close up filter trial

I recently bought a close up filter kit to try playing with macro. The man at the camera store said that the close up filters would give me as good results as using an extension tube. I'm not sure? I have been considering getting the kenko extension tube set until I can buy a "true" macro lense. Below is a photo I took of an iris with my 70-300 lens with a +3 filter. I mounted on a tripod using mirror lock up and a remote shutter release.

If I get the kenko ET set would you use the tubes along with a macro lense (say the Canon 100mm 2.8)? I'm not sure if the tubes will be needed once I get a macro lens and don't want to spend the $159 for the set. HELP!!!

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The canon 100mm 2.8 macro lens has a 1:1 magnification ratio. A.K.A. it takes life size pictures. So you wont need the tubes unless you want larger then life size photos.

man in store would be right if you bought quality filters like Canon & Nikon.

The canon will give you lifesize, the tubes will give you greater than life size, but remember... the more tubes you add the closer to the subject you need to get. A lot of bugs won't let you get an inch from them with the lens.

I'd disagree - any glass in the way of the optical path will degrade the image to some degree. Since the tubes have no glass...there's no optical degradation. True, good quality filters like Canon/Nikon will be very good optically and any degradation will be very small. You would be hard pressed noticing it. I'd go the tubes myself.

Dave