Pentax 67 800mm f4

[pollux]

i have an opportunity for this lens, which will be used to photo ships, and skylines. is it totally usable at f5.6? I know there is some fringing. does its weight add to stability? does anyone know what the optical quality is like, i will not use it at f4. is the one or two stops wider than the 800mm f6.7 ED worth it?

 

[Joachim_I]

Stabilizing these 800mm lenses (4.0 or 6.7) will not be easy. I doubt that the weight helps in this case. I read about people using two tripods in order to get decent results. If you don't need f4.0, I would probably look for the 6.7 ED lens which should be excellent wide open. As an alternative, have you thought about using the 300mm or 400mm f4 ED lenses with a converter? This would be a much more compact setup. And you would only loose half a stop compared to the 6.7 lens. There are some reports on the net which suggest that these lenses yield excellent results with converters. I only use the 300mm ED f4 lens without converter. It is excellent wide open.

 

[Doug Webb]

The 4.0 lens is an older version, and I think is a pre-set lens. I have never seen one and don't know about the optical quality. The newer 800 6.7 is a more modern lens, with modern glass, very big, very expensive, and needs a serious tripod and head and probably also a separate stabilizing accessory that will attach to the camera body and tripod. There is a review of this lens on the Luminos Landscape web site. One possibly important factor is that the 6.7 lens can be fitted with tele-extenders that match the lens, probably also quite expensive, but without a tele-converter the lens may not give you the magnification you are hoping for, I seem to remember seeing this lens sold with a matching teleconverter new. Good luck if you try this out.
Doug Webb

 

[surfotog]

The 800/4 is huge, around 35lbs. Have never used it, but it's design dates to 1969 and it uses no ED glass. If you can get one cheap it might be worth it. I saw a test report of it once, and it sharpens up by F/8, but it is a manual aperture lens, so not as convenient as an auto aperture.
I have had the M* 800/6.7 ED for a couple of months and it is an excellent lens. Sharp wide open, even better at F/8. It has a dedicated 1.4x converter, the T5-1.4x, and there is virtually no drop in performance with it. These lenses require a heavy tripod and head. I use a
17 lb. wooden Berlebach. I'm a firm believer in wood's superior dampening properties, and the axiom "mass equals stability". At slower speeds something like the Manfrotto long lens support is necessary.
If you can find one, I'd highly recommend the 800/6.7 with the dedicated 1.4x converter. Also worth noting, with adapters it can be used on just about any camera of a smaller format. I have a chipped adapter that allows me to use it on a Sony digital with in body stabilization

 

[Rod Sainty]

See this thread for comments from the Feb 1972 test report in Modern Photography:

http://photo.net/medium-format-photography-forum/0073Aq

Rod