MIR-1 37mm f2.8 on pentax body

mtkang · 02-03-2015, 07:10 AM

Hi all,

I recently got this MIR-1 lense, which is m39 thread, after an m39 to m42ring, and through an pentax original M42 to pk adapter, will it be ok to use on pentax k-30 body?

I notice the rear of lense is extruding out a bit more, will it hit the mirror?

check internet i can't find any info, so i assume it is ok. But no harm to ask around here.

thanks.

**marcusBMG** · 02-03-2015, 07:36 AM

I had the same lens - no problem!
One minor point: because the base of the lens is so narrow it doesn't extend onto the main part of the camera mount so it tends to be a bit loose with the M42 adapter.

elektrolitr · 02-05-2015, 12:13 AM

M39 lenses have slightly smaller rear flange distance (45.2 mm vs 45.5 on m42 and K-mount), so you will possibly lose ability to focus on infinity without recalibrating the lens.

mtkang · 02-09-2015, 10:32 PM

I tried the lense on sony A7 with M42 adapter, it seems it never able to focus on infinity.

I searched around internet it seems not many information about it, is it confirm M39 will lose infinity on M42 body?

Originally posted by elektrolitr

M39 lenses have slightly smaller rear flange distance (45.2 mm vs 45.5 on m42 and K-mount), so you will possibly lose ability to focus on infinity without recalibrating the lens.

noelps · 01-12-2017, 08:50 AM

I have a Pentax SV and it suffers the same problem with the mirror whenever I mount my MIR-1 (m42 mount) on it and focus to infinity. I think the only option I have is to modify the rear of the lens itself, maybe to grind down the part just enough to make a clearance for the mirror to move freely when the lens is focused to infinity. I need to take caution though not to scratch the rear element or get the metal filings into the lens barrel.

reh321 · 01-12-2017, 09:30 AM

I have a Mir-1 with an M42-mount. It works fine on my K-30, but I don't remember ever trying to focus long distances away {"at infinity"}

Here's an example of a picture I took one day at Greenfield Village when I disciplined myself to use only the Mir-1 that day.

noelps · 01-15-2017, 06:46 AM - **1 Like**

the thickness of the adapter (m42 to k mount) may be the reason why the Mir-1 works on a K-mount pentax camera. the thickness of the adapter creates enough clearance between the rear of the Mir-1 lens from the mirror of your camera. my camera is an older one which is a Pentax SV from 1962 a precursor to the popular Pentax Spotmatic. both of which are M42 mount cameras which needs no adapter for the Mir-1 to be mounted on the body.

personally i don't use the Mir-1 on the full frame Canon dslr's due to reason of the mirror clearance but it works fine with my cropped sensor apsc canon dslr's without any problem.

my concern is basically is with my vintage Pentax SV which i assumed should work perfectly since it's already an M42 mount camera but instead jams the mirror when focused to infinity.

FYI : my Mir-1 ends with 78 making it from 1978.

well anyway, i guess i have dedicate the Mir-1 for use on my Canon cropped sensor dslr's. a couple of day ago i got a message from a friend that she's giving me an M42 Takumar 28mm lens that she's no longer using. i'm pretty excited finally getting a wide angle lens for my Pentax SV. i'll keep you guys updated and try to post some photos of the lens when we finally meet this week.

02-03-2015, 07:10 AM	#1
mtkang Forum Member Join Date: Oct 2010 Posts: 65	MIR-1 37mm f2.8 on pentax body Hi all, I recently got this MIR-1 lense, which is m39 thread, after an m39 to m42ring, and through an pentax original M42 to pk adapter, will it be ok to use on pentax k-30 body? I notice the rear of lense is extruding out a bit more, will it hit the mirror? check internet i can't find any info, so i assume it is ok. But no harm to ask around here. thanks.

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02-03-2015, 07:36 AM	#2
marcusBMG Site Supporter Join Date: Nov 2012 Location: North Wales Photos: Gallery \| Albums Posts: 2,869	I had the same lens - no problem! One minor point: because the base of the lens is so narrow it doesn't extend onto the main part of the camera mount so it tends to be a bit loose with the M42 adapter.

02-05-2015, 12:13 AM	#3
elektrolitr Junior Member Join Date: Dec 2014 Location: Riga Photos: Gallery \| Albums Posts: 47	M39 lenses have slightly smaller rear flange distance (45.2 mm vs 45.5 on m42 and K-mount), so you will possibly lose ability to focus on infinity without recalibrating the lens.

02-09-2015, 10:32 PM	#4
mtkang Forum Member Join Date: Oct 2010 Posts: 65 Original Poster	I tried the lense on sony A7 with M42 adapter, it seems it never able to focus on infinity. I searched around internet it seems not many information about it, is it confirm M39 will lose infinity on M42 body? Originally posted by elektrolitr M39 lenses have slightly smaller rear flange distance (45.2 mm vs 45.5 on m42 and K-mount), so you will possibly lose ability to focus on infinity without recalibrating the lens.

01-12-2017, 08:50 AM	#5
noelps New Member Join Date: Nov 2016 Posts: 4	I have a Pentax SV and it suffers the same problem with the mirror whenever I mount my MIR-1 (m42 mount) on it and focus to infinity. I think the only option I have is to modify the rear of the lens itself, maybe to grind down the part just enough to make a clearance for the mirror to move freely when the lens is focused to infinity. I need to take caution though not to scratch the rear element or get the metal filings into the lens barrel.

01-12-2017, 09:30 AM	#6
reh321 Pentaxian Join Date: Nov 2014 Location: South Bend, IN, USA Photos: Gallery \| Albums Posts: 23,177	I have a Mir-1 with an M42-mount. It works fine on my K-30, but I don't remember ever trying to focus long distances away {"at infinity"} Here's an example of a picture I took one day at Greenfield Village when I disciplined myself to use only the Mir-1 that day.

01-15-2017, 06:46 AM - 1 Like	#7
noelps New Member Join Date: Nov 2016 Posts: 4	the thickness of the adapter (m42 to k mount) may be the reason why the Mir-1 works on a K-mount pentax camera. the thickness of the adapter creates enough clearance between the rear of the Mir-1 lens from the mirror of your camera. my camera is an older one which is a Pentax SV from 1962 a precursor to the popular Pentax Spotmatic. both of which are M42 mount cameras which needs no adapter for the Mir-1 to be mounted on the body. personally i don't use the Mir-1 on the full frame Canon dslr's due to reason of the mirror clearance but it works fine with my cropped sensor apsc canon dslr's without any problem. my concern is basically is with my vintage Pentax SV which i assumed should work perfectly since it's already an M42 mount camera but instead jams the mirror when focused to infinity. FYI : my Mir-1 ends with 78 making it from 1978. well anyway, i guess i have dedicate the Mir-1 for use on my Canon cropped sensor dslr's. a couple of day ago i got a message from a friend that she's giving me an M42 Takumar 28mm lens that she's no longer using. i'm pretty excited finally getting a wide angle lens for my Pentax SV. i'll keep you guys updated and try to post some photos of the lens when we finally meet this week.