Originally posted by Gutta Perka Could it be that we optically have the Tamron G2 24-70mm from the beginning - when Pentax showed and wanted their coatings and engineering exclusively on that very lens - but did not let Tamron to use it. Just to deliver it in it the Pentax way for Pentax only. G2 version is just now squishing in the extras cpu:s, shake reduction and double focus-motors for the Canicons . Pentax perhaps just locked in their science on that very lens - leaving Tamron with a long face - now trying to be save it?
Pentax has the know how - and used it - but didn't sell it - just wanted it to be used on a lens that was VERY GOOD - for themselves - making it better.
Saved a lot of money and time in the run as well as Pentax simplified it as well when removing the in lens stabilisation. .
If so - there will be no 24-70mm series II - and will not be needed.
We already have Pentax HD and the other Pentax optical engineering in that very lens?
Not to be used by others in plain production.
I would rather say they did cut a deal with them for using the older design because its very reliable,and well tested among the marked. And they could not make any mistake like the 16-50SDM first batches was. The stabilization module inside that Tamron re-badge is intact, only part is just missing the side switch and proper firmware.Full removal would need a serious optical formula changes. As far as I'm aware(I've seen one partialy dissasembled) this is exact tamron product of g1 24-70/2.8, with minor exterior chassis changes. Ricoh says the glass formula used and coatings are theirs but without a Tamron copy to test on a same reference camera- its hard to prove. SDM labeled on the lens, is definitely a Tamron USD drive, that is the same tech and mechanics behind Canon ring type motors. In my opinion any generation of Tamron 24-70 is a better mechanical/material design than Nikon current and previous generation counterpart.
Originally posted by builttospill I'd rather Pentax produce lenses which don't need a tune up. I understand there are variances in manufacturing, but I think the dock gives an excuse for loose tolerance. None of my FA* and FA Limited lenses have ever needed adjustments; they are sharp, as they should be.
Not at all. You are missing the point here. Older lenses, especialy primes, are not as prone to focusing issues, that because they don't use the stepper motors to drive AF. Currently designed lenses are made exactly the same for every mount, and only thing that change-is the mount itself, contacts and firmware. Older design like for example FA limited, rely simply on in camera focus hashing, with screw drive motor being only a method to move lens to exact point in the distance scale. Screw drive lenses when focusing will offten move wole lens assembly(all DA limiteds ,most F/FA Lenses, FA Limiteds-fixed rear, front part moving, most zooms-front group can be extended but is still fixed, moving rear group) and thats is very easy to tune up- just set the stop on infinity mark-if properly assembled, anything cant go wrong, if the lens feature a hard stop at infinity and minimal distance -that's even easier. For current designs- manufacturer needs to make a field for focus motor to brake from its pace,there is no hard stop. That is the field when adjustments comes into place. Most adjusts are easy to be done within the camera itself. But for zoom lenses-you offten have to adjust both the wide and tele side. The dock is a feature, for people who want to achieve more precise focusing for their needs.