Convert Century 1.33x anamorphic bayonette to 77mm thread.

[Greg_E]

This might be another of those pointless threads, but it needs to be done so I can fool with this Century 1.33x convertor. Just so we are on the same page, here's a picture of the thing.



Start by loosening the screw that stops the locking ring from moving too far, this ring then spins off its threads.



Next take out your 0.9mm Allen wrench and loosen the 5 set screws on the rotation limiting collar and pull the collar straight off.



After that remove the two screws and plasic holding the rear lens in place.



After the lens is removed, you can pull the lens housing away from the mount housing from the front.



It is now ready to drill and tap the holes to attach a 77mm to 58mm step down ring, the 58mm almost perfectly centers the ring on the lens, so you could probably drill this on a cheap drill press. Mine will go in my milling machine for better accuracy. 3 or 4 #2-56 screws would probably be enough, I'll do at least 4 in mine.

And thus ends part one of our tale, tune in next time when I drill, tap, countersink, and assemble this modification. I may also add black flocking to prevent reflections off the mount, and will probably paint the edges of the lens black to prevent internal reflections.

 

[Greg_E]

Had an hour after work. Finding the edges so I can center the tools.


Drilling pilot hole with a small center drill, decided to go with 8 screws in mine.



Drilling out to final size, a #50 drill ready for tapping #2-56 threads.

 

[Greg_E]

Got the two pieces cleaned up and back together, didn't really take any pictures. Need to program my camera for two different modes and play around a bit to see if I just wasted a bunch of time and money.

 

[Greg_E]

Ended up having to pull the front lens out... It was causing some kind of binding that affected the plastic retainer behind this lens and caused it to warp. This in turn caused the rear lens to sit at a very small angle to the front lens. Some of you know what this means, some of you don't. What this means is that the rays of light were focusing in several different planes, and none of them would make a coherent image. Taking the front out and cleaning it, cleaning all the barrels, and resetting everything made them all pop back into place and now I have an actual image that doesn't completely suck.

Yes it is slightly softer.

Yes it does work with my 35mm lens and Lens Turbo attached (about a 1.32 FF crop for sensor and booster on my GH2) with no sign of vignetting, hoping that I can get my 24mm and lens turbo working, but still waiting for the EF mount converter to arrive. Need to find my step up rings to try 55mm and 110mm lenses. But all in all so far it looks like a successful conversion. Need to get some video recorded for examples.

In theory I'm getting a .86 crop (FF) in width so my 35mm should give me a decently wide angle (trying to keep all the terms the same, full frame crop for anamorphic probably isn't correct).

 

[Greg_E]

Finally got around to finishing this, what might be a unique "one of a kind" anamorphic adapter (a little redundant), not sure I will make another unless I can get the adapter really cheap. Now with a 77mm front thread to make it easy to mount things like diopters and a lens cap.









What little testing I've done suggests that you need to be at f4 or smaller (higher number) in order to get acceptable images. Lots of internal flare that requires changing the contrast setting in the camera, and it's a bit soft on my 24mm so sharpness can come up a bit or sharpen in post. Need to make some sort of support for this, it's pretty heavy hanging out on the end of the lens. Need to get my other FD lenses adapted and or fixed so I can try with longer focal lengths, the 24mm with Lens Turbo is about as wide as you can go with this rig.