Tamron 2x SP Pro Teleconverter w/ 10D

[topomang1]

Hello to everybody,

I have a Canon 10D with tamron tele-macro 100-300 mm.

This lens works great but I need to go closer to my subjects. I use the camera exclusively for wildlife shoots.
Browsing the internet I foud this cheap solution:
http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=185156&is=REG

two questions:

1) will it work with the 10D ?
2) will I have decent photos or it is just waste of money ?

thanks

[PaulB]

That Convertor is for lens with a maximum aperture of f2.8 and I don't think your zoom will be. So unfortunatly it will not work (well, if at all - the AF certainly will not work).
As a simple rule of thumb: you lose 1 stop of aperture for a 1.4x convertor (Extender in Canon range) and 2 stops for a 2x.
Zoom lenses seldom work well with a 2x - unless they are the Canon L glass (and then the faster the better due to the light loss).
You could look for a Tamron 1.4x but even then at the long end of your zoom (300mm) the AF will not work and you will needlots of light and a high ISO to keep the shutter-speeds up to avoid camera shake.
Perhaps not such a good idea with that lens really, sorry.

[topomang1]

Thanks a lot, I am a beginner here. so let`s say I cannot spend more than 500 dollars. Which are my alternatives ? any help is appreciated.

[PaulB]

Back to the rule of thumb again. You get what you pay for, simple really. The idea would be to get as much lens as you can for what you can afford to pay - that's understandable, everyone has a budget to keep to (pity really!).
In 35mm film terms your zoom at the long end is equal to 300x1.6 = 480mm (at whatever the aperture is, 5.6?). To be honest a few years ago most photographers would have given up eating to own a lens of that foocal length at a reasonable price!
So you are unlikely to get anything much longer new within your budget I'm afraid - except perhaps a mirror lens (500mm at f8) and that will lose AF anyway.
Per5haps look for something secondhand - a good camera shop nearby or a well recommended one for mail order. I'm in the UK so maybe some of our US friends can recommend something near where you live?
A 300/4 Sigma and 1.4x to match it would give you 420x1.6 = 680mm or so and the AF should still work at f5.6. A Canon 300/4L IS would be nice but out of your price range.
Come on folks anyone else out there got any other ideas?