Enlarge details right the way Sherlock Holmes did
Photo ©© Chris Goldberg
Elementary, My Dear Watson
There might be times when you are interested in investigating small subjects and shooting at close range.
As I already introduced in my Macro Photography with Point-and-Shoot Digital Cameras page, many compact cameras have a macro mode which enables taking close-up images. Whether such a feature is (or is not) present in your specific camera, chances are that you will be looking for another way to enlarge small details.
This page will explain how this can be attained in the most obvious way: by holding a magnifying glass right in front of the camera lens.
How to take close-up pictures
There are many different ways to face the problem: the most direct one is just to move very close to your subject and focus on it, so that it renders big enough in camera.1 Try it, and you will soon discover that the helical mount of your lens does not allow you to focus too near objects. There are good reasons for this2 but, instead of dealing with such an issue here, let’s see what to do: grab the very first lens you have at hand and place it right in front of your camera. Chances are that you will try with your own eyeglasses or with that old magnifying glass laying on your tabletop.3
Basic rules of optics say that the more powerful the magnification4, the shallower the depth of field and the smaller the field of view. Which, in plain words, means that if you want to enlarge a small subject, you are not going to put too much of it into your frame and, unless it is completely flat5, only a selected part of it will be in focus, the rest being cropped and/or more or less out of focus.
This leads to a key issue: you have to carefully select what you want to have in details inside your picture. You have to be really picky on that if you want to be pleased by your photographs.
By observing the image here at right you will notice how shallow the depth of field is: most of the image is out of focus. In order to increase depth it is advisable to reduce the aperture size down to an average f/11. This also reduces optical aberrations which, in plain words means that a better image quality is expected overall.
The effect you get here is, as you can see, rather pictorial but can be easily adjusted to about any taste.
Any magnifying lens will do: glass, plastic, you can find a lot of ideas by visiting a flea market in your town.
Fell free to ask the forum if you have questions or need assistance.
Do you need anything better, maybe sharper images?
Please take one step forward and use custom designed close-up lenses: I have a whole page about them for you.
1 There should be no problem if you use an old style monorail camera allowing you to gently stretch the bellow and focus at your will. True, you will always have to take care of the lens performance, but that is part of the game, and we will write about this at a later time. (↑)
2 Simply put, average general lenses are not designed to work that way and would give very poor results. (↑)
3 In case you do not have better equipment to start with, a simple bottle full of water might do (as a proof of concept, at least). (↑)
4 Magnification is defined as: (image length)/(subject length) (↑)
5 This is not true, actually. Even flat objects my turn out unevenly sharp, for many reasons: for example, high diopter close-up lenses are usually sharp in the center and soft at the edges. (↑)
