Advantage of m43rds, use crazy M12 lenses

[dabateman]

I have been playing around with some interesting lenses. One idea I had was to pull off a web camera lens from an old Nanny IP camera we had.

The lens is a 3.6mm f2.4 M12 mount lens. I have about 6 of these from IP cameras. Interestingly they are mostly different. One had no glue holding the front element support. So I could take it apart and remove the back UV/IR cut filter. There were 3 glass elements inside with plastic spacers. I moved the elements around to allow for better focusing.

 

This is an image of the lens on my EM1 camera:

 

I have a M12 to C mount adapter screwed into a M43rds to Cmount adapter. The M434drs adapter also has a front M42 adapter. So using a M42 to 52mm filter adapter I was able to screw on my Baader Venus filter to the front.

 

Here is a quick image taken using Baader venus filter, ISO 400, aperture is fixed at F2.4. The lens protrudes just past the shutter mechanism. So this is taken in Electronic shutter mode with lower limit of 1/8 on the EM1. This lower limit I find annoying, the newer EM1mk2 electronic shutter goes to 60 seconds. I have two 365nm LED bulbs illuminating the area.

 

Also interesting is the EM1 has a digital tele-converter option. This seems to internally up sample the Jpeg image to 2x, while maintaining the 16 Mpixel output.

This is the same image from the raw file showing the true full view:

 

I know I will need a better subject than a dry dandelion, however my pottery cup does look nice.

[JCDowdy]

I thought about trying this but didn't have any M12 lenses to play with, glad to see someone show it can work.

 

Aren't there are some M12 lenses made for 1 inch sensors that have larger image circles?

 

added,

 

If I recall correctly, UKA makes UV quartz M12 lenses.

[Andrea B.]

Nice idea, David ! Thank you for the report on M12s.

[eye4invisible]

Yes, I've also had some fun experimenting with M12 mount security/CCTV fisheye lenses on my dinky Pentax Q10. I drilled a hole in a spare body cap and threaded the lens through:

 

I don't have the capacity to test in UV, as my Q10 is not converted.

 

Due to the tiny sensor size and high crop factor, I don't get much vignetting, even with the tiny image circle. I can get a half-decent 10MP image with a 3:2 aspect ratio setting:

[Andrea B.]

Body cap adapter idea is very good, Andy!

[dabateman]

Yes the Pentax Q sensor would be much closer to the sensor size designed for most M12 lenses. You also look to have infinity focus with space. My M12s are designed for a 1/4 sensor size. The Q sensors were 1/2.3 and 1/1.8, if I remember correctly.

 

I tested an other none modified 3.6mm lens and my focus limit was 6 inches. So would need a longer shaft lens, or the ability to move it closer to the sensor or rearrange the lens groups to allow for greater focus range on M43rds.

 

@John,

Yes Uka optics does have quartz lenses. But more importantly they also have the lens diagrams for each lens indicating the back focus distance and length of the lens tube. So it would be possible to see which lens will work using your adapter setup on a M43rds camera. I have 2 c-mount to m43rds adapter types. The one with the M42 threads just allows for infinity focus with C-mount lenses and may not for some lenses. The other one I have is much smaller without M42 threads but allows for closer to sensor setup. This same lens on this adapter allowed for about 5 feet of focus, compared to 6inches on the other. So people will need to calculate for what they make. There doesn't seem to be too much consistency in the cheap M12 lenses or adapters. So every person for them selves if they want to venture into this cheap realm of cheap M12 quartz lenses.

 

Here is an image of my 3.6mm f2.4 M12 lenses, one I modified is lieing down and the unmodified one with UV/IR filter in place is standing up. Next to them is the C-mount to M12 adapter and an American quarter for size. In the back is the C-mount to micro 43rds adapter with M42 to 52mm adapter on.

[JCDowdy]

Yes, the C-mount to M12 adapter was the one I was wanting to try with a M12 fisheye like Andy showed on his Pentax Q for a full circle in µ4/3.

I put off the project because my Lumix G3 grip would be in the frame. If one had a flat front µ4/3 like the GF series or GX7 or GM1 I think the fisheye might not see the camera body.