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09-25-2022, 11:57 AM   #1
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P67-to P6 -adapters here: Rafcameras M68 (not real P6 mount)

at pentaconsix here Using Pentax 6 there is a detailed description of at least two real P67-P6-adapters reaching infinity.
But here we are discussing the one(s) Rafcamera is offering. newest one for portraits 0.2-1m. second link
Pentax 67 lens to Pentacon Six camera (M68x1 female thread) mount adapter | eBay

Pentax 67 lens to Pentacon Six camera mount adapter for portraits | eBay
I am beta -tester of the normal adapter. have three since weeks.

Problem 1: no p67-body AVAILABLE to verify infinity on 200mm/4 67 new and 135/2.8 6x7 old. so have tro measure indirectly by using p67-EF and Nikon-adapters.

Problem 2:but my measurements of scale comparing both at near distance tells me nikon-adapter not precise.
shot 7.7km infinity but not yet good daylightr. details not perfect enough sharp-
I am using newest brightscreen custom sized universal 679 matte/fresnel screen.
newest bosch zamo III laser. forget cheap ones altogether. macroslider, here manfrotto 454 very advised very clever desing. tripod-adapter. here hasselblad. the one without bubblelevel since the large one is obstructing cam/lens-mounting/removal on tripod. adapters have rmovable tripod mounts. K+ F compact P67-EF and NI. actually can only check nikon-version by eye have only EOS-APC-C 60D.

Problem 3: Rafcamera adapter doesnt reach infinity. first testing are telling 200mm is a bit nonreaching infinity and 135mm is more off.
have possibility here to compare with other copy and p67-body-
yes i check back and forth with calipers. yes digital caliper not that precise like manual one. will get it. but differences speak themselves aand Groundglass not lying.
Fact is: incl. lens-mistakes 200mm is reaching only 15.5m 135mm only 10.5 with Rafcamera P67-M68-adapter. one copy has adapter-blocker-screw. since its very stiff its maybe not needed.
here are facts about how the mount are exchange and whats the difference.
M68-P6-ring is rotating in about 2 1/4 x 360- P67-M68 not even 360 . difference 1mm.longer.
registers: P67 = 85 mm or a bit shorter. whats exact size?
P6: 74 mm
I measured register with mounts: P6 74.61mm 0.6 is digital caliper deviation. with mechanical one size is would be 74.01
rafcamera p67-M68 mount measured: 86.67. minus 0.6= 86.07. 86.07 - 74.01= 2.06mm. too long. if ring would go in like original deviation 1.06mm. even when lens is reaching infinity.
I have made many calculations and speculations by how much adapter and lens is deviated. 200mm helicoid telling between 15.5m and infinity its 3.5mm. Means. 3.5mm minus 2mm too long adapter. lens is 1.5mm too long or could go beyond infinity if adjusted.
Next is checking again scale of nikkor and zeiss 135mm and zeiss 200 and comparing them with p67-lenses on aps-c and infinity. yes will also focus nearer here i have outdoor targets but will be tested also with sharp target at near distances.
NB: lasermeter Bosch Zamo also used on body-film level without lens. Manfrotto macroslider 454 very precise to adjust Zamo values must be corrected by 104mm since measured from back only and its not daylight proof, only at EV 7 and below laser is working.dayligh laser not cheap. maybe leica disto.
It doesnt make sense publishing image data now. will do when shooting at full daylight and not sunset. despite dramatic results.
at nearer but far distance 200mm is tack-sharp. made shots up to 30 secs. MLU and ST 10 sec.
more testing in the make. 200mm very sharp on digital at f8 and 11 at far distance. f8 at near distances.
i have possibility to check focus with other than mentioned but ML lenses. some processing-.enlargging lenses. next testing 240/5.6 rodagon at infinity. to have a feeling for razorsharpness. i could imagine zeiss 200mm/have also a noflexar. will show much sharper image than P67-200.
will examine and execute also two-cam-method measurng infinity. how about that astro-focus-test-filter? have a discussion on FB. but will only go into details here. Manfrotto triaut 058 tripod used on an old 2way linhof head. hasselblad simplest tripod-adapter system. very genious.
Raf telling adapter and focus checked by eye/loupe. but in my opinion not precise enough. it must go beyond infinity. will discuss fuirther steps. makes shaving sense. is thread long enough to go in completely like the original. will take images,.
Screws and tool,. be aware not stiff enough will quickly wear out. will get stainless steel screws. spent endless amount ot time checking this out thought screws are 1mm too short at certain (3 screws used) positions. will get 1mm longer screws. schraubenking in austria and locally.
for me question is which is sharpest 200mm lens which can be adapted to P6 here kiev 60.
yes also filmflatness must be discussed in a different thread. i have some vacuumbacks for graflok 23(yes RB67 but converted for using 70 AND 61.5mm (DONOR-SIDE ONLY for the latter and FOR MUP(less reliable).
rafcamera also has Biometar 120/2.8 to P67-adapter
he made me a lot of other adapter for many combinations using processing/enlarging lenses and more for MF systems mostly P6 also Novoflex involved.
just recognized the M80 sunshade clamp by mamiya can be attached on P67 200. he made adapters for filter-use if tube not matching 80mm.

---------- Post added 09-25-22 at 12:01 PM ----------

need now formula knowing Lens b, distance d and extension e to verify which extension is needed to reach infinity. or which distance is reached with infinity minus 1.6mm. here d: 7700mm b: 200mm e:15500 mm.
thanks a lot

---------- Post added 09-25-22 at 12:10 PM ----------

update register comparison P67:
reality 84.95
see here Using Pentax 6
Using Pentax 6
84.95 MINUS 86.67 MINUS 0.6(digital deviation)= 1.12 means infinity can be reached when adapter goes 2 1/4 turns like original and not about 350. difference 1mm.

---------- Post added 09-25-22 at 12:17 PM ----------

Using Pentax 6
here they say infinity not possibel almost infinity yes. but one could calibrate p67-lenses to pass infinity then not matching p67 cam anymore.
i could prove past infinity but light must be dim or i must use ND filters to slow down exposure time since special cam has no shutter. just tried grundner shutter 1/5 quickest but is a more complicated mounting than thought. cam-shake forbidden too. so sunsetshot with longer exposure time 8sec? could match
have special bessa I with P67 mount register 49mm. but i am not yet sure if working or i would need helicoid. calculated 36.6mm extension possible. details later.

09-27-2022, 04:42 AM   #2
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i checked closeup 1.5m on M68 and Nikon-cameras
both 135 and 200 closest 1.5m
M68/Nikon: INfinity
135- 1.367/1.42m 10.5m
200- 1.42/1.48mm 15,5m
register/extension differences 1-0.6mm maybe. as predicted by someone.
will retest infinity with M68 cam. and max. distance on P67-eos-adapter using near distances. 100m and more.
trying to nail these with formula see here:
Are my 135 and 200mm lenses really getting infinity? have big doubts. -
maybe someone could test p67-biometar 120 with M68-adapter. it will not reach infinity.
09-28-2022, 10:53 AM   #3
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Mistery Rafcamera-adapter-side solved:
Raf writing
My P6 mount thread has 5.6mm thread length and 1mm thread pitch. My Kiev-6C has 4.1mm thread length and 0.75mm thread pitch. They are incompatible, obviously.

Kiev thread 3.5mm!!!!! not high enough for 5 turns raf is telling. 1.72mm needed. will now remeasure with mechanical caliper and report what must be changed. 200mm is only slightly deadjusted maybe really 0.6mm and not gettng infinity 7.7km by a tiny bit on K+F concept EOS adapter- will also check deeply which difference is on NI-version.

means also i must know how far the lens will go with less 0.6mm. lets say 1mm. i am not sure if i calculated correctly. maybe 68m which i can verify easily but only on film.m or good loupe. 20x.dotn have yet maybe can use tiny microscope loupe.
09-29-2022, 07:22 PM   #4
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have now revisited actual situation. adapter only turns in 3/4. camera thread: 3.5mm. i measure 2mm gap.hard to measure but its sure its not 2.1mm. 2mm. can you confirm adapter going in 1.5mm. M68 x0.75.
question was also which are thread sizes on P6, kiev 60 and Kiev 6C. the latter are identical since araxphoto is selling the right mount ring for both. he feared one has pitch 1. its clearly 0.75.
from thjis finndings i calculated right position compared to actutal one to get 84.95mm or beyond infinity. infinity reached when adapter is 2.8mm shorter. 2mm can be reached when adapter goes in completely and 0.8 when he removes the rim.which is 0.79. not 0.83. analoge-caliper used. dont know names. pls tell me names of the three calipers. distance, thickness and gaps.. 1. distance in german: schieblehre./caliper

09-30-2022, 09:35 AM   #5
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Small gaps, particularly in combustion engine assembly, are typically measured with "feeler gauges." These gauges are manufactured so that one, two, or more gauges can be used together to get whatever thickness is needed. These should be widely available at very low cost.

Thickness is typically measured by calipers or dial calipers when the surfaces are flat and parallel. Types resembling "C" clamps are called "micrometers." These can have better interpolative precision than dial calipers. Some have ball ends for curved surfaces.

Look these up on USA Amazon for images.
10-16-2022, 07:24 PM   #6
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i have that next is wide vernier caliper. onyl forgot to use when i came home from latest shooting. noflexar still in perfect position a bit infront of beyond infinity.helicoid extion meant.- could have easily measure difference.
I have news about infinity reaching. had to use a Novoflex noflexar 200/3.8 followfocus-system on nikon to eos-adapter to prove P67 200/4 67 new on K+F comfort EOS adapter doesnt reach infinity. last time i had it compared withZeiss C/Y 200/3.5 shooting TV-tower at 7.7km. both images identically sharp/unsharp. f8 and f11 best in center. one must have a perfect lens to compare. last test showed clearly. 200mm pentax on the mentioned adapter not perfectly sharp.
I even think nikon-version of kentfaith adapter is too long. but i am unsure. had calls with novoflex and zeiss about these problems.
will now go on with more precise testings. will get a different p67-adapter. not novoflex new P67-system yet. NB: Kipon already copied it!! like they did with mirex 1:1 copy of older design of shift-adapter.
will also consider 2cam-testing.
Need calibrated 200mm. calibrating seems not that cheap. maybe i will do in Germany.
I will now get Kiev 60-version of P67-M68-adapter. Kiev 60 has different M68 thread. M68 x0.75M x 3.44(3.5mm) versus M68 x 1Mx 5mm of Pentacon 6- no wonder this adapter was too long. couldnt mount completely. he has now removed the rim which was blocking aperture lever (manual/auto). no more obstructions.
10-22-2022, 10:22 PM   #7
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Have now unanodized prototype of Rafcamera P67-M68 x 0.75 x 3.44mm adapter. register is nailed 85mm-i measured 85.1mm with analogue vernier caliper.
Hopefully i will get a version minus 1mm to go beyond infinity. advantage: deajusted lenses will reach infinity if not deadjusted too much.
Both new and old lenses aperture mechanisme now working always. option for adapter-locking with screw. not really needed but one never knows when using in special constructions.
Next is checking distance-scale to see if lenses maybe do not reach infinity on P67 camera and on Kiev 60.
I must remember: Pentacon Six needs a different version. since M68 thread is M68 x 1M x 5mm.. K60: M68 x 0.75 x 3.44mm. which stupid persons had this idea one cannot follow. Kiev 6C has even longer thread 4mm. if Rafcamera is right.

10-23-2022, 03:45 PM   #8
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P67-M68 x 0.75F-Adapter now perfect register!

Measured new prototype still nonanodized. its perfect now. 84.94 and 84.93mm register measured with digital and analoge vernier caliper. Must be: 84.95
He will make also a beyond-infinity version if lenses are a bit deadjusted. i suspect my 200mm/4 new is deadjusted by 0.6mm. infinity not yet perfect.
Will now test scales and near distances and then shoot film at 7.8km asap.

Want to repeat that on digital cameras infinity may not be reached with analoge lenses since they are made for film. lenses or adapter must be adjusted. Novoflex new P67-adapter system is going slightly beyond infinity.
10-24-2022, 08:18 AM   #9
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QuoteOriginally posted by 3dreal Quote
Want to repeat that on digital cameras infinity may not be reached with analoge lenses since they are made for film. lenses or adapter must be adjusted. ...
Surely it is within the competence of major camera companies to set the optical distance between the lens assembly registration surface and the sensing layer of the photodetector array to equal the optical distance between the registration surface and the emulsion layer of the previously used film for which the lens assemblies were initially used. Pentax does not caveat their "analogue" lenses as unsuitable for the 645D or Z. Nor do the spectacular images from the "analogue" lenses appearing in this MF forum show focus issues that I can see.

If the SLR sighting system is properly spaced to agree with the focal plane, then manual focus will be photodetector focus. It then further requires that the auto focus detectors are similarly correctly positioned.

Admittedly, the color sensing layers of film are at different distances from the registration surface, unlike Bayer filtered focal plane detectors, but I have never read that this was a focus problem. It might not be noticed given that film itself has different MTF performance among colors at the higher spatial frequencies.

Last edited by kaseki; 10-27-2022 at 09:37 AM.
10-26-2022, 10:56 PM   #10
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will write details in my other thread about reaching infinity or not.
have great news:
1. Rafcamera will make a second shorter adapter going beyond infinity.
2. i made an adjustable Nikon-P67 adapter, tested at 2m to check which distance is shown. its going clearly beyond infinity.
1 Day Ago   #11
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1. If you get an adapter with rim(first batch) keep the followin in mind. have P6-prototype. but no P6-camera-kiev 60 here. there are two versions since M68-thread is used. P6: M68 x 1M Kiev 60/6C: M68 x0.75M.
rim was meant to stop at infinity but he hadnt right adapter to check real depth of adapter. its 10.5 and not 10mm. aperture lever rotates on a circle and at center/culmination it reaches 10,3mm. hitting under certain circumstances the rim. aperture may be blocked. auto/manual function dead. only manual is working. advantage : it will stay at manual no matter if auto or manual is set. no accidental opening of aperture.
i must check at what position must be aperture(fully open or closed.) most probably closed
2. avoid using screw at level of red point= aperture lever mechanisme. it may interfere or squeeze adapter blocking mechanisme.
3. Screws : til now two screw types were used both are not best since they cause dents. flat one resulting in circels. version with tip only tiny dents. but best is screw with nylon-typ. rafcamera cannot provide but i have a uk-source. dont have yet.
also lenght of screws and material was discussed also hex key.- one should use stainless steel stuff. since both will wear out quickly.
first thought screw is falling in since too short. but it was worn out. better using 5mm screws. we will see what i get now. which 5mm screws he can provide.
I will get two final anodized adapters soon. these are the shorter ones which could reach infinity on film with deadjsuted lenses. adjusted lenses could reach infinity on digital. must collimate all my lenses. its easy. link follows. found link in mflenses forum.

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