what's the difference using macro lens and using extension tube?

[haris]

what's the difference between using macro lens and extension tube? can someone help me with this?

 

[Chris of Arabia]

As a general rule, you'll be able to get closer using a tube than a macro lens will get you by itself. There maybe a bit of overlap in what's possible with a very short extension tube used with (let's say) a normal 50mm lens, when compared with a specially designed macro lens. On the whole though, a tube or even bellows will take you into a whole new world.

 

[Mike Jordan]

Tubes can also be used on any lens. I've used my macro tubes on my wide angle zoom all the way up to my 100-400 zoom. The wider the lens the less working depth you have though. For instance at 24mm I can get a wide angle close up but I also have no working depth and my lens is right on top of what I'm trying to get a macro shot of. If I use the same tube at 85mm then I have a number of inches of working depth between my lens and the object, but I might not get as large an image... so I go to either a longer tube or add another one to the one I have on. If I go to 200mm I can sit back about 2 feet. Having a working depth between your lens and the object can really help if you are using a tripod (which most of the time you will) or you just can't get real close to the object.

I like using a macro tube on my 100-400 so I can focus really close with it. I lose the distance focus, but that's ok when I'm using it to focus within feet of me.

In addition, tubes do not have glass in them, so you don't degrade your image like you could with macro filters. They are also cheaper. The Kenko tubes come in a set of 3 of different sizes. You can use one or more at the same time to change the size and distance from your subject.

Mike

 

[Digital Matt]

A dedicated macro lens will cost more, but also be more versatile. A macro lens will focus throughout the whole range, while extension tubes render any lens to a macro only lens, taking away your ability to focus at infinity. For that matter, taking away your ability to focus on anything other than a very narrow range.

It all depends on what you are going to be photographing. If I were going to be photographing insects in the wild, I'd want a 180mm macro lens for sure. If I were going to be photographing coins or other things in a studio setting, I'd probably opt for bellows, or tubes.