 20, 46 & 80 megapixels with sensor sizes from micro four thirds to APSC to Full Frame and Medium Format, and you viewed them side by side there is no way that you could tell the difference between the results. [Though the micro-four-thirds image would probably appear slightly sharper.]
If photography is your aim you would probably find that a lighter and smaller camera would cover all of your needs.
And as an after thought. Micro-four-thirds [MFT] is a much smaller sensor with lighter cameras and remarkable lenses that cost considerably less than alternative systems. Those of us that have been shooting professionally for years are coming to realize that what we need are smaller and lighter systems with sharper lenses and the MFT approach is clearly the right one for this.
Not that we don’t use DSLR for some styles of photography. But micro-four-thirds has far less limitations than some reviewers suggest. And 20 megapixels is absolutely the optimum size for photography for many reasons. But that’s another page.