Teleconverters

bloodhunter · 29 Jan 2012 at 13:58

I am thinking of purchasing a 2X TC for my Sigma 70-200 f2.8 but i have read the usual good and bad reviews mainly concerning loss of image quality but how much loss ??
I am aware of the f stops that are lost associated with it too.

The extra reach it offers is appealing but seems pointless if IQ is seriously affected.
A 1.4X seems to have little or no affect according to the reviews i have read and this seems more of an option as i don't want to buy a 2X if it aint going to perform.

Anyone here use either and what are your opinions please.

neil_g · 29 Jan 2012 at 17:18

ive used a 1.4x on mine and saw some noticable softness so wouldnt touch a 2x personally.

Vertigo · 29 Jan 2012 at 18:13

Obviously it depends on which convertor exactly, not just brand but which generation too - Canon are up to their third with their 1.4x and 2x convertors.

Whilst you'll lose some quality with each, it's also down to the lens used with it. Not just the obvious in terms of the better the lens is to start with the better it'll be with a convertor, but also I believe that some lenses 'take' convertors better than others and are even designed to work well with them.

xaldub · 29 Jan 2012 at 18:18

I'm wary of using x2 teleconverters - the loss in visual quality can be quite obvious, especially if the lens and TC aren't of the the absolute best quality. Autofocus performance will also suffer ( your f2.8 effectively becomes f5.6 - less light to assist with accurate focus ). Personally I only bother with TC x1.4 or a TC x1.7 at a push.

Ksanti · 29 Jan 2012 at 18:47

Yeah the Sigma isn't exactly known to take teleconverters well as well as being quite soft. Probably not worth it to be honest when you could get a first gen bigma for not all that much more.

D.P. · 29 Jan 2012 at 20:42

The sigma 70-200 is not outstanding at 2.8 to begin with and is known not to take TCs very well, I would go for the 1.4x and be prepared to stop down.

neil_g · 29 Jan 2012 at 21:55

Thats subject to opinion,the sigma without tc is very good. Both copies we have.

Side5wipe · 30 Jan 2012 at 08:38

This was taken with my sigma 2.8 70-200 and 2x tele on a sony a700.

The thing i found most frustrating when using it was the auto focus, the light wasnt that good, i've yet to try it on a nice sunny day.

Tysonator · 30 Jan 2012 at 20:59

The Kenko Teleplus PRO 300 range of TC are some of the best third parties around.
Have a look at their range and i particular the Pro 300 which I think is the top model.