It’s been ages since I’ve written and a lot has changed on the hobby front. I’ve acquired another 3D printer and this time, I’m finally getting good quality prints. I will save that good news story later. As for photography, I’m happy to say that my idea of combining my maker skills with my interest in cameras has been a success. In a previous post, I have mentioned that I wanted to rehouse/convert point and shoot camera lenses to M-mount. Well, let’s just say that the topic of this post is actually my fourth successful conversion.
I started with the Canon Owl, which was made into a 35mm F11 focus free (2m-infinitely) lens. Then I made a Minotar 35mm fixed aperture (F4) lens (zone focus) and that was the practice run for a proper Minotar 35mm F2.8 lens. I’m proud and surprised to say that I managed to sell the converted Minotar for $300.
Needless to say, I was hooked. I need more lenses and I recently found a broken Olympus Trip 100R. The reason why I skipped over the Kodak 29mm F5.6 that I disassembled in a previous post is simply a matter of form factor. The Kodak lens was in a plastic barrel that I wanted to preserve. This made machining a proper housing more challenging as the barrel will be recessed. On the other hand the Trip 100R has a very simple F8 lens group that is in a small plastic disc that can be easily rehoused.
With all the previous lessons learned, I was much more confident in my abilities. I also made it an effort to improve the fit and finish of this conversion. The three aspects that I improved are:
Friction Fit: I made the contact bores of the three main components (barrel, base, and mount) tight fitting to ensure perfect alignment as well as general good looks. I made sure to skim very light cuts to guarantee this.
Liquid Rubber: One interesting new material that I’m experimenting with is liquid electrical tape, which is just a black liquid compound that forms a soft rubber when cured by air. It’s not as strong as epoxy but flows well and forms a light tight seal that can be removed if needed. This attribute lends itself well for securing the lens group when you never know if you will need to remove or adjust it in the future.
Black Primer: For the first Canon Owl conversion, I tried to use black paint on the aluminum to create an anti-reflective surface to ensure I don’t create any flare. What I had on hand at the time was some matte black paint that I used for touch up of my car rims. What I didn’t have was primer and that was a mistake. The paint chipped easily off the bare metal surface. I learned from this and spent the money for some premium auto primer in black. This time, the paint stuck well and left a beautiful matte finish. The primer has a leveling property so it smooths out all the machining marks and looks amazing.
Enough with the chitchat, here is the completed lens conversion mounted on my M3. Check out the sweet grip! That will be the subject of another post 😛
The lens group is recessed into the M3 body so I made the barrel very short to just offer the lens a little bit of protection as well as give it a more complicated look (the grooves are just for looks). The profile of the lens is so low that you can barely see it – I LOVE IT!
Now let’s see the construction. The conversion is four pieces: the lens group, the barrel, the base, and the mount.
Most point and shoot cameras are pretty simple to disassemble. The Trip 100R is no different. A few screws and you arrive at this. The lens group actually just unscrews from the shutter plate.
Barrel and Base Plate
Now the barrel and base plate can technically be made one-piece, but I had some thinner aluminium plate on hand so I decided to make it two piece to save machining. The barrel is a scrap piece of tubing stock and its just press fitted into the base plate.
Assemble into the Mount
The mount is a cheat, it’s a ltm to M-mount adapter machined to remove the threads. I only do this because I do not have the means to cut threads with the simple Taig lathe. Otherwise, I could just machine the L39 threads and use the adapter unaltered. Maybe one day I will get that lathe upgrade. The base plate is painted and the lens group is shimmed into position with a bit of the liquid tape. I used my Fuji X-T1 with an adapter to check the focus until the lens group is at the correct flange distance for hyperfocus (1.5m to infinity). I used washers and masking tape to create the perfect shim before adding more liquid tape to fully secure the lens group. The result is a very clean finish that looks much more professional than the previous conversions.
I’m very happy with the finished product. I already took it out for a spin and can’t wait to develop the photos! Thanks for reading!