so i bought couple days ago a Horseman 985 with a Topcor Super 90mm f5.6 (it is on the way from Japan to Norway...)
it was sold with the 4x5 extender spring back.
I plan to shot mostly 6x9, but will also 4x5 without movements, just for the bigger size.
One of the motivations for buying the camera is to shoot wider than what can be done with my Bronica 6x6, and for this the 65mm lenses seem good.

I read a lot of threads here and there, and got the comptabilitty list of lenses from the latest snapshot of Komamura site, on http://archive.org: (18 june 2012, after what the page is 404):
https://web.archive.org/web/20120618...lens_list.html

the Komamura requirements are:
circle for 4x5 without movements 150mm
flange: 60mm to 250mm
rear element diameter: max 65mm
shutter #0 or #1

possible lenses besides Topcor are:

  • Nikkor SW 65mm f4 circle 170mm, rear 54mm
  • Fujinon SWD 65m f5.6 circle 169mm rear 65mm
  • Rodenstock Grandagon N 65mm f4.5 circle 170mm rear 51
  • Schneider Super Angulon MC 65mm f5.6 circle 170mm rear 57mm


the native Topcor Super is f7, circle 152mm

I would go for the faster lenses: Nikkor f4 or Grandagon f4.5, because it would make the focusing much easier than at f7. Both have also small rear element 54mm and 51mm, while the Fujinon will barely fit with its 65mm.

BUT, as I see it , because the added thickness of the 4x5 extender, these lenses are of limited used, the flange being altered a lot and in fact a 65mm will be fully usable only on 6x9 film. Right?


as for movement, the lens will be so much stuck inside the camera body that no movement or too little would be possible. Right?
if so, no need to have a bigger circle than the 152mm of the Topcor, excepted that this circle is with the lens at f22, so it could be good anyway to buy a much faster lens just for the comfort of use and in case a very slight couple mm movement is possible to still keep full coverage.

i'll have in case of non Topcor, to set stops on the focusing rails, at the infinity distance of the given lens, but the 65mm cam will work anyway obviously. Right?

do i miss something?
what other advices?