I always thought that I wanted a Hasselblad.

[Sparky]

Trolls. never said that. I'm sorry you took it wrong.

 

[Sparky]

NOBODY ever said it was cheap or EASY to change a lens design. When I said 'simple' I did not mean to imply any of the following concepts: 'inexpensive', 'fast', 'easy'... when I say the word 'simple' I mean 'simple in concept' - well I explained PRECISELY what I meant already. CLEARLY you have to re-tool, reformulate everything, including all the steps you imply above. I'll at least give you credit for going to town on your descriptions (!).

 

[lxdude]

Well, first you said that you "guarantee" there were lots of times when Zeiss got lens blanks with out-of-spec refractive indexes. You didn't, by the way, explain how they got to the point of being made into blanks before the discrepancy was discovered, much less how they got shipped from the glass plant that way. If they were from an outside vendor, how would they have even made it through the door?

Materials go through final inspection before being shipped, and go through receiving inspection before being accepted, and if they are discrepant they get sent back. Literally. I have stuck "Return To Vendor" signs and rejection tape on scores of pallets of material before locking them in a secure holding area. I worked for a company that in 1977 sold over a million dollars worth of product to Kodak. Kodak's receiving inspection sent them all back, freight collect, with reports describing every issue they found. Why would Zeiss accept out of spec materials from an outside vendor?

Zeiss' grinding shop might well accept material from their own glass plant without reinspection, because they know they can trust the glass plant's QC. As the nature of optical inspection is quite exacting, and Zeiss pioneered much of the entire precision optical industry, I see no reason for such an obvious blunder to occur. I've worked with native Germans in manufacturing, and I can say from experience, they do not tolerate sloppiness. Their work is precise, and their methods are precise.They take personal pride in their work, and a blunder of that sort by an inspector, of all people, is utterly unacceptable. So for it to happen, as you say, "lots of times"? I doubt it.

You never explained what the basis is for your assertion regarding out-of-spec blanks, except as far as I can tell, something along the lines of it must have happened. I imagine out-of-spec material was made at times; whether it got to the grinding shop, much less into the final product, is something else altogether.

After your assertion that Zeiss must have gotten out-of-spec glass, "lots of times", you in another post said you think it would be a fairly simple thing to adjust a formulation for a drifting refractive index. I took that in conjunction with your prior post to refer to discrepant materials. The word "drifting" implies imprecision. If you meant "changed", based on a glass formula having permanently changed, that's something else. But that's not how it reads to me.

My post was detailed in order to show that is not a fairly simple thing to do what you suggested. I don't see how it's simple-in-concept unless you are saying that it is in comparison to an extensive re-formulation based on a change in the glass. Even then I don't think it's all that simple. A changed refractive index is one possibility in a changed glass, but what of all the other properties that can change?

Maybe a slight tweak is possible in response to a slight change in the type of materials used, but if that's what you meant, you sure could have made it more clear.

And one more thing- I ain't no troll! :rolleyes:

 

[Sirius Glass]

Sparky,

Consider yourself will spanked.

Steve