Film-Tech Forum ARCHIVE: Strong aperture plates

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Posted by Dan Lyons (Member # 1454) on 03-09-2005, 10:01 PM:

Anyone else noticed that the aperurture plates from Strong are totally useless?

I have a some new, never before taken from the package Century plates from Strong for 1:85. The damn things are seriously overcut. More like 1.66! The worst part however, is that the sides are overcut!! I checked them against Rp-40, and the sides are cut beyond the projectable area! [fu]

Posted by Brad Miller (Member # 2) on 03-09-2005, 10:16 PM:

Welcome to the wonderful world of Wrong International. I complained about this a couple of years back, so it's good to see that nothing has been done about it.

Kinoton has the BEST plates around. They are undercut enough so that you could use them in 2:1 houses or even screening rooms with extreme keystoning. To make things even nicer, the true edges are scribed so you have a good idea where to snip when you are using nibblers.

Posted by Scott Norwood (Member # 30) on 03-10-2005, 05:20 AM:

Apparently Kinoton plates are only available in 1.85 and scope (undercut, of course), though, which means lots of filing if you want 1.33 or 1.66.

Simplex plates are usualy pretty close to dead on at the top and bottom of the image, but need to be filed out on the sides (1.85 plates are within a couple of squares on RP-40; scope plates need more filing, as they are 2:1, I think).

Posted by Stephen Furley (Member # 1277) on 03-10-2005, 07:13 AM:

Kinoton also produce a plate stamped 'N', but I'm not sure what size it is originally. I've seen it filed out to various sizes, but I've never seen a new one.

Posted by Steve Guttag (Member # 268) on 03-10-2005, 08:31 AM:

Kinoton "N" plates have the same opening 400 x 800 or so but have the scribed lines for the 1.37 aperture.

Kinoton also has the "D" plates with a pinhole and crosshairs scribed.

The Kinoton "CO" plate is undercut for width but barely for height.

When judging how a plate was precut, you really need to measure it with calipers, not projected film. If you chaulk up different lamphouses, and different lenses, you will find the plate reveals more or less of the image. It has to due with how the cone of light passes through the aperture and is received by the lens.

With ISCO red lenses, they almost see around the plate with older ISCO golden lenses, the same plate will seem undercut. With Schneider it depends on the focal length as to how much the difference is.

As to the Simplex plate, Strong is guilty of having a bit too much metal on their single plates (for single lens holder machines). Thus you need to file the top and bottom for a custom fit and then file the end of the plate so it centers up perfectly for your projector. That effort is not the end of the world and affords the ability to get it precisely right for your machine.

As to sizes...Simplex has always had their "U" plates...as in 1.85:1U only undersize on width. Thus a 1.85:1U will measure .446 x .800. This was to allow for side keystone introduced by offseting the projector from centerline (pointing down).

However, Simplex also has their 2:1U plates for both scope and flat so you can get a 400 x 800 plate for flat and 650 x 650 for scope.

Again, measure the actual opening in the plate before you claim the plate was made out of spec.

Steve

Posted by Gordon McLeod (Member # 33) on 03-10-2005, 09:26 AM:

I never use pre cut plates but always start from a blank or pinhole and cut to suit the theatre

Posted by Brad Miller (Member # 2) on 03-10-2005, 10:46 AM:

Steve,

Putting the differences in lenses and lamphouses aside, I don't need a caliper to know that when I stick a new Century plate into a Century hanging on a Highlight II with an ISCO gold lens and see that it projects OUTSIDE the limitations on PA35 that it is overcut.

Century = Strong
Highlight II = Strong
ISCO = Strong

So you are saying if you buy all Strong, you will go wrong. Ok I get it now. Makes perfect sense. [Razz]

So what magical combination of equipment do you have to have for a new Century "undercut" plate to be usable? It's certainly not a Century on a Christie lamphouse with ISCO or Schneider lenses, because I've used that setup before recently as well. In the end I have to deal with those Gordon-style and nibble from a small hole. Seriously, Strong needs to get their act together on this and make their "undercut" plates truly undercut. They used to be fine, this is something that has turned up over the last several years.

Danny, you mine as well get you one of these and order 1/4" hole plates for your Century.

Posted by Steve Guttag (Member # 268) on 03-10-2005, 12:17 PM:

The spec on the Century plates predate Strong. If you measure the opening and they are correct as defined by Century (again, Prior to Strong) then they are made correctly. I know that Strong has added some new plate sizes (particularly for Scope).

ISCO....merely imported by Strong.

Highlight II...okay that is a Strong product, all the way.

For Century "SA" plates they all start with PE-518-E
The last two digits specify the plate.

Thus the standard "FLAT" plate is PE-518-E08 which has an opening of .420x.800.

Other plates of interest to some here:

E17 (400x800)
E15 (650x650)
E16 (650x775) (my preferred for Scope undercut)
E13 (675x800)

Note too, that for Century you also have Wolk and LaVezzi offering some of the plate sizes.

Steve

Posted by Brad Miller (Member # 2) on 03-10-2005, 08:53 PM:

That's news to me. Last few times I've had to order Century plates it was "undercut or pinhole" and that was the only options. I ended up getting 1/4" hole plates, but that took extra effort. (Besides, those numbers aren't truly undercut for the oddball theater setups anyway. Remember, not every auditorium out there yields perfection.)

Good tip on Lavezzi and Wolk. Next time I'll get the plates from them.

Still though my argument holds true. One should not be getting "undersize" plates for a Strong product and put it into an ALL-STRONG setup and end up projecting outside the SMPTE boundaries.

Posted by Steve Guttag (Member # 268) on 03-10-2005, 09:18 PM:

The sizes were defined by Century so any source you choose should have the same size. The Wolk plates have traditionally been all brass, no black coat.

I can not claim to have had the problem of overcut plates from the factory though I've sourced my plates from all three manufacturers.

I will give you that perhaps 800 is not sufficient for some lenses and that .775 would be a better starting point for all of the widths.

For Simplex, it is a bit overdue for their "undersized" plates to also be undersized in height. On a new Simplex projector (PR1014) they supply both .446 x 800 and .400 x .800 as well as the two scope varieties.

Steve