TC Guide II 200/2.8 + 1.4X 1.7X 2X Tests

jrfarrar wrote: Clearly the matched converter outperformed but I was surprised how much difference in color between them.

Yes, it's not just about resolution, is it?

I've tried quite a few TCs over the years and mostly found them a great disappointment for slide or colour print film - especially with zoom lenses - not merely for the reduction in resolution which could be more or less obvious, but for the loss in contrast which on a dull day would kill the picture entirely. So I basically stopped using TCs and wouldn't consider mating one with a zoom.

But I did some tests the other day to see how well my old 400mm Soligor compared to (A) the Tamron 80-210 (at 200mm) plus TC and (B) the cheap Sony 55-200mm zoom plus clearview zoom, chiefly to see which gave the best resolution & contrast. Sure, none of the lenses are top-grade.

But the TC was the tamron 2x SP 6-element converter (though in adaptall mount) and I was very surprised how good the results were on the tamron zoom lens. I guess part of the reason is the quality of the TC, but I'm wondering if the fact that they were both Tamron and well-matched helped. In the tests I did the IQ appeared to be hardly degraded at all compared with the 80-210 on its own, even at full aperture.

The lens surface on the Minolta 1.4X APO (I have versions I and II)is nearly flush to the housing flange. I would not use it on the Tamron unless the Tamron converter for the lens is of the same measurement. I just got myself a Kenko MC4 DGX 1.4X and its lens is much deeper than the Minolta.

The pictures about the teleconverters on this website are accurate. The Kenko is a Generic since the depth from lens to housing flange is about 8 mm. That should work for you. I also bought the Kenko because I read that it can autofocus with the Sony SAL70-400G. This I verified today. I cannot speak about the image quality yet but have not heard any negatives about it.