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a lot of photographers consider 'true' micro methods to be a 1:1 reproduction of the subject, i.e. the photo produced on the sensor is the similar size as the actual subject being photographed, which is different to close up photography. macro and close up photography is niche and not for all folks, however it is something all snappers should try at some time to see if it is their bag. In order to get the 1:1 reproductions it is easy as pie to procure specially manuafactured close upoptics, such as the Canon EF100m f/2.8 macro USM, although these are quite costly and a lot of people are not prepared on spending a few hundred bucks (or dollars) to see if macro methods is for them. luckily, there is a less costly alternative available. For those desiring to try their luck at close up and macro techniques a more affordable alternate is to use close up tubes which in a nut shell are hollow plastic tubes that are put between the lens and the digital camera body. extension tubes contain no lenses whatsoever, and byenlarging the distance between the glass and the sensor the camera is forced to focus closer to the object, creating a macro and close up type effect. auto focus close up tubes can be used with all lenses, therefore they are ideal for all photographers. Most new digital SLR camera optics contain autofocus technology, which in order to work requires the electrical contacts on theglass to be in contact with the electrical contacts on the digital camera body, therefore inserting a plastic tube, i.e. the close up tube, between the lens and the body of the camera may create a problem with the autofocus system. Fortunately, some close up tubes, such as those made by Canon and Kenko, have got the electrical contacts to preserve the autofocus feature however some auto focus close up tubes do not. This is worth keeping in mind before purchasing some close up tubes, although if you are comfortable using manual focus using extension tubes with no electrical contacts should not present any problems. As you'd expect, the extension tubes using the electrical contacts that preserve autofocus are more expensive than those that do not. many snappers prefer to use manual focus when taking close up and macro shots because of the shallow depth of field. As well as autofocus most up to date day optics allow the photographer to the aperture, and this is also achieved through the electrical contacts. Whilst many snappers will be willing to lose the autofocus feature it is unlikely they will be prepared to lose the ability to change the aperture of the optics. with auto focus close up tubes that do not have the electrical contacts means the optics will be wide open which is likely to lead to an unacceptable depth of field and blurred images. Very few optics are sharp when wide open therefore using auto focus close up tubes that do not allow the aperture to be varied means the optics will not be at its sharpest. When using close up tubes without the electrical contacts there is a way of fooling the camera in to retaining a pre-determined aperture setting but this is fiddly and time consuming. The process involves putting the digital camera in to aperture priority mode and setting it to the required setting. By holding down the depth of field button, taking off the optics and then inserting the extension tube before putting the lens back on, all whilst holding down the depth of field button, the digital camera will retain the aperture set. Sounds a bit of a pain right? Well, it is. As the process is so long winded and cumbersome there is the added problem thephoto opportunity may be missed. For example, if the photograph subject is a bug by the time the digital camera and auto focus close up tube has been set up the photograph subject may well have crawled away or flown off, however you shouldn't have any problems if photographing still life, insects or flowers. Removing the piece of glass over and over again to change the aperture setting increases the possibility of dirt and debris sticking to the sensor, which may cause issues. In addition, the optics fitting is likely to get worn out quicker and there is an increased opportunity of damage to both the camera body and the piece of glass, which could prove to be very costly. There are no arguments, close up tubes are a good way of getting in to the world of close up and macro photography, although it is unlikely you will get accurate micro 1:1 reproduction. That said it is possible to produce some excellent photographs using auto focus close up tubes and a normal lens. Because of the all the implications associated with extension tubes. For some essential macro photography tips check this out.
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