[robski]

When I first saw this posted I was going to say don't waste your money. I knew Sue (Greypoint) has a Jessops x2 so I thought I would wait until she reponded and she has pretty much confirmed that the results will be quite bad. One would question the logic of putting a x2 on a budget zoom.

It might be OK if you always use the full frame. If you discount the loss of 2 stops of light and AF problems introducing a converter will magnify the lens errors, increase the flare plus add the TC's own set of errors.

If you trawl the web these are the perls of wisdom you will find.

More people are happy with a x1.4 converter than a x2.
More people are happy with a converter on a Prime lens than a Zoom.
More people are happy with a converter on the Best Glass than Budget Glass.

There are a number of demostrations that show that upsizing gives better results than a x2 converter on good glass.

One reason why Canon's TC will only fit a limited range of L lens.

I use a Canon x1.4 on a 300mm f4 prime. You can see a slight degradation but the results are better than cheap the Sigma 135 - 400 zoom.

If you do go ahead and buy a x2 for the hell of it please post your results because I believe this forum should be more fact based than hearsay.