It is possible to purchase adapters for most lenses at a low price, but some less popular adapters can prove very expensive or not be available. Creating your own adapters is not a difficult task once you find the flange length of the lens and the adapter.
Finding the mounting plate for the lens is not a difficult task, either old cameras can be dissembled or I often use macro extension tubes and either unscrew the plate and remount it or glue it inside of a lens adapter that will fit either a mount or helicoid.
It is also possible to modify some bayonet mounts or adapters.
I prefer to mount lenses on a helicoid even when the lens has one inside as this gives me a closer focal distance and ensures that I can focus to infinity. Mounting to a common helicoid also ensures that I can use the lens across my many camera bodies all of which have a different flange distance.
With this in mind I often mount a camera female bayonet mount onto a common thread size as shown below which is a 42mm adaption to an Axa bayonet. This can then be screwed onto any 42mm helicoid and finding an adapter from 42mm to any camera is easy and cheap to buy. It also makes mounting different lenses on the camera and between cameras out in the field much easier as they are all a common mount.
With projector lenses I do the same thing. I glue them onto a common thread size. The lenses below are all on a 42mm threaded ring so they fit on a common helicoid or make an adapter out of an old lens as shown later in this section.
Some projector lenses already have a crude helicoid. These whilst hard to use for fine focus work fine for changing the lens into a macro lens whilst still having infinity focus..
I adapted this helicoid with lens by cutting away part of a 42mm step up ring then drilling, tapping and fitting screws to hold the lens with its own helicoid firmly in place on the 42mm adapter. Now it can screw on a standard helicoid.
The end result is a very cheap but effective lens.
It is possible to get the area of focus with the built in helicoid and then fine tune with the added helicoid. The focusing rage being from infinity to about 25cm!
It is also possible to create your own helicoid by removing the glass elements from an old lens and either using the mount as it is or by screwing a cheap m42 adapter ring to the bottom.
This adapted old lens fits all slide projector lenses as they just push inside it, the helicoid them works fine. I use a rubber band made from cutting an old cycling inertube to fit the AV lens in place.
Here I have simply filed out the centre, only needed 1mm and added three grub screws to convert any ISCO lens to an Axa mount. These brass extension tubs are very cheap to buy.
It creates a perfect push fit and the grub screws hold the lens in place.
All lenses can be adapted the only issue is focal plane distance and this can be sorted with a bit of experimentation. Free lensing (not mounting the lens but just holding it infant on the camera) can be used to establish distances required to achieve infinity focus.
It is even possible to make an adapter for difficult mounts for example the Canon 50 f0.95 Dream Lens. You can of course buy an adapter for a Canon and Sony from the US but they are very expensive and the one I ordered got lost in the post. You could make a mount from an old Canon 7 Rangefinder camera but these are not a cheap purchase and it is a shame to destroy a collectable camera. My answer was to buy a rear cap from the US on eBay and cut the back off it so I could mount it on an m42 screw mount with screws and glue. This both fits in a non-spaced M42 to Canon R for infinity focus and also fits into a very small helicoid to give me macro capabilities. The total cost of this hand made mount was around 40 dollars.
Made by cutting the back of a cheap Canon 50mm f/0.95 f0.95 (TV and RF lens) all metal anodised Rear Cap
Examples of two quick snapshots taken outside my home to simply test the lens focal planes after making the adapter above are shown below. First with infinity focus, so lens fully retracted in its own helicoid as shown in the first image above. Then the second image is with the lens fully extracted in its own helicoid and my added helicoid is shown in the second photo. Both of the sample images below have been taken with the same settings and exposure and without processing so just as taken on a sunny October afternoon.
It is also possible to dismantle an old broken camera to use the mount in the camera. I have done this where the rear part of the lens itself is fixed in the camera e.g. Zeiss Contaflex.
Some mounts are even more complex but everything is possible with a bit of thought.
This is a very rare lens with no adapter so I needed to make my own adapter. As the aperture was controlled within the camera this is a little more complicated than normal as I needed to create an aperture control system into the adapter.
I used an FD to EOS adapter to do this first removing the top and bottom mounts from the adaptor.
Take all the metal away as every mm counts, this lens has a short focal registration. The lens has a small lug that controls the aperture it needs a small slot to created in it so that the turning mechanism can control the aperture not ways.
Now you have done the hard work. You have a system where the turning adapter screw fits into the lens aperture control system.
I put a longer screw to ensure it would not slip out in use.
Glue and screw a 42mm filter step up filter to the bottom of the adapter. You may need to file the step up part off again to gain mm which are precious if you want to add a helicoid like I did and still get infinity focus although not important if you just want to mount the lens.