Usm Telephoto Zoom

Usm Telephoto Zoom
questions on picking a lens?

ok so i think i am going to get the Canon EF 70-200mm f/4L USM Telephoto Zoom Lens. Here is what i do not understand. I want a super soom lens. But i do not know how to figure out how far away i can zoom into or onto which ever you call it 🙂

I currently have the Canon Zoom Lens ef 75-300mm 1:4-5.6 lens and the canon efs 18-55m lens. Will the new one be a lot better and be able to zoom in more? I am looking to do nature shots and such like bird watching etc.
how much closer can i get zoomed in if i get a 70-400 mm lens?

Actually you will be able to zoom in less. Your current lens will go up to 300mm, thats pretty good. But if you want to get even closer you will need to go to a 400 or 500 or maybe even a 600mm lens. You are probably looking at the price of this lens and saying “why so much”. Well this lens has the same aperature throughout. With your current lens your aperature can open up to f/4.0 at 70mm but only open up to f/5.6 at 300mm. The lower the number the wider your aperature and more light. The second part of this lens is its an L series lens. It has really good glass.

A much cheaper alternative is a teleconverter. It will multiply your current lens. If you bought a 2 times teleconverter your current lens would become a 150-600mm. The drawback is that you lose a full f-stop or two so you would need alot of light.

Canon EOS450D, with EF75 – 300 mm f/4.- 5.6 III Usm Telephoto Zoom Lens