What are extension tube going to do for me?

You can see the lenses I have below ...

I want to get (quite a bit) extra range out of my Sigma 70-200mm with little reduction in quality. Currently I am into bird photgraphy an want some nice shots of a seasonal bird that arrives here over summer.

Any tips on tubes and sizes I should get?

Thanks,

Just to be sure we are talking the correct terminology.
There are extenders and there are extention tubes. (at least as labeled by Canon on the USA web sites and materials.

- Extenders (AKA tele-extenders) such as the EF 1.4X and EF 2.0X add range to you lenses by the stated factor. The 1.4x extenders add one stop of light loss and the 2x adds two stops of light loss. There is also a quality loss from using them, not so much from the 1.4x, but frequently noticeable from the 2X, but they are way cheaper and lighter then carrying a second lens which is their advantage.

- Extension tubes such as the 12 and 25 allow you to get physically closer to a subject before not being able to focus because you are too close.

Based on what you have said; I suspect you want an extender and I would recommend getting one of each as you can in addition put them together. I would look at other then Canon because you have a Sigma lens and Canon extenders don't work on all lenses, while some third-party extenders work on almost all lenses.

Extention tubes are used to reduce the closest focussing distance. For instance for macro shots. What you want is a TeleConverter.

For bhe test quality, stick to something like a 1.4x teleconverter. The IQ remains largely unaffected and you lose only one f/stop. You can get more range out of a 2x teleconverter, but you lose an additional f/stop and IQ starts to degrade.

It looks like a need an extender/teleconverter​. I would like this to function with my 100mm Macro and my Sigma 70-200mm and understand that DOF is reduced (correct me if I'm wrong) with the addition of the extended on the 100mm.

Can anyone name an ideal brand for me?

I guess there can't be too much between them given there is no glass in the extender.

Kenko seem popular.

Canon makes two extension tubes; a 12mm and 25mm IIRC. The popular aftermarket brand seems to be Kenko, which is what I happen to have. The Kenko tubes are cheaper and come in a set of three different lengths. You can use them individually or all together. The only downside to the Kenko tubes is the fit is a little sloppy. But it doesn't affect the image at all.

You are correct - DoF will diminish to being typically razor thin, mandating stopping down considerably. Which brings up the other problems... Subject distance and lighting. Naturally, a tripod would be a really good idea as well as a remote release.

Welcome to the world of macro.

Double Negative wrote in post #2133711
Canon makes two extension tubes; a 12mm and 25mm IIRC. The popular aftermarket brand seems to be Kenko, which is what I happen to have. The Kenko tubes are cheaper and come in a set of three different lengths. You can use them individually or all together. The only downside to the Kenko tubes is the fit is a little sloppy. But it doesn't affect the image at all.

You are correct - DoF will diminish to being typically razor thin, mandating stopping down considerably. Which brings up the other problems... Subject distance and lighting. Naturally, a tripod would be a really good idea as well as a remote release.

Welcome to the world of macro.

I thought he was talking about the teleconverters. Could be wrong, though.

angryhampster wrote in post #2133939
I thought he was talking about the teleconverters. Could be wrong, though.

At this point, I'm confused.

Double Negative wrote in post #2133976
At this point, I'm confused.

Mother of god, I am too.

Just to confirm (like already posted above), an extension tube lets you focus closer for macro shots. You commonly lose the ability to focus on infinity with an extension tube fitted.

You want an extender.

A 1.4x extender costs 1 stop, a 2x extender costs 2 stops.

I have the Canon 1.4x extender, it is great, it doesn't effect image quality much at all.

wayne_eddy wrote in post #2133667
It looks like a need an extender. I would like this to function with my 100mm Macro and my Sigma 70-200mm and understand that DOF is reduced (correct me if I'm wrong) with the addition of the extended on the 100mm.

Can anyone name an ideal brand for me?

I guess there can't be too much between them given there is no glass in the extender.

Kenko seem popular.

You are totally confusing the "extension tubes" with "extenders".

Extension tubes are merely hollow tubes that mount a lens further from the camera body. The purpose is to allow the lens to focus closer than it can when mounted directly to the camera body. This is so that you can take a photo of something very close to the camera - like a macro lens is designed to do.

An extender is an optical device (with lenses in it) that goes between a camera body and a telephoto lens and multiplies the focal length of the lens, making it in effect a "stronger" telephoto lens. Canon's extenders cannot be used with just any lens. Here is a link to Canon's web site describing the 1.4x extender and listing the lenses that can be used with it: http://www.usa.canon.c​om …tegoryid=154&mo​delid=7462

As said above, a 1.4x extender will multiply focal length by 1.4x. It will also reduce the available light through the lens by one stop. The 2x extender will multiply focal lengths by 2x and reduce the available light by two stops. With some lens models and body types, using an extender will eliminate the autofocus function, because autofocus requires a certain range of maximum apertures to function.

SkipD wrote in post #2135864
You are totally confusing the "extension tubes" with "extenders".

sorry I have a really bad flu and can't concentrate.

cough splutter

You probably want a Kenko 1.4x or 2x extender, because it doesn't have extension pieces on it. The Canon extenders (AKA teleconverters, AKA teleextenders) have extensions on them that would scratch your 100mm Macro. I am not sure what it would so for your Sigma 70-200. I think the SIgma extenders also have extensions on them, although not as promenent as the kenko.

Go here to shop for what you want.
http://www.bhphotovide​o.com …avBar&A=search&​Q=&ci=8468

Right, the Canon TCs only work on 135mm and up, mostly long L's (though fit lenses like the 70-200mm, etc.).

Telextenders will reduce DOF because the focal length magnification taking place, and even with the aperture size reduction (in proportion to the focal length) causing increase in DOF, there still is a net loss of DOF.

Extension tubes only have an indirect effect on DOF, simply because of the closer focusing distance of the lens there is less DOF. At the same time, use of an extension tube does cause reduction in the effective aperture size, causing some increase over DOF comparatively. But the net effect of both toghether (reduction and increase of DOF) is still very very shallow DOF in macro work.

The OP wants to get a 'telextender', not an 'extension tube'.