Hi!
You'll find what you need in the links:
Indeed.
When I said the 50/2.8 was better than the 105/2.8 I should have said marginally. But it is highly desirable for macros of insects and small animals or reptiles when you can't really get right up to them -- as you need to do with the 50mm. But I'm very satisfied with the 50/2.8 on the end of the Tokina doubler.
I saw the test you posted... Well, judging from the links, it is more or less a coin toss... Sigma is excellent. Tamron is superb. Pentax is amazing... I just have to choose which of the superlatives I prefer *sigh*.
Last week I think I mentioned (and posted a picture) that I'd tried the Sigma 50/2.8 EX Macro with a Macro Extender and found it worked fine. The Tokina doubler+ seems to be a good match as well. But we should remember this is on the *ist D where only an APS sized piece of the field is being utilized.
I have Vivitar Macro Focusing 2x which for now is for sale. I guess I should give a try and re-consider.
+ In absolute mint condition -- bought for £2.50 on eBay. The postage was almost as much as the item.
Don, what do I need to do in order to make you repeat that performance for my sake? ;-)
The problem with 50 mm macro lens is that I have few normal lenses, notably 43 Ltd and FA 50/1.7. I doubt it I need one more...
One of the tests of Tamron showed that Tamron is not immune to flare. I think it was comparison of Tamron lens with Canon 105/2.8 macro (or whatever lens Canon has in this category).
My goal is of course to use it not just for macro, but for general photography as well...
I wonder would would happen if I were to mount my 77 Ltd to that Vivitar doubler... I should give it a try...
Boris
