Apo-Summicron 50 and MM?

[Michael Geschlecht]

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Hello Everybody,

 

Actually, hand fitting should lead to the same or higher levels of consistency of handling charactaristics. I would think a lack of consistency of handling charactaristics would be more of a quality control issue.

 

With the advent of lasers, etc the quality, consistency & dimensions of parts coming out of machines can be much better than was previously possible. It is very clear that Leica has & uses machines of these types.

 

Best Regards,

 

Michael

[Jeff S]

 

Actually, hand fitting should lead to the same or higher levels of consistency of handling charactaristics

 

If you do a search you'll find much discussion about the ladies from Solms (see jaapv posts) who fiddle with lenses at the end of production to deal with stiff focusing action.

 

I've also posted about my phone conversations with techs at NJ who discussed why some 50 Summilux lenses are stiff focusing and some are not. This ground has been covered elsewhere; no need to get into it again here.

 

Jeff

[brill64]

...it is/was an interesting discussion, though:)

[Michael Geschlecht]

Hello Jeff,

 

It's not about the "Ladies from Solms". It's about quality control throughout the entire production process. Some types of manufacture require more people who have more skill taking part in the along-the-way quality control than there are people actually building something. It is also sometimes the case that more time is spent by these more qualified people who are checking the work done by the people doing the building than is actually spent by the people doing the building. Including, sometimes, in lens manufacture.

 

The only thing the "Ladies from Solms" should be doing is checking to see that everything that comes to them has been done entirely correctly & in those rare instances when things are not what they should be, send the lens back to the appropriate place. Only perfect lenses that come to them should go forward.

 

And, that's only a double check. Some people do more.

 

Best Regards,

 

Michael

[Jeff S]

The only thing the "Ladies from Solms" should be doing is checking to see that everything that comes to them has been done entirely correctly & in those rare instances when things are not what they should be, send the lens back to the appropriate place.

 

Maybe that's all they should do, but that's not all they actually do according to reports, which includes rotating and 'working in' the lens by hand as needed. Again, read the earlier threads.

 

See this brief video, which illustrates a remarkable amount of hands on human interaction throughout the entire manufacturing process. Quality control (60 different ways) is only part of the equation; human hands actually take part in significant aspects of the construction and assembly. The 'ladies' only continue that involvement, albeit at the end of the line.

 

But we're OT here.

 

Jeff

[jankap]

Also interesting would be a video about quality assurance issues: (back) focus control, check on minimal MTF values, handling of tolerances, etc.

Jan

[jaapv]

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I

 

The only thing the "Ladies from Solms" should be doing is checking to see that everything that comes to them has been done entirely correctly & in those rare instances when things are not what they should be, send the lens back to the appropriate place. Only perfect lenses that come to them should go forward.

 

They don't get lenses. They get boxes with parts. Basically what they do is assembly and tolerance matching to get the focussing "feel" as consistently as they can.

The resulting lens barrel is mated to the optical cell at a later stage.

[Michael Geschlecht]

Hello Jaap,

 

Sorry for the confusion

 

I was talking about the "Ladies from Solms" who are at the end of the manufacturing process & who are checking to see that the completely finished lenses are what they shoud be. Not the assemblers further back in the manufacturing process.

 

Best Regards,

 

Michael