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13 years old and still relevant- i have clarifications
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PostPosted: Sat Oct 29, 2022 12:14 am    Post subject: 13 years old and still relevant- i have clarifications Reply with quote

1. During infinity and scale-tests of new Rafcamera-adapter for P67 on Pentacon Six and Kiev60-cameras)NB:they have different pitches and lenghts of M68-thread) i tried to test my P67 135/2.8 and 200/4 new without P67 cameras. it was most complicated testing and measuring precisely with laser. near and real infinity 7.8km. you can read details on pentaxforums. me 3dreal there.
2. have spoken with zeiss managers quite a long time after finding out that my 200 P67 and Zeiss C/Y 200/3.5 are equally unsharp at these 7.8km- at 2.7km focus is just in center of laying 8(infinity): lacking last sharpness. then i tested also Novoflex Noflexar 200/3.8 and novoflex confirmed its going beyond infinity. and iu was really surprised. much sharper. only cannot show/prove since when i turn tighten focuslock-knob focus will go offside.
Zeiss confirmed all their new lenses are going beyond infinity.
for P67 i have both K+F comfort Nikon and EOS-adapter. they are both too long. they should be shorter than register.
why? Zeiss confirmed that analoge lenses are built for IR-sensible film which digital chips are not.
got a german answer ny kameradoktor dot de haelke telling the same. he has deep experience. they even correct viewfinder!!
so i investigated what is wrong. lens i cannot test since no P67. but i can approach the mistake.
first i tested newest Rafcamera-prototype(is in production and minus 6mm too) see later.
its M68 -cammount will be removed. other side no P67-mount but screws holding lens. on pentaconsix dot com is a solution or multiples using P67-mount on adapter.
This adapter is now has nailed 84.95mm register but at infinity on EOS 60D 18MP APS-C both P67 200 new and Zeiss C/Y 200/3.5 on different K+F-comfort adapter getting the same not perfectly sharp but almost perfect infinity at 7.8km tv-tower building contours/windows and chapel. as i told Noflexar sharper perfectly sharp. could even see without tripod and not best light.
meanwhile i knew my infinity for film calibrated analoge lenses will no get infinity at all. i continued reflecting. we agreed he must make a minus-a shorter adapte. on pentaxforums an expert calculated about 0.6mm which rafcamera will implement. meanwhile if found a sensational solution. i made a variable register adapter from two parts. and its working perfectly.
i have my near distancese here 15.5. 17.8 30 and 100m beside the nearer ones to test inside home. after finding out nikkor 135 and zeiss 135 and 200 zeiss showing correct distances. i also trusted my p67. but scale could be wrong. depending lens-desingn there could be focus-shift when stopping down.
so with knowing distances. i made markers on my base of room.i varied register of my special nikon-adapter. since eos-version will come later i must use adapter for my only Canon EOS 60D digital cam. later will get Nikon DSRL.
now adapter is almost right register 84.88(84.95 perfect for P67) i checke distances. 135mm at 15,5m is a bit below 15m on scale. 200mm at 30 is at zero. so below actual distance. i think. next is testing real infinity. but i have now fixed my ring with tapes(screws are neede) cannot change register now further. must wait for final rings. for more checking. then also 300mm new will be here.
will try to let lens controlled under collimator. local dealer has the very same 135mm and P67- we will exchange and test more also with film.
its a more complicated story since i first got P6-version of adapter-have three-but pitch is 1M K60 has 0.75M. adapters 1F and 0.75F since i cannot mount properly they were limited to 10.5n/135mm and 15.5m/200mm.
when having perfect lens and variable adapter one can easily verify focus-differences aka knowing if other lens reaches infinity. by calculations mentioned here and on pentaxforums. there are two thread. one about infinity on my lenses second about rafcamera-adapter.
the statement that adapters go past infinity cannot be confirmed per se. they should.all should do.
Lasermeter used: genious new bosch Zamo III. yes there are other for shorter distances. FORGET ALL CHEAP LASERMETERS!!! dont use nonprecise. and use only analoge vernier caliper. use both. but only analoge is always true.
I tested also helicoid-differences. knowing afterwards how long new adapter should be-or how much shorter.
on fotointern dot ch german in old thread about old lenses on digital some people dont believe me, the same problem with unsharp rotapancamera-lens which i have been preaching since decades.

PostPosted: Thu Jan 19, 2023 1:57 pm    Post subject: Reply with quote

Excellent idea using variable register adapter!

This is a common issue actually, since infinity focu is temperature dependent, hence why all catadioptric lenses focus beyond infinity, and so does its "astro" counterparts!

PostPosted: Fri Jan 20, 2023 12:50 am    Post subject: why my message is not added to old thread? Reply with quote

Fuse Rafcamera-adapter with M68-part of P6-adapter (NI, EF, M42 which have M68-mount. remember and go to pentaxforums.com about details there are two versions with different pitches for P6-cams pitch 1M/F on adapter. Kiev 60-series pitch 0.75.
he also has closeup adapter and normal and shorter version. its possible also the normal may go beyond infinity.
on pentaconsix dot com are other adapter ideas for P67 lenses to P6-mount, with real P67-lens-mount also outer.
P67-P645 adapter altered (K+F comfort, i have it)
EOS-version of adapter mentioned on line 1 matches best for standard-tripod-collar. for nikon i have found a workaround.
everything not yet perfectioned. IT MUST BE PERFECTIONED. threads added for camera and lens in 60° steps.
currently finding out how to mount adapter to P67-lens perfectly without damaging lens.see pentaxforums -treads.

BETTER ADDING OR I WILL DELETE. belongs to old thread.