Meopta Meostigmat 1/50mm

[desmes]

Hi, guys! Thank you very much for the informative topic! Thanks to it I've managed to get 3 Meopta lenses.
I removed the optics and sent the tubes for some Adapting. Though I Took notes on the lens schematics, I feel something Could have gone wrong with the reassembly of the 1/50 mm lens.
The sharpness is far from what I remember before the intervention. Even the center is very soft.
I would like to ask you for some help about the lens schematics, Especially the 3-rd front element. It seems it should fit one way only.
Thank you very much!
Deso

[hinnerker]

...
I would like to ask you for some help about the lens schematics, Especially the 3-rd front element. It seems it should fit one way only.
Thank you very much!
Deso

Hi, you cant go wrong in reassembling the elements. There is exactly one position for the 3rd element inside the tube - third element is a cemented group of two glas elements, and will fit only in one direction.
So if your lens is out of sharpness, disassemble the lens again and try reassembling. Be careful, because the cemented group of two elements often separate itself into his 2 single elements... !!!

Good luck

Henry

[desmes]

[QUOTE = hinnerker; 222813] Hi, you cant go wrong in reassembling the elements. There is Exactly one position for the 3rd element inside the tube - thirdElement is a group of two cemented lenses, and will only in one direction only.
So if your lens is out of sharpness, disassemble the lens again and try reassembling. Be careful,: because the cemented group of two elements oft separate Itself into his 2 single elements ... !!! Good luck Henry [/ QUOTE]

Thank you very much for you prompt reply and warning , Henry ! One can never be too careful with lenses . I did try 3 times , once opting to reverse the 3-rd element, but it could not fit it's bed properly. All elements are pushed carefully all the way down. Would it be too much to ask for a schematics - like drawing ? Something like : [)(] [)[)[) ) .
Could the lower sharpness be due the fact that the lens was not in a perfect optical shape - some fungus/dirt cleaning was needed ?
Thanks again ,
Deso

[hinnerker]

Thank you very much for you prompt reply and warning , Henry ! One can never be too careful with lenses . I did try 3 times , once opting to reverse the 3-rd element, but it could not fit it's bed properly. All elements are pushed carefully all the way down. Would it be too much to ask for a schematics - like drawing ? Something like : [)(] [)[)[) ) .
Could the lower sharpness be due the fact that the lens was not in a perfect optical shape - some fungus/dirt cleaning was needed ?
Thanks again ,
Deso

The schematic of the front tube part of the 1/50 Meostigmat is = a single convex/plan - Element, followed by a second single element, front is convex/ rearside is concave and on third position you will find the cemented group.. 1. glas bigger then second one...near plan/convex and small side goes first into the tube.

Pos. of front elements in front housing:
1. ___2.__ 3.
(| -- (( -- |?)... thats the way the lens elements take place in the housing. First element is the last element during reassembling procedure. (Question mark means thats a cemented group, where i dont know the "inner" curves)

Keep in mind, that there must be a small spacer/shim/washer on the back part of element No.2, please dont forget to establish this spacer !!!

Cheers
Henry

ps.: greetings to bulgaria

[desmes]

Thank you very much ! That's exactly what i needed .
Best regards, Deso

[hinnerker]

...
Could the lower sharpness be due the fact that the lens was not in a perfect optical shape - some fungus/dirt cleaning was needed ?
Thanks again ,
Deso

A lower sharpness results if you not cleaned the elements during the reassembling procedure... use gloves for the work !
If the lens elements do have some "fingerprints" or are covered with finger - fat, please clean the elements with 2-propanol and a proper lens tissue.
Keep in mind, the spacer must be in place...

A further tipp is to add a 0.4mm shim between rear part of the lens housing... this changed the game dramatically.

If you have shorten the housing of the Meoptas, the rear part has no longer a thread pitch to screw in the rear part... right?

So both parts of the Meopta (Front cell and rear cell) didnt have the same distance as before... so you must establish a 0.4mm distance ring between front and rear cell to get the correct working distance between both parts... !

Regards
Henry

[desmes]

Your schematics did the job! Thank you very much, Henry! The rear, 4-th element Which turned with it's convex side facing front. If you say did the third element is cemented, mine has to be split in two, so I have 4 elements indeed tricked me. I clean the elements with propanol each time I open the lens. Now it's as sharp as it should be ... let's say 95% new. Thanks for the tip 0.4mm shim! I'll need this soon, as I trim the rear Further On!

Best regards, Deso

Greetings to Germany !