Originally posted by skyoftexas Quoted from Photozine regarding the FA 77mm.
This is one of the criteria I have been weighing in deciding between the 70mm and the 77mm. There are a lot opinions expressed about the 77mm having slow AF. Now I am confused. Help!
Thanks in advance,
Michael
Pentax in general has slow AF. Someone just posted a video comparing (I think) a K7 to a Canon 7D where the Pentax came up looking really slow.
One of the things I noticed while watching said video is that the focus throw on the Pentax lenses seems much longer.
I suspect this accounts for some of the speed difference.
Not withstanding the reasons for it, if you want or need really fast AF, Pentax is not your friend.
To go directly to your question, I have both the 70 and 77 mm lenses. The 70 does AF faster, but it's not a huge difference.
Regarding image quality, a lot of people wax eloquent about the 77 being God's gift to photography.
It's a good lens, but when I compare shots from it to shots from my 70, I'm not seeing where the 77 is quantifiably better than the 70.