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Meopta Meostigmat 1/70mm conversion for Sony NEX
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PostPosted: Fri Aug 16, 2013 4:01 pm    Post subject: Meopta Meostigmat 1/70mm conversion for Sony NEX Reply with quote

Only for showing an exotic conversion... did that just "for fun"...
and because there is a new Thread for Meopta Meostigmat 1.4/70mm and i love "fast lenses"... Very Happy
http://forum.mflenses.com/meopta-meostigmat-70mm-f-1-4-adapted-on-gh1-t60854.html
http://forum.mflenses.com/meopta-meostigmat-1-4-70-on-ff-and-nex-via-vnex-t55218,highlight,%2Bmeopta.html


The Meopta Meostigmat 1/70mm... is a very huge and heavy (550g) beast.
With its diameter of 52,5mm on the end of tube, the rear lens cant intrude into the camera housing of a Sony NEX cam (Nex adaptors do have only 41,5mm in diameter!)... but this is neccessary because of the necessary register - distance for the infinity point rear lens must be at about 19mm away from the sensor.

How can we find a way to bring the lens to Sony NEX with an option to fokus from infinity to a good close distance?
Seems nearly impossible in first moment...

But Step by Step:

This is the "Beast"...




Without the modification shown in this article, the lens unfortunately can reach only 70mm on a Sony NEX as her max. distance (free lensing test).. not better. The lens has f1.0 an intersting speed ! So it makes sense to think about a way to convert the lens... and i did find a way for myself!

First i disassembled the whole lens, to look for the space between the lenses and the inner structure to figure out, if there is a way to shorten the total lenght of the tubus and to separate.

The rear lens has a diamteter of 36,8mm... so she will intrude in the 41.5mm diameter of camera mount, if separeted from Tubus and shorten the Tubus a bit.

Luckily i do have some experimental parts of the VNEX System by hand... especially a small helicoid (12-threads) which could fit for the job... Very Happy

(developed for the use in a VNEX LTM to NEX "Zebra" - adaptor)


So the idea was, to prepare the moving part of the Helicoid to place the rear lens into it and give her the ability to move back and forwards..




And after the work is done the 36,8mm diameter of the rear lens fits perfect into the moving part of the Helicoid...



So now we are able to fokus the rear lens... and in the next step we have to find a construction to combine the Meopta 52.5mm Tube with this new rear lens housing.

So a little measurement is neccessary..

This must be the height size of the rear - lens - element..




No matter what we do, and how we do it... the rear lens has to be there after the work is finished...

Next step is to find out the correct distance to the next glas element of the Meopta in front of the shown rear lens in his new housing. Thats because we have to shorten the Tube of the Meopta to bring the rear lens in the same position the lens has before conversion.

Luckily it will fit. The next glas element is far away enough to make a plate for connecting the Meopta Housing Tube and the new rear lens holder..




combined..




After shorten the Meopta tube to the correct value, drilling 6 inner holes for the new moveable lens housing (1.7mm) and some threats for 2mm screws and 3 holes and threats for 3mm screws for the connection plate to the Meopta 52,5mm Tube, this conversion looks like this...




And now the nearly final part of the conversion...

The counterpart of the helicoid has to build into an PK to NEX Adaptor...



With this last step the conversion is complete... the whole new Meopta Housing is able to intrude to the camera mount and the lens reaches infinity. So register - distance fits..

If anybody wants to do the same... contact me for parts if neccessary.

With this idea and realisation the lens can focus a little behind infinity.

And now the really last idea for this conversion... to limit the move out and separation off the two helicoid parts..

Another Tube from an defective Zoom lens acts as a limiter. 3 screws on top of the tube are doing that job.. in the space between the Meopta Tubus and the zoom tube is a small ring made of plastik tape, so the lens will stop at this 3 screws, just before separating the parts.... Very Happy



Here are some first shots after work is done... its a nice playing tool with f1.0 !!










heavy sunlight conditions...
















IMHO an interesting lens... lens do have problems on the edges, especially on the horizontal 24mm side, but thats normal because the projection plane is designed for only 16mm project-fields. Now, acting as a taking lens, you will see the edges are a bit soft and unsharp, but no matter for the most sujets.. especially if you use the lens upright, mostly no problem with it.

Cheers
Henry Very Happy


Last edited by hinnerker on Fri Oct 03, 2014 1:19 pm; edited 6 times in total


PostPosted: Fri Aug 16, 2013 4:52 pm    Post subject: Reply with quote

Awoesome ,just awosome conversion!!! really like all the photos,specially the orange flower one!!!


PostPosted: Fri Aug 16, 2013 7:25 pm    Post subject: Reply with quote

Once again excellent, Henry!


PostPosted: Sun Aug 03, 2014 12:49 am    Post subject: Reply with quote

How did I miss this?
Very cool.


PostPosted: Sun Aug 03, 2014 1:04 am    Post subject: Reply with quote

EXcellent job Henry, thank you for sharing it! Nice to see your lady on picture again!


PostPosted: Sun Aug 03, 2014 1:33 am    Post subject: Reply with quote

Edited

Last edited by bernhardas on Mon Jul 25, 2016 7:29 am; edited 1 time in total


PostPosted: Sun Aug 03, 2014 2:56 am    Post subject: Reply with quote

interesting results, thanks for posting.


PostPosted: Thu Oct 02, 2014 9:46 pm    Post subject: Reply with quote

Thanks to Henry i got my Meo 1.0/70mm this week.
Great smooth focusing with his velvet helicoid - the lens is usable from approx. 20cm to infinity
Here some pics













Last edited by wolfhansen on Thu Oct 02, 2014 10:59 pm; edited 1 time in total


PostPosted: Thu Oct 02, 2014 10:25 pm    Post subject: Reply with quote

Great succes, congrats to both of you!!


PostPosted: Fri Oct 03, 2014 8:13 am    Post subject: Reply with quote

Hmm, Wolf, how come the train station at night + goat looks relatively sharp, but the flowers look
quite soft and a lot or flare around?
Possible reasons:
a) the lens is extremely susceptible to flare and bright objects reflecting lots of light
b) the lens works better for further away objects, but not so well close up
c) ??

Nice shots though!


PostPosted: Fri Oct 03, 2014 8:42 am    Post subject: Reply with quote

Klaus, the lens is extremely soft at close up. In the next days i do a
concert shooting with the lens - it will be interesting to see the results.


PostPosted: Fri Oct 03, 2014 9:20 am    Post subject: Reply with quote

Thanks, looking forward to seeing your results! I expect it to perform quite well actually!


PostPosted: Fri Oct 03, 2014 11:25 am    Post subject: Reply with quote

Images for the first post recovered.

This extremly difficult conversion is no longer necessary with the new velvet helicoid.

Image recover is only to complete this article again.

Regards
Henry


PostPosted: Wed Nov 30, 2016 5:59 pm    Post subject: groundlessfears Reply with quote

i have this lens.. and i opened it for cleaning. now i am little confused about one element that i have mistakenly placed it to the wrong direction. if someone have the schematics for the Meopta Meostigmat 1/70 then kindly share with me please.. i never found on internet..


PostPosted: Wed Nov 30, 2016 6:32 pm    Post subject: Reply with quote

kds315* wrote:
Hmm, Wolf, how come the train station at night + goat looks relatively sharp, but the flowers look
quite soft and a lot or flare around?
Possible reasons:
a) the lens is extremely susceptible to flare and bright objects reflecting lots of light
b) the lens works better for further away objects, but not so well close up
c) ??

Nice shots though!


Without stopping down, your DOF is less than a millimeter at 30cm.


PostPosted: Thu Dec 01, 2016 12:05 am    Post subject: Reply with quote

Basilisk wrote:
kds315* wrote:
Hmm, Wolf, how come the train station at night + goat looks relatively sharp, but the flowers look
quite soft and a lot or flare around?
Possible reasons:
a) the lens is extremely susceptible to flare and bright objects reflecting lots of light
b) the lens works better for further away objects, but not so well close up
c) ??

Nice shots though!


Without stopping down, your DOF is less than a millimeter at 30cm.


I know that, as I use a lot of fast projection lenses. What has DOF to do with softness and flare? Nothing at all.


PostPosted: Thu Dec 01, 2016 9:38 am    Post subject: Reply with quote

Some concert shots with the 1.0/70mm - Cinema Solariens (Avantgarde/Electronics/Freejazz)



James Harrar





Rogier Smal



Crowd shot at MPS Festival Dortmund, Germany


PostPosted: Thu Dec 01, 2016 4:43 pm    Post subject: Reply with quote

Excellent Wolf!! Like 1 small Like 1 small Like 1 small


PostPosted: Tue Oct 10, 2017 11:01 pm    Post subject: Do you sell this lens with adapter to a Sony A7R2? Reply with quote

Do you sell this lens with adapter to a Sony A7R2?


hinnerker wrote:
Images for the first post recovered.

This extremly difficult conversion is no longer necessary with the new velvet helicoid.

Image recover is only to complete this article again.

Regards
Henry


PostPosted: Wed Oct 11, 2017 8:55 am    Post subject: Reply with quote

Meanwhile the Meostigmat 1.0/70mm is very hard to get -unfortunately


PostPosted: Thu Oct 12, 2017 12:11 pm    Post subject: Reply with quote

Rare & expensive

http://www.ebay.de/itm/142535696990


PostPosted: Thu Oct 12, 2017 12:46 pm    Post subject: Reply with quote

Pure craftmanship!!!

well done!!!

JN


PostPosted: Thu Oct 12, 2017 4:43 pm    Post subject: Reply with quote

did it worth to buy
- 1 meopta hyper 1.66 meostigmat 20 euros
- 1 meopte hyper 1.85 meostigma 20 euros
for a sony alpha aspc ?


PostPosted: Thu Oct 12, 2017 6:22 pm    Post subject: Reply with quote

Both lenses are auxiliary lenses for the MEO 5 XB1 and XB3 projektor.

You can read more about the lenses here:

http://www.film-tech.com/warehouse/manuals/MEO5XB1XB3.pdf (Page 9 ff.)