jonni's 35mm DOF adapter (for M42 and Canon EF lenses)

This is the DOF adapter I built for my Casio EX-F1 when I wanted to achieve a cinematic look in videos I shot with this cam. It is very cheap and one of the shortest adapters I've seen so far. It works with regular Canon EF lenses like the 50mm 1.8 and also with old M42 lenses that you can find for cheap on ebay (I got my 55mm 1.4 lens for 40 Euros).



The image is recorded upside down, but you can solve this problem very easily with a 180° rotation in post production. I also tried to attach this adapter to a Panasonic camcorder and it worked fine - I just needed some cheap stepping rings to make it fit.

Here are some videos to show the abilities of this adapter:







As you can see in the videos the adapter works very well. It is a very cheap solution to get some shallow depth of field in your homevideos that you shoot with your camcorder. The only problem is that you have some light loss and that you can see some grain in the videos (depending on the focusing screen or ground glass you use). To avoid this you have to let the ground glass (screen) vibrate or rotate. I don't like vibrating adapters because of the noise they make and I also think that the vibration has some bad influence to the sharpness (because the movement of the screen changes the flange focal distance). A rotating adapter would be a much better solution. But I have never built one because now I have this superb Canon 550D and I don't need this adapters any more ;)

Here are some tips for all of you that plan to build an adapter like this:
- try to make it as short as possible (light loss)
- don't use a cheap macro lens (distortion, chromatic aberration)
- don't use a cheap ground glass / focusing screen (hot spotting effect)
- use a high quality condenser lens (reduces the hot spotting effect)
- screw don't glue.

If you have trouble with the quality of your adapter read this:
- The distance between the lens and the ground glass (GG) is the most important thing and has to be absolutely correct. It is called "flange focal distance (ffd)". Check wikipedia for the right ffd of your lens.
- Next thing is the quality of your GG. You will loose less light if it is thinner. It also has to be very fine if you don't want to see a lot of grain. So if you have enough money and if you don't need a circular one go for a Canon screen.
- If the quality is still bad check the tips above again. Hope this helps.

If you're interested in the process of building my adapter, here's the original post in a german EX-F1 forum.

Got any questions? Write a commet.

Good luck with your project,
jonni