Close-up or macro photography is an
enjoyable and challenging part of nature photography. If "Making Little Things Big On Film" (Rod Planck) is of interest to you, these notes will be a reminder of what we covered in class and field work.
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 35mm 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 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 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). 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
MAGNIFICATION ON FILM
8 x 12 inches 1/8X
6 x 9 inches 1/6X
4 x 6 inches 1/4X
3 x 4 1/2 inches 1/3X
2 x 3 inches 1/2X
1 x 1 1/2 inches 1X
1/2 x 3/4 inch 2X
1/4 x 3/8 inch 4X
This table shows
that the magnification on film is the reciprocal of the subject height as measured in inches. (Subject height refers to the shorter side of the AREA COVERED).
By looking at the size of your subject, you can tell
about how much magnification you will need to fill your slide or negative.
A flower 2 inches wide will need about 1/2X magnification to fill a slide 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 with 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
1X 2 stops
2X 3 stops
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.
teleconverters give poor quality, all teleconverters cost light:
1.4x 1 stop light loss
2x 2 stop light loss
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. Read the teleconverter quality reports when used
with several popular lenses in THE NATURAL IMAGE, Journal 28,Winter 1991. Write to
George Lepp, PO Box 6240, Los Osos, CA 93412, phone 805-528-7385 for subscription and back issue costs and to see if this issue is still available. You can also go to Lepp's web site. This is about teleconverters for distance use rather than close-up work, but is still highly
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.
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.
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
50mm 240 0.21 - 0.34
50mm 450+240 0.32 - 0.47
100mm 450 0.22 - 0.37
100mm 240 0.41 - 0.60
100mm 450+240 0.64 - 0.84
200mm 450 0.44 - 0.57
200mm 240 0.83 - 1.0
200mm 450+240 1.3 - 1.5
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
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
62mm size 5T 6T
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
75mm 500D 0.25
75mm 6T 0.30
200mm 5T 0.50
200mm 500D 0.60
200mm 6T 0.80
300mm 5T 0.75
300mm 500D 0.90
300mm 6T 1.20
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
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
Other books on close-up are available, one of the better ones is Joseph Meehan's THE ART OF CLOSE-UP PHOTOGRAPHY.
February 7, 2001