Macro Lens with Extension Tubes

[nitsch]

Has anyone here got any experience with using extension tubes in conjunction with a macro lens?

I have the Sigma 105mm which gives a magnification of 1:1 but I want more!!! :lol:

What length of tubes would I need in order to get say 2:1? Is there any degredation in image quality using tubes? Are there any problems with the cheaper brands? I don't want it to break and send my lens crashing to the floor!!! ;)

By the way I have a 300D in case it matters.

Cheers,

Nick

[ScottE]

Get yourself a set of three Kenko extension tubes. They can be used in combination on the Sigma 105 and still give acceptable pictures. You will not be able to use auto focus because adding extension tubes decreases the effective aperture. The Kenko tubes do have electronic connections for auto focus, so you will get some auto focus with the shorter tubes. Remember that the depth of field becomes very narrow at high magnification so you will have to be selective about composition.

Scott

[nitsch]

Cheers Scott. I'm not too fussed about whether AF still works or not as I prefer to manually focus at these kind of magnifications.

Say I stacked the three Kenko's together, what magnification would that give me? Is there a chart somewhere or a formula for calculating these kind of things?

[yellow_belly]

Hi Nitch, I use extension tubes with my Sigma 105 and get excellent results with it,I have given this url before but have a look at...
http://www.lifeinthewild.co.uk/gallery/albums/album01/dragon_body_filtered.jpg
...as that is taken with the Sigma 105 and 21mm (i think) tube, the images are just as good as without the tubes. I personally use manual focus with macro but there is no problem at all with auto focus.

I use them a little different to how you want to use them because I want a little extra working distance (to stop scaring insects away etc) but with the same maginfication as I can get without the tubes, whereas you want more magnification but I dont see any problems there either :)

Terry

[nitsch]

Awesome pic Terry! Thanks for the info, I hadn't considered the benefits of getting a greater working distance using the extension tubes, but this sounds like an added bonus.

[mr.photoguy]

I am also looking into these kenko tubes also...
Nice pic Yellow belly. I haven't seen any dragon flies around lately ..

[Jon]

Your Sigma has 105 mm extension to get you to 1:1; you'll need another 105 mm to get to 2:1. You're going to have to do some mixing and matching to get about that much extension - I don't think anyone sells a single kit with that much total extension.

[SDK^]

I have just ordered the 3 Kenko extension tubes kit for my Canon 100mm USM Macro, I'll post some examples when they arrive

[nitsch]

Cheers for the info Jon. I think 105mm of extension might be a bit unwieldy!

SDK, sounds good - this would be the kit I order if I go for it so I look forward to your results.

[MrKickalot]

Kenko Extension tubes are fun!! They are worth the 129 bucks just to play with. I use them on my 50mm as well as my 75-300. You can really get crazy if you want... here is a picture of a misquito..shot through the glass... unfortunatly the glass was a little dirty.. The picture isn't the best but it does show the versitility of extension tubes! I put all 3 tubes (68mm) on my DRebel with my 50 1.8 and put the haze filter against the glass. The focus distance was about a quarter of an inch or so... Just another fun thing you can do with extension tubes:

http://www.fotop.net/allmanphoto/Insects/IMG_5493

Have fun!