Teleconverters

[nirofo]

Originally Posted by miketoll

Don't really understand what you mean by ''Quality can be obtained if the converter isn't used outside it's capabilities.''

Hi miketoll;11934

A teleconverter is usually only at it's best when used with a long prime lens, such as a Nikon 500mm f4 and a TC14E or a TC20E, Canon have similar spec converters. However, very good results can be obtained using other combinations of Lens + Teleconverter. 'providing', certain conditions are applied when using them! Zooms can be very good if used at or near their long end, if the light is good, the camera/lens support is good and the subject is photogenic. By photogenic I mean plenty of edge detail available giving good contrast between itself and an adjacent item, enabling point of focus to be accurately obtained either manually or by autofocus. Note, some lens / 2x converter combinations will not autofocus with lenses that have maximum apertures > f5.6. All Sigma converters lock up at apertures > f5.6. Kenko, Tamron and Teleplus all do a good range of 1.4 and 2x converters, they also do pro versions at higher prices. I've used the Tamron and Teleplus converters with some great successes, many of my bird pictures taken with these combinations have been published in various books and magazines.

Here's a couple more photo's taken with Tair 300mm f4.5 + Teleplus 2x converter, (Buzzard) and Tokina 150-500mm f5.6 zoom + 1.4 Tamron converter, (Stone Curlew). Both were taken using a substantial tripod and head from a hide.

nirofo.

[miketoll]

Thanks for the explanation. Those two shots are certainly nice and sharp.

[Tannin]

From time to time I ponder buying a 2X converter to use with my 500mm f/4 Canon lens and 20D. Two things hold me back: loss of autofocus, and concerns about image quality.

I really need the autofocus - these useless damn modern viewfinders are too dim and small to focus manually without a proper split image focus aid, which the 20D doesn't have. I suppose I'd get the Canon one even so, as I'm certainly very happy with the results that my Canon 1.4 converter delivers with the 500. It isn't as incredibly sharp as the bare 500 alone, but it often comes remarkably close, particularly if the light is good. As a general rule, I leave the 1.4 on the 500 all the time, only removing it when the light is problematic or when I expect to be close enough not to need it.