Sigma Reviews

See the excellent review below which lists the pitiful handful of Sigma lenses that this teleconverter is compatible with. I wish I'd read it before I ordered it (I had to return it after opening it, the list is only INSIDE the booklet*). I have several wonderful Sigma lenses, but none are on that list, and the ones on that list would duplicate what I have, so I have no intention of bying one of the few lenses this teleconverter could work with. *Also inside the booklet is a warning that trying to use the lens with any lens not on the list may damage both the converter and the lens. Well, yeah, a quick glance shows that they used the standard connecting bayonet at only one end (the camera end) and used some strange lens-specific screw mount at the other end. And the possible reason: My Nikon camera body has plenty of space behind the bayonet mount in case the lens needs to extand back a little, but this teleconverter extends FORWARD beyond its front so only a lens with plenty of space "in front of" the bayonet mount (ie, at the lens' camera end) would be able to mate with this. So it looks like they have to specially design lenses just to be compatible with this odd teleconverter, and that would explain why the list is so short.

This converter not only work only on Sigma Lenses - BUT CERTAIN SIGMA LENSES!

The converter will work in MF mode only, unless noted, on the following APO lenses:
Macro 180mm f3.5 EX IF HSM
300mm F2.8
300mm F2.8 EX HSM (AF)
Tele Macro 300mm F4
Tele Macro 400 F5.6
500mm F4.5
500mm f4.5 EX HSM
800 F5.6
800 F5.6 EX HSM
1000mm F8
50-500mm F4-6.3 EX RF HSM
70-200mm F2.8 EX HSM (AF)
70-210mm F2.8

This has really turned me off from Sigma, as this IMPORTANT information is NOT listed anywhere!

This 2X teleconverter is a great addition to any fast Sigma lens. I use mine with my Sigma 70-200 f/2.8 HSM. It is sharp, well made, and a relative bargain. I recently used it to shoot at Road Atlanta and was very impressed with the results.

Of course, it is not designed to use with Nikon lenses, only Sigma lenses on Nikon bodies! And that job it does very well.

I bought this teleconverter with a 70-300 sigma lenses and it did not mention anywhere (editorial reviews or specifications) that it is compatible with only a specific number of lenses. But the review for the nikon compatible teleconverter it does so. Make sure before you buy it that it will fit your lenses.

I bought this teleconverter to supplement a 1.4x converter that I already owned. I wanted to try it out with my Canon 200mm 2.8 lens and compare the results to my 400mm 5.6 lens.

The converter is nice and compact, has a good quality feel to it, and seems to work very well. I shot one roll of film with it so far and was very happy with the results.

Remember that you lose 2 shutter stops when using this converter so it should only be used with a fast lens such as a 2.8 or 3.5 etc.

I feel that this lens seems a lot slower then my others. Since this is not a lens that I must use since I have a better lens at the same focal length I rarely use it. I don't recommend it but others might like it.

I shoot nature semi-professionally, and use a lot of pro Nikkor glass. This lens is among the highest in optical quality that I have worked with. The images remain sharp and contrasty at all apertures (remember that DOF is very shallow at 3.5 and 4), and the bokeh is very nice opened up. The color may have a slight warmness compared to Nikkor's 60mm/2.8. I have been banging this lens around in the field for a month or so; the build quality seems excellent, and the tripod mount is nicely balanced. Focusing is silent, fairly fast, and very accurate on F5, N90s, and N80. The manual focus (primary mode in macro photog.) is nicely dampened for an AF lens. I am shooting transparency film on a tripod with a cable and focusing stage.
All in all this is a fine optic and it is priced reasonably.

Unless you need the extra distance afforded by the 180mm focal length of this lens (i.e. you want to work father away from your subject), your money would be much better spent on Canon's 100mm f2.8 USM macro lens. Canon's 100mm macro is also capable of 1:1 reproduction and offers better optics and build quality. More importantly, Canon's lens costs less than this Sigma lens. Save your pennies and work with a shorter focal length -- you won't regret it. This lens, while capable relative to the rest of Sigma's products, is not in danger of producing really impressive results.