how to extend my 28-75 tamron 2.8 on an xsi

Anyone have any tips on how to extend my 28-75 Tamron 2.8 on an xsi Trying to get to at least 200 or around there.

Im not an expert, but even a 2x teleconverter will not get you 200mm, a 2x will get you 150mm, and not very good quality, thats if your lens works with teleconverters.

A 1.4 teleconverter will get you 168mm on the long end. That is after factoring in the 1.6 crop factor and then the 1.4 teleconverter. You'll also lose a stop of light as well, so you'll be at f/4. You could get teh 2x teleconverter which would get you 240 on the long end, but also you'd lose two stops of light. Your 2.8 would become a 5.6, and you may lose AF. For what you would lose you would be better off buying a used 70-200 f/4 non IS lens for around $500-550 shipped. At least then you'd get F/4 through the entire focal length and you will have your AF.

Buy another lens...

what, may I ask is

580exII wtb EVERYTHING

Take the money you have saved for a teleconverter--and spend it on a 55-250 instead.

bohdank wrote in post #7583591
Buy another lens...

what, may I ask is

580exII wtb EVERYTHING

wtb= want to buy

weezerfan84 wrote in post #7582700
A 1.4 teleconverter will get you 168mm on the long end. That is after factoring in the 1.6 crop factor and then the 1.4 teleconverter. You'll also lose a stop of light as well, so you'll be at f/4. You could get teh 2x teleconverter which would get you 240 on the long end, but also you'd lose two stops of light. Your 2.8 would become a 5.6, and you may lose AF. For what you would lose you would be better off buying a used 70-200 f/4 non IS lens for around $500-550 shipped. At least then you'd get F/4 through the entire focal length and you will have your AF.

I wouldn't want to lose my AF. f4 would be nice. I'm shooting a wedding and need to snipe some guests from a roof top in broad daylight so I don't really mind having the 5.6.

What about image quality using these "teleconverters"

I would not bother trying to do what you want! Buy a used 70-200mm f/4L instead

A cheap telephoto will do just as good, be faster, have AF and likely cost less. If you wanna go cheap, buy a $100 used 70-300 or 80-200 or something.

55-250 is a good choice if you want some good quality though.

A Kenko pro 1.4 and the refurbished 55-250 are exactly the same price @ Adorama.

The inexpensive telephoto will give you much better results.