[sneela]

I recently bought a film camera (Minolta X-700) and I wasted a whole roll because I inverted the aperture (i.e, 2 = sharp, 32 = blur)...

I'm interested to see how the roll turns out - gave it for development the other day, had a good laugh with the employees though.

I now have a mnemonic for it: Blor - a (somewhat) portmanteau of Blur and low. So low aperture = blur.

Edit for clarification: I mean low number (2 vs 32) = blur

[Toutouxc]

Note that both very high or very low aperture settings also bring their own optical issues. At very low values (big hole) you’re getting hurt by different aberrations (essentially too many paths the same rays can take to the sensor) and at very high values you’re getting hurt by diffraction. At the low end, it’s good to go a little higher than the lens advertises, and at the high end anything over F13-F18 (depending on the gear) is usually quite bad.

[4gotunameagain]

The larger the entrance pupil is, the narrower the depth of field is.

The smaller, i.e. the closest to an ideal pinhole camera, the wider the depth of field is. A an ideal pinhole camera has infinite depth of field.

Unfortunately the aperture f numbers are the wrong way round; larger numbers correspond to smaller diameters.

[tiagod]

High aperture = Blur

Unfortunately the lower number actually means bigger aperture.

[sneela]

And that's what exactly confused me :)

With my mnemonic, I say low *number = blur

I should have been more specific