I would like to get some opinions (e.g. quality, autofocus, vignettes) on the new Sigma 1.4 X APO tele-extender. I plan to use it either with the Nikon ED AF 300mm F4.0 or the Tokina ATX AF 400mm F5.6 on the F5 to extend the range for bird photography. I would appreciate for any comments.

-- Khanh C. Tran (ktran@nvl.army.mil), January 22, 1999

Answers

Good move Khanh, you're in the equipment forum. Well, I've bought the new Sigma 1.4 EX APO one month ago. Unfortunately, I don't own the terrific Nikon 300/4 (not yet), but I have the outstanding 80-200/2.8 ED D (tripod version). I've bought the TC 1.4 merely to use it on this 80-200 when I travel and want some extra focal lenght. I've taken a lot of (Astia) slides lately to see if the New Sigma was better than the previous version that I owned (on a Minolta lenses). By the way the previous version was a disaster when used on the 400/5.6 Apo (vignetting and lack of sharpness). The new 1.4 EX apo, however is a pleasure. So far I have been critically looking to all my slides and to my surprise this converter is worth the money!!! I cannot comment on the wonderful Nikon TC 14B but I think the Sigma does a very good job. Sharpness was very good and I have not discovered vignetting so far. Naturally I cannot spea

-- Ivan Verschoote (ivan.verschoote@rug.ac.be), January 25, 1999.

Good move Khanh, you're in the equipment forum. Well, I've bought the new Sigma 1.4 EX APO one month ago. Unfortunately, I don't own the terrific Nikon 300/4 (not yet), but I have the outstanding 80-200/2.8 ED D (tripod version). I've bought the TC 1.4 merely to use it on this 80-200 when I travel and want some extra focal lenght. I've taken a lot of (Astia) slides lately to see if the New Sigma was better than the previous version that I owned (on a Minolta lenses). By the way the previous version was a disaster when used on the 400/5.6 Apo (vignetting and lack of sharpness). The new 1.4 EX apo, however is a pleasure. So far I have been critically looking to all my slides and to my surprise this converter is worth the money!!! I cannot comment on the wonderful Nikon TC 14B but I think the Sigma does a very good job. Sharpness was very good and I have not discovered vignetting so far. Naturally I cannot speak for using this Tc in combination with longer lenses like 300 or 400 mm. By the way, AF is transmitted together with metering (although the aperture on the display does not seem adjusted, the metering is perfect and does not need any correction). Hope this helps. Ivan.

-- Ivan Verschoote (ivan.verschoote@rug.ac.be), January 25, 1999.

Due to erratic behaviour of my PC I have to put this answer third in line. Sorry for this. About AF, the combination of TC with lens is naturally slowing down the speed of AF. With a F5 or F90X this is not a big concern however. The speed is comparable with first generation AF speed like F 801.

-- Ivan Verschoote (ivan.verschoote@rug.ac.be), January 25, 1999.

Hello all.

Ivan: you mentioned the "old" Sigma teleconverter vs. the "new" one. How do you tell the difference? I recently picked up a Sigma teleconverter: Sigma 1.4 APO EX. Does the "EX" mean that I've got the newer version? Thanks!

-- Jeet (jeetsukumaran@pd.jaring.my), February 02, 1999.

Jeet,

You can sleep on both your ears. The Sigma 1.4 APO EX version you have is the NEW converter. The old one does not mention EX or APO.

Ivan

-- Ivan Verschoote (ivan.verschoote@rug.ac.be), February 03, 1999.