500mm Hasselblad Mounting Problem

[arthur_gottschalk]

I tried to mount my 500mm Hasselblad CF lens to my 503CX camera today and much to my surprise it would not register or click into place.. Yes, both the camera and the lens were  correctly cocked  and the red marks were aligned,.  The lens would rotate but would not  mount.    I tried other lenses on the camera and all mounted correctly.  I also tried the 500mm with another camera and no go, although it also  worked perfectly with other lenses. Can't imagine what the problem could be.  Please help. 

[arthur_gottschalk]

I see on the internet that this is not an uncommon problem, but there are no definitive answers. I'll try releasing and re-cocking  the shutter a few times. 

[orsetto]

You may not be able to solve this easily: the huge 500mm lens suffers inordinately from the depressingly boilerplate answer to every single 'Hasselblad not working right" question. Lets all chant it together: "the Hasselblad system was marketed as a professional tool with the clear understanding/assumption it would be used daily and serviced every couple of months: not a problem during its heyday when every town had at least two skilled techs (and you didn't own a Hassy unless you were a working pro or wealthy amateur with the income to pay the upkeep)". For those of us using the system more casually and sporadically today, that "1963 Ferrari" ethos can be a headache and a half.

An unusually large percentage of 500mm teles are afflicted with shutter issues, which can in turn lead to the mount/dismount issue you're experiencing. The "gotcha" with the 500mm is its very limited purpose: even those who paid full price when new didn't need it as a daily driver lens. But that "occasional use" profile locks horns with the shutter mechanics, which are the same as in all the other Hasselblad lenses (use it or lose it: left sitting it will gum up and require a CLA service). This is complicated further by the 500mm uniquely long flange-to-shutter distance: the extra long cocking rod requires the lens be in perfect limber condition to function properly. If the shutter is dragging or the cocking spring has weakened, you may experience mount/dismount and cock/release snafus.

Due to these deeply buried mechanics, the 500mm is one of the most difficult lenses to find service for today. The old C version with Compur shutter is virtually impossible to get serviced now, which is why most used examples are DOA. Your CF Prontor version may still be repairable by either Hasselblad itself or a handful of long-term independent techs who still have the special tools. Curing this problem with a CLA is likely your only option, assuming you can locate a capable tech and feel you'll use the lens enough to offset the probable $400 repair fee.

Short of that, the only thing I can suggest is finding a secondary body that it will fully lock onto and then leave it permanently on that body. It should still be possible to find a relatively cheap 500c or 500EL body that might be able to lock on to your 500mm lens. Going thru eBay or web dealers might be a hit-or-miss proposition: better if you can drive to a dealer with the lens in tow and try out their second hand stock til one "clicks". If none click, either service the lens or get an adapter to use it as a super tele on a non-Hassy-V digital platform.

Good luck!

[arthur_gottschalk]

Tripped and re-cocked the shutter a few times and now AOK.  

[orsetto]

Fantastic: sometimes we get lucky! Hope it will continue on its merry way now that you've revived it.

I would still be extra careful with this lens: when these symptoms arise, they often reoccur without warning. My biggest concern would be the cocking spring regressing while the lens is being removed from the body: if this happens you'll suffer the ultimate in Hasselblad jams (shutter fired, mirror up, lens welded to the body, advance knob frozen), the kind that is not easily remedied by the "screwdriver down the throat" trick.

To avoid this, remove or attach the lens with a quick smooth movement (as quickly as possible, given the size and awkwardness of the barrel). Any hesitation or slowness can trigger a sync conflict between the body and lens mechanics. I've been burned by that several times with a particularly eccentric 250mm Sonnar: recovering from it requires a partial disassembly of the cocking geartrain behind the body lens mount, to release the spring tension on the body key and allow the lens to dismount. Not something I recommend as DIY unless you're stuck in the field far from any technicians.

[arthur_gottschalk]

I think something like that must have happened the last time I took the lens off the camera. I would not attempt  a DIY fix, even though I'm "stuck in the field" here in northern New Mexico. 

[andyfalsetta]

If as Orsetto suggested, the cocking mechanism is at fault, it is not difficult to remove the screws securing the mount to the lens, withdraw the tube and clean/lube the cocking spring and pawl. For those of us who have had these lenses apart, they are quite honestly the absolute most fragile of all Hasselblad lenses.  Look at where the shutter is located, then measure the length of the lens barrel.  That barrel is held on to the shutter with the same number of screws in the same aluminum casting as an 80 mm lens!  What were they thinking?.  You don't need to be a mechanical engineer to figure out the load on those screws is incredibly high.  Bump your lens/lens hood into anything more rigid than a feather and you stress those poor little screws and their threads, causing the entire lens assembly to wobble until properly addressed during service.  .