Installing the HD-144 Super-16 Aperture Plate

This plate has been manufactured by computer to the most exacting standards. It is as close to meeting specifications as any part could be short of having Eclair’s original die to work with. The HD-144 plate is made of highly polished, pure stainless steel, with a Hard Chrome Plating. Three different companies are involved in the manufacturing process. The registration pin hole in the Regular-16 plate — never utilized — has been omitted.

Top: Regular 16 Aperture Plate
Bottom: HD-144 Aperture Plate

The corners of the Super-16 aperture opening are slightly rounded — only a die punch could duplicate the square corners of the Regular-16 opening. This should have no bearing on HDTV or Theatrical 1.85. The impact on Theatrical 1.66 should be negligible because of inevitable cropping in projection, (indeed most projector apertures have rounded corners themselves).

YOUR APERTURE PLATE HAS BEEN CAREFULLY INSPECTED.  However the final test can only be made in your camera. Be sure to run test film to ensure that the emulsion is not being even microscopically scratched in any way (it is not necessary to develop this film).  Observe the film with light being reflected off of it, under a magnifier. The Aperture Plate should be the very first part to be installed and tested. Though the chances of a problem are slim, if a defect is found it is best to replace the Plate before the Ground Glass has been re-aligned and re-focused — an enormous chore that no one wants to do twice. We suggest testing with both color and black & white film — they are different in thickness and hardness. If you suspect scratching: 1) check the film on the feed side to be sure that the emulsion surface is pristine to begin with, and 2) try some different magazines just to be certain that the problem is not with the magazine. Your HD-144 Aperture Plate has been Hard Chrome Plated and Highly Polished. It is unlikely that you will experience a problem, but if you do, please contact SUPER 16 ACL by email immediately and we will arrange an instant exchange. Your warranty gives you 90 days for the exchange of any defective part.

The depth of the recess on the HD-144 Aperture Plate for the Side Pressure Bar (MIN 12) was deliberately kept on the conservative side, (about .20mm), since this depth on the Regular-16 Plate did vary minutely from camera-to-camera when shipped from the factory, (typical depth  for this recess in the Regular-16 factory Aperture Plates ranges from about .20mm to .25mm — your mileage may vary). This recess on your HD-144 Aperture Plate may need to be ground a fraction-of-a-millimeter deeper so that the bar is free to move, but without being so loose as to allow the spring to pop out. (This is typical of the custom “fudging” done in the factory with each ACL to be built).

On the HD-144 Aperture Plate, due to normal manufacturing tolerences, it is possible that the Guides (MIN 13) for the Side Pressure Bar (MIN 12) may sit just a fraction-of-a-millimeter differently than on the Regular-16 plate. This is of no consequence at all, except that the recess in the ACL’s Mechanism Base Plate (MIN 5) for the Aperture Plate Assembly leaves absolutely no breathing space. If the Aperture Plate assembly encounters resistance when being placed into the Base Plate, the tiniest bit (as little as 1/100th of a mm) should be gently scraped from the base plate where the Guide (MIN 13) is rubbing until the plate fits in (see photo below).

The Aperture Plate will be a very snug fit. If necessary, rub a little light machine oil around the edges, and then depresses at the corners. Make sure that the Guides are screwed down tight so that they will remain straight (100% perpendicular to the Pressure Bar) in order to correctly fit into the recess in the Base Plate. If you enounter resistence, then you’ll know that some slight filing is necessary. [NOTE: In the current batch of plates shipped from March, 2001 to the present, it is the UPPER GUIDE slot that seems to require the shaving.]

In the example above, a very tiny amount has been removed from the top of the recess for the Guide (red circle) — in this case so that the UPPER GUIDE (MIN 13) will fit without encountering resistance.

Eclair used a non-standard thread in the manufacturing of its cameras. The HD-144 plate uses screw holes threaded for standard metric 1.4mm. You cannot use the original Eclair screws for the Side Pressure Bar Assdembly, or the Spring Rest. (But hang onto them; original Eclair screws are scarce). The screws needed to attach the Upper and Lower Guides (MIN 13) for the Side Pressure Bar (MIN 12) are provided with the HD-144 plate in standard metric 1.4mm.  The Spring Rest Screw (MIN 18) is also provided in 1.4mm thread. Use the Distance Piece (MIN 15) from your Regular-16 plate (it’s a tiny washer that goes on the Spring Rest Screw) — this part is so small that it is sure to vaporize if you’re not incrediby cautious.

The HD-144 aperture plate, with the UPPER and LOWER GUIDES (MIN13) holding the SIDE PRESSURE BAR (MIN 12) into place. The screws are standard metric 1.4mm — Eclair screws were non-standard thread. The Spring and Spring Rest Screw are not shown.

A WORD TO THE WISE:  I suggest performing all operations with the spring inside a clear plastic bag. This spring loves to launch itself — and replacement parts haven’t been made in 20 years. This advice applies when working with any small ACL parts, such as tiny screws and washers.

When screwing down the Aperture Plate into the Base Plate, first place a drop of light machine oil into each screw hole. Then start by screwing in each of the 8 screws only part way. Do not use a Jeweler’s Screwdriver, as it doesn’t have enough torque and pressure and the slots on the screws will get ruinned. (Use a screwdriver that is the exact length and width of the slot, and at least 3-4 inches long with a good grip handle. You will need to apply some pressure at the end to get them in perfectly flush, necessary so that the Shutter doesn’t scrape against them.) Slowly tighten each screw a little more, in rotation. This will ensure that the plate is seated centered in the Base Plate in absolutely correct alignment, and that all screws go in straight. You will be tempted to slightly enlarge a hole or two in the plate if the screw thread in the Base doesn’t seem to align 100% beneath the Aperture plate. Resist this temptation. With the right screwdriver, torque, and patience, they will all go in. If a screw starts to go sideways, unscrew it and start again. Go slowly. These screws can get ruined easily.

The rear side of the Aperture Plate should be painted a very flat black.

Note: Subtle manufacturing artifacts may be visible in the recessed areas of the plate, depending on how the light is hitting it as you are viewing. This is normal, and results from the normal manufacturing process because the HD-144 Plate was milled rather than punched from a die in the manner of the original regular-16 factory plate.

FRAMELINE:  The aperture opening has been designed to shoot image right into the frameline. This has 2 advantages: If a tiny spec of dust gets caught at the bottom of the aperture, it will actually be in the frameline and not be projected, and hairs will not be as deep into the projected picture area; there is a tiny amount of room to rack the picture up or down in either the video transfer or blowup to 35mm.