On Sat, May 15, 2010 at 11:19 AM, Dario Bonazza <dario.bona...@virgilio.it> wrote: > Adam Maas wrote: > >> On Wed, May 12, 2010 at 9:27 AM, Dario Bonazza >> <dario.bona...@virgilio.it> wrote: >>> >>> Resolution: excellent (provided you put enough a lens in front of it, >>> otherwise edges are poor). Don't use the provided 2.8/28-75mm (a rebadged >>> Tamron) full open if you want good resolution at edges. >>> >>> >>> Dario >>> >> >> The 28-75/2.8 SAM is massively overpriced anyways, > > I quite agree. However, don't forget that nowadays there's no relation at > all between the manufacturing cost and the sale price of an item. Industry > tries to produce items at the lowest possible cost and to sell them at the > highest possible price accepted by the market. For a camera priced like the > A850, the price point of this standard zoom is quite OK. Sell the same lens > for APS-C, and its price must go down 50% or more.
It's massively overpriced because the exact same lens (differing only in AF drive) sells for 50% of the cost with a different name on it, where most of Sony's rebadged Tamron lenses have only a 10-20% premium. Note the 28-75/2.8 SAM is not setting any sales records, in fact it's mostly been a sales dud for Sony from what I'm hearing over at Dyxum. > >> the Tamron and >> Konica/Minolta versions of the lens are not only optically identical >> (Tamron's coatings differ, KM coatings are the same) but far cheaper >> and more functional as screwdriver lenses can use DMF focusing mode >> for manual focus override, which is lacking on SAM lenses. > > I spotted and highlighted that missing feature in the camera+lens review I > did for an Italian magazine. And on top of that, focusing is quite noisy and > continuous-AF performance is all but stellar in this combo, hence I don't > get the reason for using such kind of AF. Sony's moving to a SAM/SSM split in order to be able to do what Nikon is doing, eliminate AF drive motors in their consumer line and thus make them cheaper and simpler. > >> From the optical point of view, I don't think the Tamron is a bad lens. On > > the contrary, it's a very good performer on APS-C, while on FF it suffers at > edges (as most lenses do, by today's standards). There was a time when > judging lens performance at smaller-detail level was very difficult, while > now everybody blows up images large enough to spot such issues. However, > close down the lens a couple stops and everything goes fine. > Again, I believe the A850+28-75 to be an excellent combo for studio and > generic photography and weaker than expected (by me) for low-light and > action shooting. > > Dario My experience is that the 28-75/2.8 can be an absolutely superb performer, but has some sample variation which usually shows in edge performance. A good example will perform as well out to the edges on FF as Canon's 24-70L, but remains inferior to the ZA 24-70. AF issues in low-light and poor continuous focus performance have long been noted as this lens's weak spot (I'm assuming here that the SAM drive in the Sony-badged version uses the same technology as the EF mount Tamron version). I've owned the lens in the past and will likely be getting another one (in fact it will most likely be the KM version as I'm shooting a fair bit with film A mount kit). -- M. Adam Maas http://www.mawz.ca Explorations of the City Around Us. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
