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Mystery Minolta body cap
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PostPosted: Mon Feb 14, 2022 8:30 pm    Post subject: Mystery Minolta body cap Reply with quote

Folks,

Minolta made many body caps for their SR (& MD/MC) mount cameras, but I have only ever seen documented references to plastic caps (not very common early vinyl push-in body caps for the early SR cameras, later plastic twist-on ones for the SRT and X-series cameras).

However, over the years I have come into possession of two metal body caps. From the quality of finish & use of Minolta's trademark logo font I very much suspect these were actually produced by Minolta and are not an aftermarket item. They are very nicely finished and have been machined from solid aluminium, with Minolta's characteristic textured black anodised finish, paint-filled engraved lettering and screwed-on bayonet with slotted screws suggestive of this being an early SR mount item. They do have a red alignment dot on the edge as well, not shown in the pictures below.

Has anyone seen these before and does anyone know anything about the context in which these body caps were produced? (e.g. the very earliest caps or special edition ones for the Minolta SR medical cameras, or something like that?)


Here is the body cap in question, front & back:






PostPosted: Thu Feb 17, 2022 5:25 am    Post subject: Reply with quote

Looks nice, except for the protruding screw-heads, which are very un-Minolta like.

Probably look great on a SRT series body that is in very good shape.

-D.S.


PostPosted: Thu Feb 17, 2022 10:20 am    Post subject: Reply with quote

Doc Sharptail wrote:
Looks nice, except for the protruding screw-heads, which are very un-Minolta like.

Probably look great on a SRT series body that is in very good shape.

-D.S.


Those protruding screws are the one thing that make me wonder if this could still be an aftermarket item.

Just that lettering font is part of a trademark logo that no 3rd party has ever copied, for legal reasons, AFAIK...

But it does look nice on a camera. It is also rather heavy, not something you would be carrying around in a photo bag.


PostPosted: Wed Jun 22, 2022 12:03 pm    Post subject: Reply with quote

Genuine and rare this metal body cap is. Available probably from only 1958~65. The most adorable among them all generations of Minolta SR body caps! 👍


PostPosted: Wed Jun 22, 2022 2:53 pm    Post subject: Reply with quote

Seeing the slotted screws makes me agree with Sakyaputta. Slotted screws are usually a dead giveaway that the camera item is early -- 50s or early 60s, I'm thinking.


PostPosted: Thu Jun 23, 2022 8:34 am    Post subject: Reply with quote

Sakyaputta wrote:
Genuine and rare this metal body cap is. Available probably from only 1958~65. The most adorable among them all generations of Minolta SR body caps! 👍


I figured it would be rare; I've rarely come across them.

I generally try and minimise the amount of plastics in my optical gear (for reasons of dust mostly), and these metal body caps really help.


PostPosted: Thu Jun 23, 2022 7:41 pm    Post subject: Reply with quote

cooltouch wrote:
Slotted screws are usually a dead giveaway that the camera item is early -- 50s or early 60s, I'm thinking.

Absolutely true, Cooltouch.


PostPosted: Thu Jun 23, 2022 7:59 pm    Post subject: Reply with quote

RokkorDoctor wrote:
I generally try and minimise the amount of plastics in my optical gear (for reasons of dust mostly), and these metal body caps really help.

Quite a good strategy, Mark.

In another aspect, although plastic parts do save some weight, they aren't very appealing, IMHO. As a manual focus Minolta lover with 9 lenses so far, I've consciously avoided acquiring Minolta lenses with much plastic like the later MD-II with beveled DOF scale rings, and the MD-III lenses. However, an MD-II ROKKOR 85/2 is still on my wishlist for its good reputation of excellent resolution power for general photography.


PostPosted: Fri Jun 24, 2022 9:21 am    Post subject: Reply with quote

Sakyaputta wrote:
RokkorDoctor wrote:
I generally try and minimise the amount of plastics in my optical gear (for reasons of dust mostly), and these metal body caps really help.

Quite a good strategy, Mark.

In another aspect, although plastic parts do save some weight, they aren't very appealing, IMHO. As a manual focus Minolta lover with 9 lenses so far, I've consciously avoided acquiring Minolta lenses with much plastic like the later MD-II with beveled DOF scale rings, and the MD-III lenses. However, an MD-II ROKKOR 85/2 is still on my wishlist for its good reputation of excellent resolution power for general photography.


Use of plastics in lenses & cameras is one of the things I would like to discuss if there were a dedicated technology forum! Wink

The better plastics (glass-filled polycarbonate mostly) have primarily been used for weight saving, as they don't really cut down much (if any) on production cost (high injection mould development & production cost & short mould service life due to the abrasive glass-fibre fill).

MD-II and MD-III lenses vary quite a bit in the amount of plastics used in their construction, but even then the use of plastics in MD lenses is still really quite limited. I suspect from your comment that there are many more full-metal MD-III lenses than you think there are! Some MD-II and MD-III lenses have a plastic aperture ring. A very small number of MD-III lenses also have a plastic focus grip. Some have a plastic beauty-ring. The rest is still very much metal! Most MD-II lenses are still fully made of metal. A significant number of MD-III lenses are also still a full metal construction, and some even still have full metal hoods.

The MD-II ROKKOR 85/2 only has a plastic aperture ring, red mount indicator dot, and vinyl waffle-grip. The rest is still all metal, including the dedicated screw-mount hood. The same goes for the MD-III, other than that the clip-in hood is a combination of metal & plastic.

Edit: forgot to mention a couple of things (after I promised myself not to; must be my age Wink ):
- A very small number of MD-III lenses have their inner lens barrels (incl. the integral male part of the helicoid) manufactured out of a glass-filled plastic, probably glass-filled polycarbonate, but it could also be glass-filled nylon. The mass-produced MD-III 50mm/2 and 50mm/1.7 definitely do, I can't remember if this goes for the 50mm/1.4 also.
- Throughout the MD lens era Minolta also introduced plastic-mounted lens cells for a small number of lenses, notably the front & rear-cells. These have burnished lens mounts so are a pain to service if the individual elements in the cell need cleaning.


PostPosted: Sat Jun 25, 2022 2:34 pm    Post subject: Reply with quote

RokkorDoctor wrote:

The MD-II ROKKOR 85/2 only has a plastic aperture ring, red mount indicator dot, and vinyl waffle-grip. The rest is still all metal, including the dedicated screw-mount hood. The same goes for the MD-III, other than that the clip-in hood is a combination of metal & plastic.

Edit: forgot to mention a couple of things (after I promised myself not to; must be my age Wink ):
- A very small number of MD-III lenses have their inner lens barrels (incl. the integral male part of the helicoid) manufactured out of a glass-filled plastic, probably glass-filled polycarbonate, but it could also be glass-filled nylon. The mass-produced MD-III 50mm/2 and 50mm/1.7 definitely do, I can't remember if this goes for the 50mm/1.4 also.
- Throughout the MD lens era Minolta also introduced plastic-mounted lens cells for a small number of lenses, notably the front & rear-cells. These have burnished lens mounts so are a pain to service if the individual elements in the cell need cleaning.


Thank you so very much for elaborating on Minolta's use of plastics in their manual focus lenses. I have learned something new! 🙏 It's also good to know that the only plastic part of the MD-II ROKKOR 85/2 is its aperture ring. I assume the MD-III 85/2 is the same since the published weight of the former is 280 g while the latter is 285 g (must be due to that minimum aperture lock and its associated mechanism).

As someone who only got into the world of Minolta ROKKORs last Christmas, exactly 6 months ago, my quick and dirty way of determining if a lens is comprised of more plastic parts is to consult http://minolta.eazypix.de/lenses/index.html and look at the weight differences between it and its predecessor generations. For example, the much plasticky MC-X (2), MD-I and MD-II MACRO ROKKOR 50/3.5 weigh only 200~220 g while the MC-II and MC-X(1) weigh 325~330 g.



As for the the MD-III 50/1.4's plastic lens cells, Matt Bierner commented in his disassembly video of the lens that it has the molded, unopenable front lens cell (@02'40) while the rear one is the traditional serviceable construction (04'30). I didn't hear him commenting if the inner lens barrel is also plastic though.
https://www.youtube.com/watch?v=ItpkxuavBnY&t=1836s&ab_channel=MattBierner

Another reason I particularly avoid acquiring any MD-III lenses (even though they have the most advanced coatings than their predecessors is that they don't have "ROKKOR" in their names, which make them lose their "family pedigree", literally. Yeah, you can call my way of thinking "irrational attachment to the letter" HAHAHA!!!


PostPosted: Sat Jun 25, 2022 3:28 pm    Post subject: Reply with quote

Sakyaputta wrote:
Thank you so very much for elaborating on Minolta's use of plastics in their manual focus lenses. I have learned something new! 🙏


Minolta was very judicious in their introduction of plastics during the Rokkor & X-700 eras. Those camera bodies that are made of glass-filled polycarbonate are actually still moulded around a metal mirror box. The critical body dimensions (film register distance and mount vs. film plane parallelism are thus still fully stabilised in a metal construction. Plastics used in lenses are only used where their dimensional stability does not affect optical performance. Only for the very lightest mass-produced lenses such the MD-III 50/2 and 50/1.7 did they mould half of the helicoid as a glass-filled plastic component. Some may not like the idea, but for those lenses that was perfectly adequate.

Ignoring the vinyl waffle focus grip cover, plastic mount indicator dot, and the odd rubber or plastic lens hood here and there, many "premium" MD-III lenses are still fully made of metal (incl. the aperture ring), e.g. MD-III 16/2.8, 17/4, 20/2.8, 24/2.8 VFC, 35/2.8 SHIFT CA, 50/1.2, 85/2.8 Varisoft, 100/4 Macro, 135/2, 200/2.8, 300/4.5, 400/5.6 APO, 600/6.3 APO, 100-500/8 APO.

Sakyaputta wrote:
It's also good to know that the only plastic part of the MD-II ROKKOR 85/2 is its aperture ring. I assume the MD-III 85/2 is the same since the published weight of the former is 280 g while the latter is 285 g (must be due to that minimum aperture lock and its associated mechanism).


The MD-III 85/2 also has a slightly larger diameter focus grip. Other than some cosmetic changes it is still very much the same mechanical construction and quality as the MD-II ROKKOR version.

Sakyaputta wrote:
As for the the MD-III 50/1.4's plastic lens cells, Matt Bierner commented in his disassembly video of the lens that it has the molded, unopenable front lens cell (@02'40) while the rear one is the traditional serviceable construction (04'30). I didn't hear him commenting if the inner lens barrel is also plastic though.
https://www.youtube.com/watch?v=ItpkxuavBnY&t=1836s&ab_channel=MattBierner


Some of those molded lens cells are openable, but only destructively. The burnished lips needs to be cut off very carefully. You may then find the lenses are still pretty tight in the plastic housing but with a decent lens sucker they should come out. Mounting them back is the issue, they'll need to be cemented back in place Sad

Sakyaputta wrote:
Another reason I particularly avoid acquiring any MD-III lenses (even though they have the most advanced coatings than their predecessors is that they don't have "ROKKOR" in their names, which make them lose their "family pedigree", literally. Yeah, you can call my way of thinking "irrational attachment to the letter" HAHAHA!!!


A bit irrational, yes! I actually still tend to think of the MD-III lenses as ROKKOR lenses, even if they dropped the name. For me the "Rokkor" feel of the lenses ceases with the autofocus lenses. Somehow Minoltas AF lens & camera design, whilst optically still equalling or surpassing their "Rokkor" predecessors, just doesn't do it for me. It all just doesn't handle, feel, and look the way I would like it to.


PostPosted: Sun Jun 26, 2022 3:10 pm    Post subject: Reply with quote

RokkorDoctor wrote:

Minolta was very judicious in their introduction of plastics during the Rokkor & X-700 eras. Those camera bodies that are made of glass-filled polycarbonate are actually still moulded around a metal mirror box. The critical body dimensions (film register distance and mount vs. film plane parallelism are thus still fully stabilised in a metal construction. Plastics used in lenses are only used where their dimensional stability does not affect optical performance. Only for the very lightest mass-produced lenses such the MD-III 50/2 and 50/1.7 did they mould half of the helicoid as a glass-filled plastic component. Some may not like the idea, but for those lenses that was perfectly adequate.

Excellent info from a true expert. Thank you for taking the time and effort to write this, Mark!

RokkorDoctor wrote:

Ignoring the vinyl waffle focus grip cover, plastic mount indicator dot, and the odd rubber or plastic lens hood here and there, many "premium" MD-III lenses are still fully made of metal (incl. the aperture ring), e.g. MD-III 16/2.8, 17/4, 20/2.8, 24/2.8 VFC, 35/2.8 SHIFT CA, 50/1.2, 85/2.8 Varisoft, 100/4 Macro, 135/2, 200/2.8, 300/4.5, 400/5.6 APO, 600/6.3 APO, 100-500/8 APO.

Lovely to know! Now there's no resistance to these when a good deal comes along.

RokkorDoctor wrote:

Some of those molded lens cells are openable, but only destructively. The burnished lips needs to be cut off very carefully. You may then find the lenses are still pretty tight in the plastic housing but with a decent lens sucker they should come out. Mounting them back is the issue, they'll need to be cemented back in place Sad

Haha, to quote GunsN'Roses, yours truly has no "Appetite for Destruction".

RokkorDoctor wrote:

A bit irrational, yes! I actually still tend to think of the MD-III lenses as ROKKOR lenses, even if they dropped the name. For me the "Rokkor" feel of the lenses ceases with the autofocus lenses. Somehow Minoltas AF lens & camera design, whilst optically still equalling or surpassing their "Rokkor" predecessors, just doesn't do it for me. It all just doesn't handle, feel, and look the way I would like it to.

Think time will ease me out of that irrational zone. As for the MInolta AF lenses, I've never seen one in person, not to mention touching and using one. However, only seeing how they look in online images leads to disinterest in them, but that's just my personal taste. I've heard many say that the AF lenses' focus rings feel very loose. Is that true?


PostPosted: Mon Jun 27, 2022 9:57 am    Post subject: Reply with quote

Sakyaputta wrote:
As for the MInolta AF lenses, I've never seen one in person, not to mention touching and using one. However, only seeing how they look in online images leads to disinterest in them, but that's just my personal taste. I've heard many say that the AF lenses' focus rings feel very loose. Is that true?


Yes, many AF minolta lenses still employ helicoid focusing, but with virtually no dampened feel to them at all. If they were dampened like the MF lenses are then the autofocus motor would have to be very substantial and expend far too much power trying to focus the lens quickly enough, which would drain the battery very quickly.

It is one of the reasons I don't use any AF lenses (of any make), other than my RICOH GX100 compact. Shorter longevity and planned obsolescence of function (chips and electronics inside a lens Sad ) are another one.

I'm not a big fan of autofocus in general; my preferred photographic subjects mostly require focusing with careful attention to DOF/hyperfocal distances, which is much easier with MF lenses, or require very high focus precision rather than focus speed which again is much more convenient when using MF lenses. Everything I do could be done with AF lenses, but with a lot more hassle. Which is a shame, as there are some really good AF optics around.

If I started to do a lot of quick casual snaps or action photos then I would definitely invest in AF.


PostPosted: Wed Jun 29, 2022 7:26 am    Post subject: Reply with quote

RokkorDoctor wrote:

Yes, many AF minolta lenses still employ helicoid focusing, but with virtually no dampened feel to them at all. If they were dampened like the MF lenses are then the autofocus motor would have to be very substantial and expend far too much power trying to focus the lens quickly enough, which would drain the battery very quickly..................... If I started to do a lot of quick casual snaps or action photos then I would definitely invest in AF.


Thank you very much for sharing your thoughts on the Minolta AF lenses. 🙏 My way of shooting is much like yours that requires consideration of precise focusing and depth of field. The Minolta ROKKORs work well for me in that.

As my main camera nowadays is the Fujifilm X-Pro2, the various Fujifilm AF lenses get employed when I'm doing street photography for which quick action is required to capture fleeting moments.


PostPosted: Fri Jul 15, 2022 6:27 am    Post subject: Reply with quote

Thanks for the interesting discussion! Lots of good stuff for a confirmed Minolta collector and user here, from the Auto Press (collection only so far) to the Maxxum 7D (collection and used). Just got an A2-LT from Fedex in today...


PostPosted: Fri Jul 15, 2022 6:39 am    Post subject: Reply with quote

bmsmith67 wrote:
Just got an A2-LT from Fedex in today...

Congratulations on your new acquisition, Brad. 👍