Canon FL 58mm F1.2

[Eric Nepean]

I just received my Cannon FL 58mm F1.2 lens.

It won't mount on oy of my FD kit because of the baffle near the aperture pin, it iterferes with the aperture stop down pin in the adapter.

One option would be to sacrifice and FD to M43 mechanical adapter and remove the stop down lever, but that would mean that I couldn't stop down the lens. And I wouldn't be able to mount it on the speed booster.

The other option is to remove the baffle, it doesn't appear to have a useful function.

Some parts of attach with screws, these can be removed easily, but the rainder looks lie it would have to be cut off or ground off.

Has anyone tried this? Were you successful? Any pitfalls?

The other cosnideration is that the focus is very stiff. I might send it for lubrication (if I can still find a place - I don't know how difficult this is) and once partially disaaembled it is likely a better time to perform a bafflectomy.

 

[Aoi Usagi]

I just received my Cannon FL 58mm F1.2 lens.

It won't mount on oy of my FD kit because of the baffle near the aperture pin, it iterferes with the aperture stop down pin in the adapter.

One option would be to sacrifice and FD to M43 mechanical adapter and remove the stop down lever, but that would mean that I couldn't stop down the lens. And I wouldn't be able to mount it on the speed booster.

The other option is to remove the baffle, it doesn't appear to have a useful function.

Some parts of attach with screws, these can be removed easily, but the rainder looks lie it would have to be cut off or ground off.

Has anyone tried this? Were you successful? Any pitfalls?

The other cosnideration is that the focus is very stiff. I might send it for lubrication (if I can still find a place - I don't know how difficult this is) and once partially disaaembled it is likely a better time to perform a bafflectomy.

Remove the stop down lever inside the adapter. If you are lucky, it will just be a long screw. You can still stop down the lens by turning the ring between the focus ring and the aperture ring. It is marked by a white dot. It is essentially a preset lens.

If you remove the lever inside the adapter, try to find a short replacement screw. Turning the Open-Lock ring without the lever in place may make the spring and detent bearing fall out.

 

[Tom Caldwell]

Eric,

I don’t know your issue precisely but I came across what might have been a similar issue many years ago when the aperture actuation “rod” of the FL lens (as I prefer to call it as opposed to the machined metal “lever” of the FD lens) hit up against part of the the lens carrying tube of the then Zhongyi MkI focal reduction adapter. This in effect made sure that the lens would not mount.

You could actually see the scratches where the parts collided.

At the time ProfHank had his solution which he shared but mine was simpler and also worked. I covered the end of a FL lens with a made up guard of bent paper and masking tape and made a hole that allowed the aperture rod only to poke through then carefully filed a flat in the rod - just enough to clear the offending part.

Because I made a sort of semi-permanent “universal” guard I could remove it to test and re-apply it. As I had several FL lenses with the same issue the guard could be reused with them as well. After removal each time I gave the lenses a good air-dusting just in case some of the filings had escaped through.

This might not be your exact issue but the cure might work just the same.

It was only a minor clearance surgery and did not affect the way the lenses worked in practice.

 

[sensiblename99]

Just remove the screw in the adapter. The aperture is stopped down with a ring near the front of the lens.

 

[Eric Nepean]

Thanks all for the useful comments.

In addition I found a useful video on youtube that show the diassembly of the lens.

From evogt500 sensiblename's s comments I learned that this lens has a stop down ring - so I don't actually need this stop mechanism in the back.

The simple solution is of course to remove the stop down actuator pin in the FD to M43 adaptor.

Referring to Tom's comment, I have learned that there are two lenses with this design. There is a metal housing or baffle that extends about 6mm from the rear of the lens, further than is typical for other FD and FL lenses.




Notice the extension at top rear of the lens

This baffle is circular and covers almost half of the outer circumference of the lens; there is a hole iwhere the aperture stop down pin pokes through. The mechanical interefernce I have so far is the rear of the baffle hitting the adaptor's stop down leaver.

The real reason I bought this lens was to use it with my Metabones FD to M43 Speedbooster (0.71x), this is one item where I won''t remove the stop down lever.

From watching the Youtube disassembly video, I've learned that the rear of this baffle attaches with three screws, remove these and the rear part of the baffle comes out, and lets the entire stop down pin mechanism fall out. Apparently the purpose of this baffle is simply to hold that mechanism in place.

I intend to remove the rear of the baffle and the stop down pin mechanism permanantly, because I don't need it (the lens has a stop down ring up forwards)

If the remaining parrt of the baffle doesn't interfere with anything the I will leave it be. Otherwise the there is a reating ring around the optics tube, unscrew that and the lens mount can be removed. At that point it will be quite simple to use a file or dremel to remove the more of the baffle while keeping the metal shavings out of the lens.

--
Cheers
Eric

 

[Lightshow]

The stopdown ring on the adapter is only ever needed on the nFD lenses, the aperture ring on FL lenses is always active, and on FD lenses all you do is push the aperture lever on the rear of the lens till it clicks and holds the lever at the end of the slot, this turns the lens into a full manual lens, I removed the screw that gets in the way from my adapter 10 years ago and haven't looked back, I only have one nFD lens that I never use, so it worked out perfectly.

I'm not a fan of cutting up or modifying a lens if you don't have to, especially if it's a rare or uncommon lens, a fast lens, or one with desirable rendering, and this lens is definitely in that category of please don't cut it up.

--
A Manual Focus Junky...
One photographers junk lens is an artists favorite tool.
http://www.flickr.com/photos/lightshow-photography/
[My Lens list](http://www.fredmiranda.com/forum/viewprofile.php?Action=viewprofile&username=LightShow)
####Where's my FF NEX-7 ?????

https://flic.kr/p/Q2b9mq

https://flic.kr/p/PgwEjs

Firmware request:
-A button map for toggling the EVF & LCD
-Still waiting for the minimum shutter speed with auto ISO for my NEX-7 and A7r. I know it will never happen.
-Customize the display screen layout, I'd love to have both Histogram and level at the same time.
-More peaking options, being able to set peaking sensitivity and a threshold level.
-An RGB overlay on the histogram

https://flic.kr/p/wQd7zp

-An option to return the focus assist zoom to one button press
-An option to return to how the NEX-7 handled playback, ie. center button to zoom, then you could use the control dial to zoom in and out, then center button to exit the zoom mode.

 

[Tom Caldwell]

Thanks Eric, I was confused by a separate problem that I encountered (way back) with FL lenses where the aperture rod on (all) these lenses fouled part of the lens mounting structure of the then Mk1 Zhongyi focal reduction (FR) adapters.

Now I see the issue is what was called the “hogback” protrusion of the rear cover which I thought only applied to a certain 35mm FL lens version. Obviously that completely stopped the prospect of any FR adapter being used. I did not realise that the “hogback” construction included other lens types. I do have a 35mm “hogback” which I will have another look at with some newly revived interest.

I now have a couple of “ah-hah!” Moments. This is one of the wonders of this forum there are so many helpful members.

Firstly my “1.2” is the FL 55/1.2 and not the 58/1.2 which is of the normal back type and has no issues mounting. Also that my FL 35/2.5 is of the hogback type and will not mount on the “Chinese” moving pin FD/FL adapter type. But my memory (alone) tells me that the neat and very efficient “Polish” FD adapter which works the aperture pin/rod by an ingenious little machined hook lever inside. But I cannot find mine to double test it - it must be wandering around still attached to a lens somewhere. Must try and find it.

Also I had not realised the neat little stop down lock ring existed on my 35/2.5 “hogback”.

Thanks a bunch. If I cannot find my Polish “Ciecio7” adapter I will have to look at the rear cover.

2nd Edit - found my Ciecio7 adapter to Sony E/FE - yes it does mount a “hogback” with no issues. Will take some images. The maker does not “do” focal reduction as far as I know. Makes excellent adapters though.

A check of the site seems to indicate that common type adapters are no longer made and sold. But if you ever needed some very well made exotic adapters it might be habdy to have this as a reference

Loading…

www.ebay.com.au

 

[Eric Nepean]

The stopdown ring on the adapter is only ever needed on the nFD lenses, the aperture ring on FL lenses is always active, and on FD lenses all you do is push the aperture lever on the rear of the lens till it clicks and holds the lever at the end of the slot, this turns the lens into a full manual lens, I removed the screw that gets in the way from my adapter 10 years ago and haven't looked back, I only have one nFD lens that I never use, so it worked out perfectly.

I have already removed the screw from one of my three FD to M43 adapters.

I'm not a fan of cutting up or modifying a lens if you don't have to, especially if it's a rare or uncommon lens, a fast lens, or one with desirable rendering, and this lens is definitely in that category of please don't cut it up.

My purpose is to use one of these soft bokeh F1.2 lenses on a Speedbooster mounted on an M43 camera.

One alternative is an MC Rokker 58mm F1.2 lens and a Minolta to M43 speedbooster. Around $500US before shipping and taxes.

Split the cost with me and I will do as you wish.

Cheers
Eric

 

[Eric Nepean]

Thanks Eric, I was confused by a separate problem that I encountered (way back) with FL lenses where the aperture rod on (all) these lenses fouled part of the lens mounting structure of the then Mk1 Zhongyi focal reduction (FR) adapters.

Now I see the issue is what was called the “hogback” protrusion of the rear cover which I thought only applied to a certain 35mm FL lens version. Obviously that completely stopped the prospect of any FR adapter being used. I did not realise that the “hogback” construction included other lens types. I do have a 35mm “hogback” which I will have another look at with some newly revived interest.

I now have a couple of “ah-hah!” Moments. This is one of the wonders of this forum there are so many helpful members.

Firstly my “1.2” is the FL 55/1.2 and not the 58/1.2 which is of the normal back type and has no issues mounting. Also that my FL 35/2.5 is of the hogback type and will not mount on the “Chinese” moving pin FD/FL adapter type.

If read that the FL 35/2.5 and FL58/1.2 are the only two "hogback" lenses

But my memory (alone) tells me that the neat and very efficient “Polish” FD adapter which works the aperture pin/rod by an ingenious little machined hook lever inside. But I cannot find mine to double test it - it must be wandering around still attached to a lens somewhere. Must try and find it.

I have an RJ camera FD to M43 adapter which was made in Poland around 2010, one of the first and it cost about $100 CAD. No hook, just a screw which I have removed.

Recently I pulled out about half my gear to do some checkimng, my spouse has asked when is the camera store going to leave the living room.

Also I had not realised the neat little stop down lock ring existed on my 35/2.5 “hogback”.

I would not have noticed it either except for the helpful comments of evogt500.

This is very useful, because it means the rear stop down mechanism can be removed without loosing any function (unless you were going to mount the lens on an FD or FL camera body.

Thanks a bunch. If I cannot find my Polish “Ciecio7” adapter I will have to look at the rear cover.

2nd Edit - found my Ciecio7 adapter to Sony E/FE - yes it does mount a “hogback” with no issues. Will take some images. The maker does not “do” focal reduction as far as I know. Makes excellent adapters though.

The Metabones FD to M43 Speedbooster which I have is purely machanical, the optics must be very good as I get sharp results with many lenses and the mechchanicals are very well made. I removed some material from the foot so that it would fit on an E-M1.

A check of the site seems to indicate that common type adapters are no longer made and sold. But if you ever needed some very well made exotic adapters it might be habdy to have this as a reference

https://www.ebay.com.au/sch/ciecio7/m.html?ssPageName=STRK:MEFSXS:MESOI&_trksid=p2053788.m1543.l2654

Thanks Tom. Bookmarked.

I've just ordered a good selection of Vessel JIS screwdrivers. I do like having good tools and the right tools on hand. From what I've read JIS screwdrivers are essential to prevent damage to screwheads when dissambling lenses and cameras.

Once I have the JIS slotted screwdrivers, I will undo the three screws that hold the rear baffle in place, and then see what mechnical interference issues remain and how best to deal with them.

The baffle erves two purposes - it holds the ring with the stop down pin in place, and it prevents light reflecting from the parts inside the lens. Whatever I do, I need to control the internal reflections.

I'm finding that the lens is a bit soft, even stopped down to F4, however the bokeh is very smooth. Normally I try for the sharpest lens I can afford, this one is different.

 

[ProfHankD]

The stopdown ring on the adapter is only ever needed on the nFD lenses, the aperture ring on FL lenses is always active, and on FD lenses all you do is push the aperture lever on the rear of the lens till it clicks and holds the lever at the end of the slot, this turns the lens into a full manual lens, I removed the screw that gets in the way from my adapter 10 years ago and haven't looked back, I only have one nFD lens that I never use, so it worked out perfectly.

I have already removed the screw from one of my three FD to M43 adapters.

I'm not a fan of cutting up or modifying a lens if you don't have to, especially if it's a rare or uncommon lens, a fast lens, or one with desirable rendering, and this lens is definitely in that category of please don't cut it up.

My purpose is to use one of these soft bokeh F1.2 lenses on a Speedbooster mounted on an M43 camera.

One alternative is an MC Rokker 58mm F1.2 lens and a Minolta to M43 speedbooster. Around $500US before shipping and taxes.

Split the cost with me and I will do as you wish.

Cheers
Eric

The Rokkor 58mm f/1.2 is a great lens in many ways, worthy of the praise it gets, but in truth the Canon FL 55mm f/1.2 isn't all that different. I paid $255 for my Rokkor, and it's well worth that, but my FL 55mm f/1.2 was quick and easy to find for $200... I think the FL lens is the better value. Honestly, the Rokkor is a little too distinctive for lots of uses, especially wide open -- it's at f/2 that the bokeh are most awesome.

 

[Eric Nepean]

The stopdown ring on the adapter is only ever needed on the nFD lenses, the aperture ring on FL lenses is always active, and on FD lenses all you do is push the aperture lever on the rear of the lens till it clicks and holds the lever at the end of the slot, this turns the lens into a full manual lens, I removed the screw that gets in the way from my adapter 10 years ago and haven't looked back, I only have one nFD lens that I never use, so it worked out perfectly.

I have already removed the screw from one of my three FD to M43 adapters.

I'm not a fan of cutting up or modifying a lens if you don't have to, especially if it's a rare or uncommon lens, a fast lens, or one with desirable rendering, and this lens is definitely in that category of please don't cut it up.

My purpose is to use one of these soft bokeh F1.2 lenses on a Speedbooster mounted on an M43 camera.

One alternative is an MC Rokker 58mm F1.2 lens and a Minolta to M43 speedbooster. Around $500US before shipping and taxes.

Split the cost with me and I will do as you wish.

Cheers
Eric

The Rokkor 58mm f/1.2 is a great lens in many ways, worthy of the praise it gets, but in truth the Canon FL 55mm f/1.2 isn't all that different. I paid $255 for my Rokkor, and it's well worth that, but my FL 55mm f/1.2 was quick and easy to find for $200... I think the FL lens is the better value. Honestly, the Rokkor is a little too distinctive for lots of uses, especially wide open -- it's at f/2 that the bokeh are most awesome.

Do you have any comments on the difference between images from the FL55mm/1.2 and from the FL58mm/1.2?

 

[ProfHankD]

The Rokkor 58mm f/1.2 is a great lens in many ways, worthy of the praise it gets, but in truth the Canon FL 55mm f/1.2 isn't all that different. I paid $255 for my Rokkor, and it's well worth that, but my FL 55mm f/1.2 was quick and easy to find for $200... I think the FL lens is the better value. Honestly, the Rokkor is a little too distinctive for lots of uses, especially wide open -- it's at f/2 that the bokeh are most awesome.

Do you have any comments on the difference between images from the FL55mm/1.2 and from the FL58mm/1.2?

Don't have one of the FL 58mm f/1.2 so I can't really say. Either way, we are talking about 1960s lens designs, and the 55mm is the newer replacement for the 58mm, so it's unlikely it's worse. I do know the rendering of the FL 55mm f/1.2 is much closer to that of the Rokkor 58mm f/1.2 than most other f/1.2 lenses are....

 

[Tom Caldwell]

Something of deja vu there Eric, my second hand lens store gets banished from the living room table from time to time only to re-appear again with monotonous regularity. Wives can never fully understand our fascination but my wife’s patience seems otherwise inexhaustible ....

Like my lens accumulation, I have accumulated a reasonably good set of tools. Now quite interested in making things (small inventions) on my little milling machine that I have taught myself to use I am investing in a rotating table so that I might be able to mill rounded edges as well.

As noted - I find the FL 50/1.4 to be sharper than the 55/1.2 and it is also more compact. There seem to be two slightly different versions of the 50/1.4 and both seem to suffer a bit from slightly corroded surfaces on their aperture blades - most likely (in my guess) being from long periods with little use. In any case the blades tend to get a bit sticky and show up as slow apertures. I found the fix to be easy - remove the front element to access the aperture and use the tiniest smear of graphite powder worked into a small soft flat ended artist’s paint brush over the exposed blades and operating the internal connection of the aperture until the blades are snappy again.

I would probably get into trouble from the purists from this recommendation. But firstly the apertures blades need to be absolutely devoid of any oil and still sticking and the graphite must be not at all loose but worked into the brush hairs first. Nothing could be worse than and oil/graphite mix or loose graphite powder inside the lens.

The 55/1.2 (normal) and not the 58/1.2 (hogback) also seems a bit soft wide open but I has that look and is also very well built and re-assuring.

Lots of things to-do at the moment but that 35/2.5 hogback is still at one and of the table and my screwdrivers are not that far away .....

--
Tom Caldwell

 

[Tom Caldwell]

Probably because the optics of the designs worked better but it might be an interesting aside that there were a series of “standard” lenses that might be closer to 60mm once before the lens-world settled to to the “50mm” focal length with a vengeance. Of course nobody worries that much about this and the further-longer the focal length from 50mm the bigger the recognised common focal length “jumps”.

There are 60mm lenses about but they seem to be more exceptions than the rule. Then there is a small jump to the “75mm” focal length but the next “popular” length is of course the “85mm”. I talk in FF fov equivalents of course.

There is also this 0.7x ratio that comes in handy for focal reduction adapters that seems to be some sort of mystic incantation mumbled by optical high priests that seems to connect up sensor/film format sizes and the commonly accepted lens focal lengths.

Presumably there is some law of optics that makes sense out of all this and it was not just something that has been widely adopted by chance alone.

 

[ProfHankD]

Probably because the optics of the designs worked better but it might be an interesting aside that there were a series of “standard” lenses that might be closer to 60mm once before the lens-world settled to to the “50mm” focal length with a vengeance. Of course nobody worries that much about this and the further-longer the focal length from 50mm the bigger the recognised common focal length “jumps”.

The standard normal focal length for 135 film is sqrt(36^2+24*2) = 43.3mm.

Of course, there's that pesky mirror to swing out of the way, and a focal plane shutter in front of the film plane. Thus, you need a rear focus distance that's pretty long: FL is 42mm. No problem, you say -- after all 43.3mm is more than that. However, focal length is measured not from the rear element, but from the optical center. Well, in a simple lens, the center is the center of the single element, but in a complex lens it can be a lot farther away from the rear of the lens. Basically, as I understand it, 58mm was as close to normal as was optically easy for a well-corrected fast lens. Over time, design methods got better, and it became possible to get closer to the 43.3mm ideal... but by then, a lens in the 50mm range had become associated with high-end cameras, and slightly long focal lengths make better portraits anyway. ;-)

BTW, a lot of the lenses on 1960s or later (i.e., contemporary to SLR) rangefinder 135 film cameras had correspondingly shorter focal lengths. 50mm was actually a tad long, especially for a fixed lens -- those tended to be in the 38-45mm range. Arguably, a little shorter than 43.3mm was even more correct because the slide mount masked off a couple of mm... which is also why a lot of 135 SLRs showed less than 100% (often 90%-98%) in the viewfinder: they were trying to match the view in a mounted slide. The maximum projectable area for the standard carriers in most enlargers was also cropped to 90-some-odd%. The Beseler Negatrans I have for my 23CII allows 100% and I actually modified my Spiratone's carriers to allow a tad more than 100%. Here's my modified Spiratone carrier with a Kodak slide (Kodak cropped slides less than most):



In case you're wondering, this was a pet peeve for me. I felt, if you're a true professional, you should not need to crop very often: you should be that careful about framing things in the first place, and use all your darkroom expertise to make the print match your original vision. In fact, most of my "art" photos were printed with the natural frame edge visible to prove I hadn't cropped. Oddly, I don't have any scans of my old art prints handy -- but they all have a thin black border that was the exposure mask in the camera, and you could tell which camera I shot them with by looking at the imperfections in the black mask. Here's one that's (badly) framed and still on my wall:


Notice the thin black edge from printing slightly more than 100%

 

[Eric Nepean]

Something of deja vu there Eric, my second hand lens store gets banished from the living room table from time to time only to re-appear again with monotonous regularity. Wives can never fully understand our fascination but my wife’s patience seems otherwise inexhaustible ....

Wel, KAthleemn has one large room for quilting, it seems to have some kind of a singularity where she can store an infinite amount of fabric ...

Like my lens accumulation, I have accumulated a reasonably good set of tools. Now quite interested in making things (small inventions) on my little milling machine that I have taught myself to use I am investing in a rotating table so that I might be able to mill rounded edges as well.

As noted - I find the FL 50/1.4 to be sharper than the 55/1.2 and it is also more compact. There seem to be two slightly different versions of the 50/1.4 and both seem to suffer a bit from slightly corroded surfaces on their aperture blades - most likely (in my guess) being from long periods with little use. In any case the blades tend to get a bit sticky and show up as slow apertures. I found the fix to be easy - remove the front element to access the aperture and use the tiniest smear of graphite powder worked into a small soft flat ended artist’s paint brush over the exposed blades and operating the internal connection of the aperture until the blades are snappy again.

I would probably get into trouble from the purists from this recommendation. But firstly the apertures blades need to be absolutely devoid of any oil and still sticking and the graphite must be not at all loose but worked into the brush hairs first. Nothing could be worse than and oil/graphite mix or loose graphite powder inside the lens.

The 55/1.2 (normal) and not the 58/1.2 (hogback) also seems a bit soft wide open but I has that look and is also very well built and re-assuring.

Do you have both the FL55/1.2 and the FL58/1.2 then? If so how would you compare the center sharpness and bokeh?

Lots of things to-do at the moment but that 35/2.5 hogback is still at one and of the table and my screwdrivers are not that far away .....

 

[Lightshow]

The stopdown ring on the adapter is only ever needed on the nFD lenses, the aperture ring on FL lenses is always active, and on FD lenses all you do is push the aperture lever on the rear of the lens till it clicks and holds the lever at the end of the slot, this turns the lens into a full manual lens, I removed the screw that gets in the way from my adapter 10 years ago and haven't looked back, I only have one nFD lens that I never use, so it worked out perfectly.

I have already removed the screw from one of my three FD to M43 adapters.

I'm not a fan of cutting up or modifying a lens if you don't have to, especially if it's a rare or uncommon lens, a fast lens, or one with desirable rendering, and this lens is definitely in that category of please don't cut it up.

My purpose is to use one of these soft bokeh F1.2 lenses on a Speedbooster mounted on an M43 camera.

One alternative is an MC Rokker 58mm F1.2 lens and a Minolta to M43 speedbooster. Around $500US before shipping and taxes.

Split the cost with me and I will do as you wish.

Cheers
Eric

Ok

The speed booster complicates things, if the aperture lever prevents mounting the lens on a speed booster, then I suppose it's time to move to FF mirrorless ;-)

Heres a post I put together to show different lenses rendering, it may give you alternate options to get the look you want.

Loading…

forum.mflenses.com

 

[Tom Caldwell]

No I only have the FL 55/1.2 and I was referring to my impressions of it when last used in comparison to the FL 50/1.4 of which I have a few. Not sure why - they must have been cheap at the time - or perhaps disappointed with a slow/sticking aperture I bought another - only to find it had a slow/sticking aperture .....

Then I figured out how to fix the apertures ...

As a result of the good new for hogbacks on this thread I removed the backing plate and associated levers from my 35/2.5 hogback. Works fine without the extra hardware. Mounts straight away on an FD adapter but the focal reduction version would not mount. Diagnosed that the aperture pin on the adapter was mounted slightly higher than on the plain adapter and fouled the raised rim left on the lens.

Decided that I was never going to need to use the hog and its internal mechanism ever again so decided to remove the ridge.

Cut a precise circle from thin card and blocked off the inner works then swathed the mount mechanism and exposed body in masking tape. I thought that my mill might make a very level cut if I used a slow speed and held the lens very tightly by hand. There was no way I could vice-mount it without damaging it. Mill bit was not going to work. So I tried a drum type grinding bit. Firstly it was not centred very well on the shaft - might be ok on a dremel but not so good on a precision mill. In any case I got around one third of the raised portion but it was threatening to catch quite often and drag the lens from my grip. So discretion prevailed with the job part done. Meantime one grab had bent the edge of the mount sleeve. So I straightened this with my filter ring “fixer”.

I went back to my first idea dismissed as maybe becoming too hot. Belt sander with fine grit. With some care it on took a few minutes and a better finish as well. Holding the lens was much easier and safe. I could use the end of the sander as a visual level and took bites out of the raised portion. Worked well and as I took it in small stages I don’t think that I created much heat. I removed the sanding burr with a little de-burring device i ahve.

Then as everything was masked up I painted it .. maybe not such a bright idea.

Once the paint was dry neither of my adapters would mount.

So I scraped off the extra paint on the mating surface ... fancy that.

The plain adapter would not mount but the focal reduction adapter would not. I figured out that there was still some burr left from the grinding although I could not feel any by a finger tip test. So I used a small rod sharpening stone - to chamfer off the mating edge as I was convinced that the male mount side on the lens was perfectly round from my “fix”. In any case it works - the mount action is firm - no slop here, but working to my satisfaction. It is just a fraction tighter fit than the plain adapter - which also has no slop.

I put a bit of cut-out card inside to cover the works but I don’t think it essential and the lens looks ok without it. There are no internal light leaks or reflections. In fact the card needs a slot in it to allow the stub of the aperture arm to move otherwise the aperture ring will not adjust the aperture until “pre-set”.

I note that there are quite a number of FL 58/1.2 and FL 35/2.5 lenses fo sale - they are all complete with “hogback” and there is no mention by any vendor that they could pose a would be owner some difficulties should they with to adapt them. The FL 55/1.2 seems to sell at a bit of a premium - presumingly because some of the potential buyers realise the Issues that the hogback presents.

 

[Tom Caldwell]

The stopdown ring on the adapter is only ever needed on the nFD lenses, the aperture ring on FL lenses is always active, and on FD lenses all you do is push the aperture lever on the rear of the lens till it clicks and holds the lever at the end of the slot, this turns the lens into a full manual lens, I removed the screw that gets in the way from my adapter 10 years ago and haven't looked back, I only have one nFD lens that I never use, so it worked out perfectly.

I have already removed the screw from one of my three FD to M43 adapters.

I'm not a fan of cutting up or modifying a lens if you don't have to, especially if it's a rare or uncommon lens, a fast lens, or one with desirable rendering, and this lens is definitely in that category of please don't cut it up.

My purpose is to use one of these soft bokeh F1.2 lenses on a Speedbooster mounted on an M43 camera.

One alternative is an MC Rokker 58mm F1.2 lens and a Minolta to M43 speedbooster. Around $500US before shipping and taxes.

Split the cost with me and I will do as you wish.

Cheers
Eric

Ok

The speed booster complicates things, if the aperture lever prevents mounting the lens on a speed booster, then I suppose it's time to move to FF mirrorless ;-)

Heres a post I put together to show different lenses rendering, it may give you alternate options to get the look you want.

http://forum.mflenses.com/55-1-4-lens-in-5-groups-t81470.html#1535539

My “operation” on my FL 35/2.5 “hogback” (described on another post on this thread) might be more complex on the FL 58/1.2 Due to the fact that the rear element is considerably larger on the “58”. But it might be possible to extend the lens and thereby retract the element further for a measure of safety. It seems that the pin on my focal reduction adapter is set closer to the mount surface than on the plain adapter so that it can clear the focal reduction lenses in the lensed adapter.

 

[Tom Caldwell]

This is the FL 35/2.5 "hogback" not the FL 58/1.2


The exposed mechanism - remove screw holding spring tension. Remove large screw on RHS. Narrow slot - needs a mini-multi-grip to loosen. Two arms ans spring come off easily. Note raised black lip of male mount at top.



[ATTACH alt="I put cardboard "circle" inside mount to cover the inside of lens tightly and covered all exposed parts of outer lens with masking tape - none of this is shown but it is important. Ground raised edge now on bottom and rhs back to as close to and parallel with the lower level as possible. Then de-burred the ground edge."]2661566[/ATTACH]
I put cardboard "circle" inside mount to cover the inside of lens tightly and covered all exposed parts of outer lens with masking tape - none of this is shown but it is important. Ground raised edge now on bottom and rhs back to as close to and parallel with the lower level as possible. Then de-burred the ground edge.

Note that the plain adapter will fit without grinding the raised edge of the mount flush but the focal reduction version wouldn't.




RJ dumb focal reduction adapter FD-M4/3 mounted successfully on a Canon FL 35/2.5 hogback lens.





It works



--
Tom Caldwell