Originally posted by froeschle 6 elements in 5 groups (+ rear filter,
not 7+)
Let me remind you:
price Originally posted by Kunzite A very accurate estimation... right?
I guess even Falk can be wrong, very wrong at times.
That's certainly true.
However, my formula describes the market at the time I originally published it. There is another notable exception now: the new Sony 500/4 lens.
It means that two recent additions (Sony 500/4 and now Pentax 560/5.6) ask for more than twice as much money as was normal at the time I originally published my formula.
And you are right and I was very wrong. I didn't anticipate this. But maybe, there is a new trend and buying reasonably-priced 500mm lenses would be a good investment?
Unfortunately, the Pentax 560/5.6 is no such lens.
At that price, weight, length, focussing distance, crop designation, a 100mm diameter and possibly only one ED element (the Sigma has two, the Pentax press prelease doesn't mention them, the name says ED and Pentax scopes typically have one ED element), the price cannot be called reasonable. It is as unreasonable as the one of the Sony 500/4.
I can only assume that both companies made the lenses for the sake of reputation and special projects only where price plays no role. So, there actually isn't a new trend.
In other words:
Pentax still has no lens longer than 300mm.
Originally posted by garyk Do you have a link to that article?
Thnk's Gary
Originally posted by froeschle Thanks for looking it up and yes, it was on Fototest 3/12.
They do the tests using DxO software which should be ok. Assuming they cared about a proper focus which I am always in doubt about. Absolute resolution numbers across different bodies and sensor resolutions can't be compared of course (which they do anyway, shame on them). But some detail measurements (CA, decentering, difference of resolution between f/4 and f/8, between center and edges etc.) tell me that the Sony lens more likely performed worse, not better, than Sigma or Nikon. There may have been a lack of focus. But then, the Sony wouldn't have had an edge resolution which was better than at the center.
So, for the time being, my impression is this:
An unreasonable high price for a 500mm lens is likely an indication that the lens is an exotic project for the vendor with possibly poor performance, rather than an exceptional lens worth the extra money.
Last edited by falconeye; 09-12-2012 at 05:37 AM.