Originally posted by cali92rs The DFA 100mm could be had for cheaper than this TC alone, would be lighter and smaller than the 77+TC combo and would most certainly have better IQ. No matter how good a TC is there is always some image degradation, as slight as it may be.
You're missing the point... if you use the 77+ the TC, you can use the 77as a 77, or a 105. That's lighter and more convenient than carrying The 77 and the 100.
I'm in exactly the same situation. I've gotten into the habit of taking my DA*60-250 and my A-400. That's a lot of glass. If I take my DA*60-250 and a TC, I can sell the A-400 and have the same reach and quality, and half the weight. Essentially every lens becomes two lenses. And I'm not convinced my 60-250 and TC gives me less IQ than my A-400, my experience isn't supporting your notion.
I'm really opposed to this idea
Quote: No matter how good a TC is there is always some image degradation, as slight as it may be.
A TC adds another 5 elements to a lens, so you're saying a 7 element lens isn't as good as 12 element lens? I'm not un-aware as to the possible conflicts of adding to a lens that's already complete, but I'm not convinced a TC automatically reduces image quality.
With a good lens like our Tamron 90 or DA* 60-250 we don't notice image degradation, if you don't believe me go back up the page and look at the examples I posted, one with a TC, one with a prime. IN fact we love the results we get using a TC with a Macro, definitely more detail in the macro than shooting without the TC, that's not even open to speculation.
Or have a look at this, a 1:1 pixel peeper taken with the Tamron 90 and the Pentax 1.7 TC.
The case that a TC degrades your image really hasn't been made to my knowledge. I've heard many people say it, I've never seen anyone back it up with examples, and all the examples I've produced say it's not true, at least not for people using quality lenses. If you use a lens that's soft, obviously you'll just magnify the softness.
I think perhaps it's possible that people don't realize that when they take their 100mm lens and make it a 170mm, there's a whole new level of image stabilization that has to go with that. It's not that they can't take as good images, it's that they naively believe they can shoot with a 170mm lens the same way they could when it was a 100mm lens.