Originally posted by str8talk83 Thanks for sharing. I agree with your assessment. They are probably very similar in real world image quality. Have you ever done any bokeh comparisons? I find that the TC usually degrades a lens in this area. Zoom lenses tend to be inferior to primes (in my experience) so they might tie in this regard as well...
Those aren't the kinds of generalizations I'd live by. Not in Pentax land anyway. You need to evaluate the lenses you might want. I originally bought the DA*60-250 because it was as far as I could tell better or equal to both the DA*300 and the DA*200 and used with my HD DA 1.4 TC (sometimes) it has been used for a good number of my wildlife images.
As for the bokeh, a TC puts your wide open Aperture down a stop so the 300 ƒ4 is now the 420 ƒ5.6. Any difference in bokeh is probably a product of shooting wide open at a lower f-stop. The comparison one could make would be with the DA*200 2.8 with the 1.4 TC compared to the DA*300 both at ƒ4.
DA*200 and HD DA 1.4 TC wide open (ƒ4).
Unfortunately, I don't have a DA*300 so I can't really help too much.