DIY T-Mount Lens Mount Adapter Ring for C/FD?

<p>Have you ever tried to find the reverse of a T-mount? By that, I mean a camera mount to which a lens of a dedicated mounting style is mounted to, using the T-mount system. This "Lens Mount Adapter Ring," which is what Vivitar called the ones it made, is an adapter with male T-mount threads on one side and a camera mounting flange on the other. Vivitar supplied these with their macro bellows. That way they could fit the adapters, front and rear, to a universal set of bellows, and supply them for most any application. I suspect others may have done this as well -- perhaps other makers of universal bellows. Spiratone comes to mind, although I don't happen to know if they ever made these.</p>

<p>But it is a Spiratone bellows I have that prompts my search. The bellows front standard has female T-mount threads (42mm by 0.75mm thread pitch), into which a Spiratone 150mm macro lens is threaded. My problem is, I want to be able to use other lenses with this set of bellows. Preferably one of my Canon FD macros. In order to do this, though, I need to find a "lens mount adapter ring" for Canon FD.</p>

<p>I have been searching high and low for these things and so far have found one -- in Minolta SR mount, which I have no use for. I'm even considering buying a Vivitar bellows, complete with both adapters, if that's the only way I can get that ring. But that is overkill.</p>

<p>The scarcity of this adapter is what brings me to the subject of this post. I wonder how difficult it would be to make one? I'm thinking I can scavenge the lens mount off a dead Canon FD body and perhaps figure out a simple way to attach this to a threaded adapter that has the male 42x.75 threads I need. I'm not going to know what all's involved, I suspect, until I actually scavenge a mount from an FD body. And I'm also thinking it's pretty safe to assume that Canon has varied the way the mounts attach to the bodies over the years, such that some might be better candidates as donors than others. But I have no idea which would be the best way to go. </p>

<p>I'll probably err on the practical side, though. I have a dead A-1 and a FTb that functions, but which is in rather poor shape. So I have two possible donors from two different eras.</p>

<p>So, just wondering -- has anyone here done anything like this before? If so, got any advice?</p>

 

<p>Can't help you with the Vivitar adapter ring, but one project I have on a back burner is replacing the EF mount on an old EOS film body with an FD mount that will focus to infinity. This is purely for educational purposes. If it's relatively straightforward, the next step would be to make the modification to a digital EOS body.</p>

<p>Rather than scavenge a non-working FD body (of which I have many), my thought was to use the male FL/FD mount from a third party extension tube or teleconverter (of which I also have many). My recollection is that the male portion of the breech mount, whether Canon-made or third party, has always been a separate piece attached with machine screws. As a dry run, you could also use a modified FL/FD rear lens cap which is essentially a plastic male breech mount.</p>

<p>Hey Gordon, thanks for the idea about using a teleconverter or extension tubes. Now why didn't I think of that? Too close to the problem, I suppose. I have several FD TCs laying around, some of which I'll never use, so that'll be a good place to start. I had thought of using a rear lens cap, but rejected the idea because I was afraid I might break things too easily.</p>

<p>I'll take a look at my TCs and report back my findings.<br>

<br /><br /></p>

<p>Over the years, I've purchased a number of "camera kits" in order to get one or two specific items. As a result, I have lots of stuff I'll never use, including a bunch of third party TCs and extension tubes. If you need one to scavenge the mount, you're welcome to one of mine. The harder part to source, I would think, is the male T-mount. Offhand, I can't think of an easy source other than amputating a T-mount lens or one of the scarce adapter rings. I guess you would graft on a flange and drill it to accept the Canon breech mount, or bond the pieces with adhesive. If you're really adventurous (or just plain loco), you could articulate the joint to tilt the lens a bit for DoF adjustments.</p>

<p>similar but almost the same.<br>

I started with miranda and miranda brand bellows that have a miranda bayonet on the rear,<br>

but I have a Kopil bellowscope that has a threaded 44 miranda back flange.<br>

presumanly I could purchase another brand Kopil bellowscope<br>

and remover its rear ring and use the miranda macro bayonet lens and 135 short lens <br>

wuth that modfied "cross brand bellowon" other cameras..<br>

Howener for some strange reason my Miranda 135mm SB lens is a T mount lens<br>

and I can add a $3.00 t adapter with a pentax or canon bellows.</p>

<p>the 55 macro lens would be useful for extreme close ups. but there is no inexpensive way to adapt miranda bayonet lenses to other brand camera mounts. I would have to use an enlarger lens., no real hardship.<br>

most camera lenses are not the best choice for use with a bellows or other extreme close up work.<br>

I feel the eos (ef) cameras with no mechanical linkage mat be more awkward to use for close up work with an aftermarket lach up.</p>

<p>Walter, I have a large inventory of manual focus lenses, and probably a half-dozen macro lenses, all of which are manual-focus. The mounts vary: Canon FD, Nikon F, and M42. </p>

<p>Gordon, I agree it is the male T-mount threaded portion that is tough to find. But there is only 0.25mm difference in pitch between t-mount and M42. Back when I was young and stupid, I had inadvertently cross threaded the two before, and it wasn't very hard to do, the pitch is so close. So, what has occurred to me is that, since the pitch is so close, I could take an M42 mount with the male threads and just chase them for T-mount. I have a metal lathe that will cut threads, and I can probably play around with it some to figure out how to chase the M42 threads to T-mount. I suppose I could make a T-mount threaded collar of sorts with my lathe from scratch, but I was trying to avoid the hassle.</p>

<p>I dismantled a cheap FD teleconverter yesterday and here's what I found. The three screw holes that mount the flange onto the TC body are wide enough apart where they just sort of touch the outside of the screw-in T-mount adapter. So I won't be able to tap and thread the adapter for the flange. And I don't want to drill holes in the front standard of the bellows. It occurs to me, however, that I might could epoxy the flange onto the front face of the adapter. I will go with a Canon FD flange instead of a Nikon F or a M42 because I already own glassless adapters for Nikon-to-FD and M42-to-FD, which means I can mount any and all of my macros to this bellows if I can install an FD camera flange. I just hope epoxy will provide a strong enough bond. Maybe JB Weld will work better. Rough up the surfaces some with some coarse sandpaper to give the epoxy something to grab a hold of. What do you think?</p>

 

<p>The chrome plating on the Canon FL/FD mount flange might be resistant to epoxy and other adhesives. You may need to remove the chrome on the mating portion to give the adhesive a surface on which to grip. Or, you could go Rube Goldberg and make an intermediate flange from the female portion of a cheap T-mount to which the Canon flange could be attached with screws and which would then thread on to the male T-mount piece.</p>

<p>Nah, too complicated. I dunno if the chrome will be more "slippery" than the brass underneath. Brass has inherent lubricant-like properties.</p>

<p>It occurred to me that I might be able to drill and tap both the FD flange and the existing threaded adapter so that I could just screw it on. Unfortunately, there just isn't enough flange where I need it.</p>

<p>When I was checking this, I noticed that that back surface of the flange is not flat. There's a very shallow ridge that runs around the inner circumference -- probably no more than about 0.005", but still this will have to come off. I can probably sand everything flat by mounting sandpaper to a flat surface and then just "scrubbing" the flange across it. Easier than chucking it up in a mill and milling it flat.<br /> <br />The only alternative I can see to gluing the flange would be to fabricate a flat plate with the right size lens opening, size it for better positioned screw holes to attach it to the existing adapter, and then attach this plate to the flange, using another group of screw holes. Seems a lot of work.</p>

<p>But as luck may have it, none of the above may be necessary. Yesterday, I located an old Soligor bellows with a Nikon-mount lens mount adapter that has the right male T-thread. It's priced very cheap, so I plan to buy it anyway, just to have that adapter. Nikon is better than nothing. I can buy glassless adapters on eBay for both C/FD and M42 lenses to Nikon F mount. So if it fits, I'll just go this route. It also occurs to me that I should do this anyway. I have a Nikon PB-4 bellows (yeah, I know, the best one), and it would be nice to be able to use more than just Nikkors with it.</p>

<p>But this Spiratone bellows is special. It's the Bellows Master SST (made by Hama) with all the movements of a view camera:<br /> <img src="http://michaelmcbroom.com/images/spiratonebellows1.jpg" alt="" width="1200" height="900" /></p>

<p>Because of the movements, I'm also thinking about snagging an adapter so I can use my Bronica ETR lenses on it. The Bronica's bigger image circle will provide me with more movement possibilities. One good thing about using a Nikon interface instead of Canon FD is I can get an adapter for the Bronica lens to Nikon F, but I don't think anyone makes one for Bronica ETR -> FD.</p>

<p>Good news! I just won the auction on eBay for the Soligor bellows. Wasn't gonna let it get away. But then, I was the only one who bid on it, so I guess I needn't have worried.</p>

<p>So now I guess I can go reattach the FD lens mount adapter ring to that cheapo teleconverter. I'll report back to y'all after the Soligor bellows arrive and I've had a chance to install that Nikon flange mount on the Spiratone unit.</p>

 

<p>The Soligor bellows arrived today. They're a pretty cool and well made set. I'm figuring they date back at least to the 1960s, maybe even earlier. The stout box has a velvet covered pad at the bottom for the bellows to rest on. Don't see that sort of stuff anymore with new gear do you? Instead, it's styrofoam. :) The box has a price sticker: $57.50. A pretty hefty chunk of change if it dates back to the early 60s or 50s, as I suspect.</p>

<p>So anyway, the lens mount adapter that came with the bellows is exactly what I needed. Nikon camera flange with male T-mount threads on the other side. The seller tossed in two t-mounts as well. One's Nikon F and the other I'm not sure about. It has an "L" only painted on it. Leica R? It isn't M-mount, and I'm not familiar with Leica R mount.</p>

<p>I already own an M42 to Nikon adapter so I can use my 100mm f/4 SMC Tak on the bellows now. I just ordered one for Canon FD, which I'm really looking forward to. In addition to my FD 100mm macro, I have a variety of FD glass ranging from 17mm to 200mm. It'll be interesting to see how various ones perform on the bellows.</p>

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