95mm filter thread (Bronica PE 100-220)

[abruzzi]

I just got the PE 100-220 zoom, which has 95mm filter threads. The lens cap is screw-on and it screws on and off easily so it doesn’t seem like there is any damage to the threads. I also have a Cokin adapter ring for the Z-Pro 100mm square filter holder. The adapter ring is also for 95mm threads. Specifically on the ring is says Cokin - (/) 95 - th 1.00 - France. Presumably the 1.00 is the thread pitch. The threads look fine. When I screw it on to the lens it turns a little, then jams. It feels like a mismatched thread pitch. I know some other large sizes (105mm for instance) are available in multiple thread pitches, I’m wondering if that’s the case for 95mm? Does anyone know if this lens has a non-standard pitch?

 

[mshchem]

I had one of these lenses probably 15 years back. Fabulous but heavy. I always use UV filter, I'm pretty sure I had a Nikon L37c. There's nothing odd on any of the Bronica equipment I've had. I had a 40mm PS ,pretty sure that was 95mm, I had a standard Nikon L37c on that as well. I think it's either gunk in the threads or a lubrication problem, take a pencil and gently rub a tiny amount of graphite onto the threads . If the lens cap is screwing in you have a good lens.

That lens is amazing, it absolutely requires support to do it justice

 

[abruzzi]

Yeah, I was kind of blown away by the size and weight, but I’m looking forward to the Thanksgiving holiday to give it a good run through.

I’ll muck around with the threads in better light, but even if it doesn’t go on any further, it does seem to be enough to hold (though there seems to be a couple of kilometers of thread visible on both the ring and the lens)

 

[AgX]

I know some other large sizes (105mm for instance) are available in multiple thread pitches.

Is there a comprehensive listing on this?

So far I do not know one listing that shows two pitches for one thread diameter, but only references in postings.


By the way, here is an independant (non-manufacturer) listing:
https://de.wikipedia.org/wiki/Filtergewinde
But this listings shows some miniscule thread diameter variants.

 

[abruzzi]

When I got my Pentax 67, it came with the 55/3.5 lens which takes a 100mm thread. I wanted to attach the Cokin 130mm square filters holder, and they didn’t make a 100mm adapter. I found a step up ring from 100mm to 105mm then got a 105mm adapter. While I was researching that I found that there were multiple thread pitches—last night I was thinking it was on the 105mm side, but it may have been on the 100mm side. Based on that research I don’t assume that the large filters are all the same pitch. When I was looking for info on the 95, I found a page suggesting that there are two 107mm pitches as well (not that I've ever seen a 107mm filter)

 

[abruzzi]

I thought I’d update. I received a PE 45-90 lens today, the other Bronica lens with 95mm threads. That lens happened to have a 95mm UV filter on it. So for testing I had:

100-220 lens
45-90 lens
Threaded lens cap that came with the 100-220
UV filter
Cokin filter adapter

So three attachments (cap, UV, Cokin) and three receivers (UV, 100-220, 45-90)

All three attachments screw fully into the 45-90, at least two to three full turns.

The UV and the lens cap screw fully into the 100-220, again 2-3 turns. The Cokin jams at about .75 turns.

The lens cap and the Cokin screw fully into the front of the UV filter.

My conclusion is the 100-220 and the Cokin are a little out of spec, enough that together they bind. If I had to guess, maybe the powder coating or what ever it is that turns the metal black, was put on a little heavy causing a smaller gap between the threads. I haven’t tried graphite to lubricate, but that will be my next try.

 

[moto-uno]

Have you tried putting the the Cokin threads into the threaded section of the UV filter . They should engage completely
at any spot you place them against each other . A bright light from behind should help . Peter

 

[abruzzi]

yeah, the cokin threads into the UV without a problem at all, the only combination that has issues is the cokin into the 100-220 lens.

 

[neilt3]

I thought I’d update. I received a PE 45-90 lens today, the other Bronica lens with 95mm threads. That lens happened to have a 95mm UV filter on it. So for testing I had:

100-220 lens
45-90 lens
Threaded lens cap that came with the 100-220
UV filter
Cokin filter adapter

So three attachments (cap, UV, Cokin) and three receivers (UV, 100-220, 45-90)

All three attachments screw fully into the 45-90, at least two to three full turns.

The UV and the lens cap screw fully into the 100-220, again 2-3 turns. The Cokin jams at about .75 turns.

The lens cap and the Cokin screw fully into the front of the UV filter.

My conclusion is the 100-220 and the Cokin are a little out of spec, enough that together they bind. If I had to guess, maybe the powder coating or what ever it is that turns the metal black, was put on a little heavy causing a smaller gap between the threads. I haven’t tried graphite to lubricate, but that will be my next try.

I also have the 45-90mm and 100-220mm and both the screw in hood I got for the 100-220mm and my Cokin Z-Pro adapter are a perfect fit for both lenses .
Check the threads are clean on the lens , run a pencil on the threads of the Z-pro holder and see how you get on .
The Z-Pro adapters you have are genuine Cokin and not a cheap knock-off aren't they ?

 

[David Lindquist]

While my 95mm filters from Hoya, Tiffen, Heliopan and B+W have a pitch of 1mm, the two 95mm filters I have from Formatt Hitech have a finer pitch, 0.75mm if I recall correctly. I thought I had kept notes on this but I can't find them. I can't re-measure as these two filters are now secured with Loctite in 105mm step-up (or is it step-down?) rings for use in the filter holder for my Sinar Norma.

I think it's fair to say that if an occasional filter maker may use a less common pitch for a given size, then a lens maker may do the same thing. Only my Tiffen filters are marked with the pitch, viz. "95C", "C" = "coarse."

After re-reading post #6, abruzzi, where you describe your carefully trying the various permutations and combinations of lenses and accessories I agree that the problem here is not a miss-match of thread pitches. Rather it sounds like the Cokin thread is ever so slightly too big and the lens thread is ever so slightly too small. Working things back and forth with graphite from a pencil as lube as suggested may fix things.
David