One of the generally underexposed (pardon the joke) types of DSLR picture taking is macro photographs. Frequently the cause is the lack of access to pricey, limited functionality macro equipment for getting ultra close ups of possible shots. Yet, with the purchase of a Canon extension tube to your sack of gear, lots of of your existing lenses are able to be transformed to have macro functionality at a price of under 100 dollars.
For those not familiar with extension tubes, they are simply pieces of metal or plastic that attach in between the lens and DSLR itself. They can be bought approximately in 10mm, 20mm and 30 sizes and serve to increase the focal distance of the already used lens. This serves dual purposes. The first is enlargement. If you own a lens with a focal length of 50mm and add a 25 tube, it can now work as a 75 lens, thus a 1.5 times larger enlargement than the original 50. The second consequence from adding a Canon extension tube is lessened minimum focusing distance. While the calculations resulting in this is far more difficult, I've found that for a 50 lens with a minimum focus distance of 300mm, this can without difficulty be lowered to 100 or lower with a macro extension tube, letting you to get exceptionally close with your potential shots for pictures not ever formerly imagined possible.
One important piece of information on the topic of extension tube equipment is whether you can get electrical contacts in the extension tubes to keep connectivity between the lens and SLR body. If you've got them, you will have the option to keep autofocus and aperture control as if the tubes weren't attached. Lacking this electrical contact, you'll only have the ability to focus manually and will need to adjust f-stop before attaching the macro extension tubes, and this might be a large hassle and quite annoying.
An additional handy tidbit of info is the manufacturer of macro extension tube bought in reality makes no difference, which can be a surprise to many. A namebrand Canon extension tube at 12 or 25mm will likely cost upwards of $120 for just one. However, so called no name brands like Opteka or Zeikos should get you a trio of extension tubes that work equally well for around 70 dollars, a significantly better use of money. And if the omission of electric connectivity does not trouble you, vanilla plastic macro extension tubes can be bought for just over $10. I very much urge saving your dough and getting the Opteka brand, I've been taking photos with them for quite awhile with excellent success.
There can be a a small amount of shortcomings you need to be informed of versus buying an actual macro lens (which could come at a price of in and around $500). The first is the extension tubes have a very narrow depth of field due to the bigger magnification. As a result the f-stop as a rule needs to be put much bigger, which lets in less light and can cause problems without the right lighting conditions and somewhat lessen contrast or sharpness. Secondly, not only do macro extension tubes lessen the minimum focusing length, they eliminate the ability to focus beyond that to infinity. It's not out of the question that you can just focus in a length of 100 to 200 mm, so you'll need to get very near to the subject, excluding the shooting of mobile objects (or those that bite) like insects or pets.
To sum it all up, for folks in the market to expand in the realm of SLR photography, I highly urge investigating a collection of macro extension tubes to seriously boost the range of pics you can capture.
