Why did Pentax choose to make a f/4 constant zoom using the diaphragm to maintain that, rather than > making a f/2.8 - f/4 zoom on this lens. > > Am I making sense? :-)
Yep sure. One answer is that the constant relative aperture makes it much easier to use with non-ttl flash. Another answer is that Pentax may have chosen to make a better quality f4 (with the above mentioned advantage) lens rather succumb to the marketing allure of that F/2.8 aperture on the wide end. (As explained by our fellow Pentaxians.) See, that way, instead of us complaining about how bad this lens is wide open (like some other Pentax 2.8-4 zooms), it's pretty much universally loved with the slight criticism that it takes a bit of a quality hit at 28mm. (just a bit of barrel distortion.) I love this lens. I don't think opening up the wide end to 2.8 would do anything good for it. F2.8 just never cut it for me in any low light situation, anyway. Carry a couple of fast primes. Or an extra body with a fast prime. Too expensive? Naa. Try an old Vivitar 28/2 (close focus) or 28/1.9. I got a 28/2 CF for $60. A $90 F 28/2.8 would probably be much better than the 28-70 opened up to 2.8 on the wide end. I hear the FA 28/2.8 is great. I couldn't live without a fast, wide lens. I carry that old viv 28/2 everywhere. Fits in a jacket pocket. Now I'm looking for that M 85/2 to put in the other pocket. But the 28-70/4 pretty much lives on my MZ5.... Christopher Lillja Publications Coordinator The Pennington School www.pennington.org - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
