telephoto

[recon photography]

So i want to get a telephoto lens that work on full frame i was sold on the 70-300 IS, till i found out you cant use teleconverters or at least thats what the list said any other cheapish zooms in that range that can use converters btw i dont want a tamron

 

[Loswr]

It's correct that the 70-300mm f/4-5.6 lenses cannot use Canon teleconverters (neither the non-L nor the L version). 3rd party teleconverters can be used, but as an f/4-5.6 lens, you'll have problems with autofocus if you use it with a TC.

But...what is your budget? If by 'cheapish' you mean under $1K, your selection of Canon lenses that can use a TC is limited to one zoom lens, the 70-200mm f/4L, and two prime lenses, the 200mm f/2.8L II and possibly the 135mm f/2L (just over $1K with the current rebate).

If you are looking at the 70-300mm non-L, I'd recommend the 70-200mm f/4L instead. With a Canon 1.4x II, that will still come in under $1K, give you a 70-200/4 or a 98-280/5.6, and better IQ than the 70-300mm non-L. But, if your budget is higher, Amazon has the 70-300mm f/4-5.6L IS for under $1400, and will give better IQ and more convenience than the 70-200/4+1.4x (and though the 70-300 L doesn't take TCs, it still gives a broader range at approximately equivalent apertures).

 

[Mt Spokane Photography]

A Canon TC will physically not fit with it, and, it will not autofocus with a TC unless you have a 1D series camera. There is no real reason not to consider a Tokina TC. They are excellent, and will fit the lens fine. You can attempt autofocus, but it may or may not work with your camera, and will be very slow at best, so just figure on manual focus when you use a TC.

Either get the 70-200mm f/4 non IS, or step up to the 100-400mm L where you won't need a TC.

Another option is the 300mm f/4L which takes a TC just fine, and has excellent resolution, far better thann a zoom. It focuses very closely as well, which allows you to fill the frame with small birds.