Closer still. A guide to Photomacrography
Photomacrography (with film)
Note: this was actually written for an ‘A’ level English assignment in ages past, long before digital cameras came out. That said, everything here is almost as valid now as it was then. Enjoy.
Have you ever wanted to fill your camera frame with a tiny insect, or turn an ordinary household object into something bizarre? If so, then this article is for you.
Whether for aesthetic reasons, or used to provide a technical record, working very close can reveal with great clarity the patterns, textures and colours of ordinary objects.
Photomacrography can be defined as the art of taking photographs at, or greater than life-size. As a definition of x1 magnification, a piece of leaf 24mm x 36mm will fill up the entire 35mm format at this life-size reproduction ratio. (This will vary for digital cameras, depending on the sensor). At 3:1 (x3) a vein on the leaf 5mm would be magnified to 15mm in length in the image.
Equipment is your first consideration for entry into this fascinating subject. A sturdy tripod is essential as the movements are magnified by the same factor as the image itself and the slightest movement will ruin the shot. A cable release, or preferably a remote, will prove a necessary investment as it will help cut down vibrations. For still life the self timer, if your camera has one, will be as good, if not better, for reducing camera-shake.
For the actual close-up equipment you will want to consider a coupling ring, a macro filter (or better still a true macro lens) and extension tubes. You’ll also need an off-camera flash or, if you can run to the cost, a dedicated macro flash such as the Nikon Close-Up Speedlight Commander Kit R1C1 (set you back about £600 mind!). A small light tent is ideal if you are doing still life.
Macro filters are close-up lenses which screw into the front of your lens. They have set diopter rating of between 1 and 10 (0.1x to 1.0x magnification). This does not change with the lens in use, but the focusing distance does. The wider the angle of the lens the closer you must be to the subject. This applies equally to dedicated macro lenses. Macro filters can be used in conjunction with bellows and extension tubes, but not with coupling rings. you can get a reasonable set for about £12 on Amazon, with the higher quality achromatic macro filters starting around £30
The mushrooms pictured above were taken with a 75-250mm zoom and a 5 diopter macro filter.
True macro lenses
True macro lenses* offer 1:1 closeup built-in, but they aren’t cheap, coming in around £650 to £1,200 for the 180mm to 200mm ones.
*(such as the Nikon 200mm f4D AF Micro, Canon EF 180mm f3.5L Macro USM AutoFocus and Sigma 180mm f3.5 EX DG HSM Macro)
Cost aside, another advantage of these is the working distances : with a 50mm you have to be within just 1.5" whereas an 180mm macro lenses will give you 9" of breathing space.
Not tried it yet myself, but in his ‘how to Frank Phillips recommends trying a 2x teleconverter. For the 180mm macro it would extend the working distance to 18" and give the added benefit of becoming 2x magnification. No pain, no gain though, as the say, as you’d also lose 2 f. stops.
Extension tubes fit between your lens and camera and allow magnifications of around 0.25x to 2x life-size, based on a standard lenses and a 50mm extension. Like bellows, they work by increasing the distance between the lens and the film plain or sensor and have no direct effect on image quality. A decent brand like the Kenko shown sell for around £120 on Amazon.
The formula for using extension tubes is : tube length ÷ focal length = added magnification
Coupling rings work by mounting a standard or wide-angle lens – in reverse – onto a telephoto lens. This will give magnifications from 2x life-size to an amazing 10x life-size or even greater, depending on the lens combination in use (and the sensor with digital cameras). Using extension tubes with the above will increase this still further. The 11x image of the eye of a needle to the right was taken like this.
To use a coupling ring, first remove any existing filters from the lenses as these will reduce the picture quality and can cause vignetting – dark corners on the image. Next mount the telephoto lens onto the camera body and screw the standard lens onto it with the coupling ring.
With this set-up you should have the reversed lens set at infinity and at its maximum aperture (i.e. f1.8). If you are using a zoom lens as the telephoto it must be set to its maximum focal length (i.e 300mm for a 75 to 300mm zoom), otherwise very strong vignetting will occur.
The image above shows the equipment I used to take the images in this article. Included cable release (not shown), Nikon F3 (film), Sigma 70-210mm zoom, Kenko coupling rings and a Nikon 50mm lens (reversed) with a Sunpak flash, positioned off-camera.
When choosing the appropriate ring just check the filter sizes of your chosen lenses and use that; for a telephoto with a 55mm thread and a standard lens with a 52mm thread you will need a ’52/55 coupling ring’
Using the coupling ring will take you within inches of your subject, or closer still, depending on the magnification, so you must take great care not to bang the unprotected rear element.
Note that it is best to avoid zooms or fixed focal length lenses over 200. Similarly, for the reversed lens, image quality deteriorates if you uses lenses shorter than 28mm.
To calculate the approximate magnification simply divide the total extension in use by the focal length of the reversed lens.
For instance, a 200mm telephoto with a 50mm extension tube and a standard 50mm lens mounted in reverse will give a magnification of 200 + 50 ÷ 50 = x5
The table below gives an idea of the combinations and magnifications possible.
Depth of Field
Focusing will be the hardest obstacle for you to overcome due to the miniscule depth of field available at high magnifications.
Beyond 3x life-size the easiest method is to move the equipment (or still life) back and forth until the object is nearly in focus, then manually use the back telephoto lens to do the fine tuning. If you intend to do much close up work then you’ll want to buy a focusing rail; you can pick them up on Amazon for about £45
I did have a table for this but as I can’t remember the formula I used when I originally wrote the article I’ll leave it out. You can look it up on Wikipedia if complex maths gives you a thrill, but for the rest of us, just remember that as the magnification increases the area in focus will decrease accordingly. Here’s a vague rule of thumb:
At f22 and 0.5x you’ll have 6mm in focus, by life-size it is down to 2mm and by 3x magnification its shrunk to a paper-thin half a millimeter!
Still life is easy enough, but when photographing insects always try to focus on their eyes, otherwise the pictures tend to look wrong; naturally this is a generalisation, you could prefer to specifically focus on the vibrant wings.
For a slow-moving insect try focusing where you expect it to move to and press the shutter just before it gets there, this is so the delay between you seeing it in focus and actually pressing the release doesn’t result in a wasted shot. (Not as important with digital, but when you used to use Kodak slide film, it got expensive!). Remember also that at high magnifications you will need a flash and a shutter speed fast enough to freeze the subject as the slightest movement will result in blurring.
If you have a depth of field preview use it as this will tell you how much – or rather how little you will have in focus. It will also tell you if any vignetting will occur, so you can compensate accordingly.
Working out the exposure can be a big put off with close-up work, but happily you should have no real problems here as, due to the minute angle, the TTL reading will be close to the true reading. If you have any doubt, or it is an important picture you can always bracket your exposures by one or two stops. Use your TTL meter reading to find the exposure and vary this to give you the maximum depth of field possible.
If your pictures consistently turn out over-exposed (as used to happen with manual only cameras), your camera is giving you a stopped down reading, so you must add three stops to compensate.
(The next bit no longer really applies but I’ll include it for completeness. That said, the rule still applies, the only difference is now you can now set the ISO rating to pretty much whatever you want with digital SLR’s).
For people with no light meter and with older cameras, without TTL metering, use the ‘f16 rule’. This is found on the instructions of most film packets and simply says to set the shutter speed to that of the film rating (i.e. iso 64 slide would be 1/60) and use f16 for a sunny day, f11 for a hazy day etc. From there lower the exposure three stops to account for the extension in use, then bracket your exposure to find the optimum setting. Then, for future settings, alter your exposure accordingly.
Your next consideration is lighting. Unless you are doing still life where you can use studio lights and long exposures, you will need a good, portable light source. Even on the brightest of days you may find yourself needing a flash to get enough depth of field and to freeze subject movement. Where possible you should try to use a white or aluminium wrapping card or a similar reflector to bounce some of the light back onto the subject. (Or, nowadays, you can also splash out on a bespoke macro flash, as mentioned earlier).
When using flash it is best to put the flash on auto and similarly set the camera on auto, or for (old) manual cameras use the flash synch (x) and stop down to an aperture of f11. It is obvious that this exposure will not suit all subjects, but closing down to f16 or lower – so long as no vignetting is obvious – and moving the flash a little closer or further away from the subject should cover both situations. If you cannot move the flash off-camera with a flash extension then use tissues or flash filters to vary the intensity, and a white card over the flash to bounce the light down to the subject.
For still life I found the best method is to set everything up in a sunlit spot, where you won’t be in anyone’s way. On a bright day this will allow exposures of around f11 and 1/15 with 100 ASA film.
DO bracket your exposures.
DO use a tripod and cable release whenever possible.
DO keep to small apertures – but watch out for vignetting.
DO remove filters if coupling lenses.
DO be patient. It may take a while, even with experience, to get a good shot.
DO NOT take chances when set up with a reversed lens. Cover it with a rear lens caps when not in use.
Finally, DO enjoy yourself!