Originally posted by Mike.P®
I sold my 50-500mm OS (and 100-300mm f4) to buy the 150-450mm. I had some great results from the Sigma but I'm hoping the Pentax lens is that little bit better. Also the Sigma wouldn't play well with the Pentax 1.4x and from what I can see the 150-450mm works fine.
Exactly what I'm thinking Mike! I have the 50-500 which is really good and I'm considering the Pentax 150-450 for the extra something! My concerns are whether the 450mm will give noticeably less reach (or is it in my mind?) and also as I like shooting airplanes the 50-150mm is very useful as it allows to carry only one camera-lens.
On the other hand I had read (I can't remember where) that the 50-500 is really somewhere over 450mm at the long end, so the difference might be very small. That is why I'm asking!
In fact I would prefer to buy a 150-600 lens but since it is not an option for Pentax (and I really love my K-5IIs) I'm considering all my alternatives! The 150-450 works with the 1,4TC so you have a decent (as far as I have seen) 225-675/F8 which is not so bad as it is longer and only 2/3 stops darker than the Sigma-Tamron super zooms. I don't know what happens with the AF performance though. If the 150-450 was cheaper I would not think twice about buying it . But if Pentax has a longer or brighter zoom in mind I won't be able to buy anything else in the future! Being an amateur is really hard to justify so big investments...
So the DFA 150-450 most probably will be my MAIN and ONLY zoom and I want to be sure that I have done the right thing when I give my money!