Macro Photography: Getting Close

I recently bought a set of Close-Up filters for my Pentax camera. At first, I was a little confused on how exactly to use them. I slapped them onto my 50mm lens and I just couldn't seem to get it to focus. That's when I moved the lens closer.

Close-Up filters typically come in +1, +2, and +4 increments. The larger increment always goes closest to the lens. You can also stack the filters on top of each other for additional power.

The purpose of the close-up filter is to allow the lens to get closer to a subject. All lenses have a minimum focus distance. The minimum focus distance for a 50mm lens is about 3'. But the close-up filters allow you to move the 50mm lens closer, allowing the subject to fill the frame. I practiced focusing on a penny. With the 50mm lens, the penny filled about 1/20 of the frame. With a +1 filter, the penny filled about 1/10 of the frame. The +4 filled the entire frame, and the lens was just a few inches away.

I took this photo using a 50mm lens and a +2 close-up filter. The flower itself was only about 4 inches in diameter, but with the close-up filter I am able to fill the entire frame with the subject.

This can come in handy when I want to take photos of very small objects such as insects, coins, or pieces of objects such as a bottle neck or tip of a pen. The difficult part about using this lens, however, is that the focus area is much smaller. With a +4 close-up filter added, the lens can only move half an inch either way before it loses focus. This means it is very wise to use this with a tripod or clamp to hold the camera steady.