teleconverter question

[Bob Keefer]

Hi all:   I have the Pentax 2X-S teleconverter, which frankly doesn't produce very sharp images with my FA*300/4.5, not even locked down into the tripod with careful technique. (I get better slides with my son's Canon 300/4.0 with a Canon 2X. Sorry.)   Anyone know whether the 2X-L would be any better?   Also, any thoughts on the 1.4X-L?   Thanks,   Bob Keefer