When I looked at the same basic issue, I ended up going with the 100-300/4 EX Sigma. For me, a 2X converter is just too much. I have the 1.4X Sigma EX converter and use it sometimes. I have shot about 15,000-20,000 frames with that lens (mostly baseball - little leagues) and it is a good one. I considered the 50-500 but felt the speed was just to slow. Also, look at the price. The 100-300/4 is about the same price or more than the 50-500. That should tell you something. The 100-300/4 is internal zoom and internal focus - the 50-500 is not internal zoom. So the size/weight balance is going to change as you zoom in/out - may not matter to you, but for me it does. Also, AF was something I needed/wanted for the baseball. The 100-300/4 focuses pretty well - not as good with the 1.4X on it. The 50-500 is slower (aperture) and will probably not focus as well, especially if the light drops.
Good luck in your quest. -- Bruce Friday, May 11, 2007, 10:41:36 AM, you wrote: PG> I'm looking for a long tele zoom and i've whittled the choices down to PG> the following options: PG> I need to cover the focal length range from around 100mm to 400mm PG> (before crop factor being applied) so here are the shortlist of PG> options: PG> a) Sigma 70-200 f/2.8 + 1.4x tc (98-280f/4) or 2x TC = (140-400 f5.6) PG> With option I would think that the optical performance with the 2x PG> converter may not be stellar... so i'm not too happy with that option. PG> But OTOH i get f 2.8 between 70-200mm PG> b) sigma 100-300 f/4 + 1.4x convertor (140-420 f/5.6) I guess the PG> 1.4x converter is not too much of a compromise. PG> c) sigma 50-500 ... this is the cheapest option but i have no idea how PG> good this lens is. anf th f6.3 aperture at the long end puts me off a PG> bit... Does any one know what the max aperture is at 400mm ? PG> A this stage I dont want to factor the financial aspect into the PG> decision coz i'm willing to wait a bit until i've put away enough PG> funds for the "right" option. PG> It would be nice to be able to factor in the new SDM lenses into the PG> shortlist but unfortunatley they get eliminated because I want to use PG> this setup on my MZ-S as well as the K10D. PG> Regards PG> Patrick Genovese -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
