Acceptably Sharp

A photo on the computer screen isn’t asking a lot of an image file. If it was printed at A3 size then you would see what it looks like. It might ‘fall apart’ like photos from smartphone cameras fall apart when you print them at this kind of size.

The reason is simple – despite all the clever computational photographic capability in a smartphone, the sensor is tiny and that limits how big you can print a photo.

That is why professional studio photographers use cameras with at least full-frame sensors.

A full-frame sensor is nearly 40 times the size of the sensor in an iPhone.

Sony RX100 Mk III

The photo at the top here is a scene on a river in South Africa. I shot it with a Sony RX100 Mk III. It has a 20 megapixel, one-inch sensor.

Now we are stepping up a notch in sensor size. A full-frame sensor is about seven and a half times the size of the sensor in a Sony RX100 Mk III .

And the Sony RX100 Mk III camera itself is small – 102 x 58 x 41 mm – about as long as the width of your hand – and it weighs 290g, which is just over half a pound.

The camera has a rear screen, of course. It also has a viewfinder, which for a camera this small is unusual. Because the camera is so small, the viewfinder is in a spring-loaded recess and you click to release it and up pops the viewfinder.

And it has a 24-70mm (35mm equivalent) zoom lens with a maximum aperture from f1.8 at the wide end to f2.8 at the long end of the focal length range. A maximum aperture of f1.8 means it lets in a lot of light – and for a small camera to have a lens with that aperture is impressive.

So now looking at the river scene with the trees and the mountains behind – is the shot sharp enough? Is this attractive enough? Are the colours acceptable?

Is it detailed enough to satisfy the eye? The trees over on the right seem to have good detail in them.

Let’s look at bit closer at those trees. Ah now it is beginning to show the limitations of the sensor.

But if I look at the scene overall, it looks OK, doesn’t it?

Must It Be Sharp?

I shot this next photo with a Ricoh GR III, which has an APS-C size sensor. Now we are really getting up there in sensor size. A full frame sensor is just two-and-a-half times as big. Shooting in good light you might be hard pressed to tell any difference.

But about sharpness, when I blow this up on the computer screen I see that I missed focus on his face. Does it matter? Overall the shot looks OK, don’t you think?

So for a carry-around camera, maybe one with a 1″ sensor is all you need. And with the Sony you get a zoom from wide to moderate telephoto and a lens with lots of light gathering capacity.

There are a number of cameras in the RX100 range. My particular favourites are the Mk III through to the Mark VA. Later models have a different zoom range and don’t appeal as much.

Not to forget that the camera is pocketable.