Close-up or macro photography is an enjoyable and challenging part of nature photography. If close-up photography is of interest to you, these notes will be a reminder of what we covered in class and on our field trips. If you haven't been in my classes or workshops, or on one of my field trips, this will be an introduction. Be sure and look at the more detailed information in chapter 16 (the close-up chapter) of my new book, Digital Photography Exposure for Dummies.
I use the word film to refer to both digital cameras (your digital sensor is your film) and film cameras. Whenever you read "film", just think "digital sensor" if you are using a digital SLR camera.
Magnification is a handy way to compare close-up tools and techniques and estimate image sizes when going from the real world to film. For for frame digital cameras, and 35mm film photography, a full frame close-up of a 3 inch daisy is 1/3X or 1/3 life size on film. How is this figured, and how do you get 1/3 life size on your digital sensor or film? This section answers the first question and the next section answers the second.
The ratio of image size on film to the subject size in real life is the magnification ratio. (Size on sensor/film divided by real life size = magnification). If a flower is one inch wide on film and 4 inches wide in real life, the magnification ratio is 1:4 or 1/4X on film. If a stamp is one inch on film and one inch in real life, it is 1X magnification or "life size" on film. If a beetle is 1 inch on film and 1/2 inch in real life, it is 2:1 or 2X magnification on film.
Another way to look at magnification is in the rectangular area covered when focusing on a flat surface (or the plane of sharpest focus when photographing 3 dimensional subjects). A full frame digital sensor or 35mm film has an area of 1 x 1 1/2 inches. A 1/4X magnification picture takes a subject area 4 x 6 inches and reduces it to 1 x 1 1/2 inches on film. Some examples:
AREA COVERED MAGNIFICATION ON FILM*
8 x 12 inches 1/8X
*If you are using a digital camera with a cropped frame (1.3x, 1.5x, 1.6x, or 2x) you will have more "apparent" magnification thanks to your camera's field of view crop.
By looking at the size of your subject, you can estimate about how much magnification you will need to fill the frame.
A flower 2 inches wide will need about 1/2X magnification to fill the frame. An insect 1/2 inch long will need about 2X magnification to fill the frame.
Since most "normal" lenses will only focus close enough for a magnification of about 1/12X to 1/8X and macro zooms only get to about 1/5X to 1/3X, special equipment is needed for close-up photography when you need more magnification.
WAYS TO GET CLOSE
Simple one element, close-up, diopter filters, often marked +1, +2, +3, +10, are an inexpensive expensive way to get close. The first three, used individually on a normal 50 mm lens will give you magnifications from 1/7X to 1/4X. Used in combinations, they will give magnifications to about 1/2X. A +10 by itself will give you a magnification of 2/3X. When using more than one close-up filter, put the strongest (highest diopter) filter on first (next to the lens).
Disadvantage: less image quality, especially closer to the edges of the frame. I prefer other ways to do close-up photography.
EXTENSION: TUBES AND BELLOWS
Extension tubes are a high quality way to do close-up work at reasonable cost. They are essentially hollow tubes with couplings for your lens and camera body to communicate. I recommend using a pair of extension tubes with lenses in the 24 to 300 range. Normal lenses will give excellent results if stopped down.
Tubes and bellows inserted between the lens and camera allow the lens to focus closer. Magnification equals extension divided by the lens length (ext/lens = mag). A 50mm tube with a 100mm lens equals 1/2X magnification. A 50mm tube with a 50mm lens equals 1X magnification. A bellows (essentially a variable extension tube) set at 200mm extension with a 50mm lens equals 4X magnification.
Select extension tubes that couple the lens to the camera for full aperture metering, and stop the lens down to taking aperture for the picture. You are probably best to stick to your camera brand extension tubes.
Bellows come with varying degrees of automation. My advice for tubes applies to bellows. Novoflex is a quality, expensive alternative to your camera brand bellows (contact CALUMET in Chicago for Novoflex info). A bellows with a 50mm macro lens is a high quality way to dupe your own slides.
I use a pair of extension tubes (25mm and 50mm) and a bellows (30mm - 180mm). My bellows is fine for around home, but inconvenient for field use. Tubes are far more convenient to carry around.
Extension tubes cost light. Using extension for close-up work, depending on the exact equipment is use, will cost approximately this much light:
Magnification Light Loss in Stops
1/2X 1 stop
A number of nature photographers use extension tubes in the 50-60mm length on their 300 and 400mm telephoto lenses for closer focus for bird and small mammal photography.
A lens will not focus to infinity with an extension tube in place.
1.4x and 2x teleconverters allow your lenses greater working distance at the same magnification, or more magnification at the same working distance.
If you have a lens that gives 1/4 magnification at a working distance of 20 inches from the subject, a 2x teleconverter will give you a choice of 1/4 magnification at 40 inches (say for that rattlesnake you don't want to get too close to) or ½ magnification at 20 inches for that flower you want a closer view of (or some combination of magnification and working distance in between).
A 1.4x teleconverter will give you 40% more magnification at the same distance, or 40% more working distance at the same magnification, or a combination in between.
Disadvantages: cheap teleconverters give poor quality, all teleconverters cost light:
Camera brand teleconverters give the best quality, and cost $200 to $300 or more. Aftermarket teleconverters from the better manufacturers (at 1/2 the above prices) can also be quite good. Buy the best you can afford. Stay away from the $20 to $40 odd brand cheapies.
Teleconverters work best on single focal length (non-zoom) lenses. A teleconverter on a straight 200mm lens will give better quality than on a 80-200 zoom lens set at 200. One possible exception might be the premium quality, low-dispersion glass lenses (i.e. highest price) being produced recently.
The better quality teleconverters will give good quality images when used on single focal length lenses or on some of the high dollar, fast aperture telephoto zoom lenses athat have been designed to work with teleconverters. Tney might give acceptable results when used with less expensive zoom lenses when the lenses are stopped down for closeup work.
Don't buy 3x teleconverters. The image quality is disappointing. They also cost you three stops of light so the viewfinder is very dark, making it difficult to focus.
Lenses will focus to infinity with teleconverters.
True macro lenses are one of the best ways to do close-up work, also one of the most expensive. Commonly available in 50mm, 60mm, 90mm, 100mm, 105mm and 200mm sizes (depending on the brand), they reach 1/2X magnification by themselves and 1X with the appropriate extension tube (which usually comes with the lens). Some macro lenses reach 1X without any extension tube. Macro lenses with matched extension tubes is the highest quality way to do close-up work, especially when copying flat subjects like stamps or when copying slides.
Macro lenses focus closer than normal lenses of the same focal length (basically built in extension), and are optically corrected to give sharp, flat-field images to the edges of the film frame. They also make excellent lenses at normal focusing distances for other kinds of photography. Many nature photographers carry a macro lenses rather than normal lenses in equivalent focal lengths. Macro lenses are often 1 to 3 stops slower than their normal counterparts.
SUPPLEMENTARY CLOSE-UP LENSES (FILTERS)
CANON 450 and 240 CLOSE-UP LENSES
These are for lenses in the 50-200 range. They are good in quality and have been around for a number of years.
Canon made (until recently) two double element close-up filters for use on normal to short telephoto lenses. They can be used on any brand of lens and screw onto the front of your camera lens like any other filter. They are more expensive and significantly higher in quality than single element close-up filters. They are a not a common item. The following minimum and maximum
magnifications are from Carl Shipman's HOW TO SELECT AND USE CANON SLR CAMERAS (page 74). Magnifications are in decimals rather than fractions. 0.25 = 1/4X, 0.33 = 1/3X, 0.47 is a tad smaller than 1/2X and so on.
Camera Lens Close-up Lens Magnification (min & max)
50mm 450 0.11 - 0.23
100mm 450 0.22 - 0.37
200mm 450 0.44 - 0.57
These close-up filters can be used on any brand of lens. Be sure when ordering that you are getting the double element or "doublet" version. Order these close-up "lenses" in a filter diameter as large or larger than the lenses you want to use them on. If using a larger size than one of your lenses, get the appropriate step up ring.
For lenses in the 38 - 135mm range. A new double element (doublet) close-up lens (filter) from Canon. Made in 52 and 58mm filter sizes (and can be used on any brand of lens), this is a high quality way to do close-up work. Magnifications are close to those listed for the Canon 240 above.
CANON 500 and 500D
Newly released and designed for lenses 70mm to 300mm in focal length. They can be used on any brand of lens with the appropriate filter size, or with step up rings. They come in four filter sizes: 52, 58, 72 and 77mm (the Nikons below only come in two). The 500 is a single element lens. Buy the 500D, it is a double element lens of high quality. The 500D is in between the Nikon double element lenses in power and is comparable to the Nikons in quality.
NIKON 3T, 4T, 5T and 6T
Designed for lenses 70mm to 300mm in focal length. They are high quality double element close-up "filters" although they are called lenses. They come in two "strengths" (the Canon 500D only comes in one). They can be used on any lenses with the appropriate filter sizes, or with step up rings. Filter sizes and approximate diopter strength are as follows:
1.5 diopter 3 diopter
52mm size 3T 4T
Here are some approximate maximum magnifications for the Nikon and Canon filters when used on a Nikon AF 75-300mm zoom lens:
Focal Length Filter Max. Mag.
75mm 5T 0.20
200mm 5T 0.50
300mm 5T 0.75
With one telephoto zoom lens, one of these supplementary lenses gives a wide range of magnifications.
Two-element supplementary close-up lenses are an excellent way (and my favorite way) to do close-up work in the field. Unlike tubes and teleconverters, these "filters" have no light loss.
My Canon 80-200 zoom lens gives up to 1/3X (0.33) magnification at 200 mm and closest focus. By adding a Nikon 6T, I get everything to 1X with no light loss.
CLOSE-UP SUPPLEMENTARY LENS CHOICES
Since quality is comparable, the choice between these supplementary lenses is a matter of filter size, cost and magnification desired. My zoom lens uses 58mm filters so I had to get a 58-62 step up ring when I bought my Nikon 6T. Today I would probably get the 500D in a 58mm filter size. Sizes and magnifications are given above.
Stacking short lenses on longer lenses is a good way to get high magnification in the field. The shorter lens is reversed so if faces the longer lenses. They are connected via a male to male filter thread adapter. Called Lens-to-lens-stacking rings, they are available in various sizes from MIKE KIRK ENTERPRISES, 107 Lange Lane, Angola IN 46703 (write for a catalog).
With this technique, magnification equals the focal length of the long lens (next to the camera body) divided by the focal length of the shorter reversed lens. A 100mm lens with a reversed 50mm lens gives 2X magnification. A 200mm lens with a reverse mounted 50mm lens will give 4X magnification.
The shorter reversed lens should be set at its widest aperture. Exposure is controlled by shutter speed and the aperture of the normally mounted lens. Some lenses (like Canon FD) when reverse mounted will stop down since the rear elements and connections are not connected to a camera. Special adapters are made to go on the back of these lenses to keep the aperture wide open (or set to the aperture of your choice). You can make your own by cutting off the flat portion of a rear lens cap, making a kind of rear lens hood. This is recommended, even if you don't need aperture control, to protect the rear lens element.
Some combinations of lenses suffer from vignetting. Experiment with your lenses before ordering stacking rings.
Stacking lenses is one of the best ways to get high magnification (1X or greater) close-up work in the field.
REVERSE MOUNTED LENSES
Reverse mounted lenses can give high magnification. A 50mm lens reverse mounted on the camera body will give about a 1X magnification. Reverse mounting takes a special adapter designed to fit the lens mount on your camera body and the filter threads on the front of your lens. You will need an adapter for the rear mount side of your lens as described above. You must have a lens that you can set the aperture manually on the lens, autofocus lenses which have their aperture set by the camera body won't work.
This technique works well in terms of image quality (with the right equipment) but is somewhat of a pain to mess with in the field and usually involves stopped won metering. Reverse mounted lenses are used most often by macro specialists in high magnification work with a macro lens reverse mounted on a bellows.
The "bible" of close-up work in the field is John Shaw's CLOSE-UPS IN NATURE, Amphoto, 1987. If close-up work is important to you, this book should be required reading.
Other books on close-up are available, one of the better ones is Joseph Meehan's THE ART OF CLOSE-UP PHOTOGRAPHY.
Be sure and look at the more detailed information in chapter 16 (the close-up chapter) of my new book, Digital Photography Exposure for Dummies.
You can find these and other excellent books in the photography sections at my photography store, (powered by Amazon).
Copyright © Jim Doty, Jr. All rights reserved.