Theory for beginners Part 2 - Reciprocal rule and Rule of 3rds

Once again thanks to Redharzo for the sterling work

Reciprocal rule: how to minimise camera shake when you don't have a tripod.

Ok, this is just a general purpose rule. We need to start back in olden days when film was still used. The rule states:- you can handhold a camera with lens of length X mm provided your shutter speed is 1/X or quicker

NB - this is without a tripod.
eg: you're using a 100mm lens. To minimise shake, you need a shutter speed of 1/100
eg: you're using a 200mm lens. To minimise shake, you need a shutter speed of 1/200
eg: you're using a 300mm lens. To minimise shake, you need a shutter speed of 1/300

However, that only works for full frame. Most digital camera sensors aren't as big as a 35mm negative. The usual multiplier is 1.5x or 1.6x. We'll use 1.5x for simplicity of counting.

So when a film lens is used on a digital camera body:-
a 100mm lens is effectively 150mm-
a 200mm lens is effectively 300mm-
a 300mm lens is effectively 450mm

Therefore: -
rather than using your 100mm lens at 1/100, you must use it at 1/150-
rather than using your 200mm lens at 1/200, you must use it at 1/300-
rather than using your 300mm lens at 1/300, you must use it at 1/450

So, in summary - for a digital body with a film lens:- you can handhold a camera with lens of length X mm provided your shutter speed is 1/1.5X or quicker




The rule of thirds is a compositional rule of thumb in photography. The rule states that an image should be imagined as divided into nine equal parts by two equally-spaced horizontal lines and two equally-spaced vertical lines, and that important compositional elements should be placed along these lines or their intersections. Proponents of the technique claim that aligning a subject with these points creates more tension, energy and interest in the composition than simply centering the subject would.

FOLLOWING THE RULE OF THIRDS WILL MAKE YOUR PHOTOS LOOK MUCH BETTER - A LOT OF PEOPLE IGNORE THIS INITIALLY AND REALISE AFTER A WHILE THEY SHOULD HAVE FOLLOWED THE RULE OF THIRDS - TRUST US.