Ok, you want to venture into the world of
macro photography however are a bit on the
unwilling side to
cough up $400 for a normal micro, or $700 for a
slow zoom micro... much less the $1000 or more that a high end micro costs. Lets face it - something under $100 just to see if it is interesting. This assumes that you have at least one lens that
will work and a
tripod - do not think of trying to do macro photography without a tripod.
There are five options you can take - each with its own set of features. Realize that in many cases, these options defeat the new fangled features on cameras today. Many cameras fail to do metering when they loose coupling to lens which nearly all of these solutions do - along with the ability for the camera to select the f-stop.
- Reversing Ring
- Frequently known as a "Macro Adapter Ring" this chunk of metal will cost about $50 and allows you to put a lens on backwards (the one I just got was $45.50 and the salesman couldn't recall anyone purchasing one in the past few years). This obviously defeats the coupling.
Think about a pair of binoculars. Most everyone has looked through them backwards at one time or another and gotten a small image. The camera lens works the other way around, presenting the small image to the film. The reversing ring lets you present a fraction of the large image to the film thus magnifying it. These magnifications are fairly good. That 60mm f/2.8 Micro that runs $600 gives you 1:1 - well, a $60 50mm f/1.8 mounted backwards gives you a 1:1.4. That ain't half bad. Wide angle lenses can give up to a 3.4X magnification while telephotos aren't that useful backwards.
- Extension Tube
-
The extension tube moves the lens away from the camera body. They are
often just a simple hollow tube. This has a twofold effect: as the lens moves away there is a drop off in light.
light loss = ((extension + focal length) / focal length)2
stops lost = log2(light loss);
With a 27.5mm extension tube (one of the standards) a 28mm lens would lose 2 stops, 55mm would loose 1 stop, and a 200mm would loose 1/3 stop. The reproduction ratio = focal length / amount of extension. A 50mm extension to a 50mm lens would give you 1:1 ratio. The extension tubes also reduce the minium focal distance allowing you to get closer to the subject. These are ideal for photographing plant life in the field.
Extension tubes do exist in both manual and auto focus capable designs. The manual version are obviously cheaper - an entire set (68mm total) goes for about $100 while the same set with the auto focus coupling would go for about $150.
- Bellows
- Bellows are in essence a long variable length extension tube allowing a camera to be mounted on one end and the lens on the other end. A small knob or such then allows you to move the bellows back and forth on a rail of some sort to give some support.
Bellows are most often found as part of a copy stand or focusing stage:
Camera
b
e
l
light l light
\ o /
|\ w /|
| s |
| lens |
| |
| O |
_____________________
In this set up the object (O) is illuminated by two lights. The camera and bellows are mounted above the subject pointing down.
Bellows can give a reproduction ratio of between 1X to 11X depending if the lens is mounted normal or reverse. With most bellows systems, the coupling is lost. A typical bellows costs about $220.
- Closeup lenses
-
Close up lenses take the place of filters on a camera and change the closest focusing distance. Its like giving your camera a pair of glasses. These lenses come in two sizes 52mm and 62mm (this size relates to the filter size, not focal length of the lens). A typical set of close up lenses costs about $40. The hidden price though, is in the quality of the photograph. Compared to the primary lens, these closeup lenses are poor quality especially with single element closeup lenses that fail to correct for distortions. Thie big advantage is that these filters are portable and do not affect the metering of the lens in any way.
- Macro couplers
- Macro couplers work similar to the closeup lens by placing another lens in front of the primary lens. This time, however, it is by means of a thread that couples two camera lenses together (frequently 52mm to 52mm). These couplers are only about $10. The magnification factor for this is the focal length of the main lens / focal length of the reverse lens. You won't get anything mounting two 50mm lenses back to back, however if you mount a 50mm lens on a 200mm lens you get a 4x magnification.
Yes, if you look, you may well find various things cheaper - especialy
that of items where you lose the autofocus coupling.
http://www.nikonlinks.com/unklbil/macro_adapter.htm