It strikes me that the new 560 f5.6 most closely compare to the A*600 f5.6:
A* 600/5.6 ED [IF]
560mm vs 600mm
both f5.6
close focus 5.6m vs 5.5m
both have 112mm filter thread
3040g vs 3280g
diameter 130mm vs 133mm
both have ED glass
But the important differences are
1) length 522mm vs 386mm
2) 6 lenses in 5 groups vs 8 lenses in 6 groups
which are of course connected.
The old A*600/5.6 have two extra lens elements in the front group which is what I presume is what makes it a telephoto design rather than a telescope design and accounts for the shorter length.
Anyway, they seam to occupy much the same niche in the super tele biosphere. Why did they go for that instead of a 400/5.6, 500/4.5, 600/4 or some other combination of focal length and max aperture. I'm not saying it is necessarily wrong, but I'd like to understand why this is the first new super tele. There may be coming more later on occupying the other niches, but why go for this first?
Another maybe related question:
What happened with Pentax old telescope manufacturing? It had a stellar reputation and was way expensive. But what happened with it in the purgatory years with Hoya? Do they still make telescopes? Could it be that Ricoh, having listened to costumers complaining about the lack of lenses longer than 300mm, but seeing that they can't soon enough make room for production of a longer tele in the lens plants in Vietnam, discovered that they inherited a telescope factory somewhere with too little to do, and came up with the idea to let them design a long camera lens? It is a crazy explanation, I know, but somehow it would make sense.
EDIT: Can't find any evidence online that Pentax still makes telescopes, but the binocular and spotting scope sections are alive:
http://www.pentax.jp/english/products/binoculars/scope/index.html
And surprise surprise! "All Weather" protection is a concept they already use for their spotting scopes. My hypothesis is that Pentax/Ricoh let the spotting scope department design this lens with some people from the camera section, and that it will be manufactured at the same place as the spotting scopes. It is not more strange than when Pentax let their CCTV section make COSMICAR branded SLR lenses and other non-SMC lenses with various names, some named Pentax without the SMC prefix, some named Takumar-A etc. Use the production lines you have. But it looks like it influenced the design quite a lot. Maybe a good lens, but expensive and half a meter long!
Last edited by Douglas_of_Sweden; 09-11-2012 at 06:46 PM.