Extension Tubes?

Hi all,

I've been asking around about macro photography here and there, and extension tubes have been recommended to me a few times. Sorry to sound stupid, but what do these do, and how do they do it? I think I might be interested in buying a set, as I've heard that they're really useful for macro, but I have no idea what to look for or what prices to expect.

Sorry for asking what's probably a FAQ, but thanks for any help!

I got the tube version without contacts and it was quite cheap (less than $10). However, I find it very difficult to manual focus. The depth of field is definitely reduced and any movement would blur it. So I never use it haha

I have read about reversal rings so you can mount a lens backwards but I have not tried that so I don't know how easy it would be to use those.

Extension tubes allow your lens to be further from your digital sensor and thus, you are able to focus closer to get a higher image ratio. How close you can focus depends entirely on the focal length of the lens you are using and the length of the extension tube. Each extension tube/focal length combination has a minimum and maximum focus distance so it is sometimes less than convenient to use a tube or combination of tubes. Additionally, the tubes will cause a loss in light requiring a larger f/stop, longer exposure or higher ISO (or all of the above).

A good set of extension tubes is fairly expensive. Adorama and B&H sell a set of Kenko tubes for $170-$180. However, I was able to find a used Tamron 90mm f/2.8 dedicated Macro lens for less than $125 with shipping on eBay. That is a much better option than a set of tubes since it can focus from infinity to a 1:1 image ratio.

There is a Phoenix (marketed under a slew of names) 100mm f/3.5 Macro Lens which is less expensive than a set of tubes, produces decent quality imagery and IMO would be more fun with which to shoot than a set of extension tubes. This will focus from infinity to a 1:2 ratio and obtain a 1;1 ratio with an adapter.

http://www.nikonians.o​rg …les/phoenix/100​f35-1.html

In response to the second post:

Beware of the "el-cheapo" extension tubes sold on eBay for peanuts. There is no way to control the f/stop when you shoot with these tubes. Shooting macros wide open doesn't make sense.

You can purchase a manual focus 50mm lens for a few bucks on ebay and use an adapter to mount this lens reversed in front of your lens. However, it is limited in the focusing distance and is generally not a cheap cure all for macro photography.

By the way:

Extension tubes are not only for macro work. You can often add a short extension tube (12mm or so) to allow you to focus closer when using a long telephoto.

Thanks for all the info!

At the moment I use my Tamron 70-300 Tele-Macro for all of my macro shots, such as the one below of one of my orchid mantids:

I've been looking at the Sigma 50mm for a while too, which apparently is a good lens. Would I be correct in saying that this lens would be a better investment than the extension tubes? I'm hoping to buy it when I go back to school in a couple of weeks, but it's quite expensive if you're still at school!

Jack McEntire wrote in post #8521057
Thanks for all the info!


At the moment I use my Tamron 70-300 Tele-Macro for all of my macro shots, such as the one below of one of my orchid mantids:



I'm wondering, how beneficial would extension tubes have been when taking a shot like this? I think that the lens is capable of 1:2 lifesize (the head of the mantis was less than 1/4" in reality), so would extension tubes be able to push it to 1:1?


I've been looking at the Sigma 50mm for a while too, which apparently is a good lens. Would I be correct in saying that this lens would be a better investment than the extension tubes? I'm hoping to buy it when I go back to school in a couple of weeks, but it's quite expensive if you're still at school!

Yeah, extension tube with a macro focusing lens = greater reproduction factor (magnification). D'nt forget that higher reproduction factor is simply caused by closer focusing distance, and bugs aren't likely to stay in place when you get much closer!