Question About Extension Tubes

[clickin girl]

Hello! I have been shooting Macro for about a year now and am finding that I want to get closer. I have a Canon100mm 2.8 and it still is not getting close enough. I would like to get some extension tubes. Can you put extensions on a macro? If so which ones are best? I have heard Kenkos has a good set but I have also found some for about 100 dollars cheaper and am wondering if they just go between your lens and body why the difference in the price? Can anyone give me some good advice about this? Thanks!

[GeoffWessex]

Short question - long answer..... so take a look at the "pros and cons of extension tubes" on this page. And also check out the "Pros and Cons of Close-Up lenses (filters)" on the same page.

That's the technical stuff..... maybe somebody who shoots macro more than me can chip in.

[OldBoy]

With the Nikon 105mm F2.8 macro lens I use either the 1.4 or 2x converters to get closer. So, with the 1.4 it's 150mm F4 or with the 2x it's 210mm F5.6.

[Markulous]

I use both extension tubes and teleconverters on my Sigma 105mm macro (and have even used both!)

Any lens can have extension tubes added (but stabilisers usually don't then work) but to be really effective, it's best to get ones that have electrical contacts (which tend to be quite a bit more expensive). This ensures that you can set the exposure and usually allows autofocus (the former is near essential the latter not so important - I usually use manual focus). I'd also recommend metal lens mounts as there's a fair bit of extra stress put on the mount.

Effectiveness of tubes decreases with focal length of the lens i.e. better on a 50mm than a 100mm (can never remember the formula of magnification but it's something like the increase is tube length + focal length divided by the focal length) - but I even use my tubes with my 500mm (but that's to ensure nearer focus rather than to magnify image)

[Cathus]

The cheaper ones you've seen probably are cheaper because they don't have the electrical contacts to talk to your camera so all your settings must be manual, whereas the more expensive maintain the electrical contacts and are just like using your normal lens.

They'll do the same job, there's no glass in an extension tube so no quality issues between both sets, it just depends on if cost is an issue and if you are happy to shoot by setting the exposure manually rather than auto/semi-auto.

[donoreo]

The page Geoff linked to has some very good info.

[clickin girl]

Thanks guys! You have been very helpful!