Another Mystery - Lens aperture coupling on Topcon Mounts.

[conan]

Despite some considerable research I still cannot find an answer to this – possibly someone on here has an easy answer that I have missed.


Please see the picture of the Topcon RE Super (Super D in USA?) the aperture read lever is at the top of the lens mount and as the aperture read out from the lens get smaller it turns clockwise. You can see this on the standard 58/1.8 Topcor. However, the 35/28 Topcor goes in the opposite direction ie opening the lens to a wider aperture (not smaller) also turns the lever clockwise which means the meter reading is incorrect. Anybody know why? This is a standard Exakta bayonet with Topcon’s internal aperture open/close lever.


Obviously there were some changes between the introduction of RII, RIII and C models (which have the same double ring as the WA lens) and the RE models but why a different direction for the meter coupling pin. The WA is obviously a slightly earlier lens but still has the distinctive Topcon rubber grips. One site suggests that some of the lens were in fact not made by Topcon although why would somebody make a lens that was not fully compatible?


Any suggestions or answers – anybody?

[daveh]

I've got a 35/2.8 and mine goes in the same direction as the other RE AUTO TOPCORs that I have. Moreover it is physically longer with possibly less diameter than the lens you have.

[daveh]

I was in a bit of rush posting this morning. I realise that I have got the lenses the wrong way round. Outwardly my 35/2.8 is as the lens on the left of your photo, as well ok at it. All the lenses I have have th e 2.8 (or whatever) as per the silver lens of your photos. I can't lay my hands on the 58/1.8 at the moment but I'm sure that is the same as the other three.

Your black lens above appears to have a window over the distance scale. None of my lenses have this.

[conan]

Dec 15, 2016 8:19:06 GMT -5 daveh said:

I was in a bit of rush posting this morning. I realise that I have got the lenses the wrong way round. Outwardly my 35/2.8 is as the lens on the left of your photo, as well ok at it. All the lenses I have have th e 2.8 (or whatever) as per the silver lens of your photos. I can't lay my hands on the 58/1.8 at the moment but I'm sure that is the same as the other three.

Your black lens above appears to have a window over the distance scale. None of my lenses have this.

It does have a window over the distance scale and I found a very oblique reference to this on a Topcon forum stating that the style of lenses was not made by Topcon – well whoever made them used Topcon name engravings and did a perfect copy of the other Topcor lenses.


Now if these were Nikkor's we would be deluged with replies even telling us the name of the supervisor on duty that day at the factory and his wife and children’s names. Sadly some Topcon development history is still very clouded.

[daveh]

I have a couple of non-Topcon lenses. A wide angle and a 200mm. Neither of these has any similarity to the Topcon made lenses other than the mount. I would have to find them to check which way the f-stop (and focusing for that matter) runs.

There always seems to be a law about brand lenses: if they weren't made by the company itself, then they were made by Cosina.

I can't think of having seen a Topcon lens with a window covering the scale but then, to be honest I haven't really looked at what lenses have been available since I was using the SuperD in the 1970s. Well, I've not really been any help. What would be interesting, though would be to compare my lens fully with yours to see exactly how they compare e.g. Colour of lettering, typeface used etc. If I get round to it I post some more photos of my lens

[conan]

Dec 16, 2016 15:25:38 GMT -5 daveh said:

I have a couple of non-Topcon lenses. A wide angle and a 200mm. Neither of these has any similarity to the Topcon made lenses other than the mount. I would have to find them to check which way the f-stop (and focusing for that matter) runs.

There always seems to be a law about brand lenses: if they weren't made by the company itself, then they were made by Cosina.

I can't think of having seen a Topcon lens with a window covering the scale but then, to be honest I haven't really looked at what lenses have been available since I was using the SuperD in the 1970s. Well, I've not really been any help. What would be interesting, though would be to compare my lens fully with yours to see exactly how they compare e.g. Colour of lettering, typeface used etc. If I get round to it I post some more photos of my lens

In regards to non-brand lenses there were many Japanese manufacturers that also made for the name brands. Cosina were probably better known for their bodies – and the incredible variety of ‘brand’ cameras based on their CT chassis. Topcon seems to have a problem with their mounts – the early ones with the Exakta mount but no coupling because Exakta used external coupling and then with their Uni? range. I have a Topcon IC Auto and the seller sent a ‘gift’ of a 35mm WA with it with a note saying be careful it probably does not fit later Topcon’s and its not an Exakta mount.


I have 3 Topcon’s with the Exakta mount the RE2 and the later one with the mirror lock up. This later one is in superb condition and is marked US Navy. (Part of the US Navy contract) Probably used by an admiral because for a military camera it’s in superb condition


Would like to see some photos of your lenses

[johnbear]

I normally keep quiet when I don't own and have hands on experience of a model, but ... that doesn't look like any Topcon lens I've ever seen (but I only have UV types). The window thing is way too modern.

Logically, if things turn in the opposite direction, I can't see anyway it could possibly work.

Conan is right ... we need more photos, because this is a mystery that needs to be solved.

[daveh]

Johnbear, I'm sure you're right about the window covering the scale. The earliest lenses I have with that are the Pentax-F which date from the early '80s. Of course some lens manufacturer could have used them earlier, but it would seem to be that era, around the 1980s, when they became more commonplace.

Conan, it would appear to get interesting here. I was looking at your photo and comparing it to my lens. The auto-diaphragm lever (to the mid-left of the lens as we look at it0 in your photo is in the closed position i.e. the blades are at the f22 position - at least they are in my lens - and yet the scale is set to f2.8. When I set my lens to f2.8 the lever is at the very back of the slot.

additionally the the lever that connects with the metering linkage is at the very front of its slot (i.e in the same position as yours) when it is set at f22 (rather than the 2.8 yours is set at).

From what we have so far it would appear that the numbering on yours is the wrong way round, but everything else is the same, that is to say it would operate perfectly but when set at f22 the lens is actually operating at f2.8 (and so on through the scale - f16=f4, f11=f5.6 and f8=f8).

Anyway, here are the photos referred to above - at least they would be if I hadn't used "quick reply". I'll post this as is then use "reply" to do the photos.

[daveh]

Photo 1 - set to f22

Photo 2 - set to f2.8

Photo 3 - as 2, but focus altered to emphasise the auto diaphragm lever

[daveh]

Soligor 35/f2.8
My brother got this lens for me when he had a year in Charleston, SC in the mid 1970s. Optically okay but certainly not the build quality of the proper Topcon lenses.





Note the missing screw, photo 3. This came loose fairly early on and then fell out (never to be found again) when the thread in the lens body fully stripped. Actually I do have it somewhere; just don't know where.

[daveh]

Further photos of the Topcon 35/2.8 RE Auto Topcor

[daveh]

RE Auto Topcor 135/3.5
This is the nicest lens ever.





135 and 35 side by side:


The 35mm focuses down to 9".

[conan]

Dec 17, 2016 19:10:28 GMT -5 daveh said:

Johnbear, I'm sure you're right about the window covering the scale. The earliest lenses I have with that are the Pentax-F which date from the early '80s. Of course some lens manufacturer could have used them earlier, but it would seem to be that era, around the 1980s, when they became more commonplace.

Conan, it would appear to get interesting here. I was looking at your photo and comparing it to my lens. The auto-diaphragm lever (to the mid-left of the lens as we look at it0 in your photo is in the closed position i.e. the blades are at the f22 position - at least they are in my lens - and yet the scale is set to f2.8. When I set my lens to f2.8 the lever is at the very back of the slot.

additionally the the lever that connects with the metering linkage is at the very front of its slot (i.e in the same position as yours) when it is set at f22 (rather than the 2.8 yours is set at).

From what we have so far it would appear that the numbering on yours is the wrong way round, but everything else is the same, that is to say it would operate perfectly but when set at f22 the lens is actually operating at f2.8 (and so on through the scale - f16=f4, f11=f5.6 and f8=f8).

Anyway, here are the photos referred to above - at least they would be if I hadn't used "quick reply". I'll post this as is then use "reply" to do the photos.

Thanks for the photographs.
Interesting about the stop down lever. I will have a good look at all my Topcon lenses tomorrow

[johnbear]

Take a look at this page on the Japanese Topcon Club website.


www.topgabacho.jp/Topconclub/lens4.htm


The translation is pretty dire, but the text does reveal that these lenses with a plastic window were made for the 1960 Topcon R II. The description talks about the direction of rotation of the aperture ring being different, but claims that it will work on an RE Super (well that's how I read it).

This is a great site for all info Topcon, but exactly what it is saying is often hard to fathom.

[daveh]

Well done, John, for finding them. I looked through those pages but totally missed them. There were pages elsewhere which explained the different sitings of the auto-diaphragm lever. I shall have to find it again to see what the differences are; when I have time, that is.

In terms of the translation, the daughter-in-law of friends is Japanese so I could get her to translate. The trouble is she Iives in San Francisco: USA that is.