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02-01-2009, 03:07 PM   #1
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Join Date: Jan 2009
Location: Oregon
Posts: 4
Use of Sigma Teleconverter with Pentax 50mm?


I'm wanting to add a new lens to my collection (Pentax 200D base) - around a 100mm f/2.8 for theater photography (often dim light conditions). I currently have the Pentax 50mm f/1.4 and absolutely love it. I also have the Sigma 50-500 (nature photography) and have been looking at purchasing a Sigma AF teleconverter - either the 1.4X or the 2X.

Is it possible for me to "kill two birds with one stone" by just purchasing the Sigma 2X teleconverter and using it with my Pentax 50mm? Will it turn the lens into a 100mm. f/2.8? Has anyone tried this? Sigma puts out a list of teleconverter compatible lenses and the Pentax 50mm is not on it. Does this mean that it will ruin the lens, or that the AF just won't work?

Thank you for your help!

02-01-2009, 04:14 PM   #2
Senior Member

Join Date: Oct 2008
Location: NYC
Posts: 258
Teleconverter gives you the 2x range, but it decreases the light alot. Even at f1.4, you will see it darking the exposure alot. so only work with very bright area. Not worth it. better spend the money on a cheap zoom lens or a manual 135mm.

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100mm, 2x, 50mm, f/2.8, k-mount, lens, pentax, pentax lens, sigma, slr lens, teleconverter
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