please explain

[rollingrockmom]

On this Tamron lens............Tamron AF 200-500mm f/5-6.3 Di LD IF SP............... What does Di LD IF SP mean?
I am researching to find a new lens for my Rebel XST. I am currently using a Canon EFS 18-200mm f/3.5-5.6 IS, but really would like a better reach . We live on the Mississippi River, and the wildlife is plentiful. I like to go out into the backwaters and see what I can find. This lens thing is all new to me, and I have spent a lot of time looking at the choices. So confusing.

[RichardTaylor]

See the Tamron abbreviations in this thread:

Lens Abbreviations for Sigma, Tamron, and Pentax: Pentax SLR Talk Forum: Digital Photography Review

[TerryMC]

From Tamron site:

[LeeR]

If you are planning to hand hold this lens you may also want to look at one with vibration control. Hand holding a 500mm lens you can literally see the effects of your pulse in the movement of the lens. A good tripod would make sense as well.

[rollingrockmom]

Does Tamron have non vibration, or do I have to go to Canon and if I go to canon will a 400mm do what I want in range?