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03-19-2013, 02:55 AM   #16
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Seems to be even more resistant to twisting without pressing the lens release button, than when the button is depressed but one can remove adapter and lens without depressing the lens release button. The absence of the spring would account for this I expect.
I don't wish to drill a hole in the lens to catch the Pentax pin.
Chhayanat


Last edited by chhayanat; 03-19-2013 at 03:34 PM.
04-17-2013, 11:45 AM   #17
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With Flektogon 35/2.4 and this adapter, the focussing ring does reach the infinity mark. With an Industar 50/3.5 M42 mounted on the adapter, the focussing ring stops well before the half-way mark. Is it being blocked by the mirror of the cameras, K200D and Samsung GX20. I have not seen a clear-cut statement on any of the threads in the forum as to whether an Industar with the specifications above can reach infinity focus on a K-mount body using the type of adapter discussed in this thread.
Though slightly off-topic would welcome a clarification by the cognoscenti.

2. The adapter remained in the camera mount while trying to remove it while attached to the Industar. It did not prove possible to remove it with the fingernails alone. A screw driver had to be inserted into two separate slots with a helper holding of them. Then the adapter came off after some gentle force was applied simultaneously with the screw-drivers in an anti-clockwise direction. With the Flektogon, the lens and adapter come off together though there is a degree of resistance from the camera mount as observed in post 14.
Chhayanat

Last edited by chhayanat; 04-21-2013 at 03:50 AM.
04-18-2013, 11:19 AM   #18
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QuoteOriginally posted by chhayanat Quote
Is it being blocked by the mirror of the cameras, K200D and Samsung GX20
Highly unlikely!! I would suspect that the focus ring is binding against the mount or adapter face in the same manner as certain Helios 44-3 variants.


Steve
04-18-2013, 12:36 PM   #19
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Thanks. I am moving my remaining questions to personal messaging as this is going off-topic.
Chhayanat

04-20-2013, 12:10 PM   #20
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QuoteOriginally posted by chhayanat Quote
With Flektogon 35/2.4 and this adapter, the focussing ring does reach the infinity mark. With an Industar 50/3.5 M42 mounted on the adapter, the focussing ring stops well before the half-way mark. Is it being blocked by the mirror of the cameras, K200D and Samsung GX20. I have not seen a clear-cut statement on any of the threads in the forum as to whether an Industar with the specifications above can reach infinity focus on a K-mount body using the type of adapter discussed in this thread.
Though slightly off-topic would welcome a clarification by the cognoscenti.

2. The adapter remained in the camera mount while trying to remove it while attached to the Industar. It did not prove possible to remove it with the fingernails alone. A screw driver had to be inserted into two separate slots with a helper holding of them. Then the adapter came off after some gentle force was applied simultaneously with the screw-drivers in a clockwise direction. With the Flektogon, the lens and adapter come off together though there is a degree of resistance from the camera mount as observed in post 14.
Chhayanat
I am bringing this back to the thread from private messaging. I fitted the Industar 50-2 50mm f3.5 M42 screw mount back again on the same two K-mount DSLR cameras with the adapter which this thread discusses. I took greater care to fit the lens+adapter into the camera mount. The Industar found infinity focus and took fairly good pictures but the adapter remained in the camera mount as before, being removed only with the dual screwdrivers operated by two persons in an anti-clockwise not clockwise as stated earlier direction. Fingernails did not help. With the Flektogon 35/f2.4, the lens and adapter came off together though the much larger Flektogon might have exerted more leverage. Thanks to all who contributed.
Chhayanat
11-23-2016, 12:53 AM   #21
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Generic M42 to K-mount adapter - focussing beyond infinity

I am reviving this old thread as an update. I have noticed unusual behaviour of the Flektogon 35mm f.2.4 used with a Samsung GX20 camera. I am using the same generic M42 to K-mount adapter which is the subject of this thread. It is without a flange and spring locking plate. The adapter remains on the lens.

I tested the lens by focussing on distant objects approximately 100 metres away. The focussing LED lights up at a point between the infinity mark hard stop and the last mark at 10ft on the focus indicator ring. Sometimes it lights up at the infinity lock or remains unlit there. On car number plates at that distance, there is a very slight difference in sharpness, with the pictures taken with the LED lit just before the infiinity mark appearing slightly sharper. Since the viewfinder of a DSLR is rather dim it is difficult to see if a distant object is in focus with a 35mm lens.

At the near focus end, the focussing wheel hard stop is at a point a little more than 8mm beyond the last 0.2m minimum focus mark. I am able to take the front element of the lens to abut 15 cm from the object and retain focus. I assume this means that the distance from the object to the sensor is 20 cm, i.e. the specified near focus limit.

I posted these observations on Manual Focus Lenses Forum and, from the replies received, the following are germane:

i) The adapter is too thick.

ii)The lens is focussing beyond infinity.
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