Teleconverter a good investment?

[jonh68]

I have access to a 300 mm 2.8 AF lens. I am thinking of getting a kenko pro 300 2X as I understand the lens will retain AF with this converter. I want to get more reach in preparation for Osprey nesting in the spring. Would I be better off with a 1.4 converter or go with the 2X converter? I realise the sharpness would go down with the 2X, but would it be any worse than the Bigma or any other non pro lens in the 400-500 range? I would also like to use it for taking pictures from centerfield/outfield for baseball when the lighting is good.

[Telecorder]

I have access to a 300 mm 2.8 AF lens. I am thinking of getting a kenko pro 300 2X as I understand the lens will retain AF with this converter. I want to get more reach in preparation for Osprey nesting in the spring. Would I be better off with a 1.4 converter or go with the 2X converter? I realise the sharpness would go down with the 2X, but would it be any worse than the Bigma or any other non pro lens in the 400-500 range? I would also like to use it for taking pictures from centerfield/outfield for baseball when the lighting is good.

From what I've read, most any 2X TC is pushing the envelope a bit much on both IQ and extra stops. Best results reported with the 1.4X and a bit more degradation with the 1.7X.

FWIW, the Sigma EX 1.4X TC can allow AF if you tape over/nail polish the first contact to disable the reporting lens' side pin. For the ~$130, the Kenko is a good 1.4X TC. I have both the Kenko and the Sigma for use with my Bigma. Both allow AF (Sigma's taped) with both giving good IQ on my Bigma...

Since you're using the TC w/a prime, the IQ should be better than the native Bigma at the same reach and using the 1.4X TC...

[jonh68]

Thanks for the reply. I suspected the 2X may be a bit much. I may also get the Bigma down the line so it's good to know it works well with a converter.

[Photoskipper]

Tried the Kenko 2X before with both old Canon 75 - 300, and new 70 - 200 F2.8 IS. Rather disappointed, particularly at the extreme focal lenght. we have to be reasonable. A 6 years old 300 mm lens with 2x on a 300D got almost 1000 mm. I cannot expect too much.

Just got the Canon 2X couple days ago and tried on the 70 - 300 F2.8 IS with the 5D. It works fine and great result. Both IS and autofocus works well.

I agree the 2 X is a bit too much. 1.4X may be a better choice for more promising result.

Again, due to budget issue, 2X with 70 -200 gives me the 400 mm at 5.6. Cannot complaint too much. Wait till i save enough to get a 500mm F4.

[gluwater]

The 300 f/2.8 is one of the sharpest, fastest focusing lenses out there and works well with a 2x converter. It will not be as sharp as a 500 or 600 prime and it will AF slower but it is definitely usable. Some people will even stack the 2x with a 1.4x TC on this lens but I believe you lose AF unless you tape the pins.

[claudermilk]

From all reports and examples I've seen, the 300/2.8 should take the 2x TC just fine. While the 70-200 does suck with it, that is not at all relevant to the prime.

[jonh68]

Well, looks like the 2X is back in the picture!

[CatOne]

Well, looks like the 2X is back in the picture!

I'd still go with the 1.4 tc over the 2x, if you want sharpness :wink