Killer deal on a telephoto lens?

[river251]

This telephoto lens:

2X TELEPHOTO LENS FOR CANON POWERSHOT S3 + TUBE ADAPTER - eBay (item 110358589168 end time May-26-10 05:52:36 PDT)

has about the power of this lens (first one):

Raynox accessories for Canon PowerShot S5 IS, S3 IS, S2 IS Digital Cameras

The obvious physical and price differences must mean the cheaper one will not do what the more expensive one will do. What is probably lacking in the first lens?

Thanks very much for any enlightenment for this beginner, I'm using a Canon S3 IS.

Jim

[inkista]

Those aren't telephoto lenses. They're teleconverters--add-on lenses that go in front of the S3IS's built-in lens. As such, neither one is going to give you stellar optical quality. You're also likely to introduce softness, no matter how much the thing costs. The Canon one is more expensive because it's Canon branded, just as the accessory tube you need to attach it is going to be a plastic tube for the same amount of money as a Lensmate, which is machined aluminum. In this case, you really aren't necessarily going to get much better results from the Canon than the Raynox.

I'd say google up some samples from both and see if you can see any difference.