Yes that's a good question and then, what is the distance from the paper to the lens mount, compared with the distance between the lens mount on the body and the film plane ?
Yes! Or hold it side by side with another Bronica lens that is known to work. Ideally they should both project the infinity image at the same distance from the paper even if they have different focal lengths.
I have a white fridge opposite the kitchen window that I use for simple experiments like checking the focal length of single lens elements or the front and back components of convertible lenses.
there doesn't seem to be an extension ring on it!It does not focus on anything. The groundglass remains OOF. The split microprism does not change. Where would one find this "expansion ring"? It's appearance is similar to my other lenses.
I'll post a better photo tonight.
Still working on getting the front elements out. Does anyone know they come out as a group, or one at a time? I got the rear elements out easily, and confirmed the fourth element from the rear is properly oriented.
It's so very strange that your lens is like this. I wish there was more advice I could provide, but if you counted all the elements, and they are all there, and in the right direction, and in the right place, then they can't be the problem. I would suggest that maybe the helix has been disassembled and re-assembled wrong, but I think that would cause focusing problems at infinity, not the extreme focusing problems at all distances you are experiencing. The only other thing I can think of is a complete seperation of an element, and that element being removed. But complete separation is a massively major rarity, I don't think I've ever seen it, it would almost be so rare as to be something that can only happen at the Zenzanon factory. This lens might be a lost cause.
Like @moto-uno said, be careful of finding this fun! After I figured out how easy it was to take apart lenses, I took most of mine apart and cleaned out what I had previously thought to be minor haze and image sharpness and resolution was massively improved. This is on Pentax 6x7 lenses, almost all of which have haze at the elements near the aperture from whatever lubricant Pentax used on the helix. And, this is a topic for discussion, but after reading repair manuals from Hasselblad and Zeiss, I have come around to the opinion that when disassembling and re-assembling lenses, the tilt and rotation of the elements doesn't matter in the case of these lenses (in modern zooms, it would) so I do not find that to be a major deterrent.
Sounds to me that the focusing helical isn't set properly to its stops.
If you could compare yours to an identical lens, set both at infinity and measure the distance from the rearmost lens surface to the mount, you would know, no?
Sounds to me that the focusing helical isn't set properly to its stops.
If you could compare yours to an identical lens, set both at infinity and measure the distance from the rearmost lens surface to the mount, you would know, no?
At infinity the rear element protrudes from the mount about 4mm.Maybe, but I’d have to buy an identical lens to do that!
How does one adjust the helical?
At infinity the rear element protrudes from the mount about 4mm.
Unfortunately at the moment i don't have a caliper to measure it correctly.
Did you have to unscrew the helical to do this?
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