Protar V Problems

[alec4444]

Snagged a 182mm Protar V lens (B&L, not Zeiss) that has a mildly frozen aperature. I've been given some tips to unfreeze it but it's since wrecked my fingers (still hurt from yesterday) and it's not much better. It turns, but with horrible effort. That's only problem one.

Problem two is that I mounted the lens on my 11x14, and it's too wide (and my shortest bellows is too long) to focus it. Sure, I can get someone to make a recessed lensboard, but this is a seriously wide lens and I'm worried it's going to vignette. (And if that's the case, why bother with a lens that covers 11x14?

Any suggestions on either problem? Keep in mind that I'm not that handy, so if you know of a person that can help me with problem one that may be the way to go....unless problem two can't be solved!

Thanks!
--A

[Kirk Fry]

If you can unscrew the lenses, try lighter fluid and see if that loosens it up. If you can not unscrew the lenses you need professional help. Tim at lens2shutter might help.

Bag bellows??? Seems your bellows is removable.

[alec4444]

Thanks, Kirk. I've actually spoken to Tim about the stickiness and he recommended lighter fluid too. Great minds, I guess. Lighter fluid...is that like the stuff you'd put in your Zippo or what you'd light your charcoal grill with? Or perhaps it doesn't matter.

The bellows isn't the problem, I don't think. It's more like I can't get the front and rear standards close enough to each other; a limitation of the camera design. Something protrudes backwards from the front standard and hits the base of the rear standard...and that's as far as it goes!

--A

[j.e.simmons]

I've used Ronsonal - the kind of fluid you'd put in a Zippo. I don't know what the grill stuff is, nor do I know if name brand lighter fluid is better than generic.
juan

[sanking]

Thanks, Kirk. I've actually spoken to Tim about the stickiness and he recommended lighter fluid too. Great minds, I guess. Lighter fluid...is that like the stuff you'd put in your Zippo or what you'd light your charcoal grill with? Or perhaps it doesn't matter.

The bellows isn't the problem, I don't think. It's more like I can't get the front and rear standards close enough to each other; a limitation of the camera design. Something protrudes backwards from the front standard and hits the base of the rear standard...and that's as far as it goes!

--A

Alec,

Are you able to figure out how much closer the lens would need to be to focus? If the distance is not very great a recessed lens board might do the trick.

Sandy King

[C. D. Keth]

Thanks, Kirk. I've actually spoken to Tim about the stickiness and he recommended lighter fluid too. Great minds, I guess. Lighter fluid...is that like the stuff you'd put in your Zippo or what you'd light your charcoal grill with? Or perhaps it doesn't matter.

The bellows isn't the problem, I don't think. It's more like I can't get the front and rear standards close enough to each other; a limitation of the camera design. Something protrudes backwards from the front standard and hits the base of the rear standard...and that's as far as it goes!

--A

Definately zippo fluid. The fluid you light a grill with leaves an oily residue after it evaporates off. Naptha doesn't.

[alec4444]

Are you able to figure out how much closer the lens would need to be to focus?

Hmmm, not visually, no. It looks like it may be a matter of an inch or two but that's speculating based on the amount of blurriness I see in the ground glass.

Might be able to figure it our mathmatically. The minimum focus distance according to the Wisner site is 6"...I'd have to measure myself to be sure. Does anyone know what the focusing distance is for this lens at infinity?

Thanks for the further info on the lighter fluid; I'll go get some today. Oh, my wife is going to love this!

--A

[Ernest Purdum]

Your lens has, I think, a diaphragm adjusted by a ring around the barrel. If so, it is very common for these to be stiff and the problem usually is between the ring and the barrel. Try putting WD-40 or similar on a toothpick and putting one drop at a time between the two from both top and bottom. Be careful about using too much because you definitely don't want it getting on the diaphragm blades. With a ;ot of patience, this should loosen it up.

The focusing distance at infinity for this lens should be quite close to the nominal 182mm, or a little over 7 1/8" measured from the diaphragm to the front surface of the groundglass. Since you have a removable bellows, try taking it out entirely, draping something over the area between frames and seeing if you can get an infinity focus. It might help to have the camera indoors pointing outside to a brightly lit area.

[alec4444]

Thanks, guys. An update:

I was sucessfully able to focus the lens (finally) after realizing that I needed to adjust the Wisner patented rear tilt (finally found a use for it!) all the way forward, then adjust the back standard to the full upright position. This gave me nearly another two inches of forward movement. Interestingly, I believe that this configuration is what was used to measure the minimum bellows extension (6") as posted on their site. Tomorrow AM (or Saturday) I'm going to check the coverage in full light. I'm expecting some light falloff, but hoping I won't get an absolute vignette.

The movement of the aperture blades is another story. Gave the Ronsonal a try, and it seemed to help some, while drying the hell out of my cuticles and turning my fingertips into bloody stumps. I'm going to keep doing this for an hour each night and see if I can't get this thing smooth in a week or so. I take it that there is no way to take this lens further apart to get direct access to those threads?

Cheers!
--A

[erie patsellis]

Pure conjecture follows:

If it's similar to the other lenses I've cleaned, there should be a screw that engages the aperture assembly, with a longish end. unscrew that, the aperture ring should screw off, removing front and rear elements, drop it into a container of Naptha, marinate for a day or so, then see if it's better, repeat as neccesary.


erie