Disadvantages and Advantages Extension Tube

 
When we want to capture a small subject close-ups such as insects, flowers, coins etc. usually we need to use the help of a macro lens to do so. This type of photography is commonly called macro photography very interesting to explore as many small objects very beautiful around us. This hobby is not something that is cheap because we need to buy a macro lens, of course, with a wide selection of focal lengths. But there is a cheaper option for those who have limited funds, ie using camera accessories like close up lens, lens reversal and also extension tube. However on this occasion we will only discuss the benefits, advantages and shortcomings of the extension tube.
Benefits Extension Tube

Name extension tube itself is basically explaining the benefits contained therein which extend = extend and tube = tube or tube which serves to extend the distance between the camera and lens. This tube away from the camera lens and the lens closer to the subject so that the lens is able to focus in a shorter distance to the subject, so the effect will be obtained also enlargement / magnification. Focus Magnification at close range and also this is the flagship feature of the macro lens, which is not found in other lenses. Extension tube does not have an optical lens or a glass material in it, so it will not alter the optical quality of the lens that we use. Extension Tube is currently offered with a wide choice of focal lengths such as 12mm, 25mm, 36mm. For example, when we put the extension tube of 25mm to 50mm lens, it will increase the effects of 0,5 x magnification. Usually 50mm lens has a magnification ratio 0,15x magnification effect so obtained was 0.15 + 0.5 = 0,65x. Magnification ratio is the result of a mix of 50mm and 25mm extension tube has been able to approach the capability macro lens generally has a 1x magnification ration. We can also use 2 or 3 at once extension tube to get enlargement liking. The thing to be noted is very effective extension tube combined with a lens that has a shorter focal length sd. medium and will not effectively integrated with a telephoto lens, it is certainly very contrary to the close-up lens is very well combined with a telephoto lens.
Type / Type Extension Tube

Extension tube consists of two types namely the extension tube that has a connection with the camera and the camera does not have a connection with. The second type would cost less because there is no electrical devices connected to the camera, but of course we can not control the auto focus and exposure, or we can just do it manually. For some people this is not a problem because most of the macro picture is using manual focus to get the best results. One of the disadvantages of this is that we can not control the lens aperture setting. Only when we have a lens ring settings we can change the aperture manually. However, if no then the aperture will be locked on Telebar openings. Extension Tube is the second type which have electrical connectivity. This connection allows the camera to control the exposure, auto focus and aperture. Both types give us the option, if we just want to try, use the first type and if it has sufficient funds then it would be better to buy a second type.

  Nikon, canon, olympus also produces extension tube, while the Sony does not. But of course, we could also use a third party product, call it a product of kenko and VIVITAR. There is little specific peculiarity brands pentax extension tube sold as more expensive than a macro lens itself.
Disadvantages Extension Tube

Disadvantages of extension tubes is that we will lose a little light so it needs to slow down the shutter speed and raising the ISO. Do not hesitate to increase the ISO to get the widest aperture to get a narrow depth of field. Another thing if the subject we are silent, a tripod is very useful to help slow down the shutter speed and lower ISO. While the best way to use the extension tube is to use manual focus.