Can you folks tell me abit about the quality and use of your teleconverters, if you have them? a quick Amazon search reveals the followings (USD):
1. Kenko DG, 2X, $69
2. Sigma APO EX, 1.4X, $189
3. Sigma APO EX, 2X, $189
4. Pentax SMC-A, 1.4X, $379
Of course, some of you have other teleconverter in the inventory. so the questions are:
a. are any of these retains automatic apperture or auto focusing?
b. is the loss of IQ significant (pixel peeping bad)?
well...i've been saving for a DA50-135 (or, a 100mm macro) as i heard they are outstanding portrait lens. The problem is a lack of long range end. a 1.4x would bring it to 189mm, quite adequate w/o too much loss of light, while retaining the same close-focus ability (not that the 50-135 is famous close-focusing or anything like that, it's at a lousy 1m, the 100mm macro in the other hand...)
Of course, if you think such combination will result in a lousy IQ... I'd just rethink my LBA otherwise.