Call me Clueless (extension tubes) . . .

I just got 3 Vivitar Automatic Extension Tubes in sizes 12, 20, and 36 (all connected.) However, they have no glass in them -- are they supposed to? I've never seen/ used extension tubes before . . . They are also too small for my Canon (T2i) -- do you think older model or Nikon?? Thanks for any feedback.

They should not have glass, but they are made for specific mounts, so unless you got ones for Canon EF mount, they will not fit.

EF and EF-S should be the same mount for tubes AFAIK.

as said already it's not supposed to have glass as for the mount post a picture of the mount someone here may recognize it also as per the above I do think there is a difference with EF and EF-S mounts even on tubes .

David

Newer extention tubes for Canon cameras are made to fit both EF and EF-S mounts. You can tell by the color of the index marks on the side; a tube that fits both mounts has red (EF) and white (EF-S) dots/index marks. Older tubes, including some manufactured by Kenko, could only fit a single mount.

What I don't understand is since there is no glass, why are the Kenko and Canon extension tubes >$100? What is it about them that make them so great?

Hello! The tubes will have just air, don't worry about that. Your problem is that you may have bought the wrong tubes for your camera. They could be for minolta, olympus, nikon or something else. If you could get as much info for as possible, that will help.

Where did you buy them, on ebay or amazon? Did you recently buy them? If you bought them online, is there a way that you can check your email for a description of the product you bought, or give us a link to what you bought?

If they are olympus, nikon, or whatever, you could POSSIBLY buy an adapter to connect the tubes to your camera, but you would probably need 2 adapters, one to connect to the body, and one to connect to the lens. If they were made for another camera company (not canon) you may want to return them, if you can not, you can possibly get cheap adapters.

Are you able to connect a lens to the tubes?

KirkS518 wrote in post #14874805
What I don't understand is since there is no glass, why are the Kenko and Canon extension tubes >$100? What is it about them that make them so great?

it's the build quality that you are paying for. The cheap $10 tubes are made of very very cheap plastic. They all do the same job, its just air, separating the lens from the body further. If you are using huge pieces of glass, or expensive lenses, it would not be great to use cheap tubes because if they get bumped or something hits them, they could easily break and your lens will quickly meet the ground. I use the kenko tubes, they weren't too expensive compared to the official canon ones. $200 for all three. Expensive, yes.. but i use expensive glass on them so i prefer the added build quality

By pushing the lens away from the sensor/film, the image projected by the lens is larger at the film plane. This effectively magnifies the image for macro work. At the same time the lens is able focus closer to the subject, though the is unable to focus at infinity. Because the lens is further away from the sensor, the light intensity is reduced.

Extension tubes are a cool and quite inexpensive way to get into macro photography..

The mounts have to be machined and sturdy enough to support any lens that is attached to it. There's also electronics that allow the lens to communicate with the camera.

You can also find cheap tubes, since as pointed out there are just air, but they certainly aren't as sturdy as the more expensive ones and they wouldn't have the electronic components.

KirkS518 wrote in post #14874805
What I don't understand is since there is no glass, why are the Kenko and Canon extension tubes >$100? What is it about them that make them so great?

OK -- thanks for the great information! I did not buy these, but found them in a FREE box at a yard sale! I was hoping that they would work for my camera but, since they don't, I might see what I can get for them on Ebay. They are a Vivitar in sizes 12, 20, & 36 mm and the 36 says AT-3. I assume this is made for older models, but I suppose it's possible for another brand (Nikon, Olympus, etc.)

They are completely metal (no plastic parts) and came with a leather-like case. Here is a pic . . . Bummer that they won't work for me!

IMAGE LINK: http://www.flickr.com/​photos/yankeemom/78096​32732/

wow those look old.. maybe 70's or 80s. Wacky! Looks like you have to screw them to connect each one. Very wild! Thank god for the future...

The screws just set in to make sure they are aligned -- they twist on and off. Yeah, they are probably pretty old.

They are for a Nikon I think, looking at the 'rabbit ears' near the mount.

NinetyEight wrote in post #14874982
They are for a Nikon I think, looking at the 'rabbit ears' near the mount.

Yes, Nikon AI

Thanks for narrowing it down! It looks like these are the same ones:

http://www.ebay.com …3cc9cdea24#ht_3​633wt_1397

Well, for free I guess I can't complain. Maybe I'll get a few bucks for them. Thanks again!