[spiffariffic]

I was browsing for cheap m42 lenses when I stumbled across a Super 8 lens that had a 19mm thread mount rather than a standard D or even C mount.

Can’t find almost any info on them, except 1 forum thread: 19mm thread diameter C mount or D mount cine lenses ??

And a 3d printed adapter from 19mm to Sony FE on Shapeways.

Has anyone adapted these to the Q??

I wonder if a body cap hack could work? I don’t quite understand the technical details of flange distance etc (how do you figure that out?) but for $5, I’m willing to try.

Seems like it would be ideal. These lenses cost nothing because they’re basically incompatible with everything, heh.

[Stylsini2.0]

I was browsing for cheap m42 lenses when I stumbled across a Super 8 lens that had a 19mm thread mount rather than a standard D or even C mount.

Can’t find almost any info on them, except 1 forum thread: 19mm thread diameter C mount or D mount cine lenses ??

And a 3d printed adapter from 19mm to Sony FE on Shapeways.

Has anyone adapted these to the Q??

I wonder if a body cap hack could work? I don’t quite understand the technical details of flange distance etc (how do you figure that out?) but for $5, I’m willing to try.

Seems like it would be ideal. These lenses cost nothing because they’re basically incompatible with everything, heh.

I have also begun searching for this information... I have a lens from a super8 camera - a Nalcom f1.1 10.5mm - 30mm zoom.. that I would like to mount to my pentax q-s1...
At the wide end of the focal range, the lens has barrel distortion, however at the telephoto end distortion appears to be pretty minimal.

It has an aperture of f1.1 which could make it great as a lens that works very well in low light situations. I have no idea how sharp the lens is, but even if it is of "reasonable/ acceptable sharpness", which I know is subjective, it could end up being a great 'bang for buck' purchase for low light photography.

I found this article useful in terms of defining flange distance:

https://en.wikipedia.org/wiki/Flange_focal_distance

According to Wikipedia, the flange distance is "the distance from the mounting flange (the interlocking metal rings on the camera and the rear of the lens) to the film or image sensor plane. This value is different for different camera systems. The range of this distance, which will render an image clearly in focus within all focal lengths, is usually measured to a precision of hundredths of millimetres, and is not to be confused with depth of field.

The sensor size of the pentax Q-S1 is 7.44mm x 5.58mm = 41.52 mm2, and the flange distance is 9.2mm...
The negative or in today's terms "sensor" size of Super 8 film is 4.01mm x 5.79mm = 23.22 mm2, which is almost half the area of the Pentax Q-S1's sensor.

I am yet to work out the exact maths as I'm not that mathematically inclined, however, my suspicion at this stage is that when a Super8 lens is used on a Pentax Q-S1, its flange distance would have to be increased beyond 9.2mm in order for the image to be in focus throughout the lens' zoom range.

[kwb]

I was browsing for cheap m42 lenses when I stumbled across a Super 8 lens that had a 19mm thread mount rather than a standard D or even C mount.

Can’t find almost any info on them, except 1 forum thread: 19mm thread diameter C mount or D mount cine lenses ??

And a 3d printed adapter from 19mm to Sony FE on Shapeways.

Has anyone adapted these to the Q??

I wonder if a body cap hack could work? I don’t quite understand the technical details of flange distance etc (how do you figure that out?) but for $5, I’m willing to try.

Seems like it would be ideal. These lenses cost nothing because they’re basically incompatible with everything, heh.

I have no experience with the lens but the fact that there's an adapter for SONY means that the body cap hack for Q won't work. SONY FE mount flange focal distance is 18mm, so the flange focal distance for the lens is most likely more than 18mm. OTOH, the Q flange focal distance is 9.2mm and the body cap only adds a few mm at most.

There are many ways to measure the flange focal distance, see attached for example for the most primitive one, hopefully this is self-explanatory. You cannot achieve any great accuracy this way but you can go within +-0.5mm or so, somewhat better after you worked on your technique. That's actually a good start for a DIY first article adapter which you'll improve upon later.

You need to develop a good technique to align the lens, the card and the light. Practice using a known lens, again and again, until you consistently obtain a reasonable accuracy. In my example I'm measuring my C mount lens with the nominal focal flange distance of 17.526mm. If you look at the last picture you'll see that this provided a pretty good measurement for me.

(*** Warning *** The light source should be as distant from the lens as possible, like 100 times the focal length or more. For convenience I use sunlight. However, pointing the lens to the sun, you might burn things which may lead to serious damages to your property, health and even life. Use ND filter in front of the lens if necessary. Understand the risk, otherwise don't do it. You've been warned.)