Teleconverter for 300D/Sigma 135-400mm (1 Viewer)

[CJW]

Anyone got any suggestions as to what to buy? Preferred choice is 1.4x but will consider a 2x
I don't want to spend "Canon money".

Chris

 

[digi-birder]

Chris, I have the Sigma 1.4x and it works fine. I was told that you have to use one the same make as your lens, but I don't know how true that is. I've heard that the 2x is not as good.

I bought mine from Jacobs (not sure if you have them over there) and it cost me about £140.

 

[CJW]

Thanks Diane, does it affect the Auto-focus system?

 

[digi-birder]

Yes, you have to focus manually.

 

[CJW]

Righto, thought I might have to.

Thanks mate.

 

[digi-birder]

OK pal!!

 

[Steve G]

Chris the Ex series Sigma teleconvertors are pretty good & the difference between 1.4x 2x quality is barely discernible. You lose 1 f stop with the 1.4 & 2 with the 2x so if your lens is a f5.6 max aperture you'll lose autofocus with either convertor but the 2x will result in a f11 aperture which might be too dim to easily manually focus in anything but bright conditions. The shutter speed will then inevitably be slow so that in what effectively becomes a 800mm lens you are almost bound to get blurring due to equipment shake (as a rough guide equipment shake is minimised by using a speed > or = the inverse of the lens focal length (in this case 1/800).

 

[CJW]

Thanks Steve, I've been and gone and ordered the Sigma 1.4x