Well I thought of this new lens for a number of reasons. I put it up on the POLL on where to put R&D money to in bringing out new lenses for Pentax. The poll:
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/146454-wich-le...r-d-money.html can still need your attention.
This new lens should have a new thread, just to talk about it and see what use it can be and if there is enough interest for.
My thoughts:
It should be in the DA*-zoomrange and adding up to the two current zooms DA*16-50mm/f2.8 and DA*50-135mm/f2.8. This because I was looking for some time now for a lens longer then current in Pentax line-up with fast aperture f2.8. At the time only DA*200mm/f2.8 is available. I use these fast lenses mainly for sports and for some occasions having f4 and even with K-5 and his great high-iso-performance isn't the best thing to have. For sportsarena's (indoor) and swimarena's I could really use a f2.8 lens. Options I looked at are FA*300mm/f2.8 and A*300mm/f2.8 (also the sigma 300/2.8). I was at a swimmingevent and you really need 300mm to get a picture off the lanes 3 and 4 (that is where the fast swimmers are, it was a 10 lane olympic sized pool of 50 meters). So scoring a Sigma 70-200 or a Pentax FA*80-200 would help some, to my current DA*50-135mm, but not enough. With the upcoming Sigmalens 120-300mm/f2.8 I think there is a great lens in the line. Only thing is that that is not a Pentax lens.
Why this range:
Well the Sigma is going to weight almost 3 kg and since I rescently bought a DA*60-250mm as my long range for this summer I know what weight means when you are walking all day. So when Pentax should make a new lens it should also give a new range, not to much competing with current lensline. Making some compromise on length would make this lens lightweight as is with making it APS-C only instead of a Full Frame compatible lens. Making it only a 2x times zoom would simplify the design in the way off optics. And there you have my idea, making it DA*135-270mm/f2.8.
This is a big lens, make no mistake about that. It weights 2 kg easily. It should also be a topdesign in optics and image quality since it will be very expensive (compared to current Pentax lenses). I expect it to be twice the price of DA*60-250mm.
Reach:
Well it is 135-270mm on our APS-C body so it will give a very nice telerange (206-412mm/f2.8 to FF range). When there is also a 1,4x TC (wich makes a lot of sence to buy with this lens even when it will cost 450 euro) you have a reach of 189-378mm/f4 wich is a very strong telelens (289-578mm/f4 to a full frame camera). It is on the short side for birding, but it is 26 % longer reach then the current longest lens the DA*300mm/f4. With no light loss and a more versatile tool then a prime.
Question:
Is it possible to design? How big would this lens be? How expensive is this lens? Would you be interested? Do you have any ideas about such a lens or something alike?
Last edited by RonHendriks1966; 06-19-2011 at 03:34 AM.