Installing the Lens Flange

The HD-144 Lens Flange is practically indistinguishable from the Regular-16 version to the untrained eye. It is computer crafted of pure stainless steel.

HD-144 Flange (Right) Regular 16 Flange (Left)

To attach the HD-144 Flange, very slight but critical modification needs to be done to the front of the camera body. The circular opening in the body needs to be extended 1.1mm to the RIGHT (as seen from the front), and the recessed area must also be extended 1.1mm to the RIGHT to allow room for the CA-Adapter to screw in.

FRONT OF ACL BODY: The two silvery-metallic areas show where openings have been extended to the right by 1.1mm; the hole in which the Flange is seated, and the right side of the recess — allowing the CA Adapter to screw in.

In most cases the flange will need to be shimmed in order to achieve the correct distance between the flange and film plane of 17.52mm.  I recently encountered one ACL that instead required the rear of the flange to be milled by a fraction of a millimeter.

If you are planning to re-center the mirror, see the  instructions on the Mirror Spindle Page on possible filing of an area, or areas, of the Mirror’s rear rim to give the mirror extra clearance.

It is highly recommended that at this stage the Filter Slot, and Filter Guides inside the housing, be done away with. Gelatin Filters directly behind the rear lens element went out of vogue long ago, as they can create dust patterns on the image. The only thing that the filter slot can really do today is present a potential source of light leakage. It is suggested that the slot at the top of the housing be filled-in with either black epoxy or black plastic rubber, and that the plastic top of a filter clip be cemented in-place as an ornament.

Finally, just as a precaution, inside the housing it would be a good idea to fill any gaps between the rim of the Flange and the modified opening into the Body with some Plastic Rubber-type of compound.

Above: Black Plastic Rubber from the Super Glue Company. It can be removed easily.