my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Scope Aperture Plate question (Page 2)

This topic comprises 3 pages: 1  2  3

Author Topic: Scope Aperture Plate question Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 11-11-2004 03:15 AM                     Frank, you start with a pinhole and use a nibbler to get yourself in the ballpark. You can get "in the ballpark" within a couple of minutes using that nibbler. From there you have your own customized undercut plate. Pinhole plates are not literally "filed".  |  IP: Logged Phil Blake Jedi Master Film Handler Posts: 558 From: esperance western australia Registered: Nov 2003 posted 11-11-2004 06:20 AM                        We had the opposite problem when installing the new Cinemaccanicas , the standard plates were too big , we had to hammer the edges with a parallel punch and hammmer to spread the metal , then file them back. (without warping the plate so it may stick when changing) not that Cinemaccanica aperture plates stick that much  |  IP: Logged Hugh McCullough Expert Film Handler Posts: 147 From: Old Coulsdon, Surrey, UK Registered: Jan 2003 posted 11-11-2004 07:50 AM                        quote: Ed Inman smaller is .650 x .650 and marked "SuperScope I remember projecting Superscope films in the 1960s. The picture was squeezed, like Cinemascope, but had a black line down both sides. I think that this was to get over the problem of not paying Fox any royalties for using their scope system. They seemed to have the World Patents nicely tied up. At the time there were quite a few weird scope ratios such as MGMscope, Megascope, and Hammerscope are some that I remember. Kalee made a special anamorphic lens called a Varamorph. This had a knurled knob on the top. By turning this knob you altered the position of the two prisms inside the barrel to match the ratio of the print. I think Delrama also made an adjustable scope lens. As for cutting plates. Start with an undercut plate, and use a very fine brand new, and therfore sharp, flat file about an eight inch wide with two safe edges. Cut plate to a very small overlap on the screen masking. When finished throw the file away. Use a new file for every plate you cut.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 11-11-2004 09:36 AM                     I use a dremel tool and a dentist bur to open them up  |  IP: Logged Ed Inman Expert Film Handler Posts: 103 From: Jackson, Mississippi USA Registered: Jul 2004 posted 11-11-2004 10:52 AM                        I found the G-2414 plate at the rsem site. I think that will probably be my best bet. I wish that had been sent in the first place, but you live and learn. I don't have much faith in my ability to accurately file a 650 x 650. Thanks for all the info. Ed  |  IP: Logged Ian Joseph Parfrey Film Handler Posts: 56 From: Bollier Queensland Australia Registered: Sep 2004 posted 11-12-2004 03:55 AM                     Hi Hugh. Do you remember the old "Hi-Lux Fix" British prism 'scope lenses? The pair I bought have a 70' mark on the front element. I gather that these weren't built with wide focus-ing range in mind. They do throw an o.k picture though.  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 11-12-2004 04:25 PM                     Wow. I was sure Mark G. would side with me and use a caliper. But it sounds like you're right, Brad, most people don't use them. So how do you know how far to cut? It seems like a lot of effort to either keep the loop running in the projector and keep iterating between cutting and re-inserting the plate, or to restart the the projector each time. I realize cutting is iterative, but the difference between 20 iterations and 100 iterations is substantial... I suppose you can eyeball the plate against a piece of RP40 as you are cutting it... I guess, for me, using a caliper falls under "using the tools you know." --jhawk  |  IP: Logged Paul Mayer Oh get out of it Melvin, before it pulls you under! Posts: 3836 From: Albuquerque, NM Registered: Feb 2000 posted 11-12-2004 04:46 PM                        How do know when you're there? By looking at the screen. Yes, filing plates is an iterative process.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 11-12-2004 05:16 PM                     I set the masking to the 35PA loop and then file the plate to the masking A caliper will only tell you the size of the opening not its relative position  |  IP: Logged Chris Byrne Expert Film Handler Posts: 102 From: Kirwan, Australia Registered: Jan 2003 posted 11-13-2004 07:56 PM                     I went looking for a nibbler at a couple of local hardware stores and they were all priced at around the AU$100+ mark. I guess this would equate to about US$75+. Is this comparable to what you guys paid? I have had to re-cut a couple of undercut apertures using a fine points file and RP40, however I only have pinhole style apertures left and no nibbler.  |  IP: Logged Pete Lawrence Expert Film Handler Posts: 192 From: Middleburg, PA Registered: Aug 1999 posted 11-13-2004 09:39 PM                     That's an expensive nibbler! They are typically $12 to $15 for a hand operated one. Available in the US from many sources including www.mouser.com. (Edited to replace link with JPG before I got yelled at.)  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 11-13-2004 11:36 PM                     be wary of cheap nibblers they tend to tear at the edges badly  |  IP: Logged Frank Angel Film God Posts: 5305 From: Brooklyn NY USA Registered: Dec 1999 posted 11-14-2004 08:42 AM                        But John, I still don't understand how a caliper can help getting an accurately plate. If you cut the plate to an exact external number, how do compensate for keystoning or for the descrepancies between various formats were the lens steps will not give you an exact match when you are doing common height screens? I mean, the whole idea of filing a plate is to compensate for minute anomonolies that you CAN'T easily predict with numbers. How, for example, do you use the caliper to file for a curved screen or for a projector that is not dead center (which can never be the case in a change-over house)? But then, if the projector is dead on, the screen dimentions are exact, you would just use a precut plate and not have to file anything (then you wouldn't need a caliper at all).  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 11-14-2004 10:27 AM                     quote: Frank Angel But John, I still don't understand how a caliper can help getting an accurately plate. If you cut the plate to an exact external number, how do compensate for keystoning or for the descrepancies between various formats were the lens steps will not give you an exact match when you are doing common height screens? Oh geez, I can't believe this has gone on for so long. The answer is that it does not help. A caliper is completely useless in filing plates, except to possibly make the person cutting them look "more technical and sophisticated" or some such nonsense. That's why I was teasing jhawk about it earlier in the thread.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 11-14-2004 10:48 AM                     "the screen dimentions are exact, you would just use a precut plate and not have to file anything (then you wouldn't need a caliper at all). " That still assumes that ones lateral guides and lens mount are smack on I have never seen a precut plate do an acurate job  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 3 pages: 1  2  3

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.