"Plastic Summicron"

varjag said:
The lens assembly is not plastic, it's made from Silumin, a silicon-aluminium press powder material. It has no advantages other than cost in mass production. The material is very fragile, and the lens hood effectively attaches to it. Any stress (e.g. from a bump) is transferred to this part and it doesn't takes much to crack it.

tl;dr made from cheap sh*t with poor mechanical engineering
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So far as I know, silumin is a somewhat generic name for a family of melt-alloys and sintered metal matrix composites. Some of these have quite good strength-to-weight ratios and toughness; similar alloys have been widely used in aerospace applications. Many such materials are anything but "cheap sh*t."

Depending on the specific alloy, manufacturing process, mechanical design, and finish treatment, a silumin part could be strong or weak. Just as with nearly any other material. The devil is in the details. Is there evidence that fracturing of the optical cell is a common failure mode for v. IV Summicrons? Is there evidence that failure is more common for v. IV vs. other Summicron generations?
 
As long as it working fine while you purchased it and you take good care of it, I dont think it should be any heavy issue about it..
 
Harry Lime said:
Guys you are making mountains out of molehills. No, the v4 is not all brass and steel, but they have been used professionally for over 30 years and are still going strong.

But go ahead; be my guest and create another internet myth. Hopefully you'll drive the prices down on this supposed piece of sh*t and I'll be able to pick up another one or two for peanuts.
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Harry, just because yours has not failed on you does not disprove anything. The v4s can be problematic, and that particular assembly is typically the culprit. I restored mine (the link Vic posted references my site) and there most definitely is a problem, it's not like I crashed it to preemptively win an Internet argument :)
 
Thanks. I'm not into creating a myth, or revealing a embarrasing truth, I want to know if the first 1979 lens had the same construction? My own feeling is that quality in terms of material used, has dropped ever since the 1950-1960's. That goes for everything cars, houses etc. SO the chances that 1979 prod. was a little better than later on is likely.
 
semilog said:
Some of these have quite good strength-to-weight ratios and toughness; similar alloys have been widely used in aerospace applications. Many such materials are anything but "cheap sh*t."
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Well this one is not among them then.

Is there evidence that fracturing of the optical cell is a common failure mode for v. IV Summicrons? Is there evidence that failure is more common for v. IV vs. other Summicron generations?
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I've seen a few posts over the years describing the problem, and the sample I got was a perfect exhibit of it. There also was a shot or two at tokyocamerastyle of well-worn v4s with with replaced pristine nose part, indicating the same issue. So while am not collecting any rigorous statistics, yes, I assume it's common enough.

Complaints on rough aperture are also common. It is certainly rough on mine, most likely the wear on plastic detent-ball holder although I have not researched.
 
micromoogman said:
Thanks. I'm not into creating a myth, or revealing a embarrasing truth, I want to know if the first 1979 lens had the same construction? My own feeling is that quality in terms of material used, has dropped ever since the 1950-1960's. That goes for everything cars, houses etc. SO the chances that 1979 prod. was a little better than later on is likely.
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Mine is 1979/1980 according to the serial, so no.

The tooling and castings were probably set up once and amortized throughout the whole lifespan of the product.
 
My version 4 had a bit of a mushy feel to the aperture. It was tightened by Malcolm Taylor during a service and, whilst not as snappy as the ASPH, it is much improved; so much so I can't decide which one to sell now :bang:. I also found myself buying a Summaron f3.5 :bang::bang:
Pete
 
Well I'm certainly going to shoot mine as long as it works, ergonomically it's nice and optically is great IMHO.
 
varjag said:
IMG_0173s.JPG
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OMG, the Horror!


Won't somebody please think of the children?
 
Gabriel M.A. said:
Just creating a thread with a sensationalist title. If this weren't news to you, why open a thread about the "Plastic Issue" requiring opinions on The Horror prior to purchase?
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Might drive the market and the prices down for the said model :D I'd be happy to see more of these threads in the near future...
 
karlori said:
Might drive the market and the prices down for the said model :D I'd be happy to see more of these threads in the near future...
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Ah! :cool:


In that case: the 35 ZM Biogon f/2 is ::gasp:: made in Japan! It's not German!!! And some of them are wobbly. It's the "Wobbly Biogon".
 
Oh les vilains gros mots.

Yes there's plastic. I have had two and none had any issue of the sort. Buy Summicron IV and enjoy them. (not my favourite lens though)
 
Give me facts. Has some Leica-buff-nerd-technician info regarding the materials used in a 1979 Summicron?
Talk about can of worms!
 
One fact I know for sure: the 35mm Summicron v2 has a very flimsy aperture ring (which is, btw, plastic). I've never heard anybody go berserk over that.
 
Harry Lime said:
Guys you are making mountains out of molehills. No, the v4 is not all brass and steel, but they have been used professionally for over 30 years and are still going strong.

But go ahead; be my guest and create another internet myth. Hopefully you'll drive the prices down on this supposed piece of sh*t and I'll be able to pick up another one or two for peanuts.
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I read somewhere that apprentices moved from Weltzar to Solms. I've also read pagan rituals were practiced centuries ago in the region. I've also read something about the Leica Glow. This must be explored further.
 
varjag said:
Mine is 1979/1980 according to the serial, so no.

The tooling and castings were probably set up once and amortized throughout the whole lifespan of the product.
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Hi,

Does the issue happen to the Canadian version only? I can't remember where in RFF but I read that the German version doesn't have this kind of plastic issue.
 
It's a beautiful lens regardless.

Buy some film and go out and shoot with what you have. I promise you, you'll enjoy it.
 
kiemchacsu said:
Hi,

Does the issue happen to the Canadian version only? I can't remember where in RFF but I read that the German version doesn't have this kind of plastic issue.
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Can't say with certainty but I doubt it. It's more likely that Solms specimen are simply newer and thus less prone to developing problems yet.
 
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