2.) A Word on Focal Length

As a rule, a shorter focal length increases magnification while decreasing working distance from the lens to the subject. Conversely, a longer focal length allows for less magnification and greater distance between the subject and the lens. A 50mm lens will allow you to enlarge a subject more than a 150mm lens. However, with a 50mm lens you have very little working distance between the lens and subject. Working distance is important for light control and comfort.

Increasing the distance between the lens and subject permits additional light to fall on the subject. Light is at a premium with macro photography. Like depth of field, there are times when there is not enough light.

Increasing working distance can also be more comfortable when shooting subjects that are low to the ground. Your camera and lens can be placed father away and there is less crouching or stooping over the camera while composing.

My preference is between 105mm and 135mm. I find this is adequate magnification and while maintaining comfort. Many people enjoy using a 180mm or 200mm macro lens for even greater working distance.

Read on under section 3.) Option A – Dedicated Prime Macro to learn more about manual focus macro.