The DFA 150-450 is a great lens. Great build, unquestionable quality, etc. It's also very heavy and large.
I understand a 400 5.6 lens is perhaps not marketable or profitable, and maybe Pentax should be rightly focusing their efforts in other areas that need immediate attention, but... I would like to say that I would love a metal build, weather sealed, DC, 400mm 5.6 lens with great image quality.
The reason is that a 400mm 5.6 lens can be smaller and lighter than a 150-450 zoom while providing the same quality. I think this could appeal to birders and wildlife photographers who are dissuaded from purchasing the 150-450 because of the weight and the need for a monopod or tripod - if they are confident that they do not need the zoom.
I myself own a Tokina 400mm 5.6 ATX AF for this very reason - I need more reach than my HD DA 55-300 offers, yet even if I COULD afford the 150-450, it is an impractical lens for my uses.
I also understand that the DA* 300 f/4 with the HD DA 1.4x TC is equivalent to a 420mm 5.6, but it is not the same as a single lens, it doesn't inspire the same confidence. Maybe those who have used the combo might differ in that opinion. But it doesn't work with FF (?) so perhaps, potentially, somewhere down the line, Ricoh:
Keep a DFA 400mm 5.6 AW DC lens in the back of your mind! Maybe even DFA*? The goal is to support the many Pentaxians who strive for smaller and lighter lenses, and who are feeling perhaps a bit uncertain about the longer lens choice of the DFA 150-450 or the DA 560...
Last edited by Imp; 07-18-2017 at 06:46 PM.