Film-Tech Forum ARCHIVE: Masking Tape Aperature Plate

This is topic Masking Tape Aperature Plate in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Sean McKinnon (Member # 612) on 11-27-2000, 11:04 PM:

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I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

Posted by Randy Stankey (Member # 64) on 11-27-2000, 11:21 PM:

Don't you know that the photons comming out of the lamphouse wear away the edges of the aperture plate, causing the hole to get bigger?

Happens all the time!

That's why they had to mask off the window. The aperture plate needs replacing because the hole's too big!

Posted by Sean McKinnon (Member # 612) on 11-27-2000, 11:39 PM:

Oh geez how could I forget! DAMN cheap aperature plates! why dont they make those things out of metal?

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I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

Posted by Mike Spaeth (Member # 524) on 11-27-2000, 11:58 PM:

The only time I've ever seen this was during one of those rush opening jobs. It was just during the "pre-opening" screenings (Thursday). They had the plates cut in time for opening day (Friday).

Posted by Sean McKinnon (Member # 612) on 11-28-2000, 12:03 AM:

its wierd though it looked fine on screen

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I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

Posted by Jerry Chase (Member # 660) on 11-28-2000, 12:27 AM:

IIRC, when some of the 1970s 3-D came out, we had to go full heat shield opening and use construction paper and tape to mask the edges on the port glass. Those were the instructions from the installers of the time. Of course it was the 70s, their clothes did smell of wacky 'backy, and they had an aversion to bright light.

I've seen lots of masking tape cardboard shields in theatres where the architect designed a picture window port and a flourescent ceiling fixture light in the booth. A lot of these ended up with a tiny beam hole for the projector and a slit worthy of an armored car port for the projectionist. (Which reminds me, CPI makes a pretty darned good two piece port, but some theatres are neglecting to install the caulking or sound insulation to keep the projector noise from leaking through the joint. Ever attended a movie when the projectionist didn't know he could be heard in the auditorium? Oops!)

Sometimes the masking tape might have been better than the mis-filed or swapped plates in some theatres. I remember walking into one theatre (which shall remain nameless) where the manager/projectionist had installed a new factory plate and couldn't understand why the picture didn't fill the screen... At least that was fixable. I've seen massively overfiled plates as well, that looked like the rats had nibbled the edges.

Posted by Aaron Sisemore (Member # 145) on 11-28-2000, 12:33 AM:

I too have had to do taped aperture masking in 'emergency' situations where I have corrected the screen dimensions and changed lenses (in most cases to the CORRECT aspect ratios, many were WAY off) and either had no undercut apertures on hand, or the powers-that-be wanted a show on screen 'like right NOW!' and I was unable to have a plate cut in time for the show. When doing the glass-masking, I preferred to use cardboard or heavy paper and small amounts of masking tape. Next choice would be to use carefully placed duct tape. Of course soon as I was able to do so, a new set of correctly cut aperture plates were done for all these booths.

Aaron

Posted by John Pytlak (Member # 331) on 11-28-2000, 06:48 AM:

Must be interesting when they change between "scope" and "flat" --- do they have automated tape changers?

Not using an aperture plate in the projector also throws alot of additional "stray" light into the lens, killing contrast. There is nothing really wrong with using opaque (black) tape or black cardboard to control stray light, and keep it from hitting the screen, but it should not be used to replace properly sized aperture plates. Non-opaque masking tape is probably throwing alot of stray light into the theatre as well.

For more on "contrast killers":
http://www.kodak.com/US/en/motion/newsletters/reel/december99/pytlak.shtml

My next article in Kodak's "Cinema Notes", "Caring About Composition", discusses the need to maintain proper image size and masking.

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Barry Floyd (Member # 385) on 11-28-2000, 07:59 AM:

It would be safe to "assume" that the Gloucester Cinema 1-2-3 in NOT a THX approved house??

Posted by Bruce McGee (Member # 131) on 11-28-2000, 09:21 AM:

The now defunct Columbia Theatre on Peachtree Street in Atlanta used to have a cardboard aperture in front of the glorious Cinemeccanica V8. I never thought anything of it. The on-screen image was glorious.

The cardboard plate was cut to prevent any stray light from hitting the masking around the screen, or from bouncing off the ceiling. When watching something like Oklahoma! in 70mm 30fps I could see a very slight overlap on the mask at the sides. A dab of black duct tape and it was perfect. By the way, the image was mirror-like. I miss 70mm and that theatre!

Posted by Adam Martin (Member # 641) on 11-28-2000, 09:35 AM:

I remember running a couple of Norelcos (don't remember the model, the big gold ones) that had plates that were fastened in and couldn't be changed without unthreading the projector. To do a lens change, we put the scope plate in the projector and a cardboard cutout in the port and the flat lens in the projector. Then close the dowser, remove the cutout and change the lens for the scope feature.

Of course, this was back when we actually had curtains that we could close while the masking was moving and a film tag that said something like "Our feature presentation is in the widescreen format. Our projectionist will now making these adjustments." Then the curtains closed and reopened with a wider scope screen.

Gee, I miss those projectors. Too bad the parts are so expensive now that theatres are pulling them out and putting in cheaper projectors.

Posted by Jim Bedford (Member # 4) on 11-28-2000, 10:04 AM:

They should have at least used paper tape. Everybody knows that masking tape and film don't mix!

Posted by John Walsh (Member # 168) on 11-28-2000, 10:46 AM:

Yeah, I've seen and used tape on the window, too. You have to give those people in Mass. a little credit; I've also seen places that didn't bother to mask the image at *all*

Maybe, someone could be nice and send them a used aperture plate they don't need that is already too open. While it wouldn't trim off the screen, it would at least prevent the light from shinning all over the inside of the booth - better than nothing!

Personally, I like to use black electrical tape, as it sticks well and comes off cleanly (unlike the "remove within 24 hours" cheap stuff.)

When we first installed DTS, we quickly found which apertures were filed to far, and had to use tape to clean it up until new plates could be ordered and installed.

Posted by Ken Layton (Member # 133) on 11-28-2000, 11:08 AM:

I've seen some theater owners who were so cheap they didn't have ANY aperture plates! They thought it was better just to buy a roll of masking tape.

Posted by Rory Burke (Member # 512) on 11-28-2000, 01:07 PM:

I guess I would rather have a masking tape MacGiver type slap it together job that reflects the proper aspect ratio than a poorly cut aperature plate with a piece of lint hanging off it.

Rory

Posted by Sean McKinnon (Member # 612) on 11-28-2000, 02:01 PM:

I think that they have 2 pieces of glass one for flat and one for scope and they swap them

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I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

Posted by John Pytlak (Member # 331) on 11-28-2000, 02:50 PM:

Then they have automated port glass changers?

Posted by Ben Wales (Member # 92) on 11-28-2000, 03:24 PM:

Hello John at Kodak.
Gloucester Cinema 1-2-3.

I wonder this cinema will apply for the Screen Check in the future?

Posted by John Pytlak (Member # 331) on 11-29-2000, 06:01 AM:

Hi Ben:

As I originally noted, there is nothing wrong with using opaque tape or cardboard around the ports to keep stray light off the screen. But it should NOT replace properly sized apertures. Projecting without an aperture allows lots of additional non-image light (from the soundtrack and edges of the film) to enter the lens --- this stray light reduces the contrast of the projected image.

Standard SMPTE 195 specifies the projectable image area for 35mm prints. Correct image size should always be verified using the SMPTE 35-PA (RP 40) Projector Alignment test film.

Incorrect image size or excessive stray light are severely penalized in the Kodak ScreenCheck Experience program, and this theatre would likely fail certification until this problem is corrected.

Posted by John Wilson (Member # 269) on 11-29-2000, 04:29 PM:

IMAX uses the cardboard on the port. Works just fine...although there is no automation to change it from top deck to bottom deck...

Posted by Carl King (Member # 398) on 11-29-2000, 09:35 PM:

I've never heard of anything so stupid in my life.

Posted by Sean McKinnon (Member # 612) on 12-01-2000, 02:04 PM:

Well I just got an E-Mail calling me a "little inconsiderate son of a bitch" because they were nice enough to do me the favor of letting me into the booth and I posted this article! Hey, Sorry! why dont you register and posta reply here explaining why you do this? be constructive hey you know what maybe someone woulda sent you a couple old aperature plates. The whole cinema industry on the NOrth Shore already knew you guys did that I wanted to see for myself. as I said IT LOOKS FINE ON SCREEN! if your ashamed of it or something then try talking to your owners anf convince them to get aperature plates PRINT OUT THIS THREAD AND USE IT TO BACK UP YOUR ARGUMENT! and I apologize if I sounded negative I forgot to mention that the lobby was very clean. and They have new seats.

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I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

Posted by Scott Norwood (Member # 30) on 12-01-2000, 03:05 PM:

I can just see someone making the budget decisions for this place: "gee...let's see...we can spend $6 apiece on aperture plates (2-4x per projector) and maybe $20 for a file or we can spend $35-200 apiece on seats (several hundred per screen); what should we buy this year? I vote for the seats and $2 for a roll of masking tape!"

That isn't to say that seats are unimportant (I hate uncomfortable theatre seats), but any place that can afford new seats and installation of same ought to be able to splurge on new sets of aperture plates.

Posted by Gordon McLeod (Member # 33) on 12-01-2000, 05:46 PM:

Most of the newer Imax machines actually have apperture plates fitted in the fieldflatner block
The older ones didn't mainly because the machine is fixed back about 3-4' from the port to allow the operator to walk in front to thread.

As such the image on the port is about 3' across making it much easier and sharper to tape the glass

Posted by Sean McKinnon (Member # 612) on 12-02-2000, 01:51 AM:

Hi I just want everyone on the forum to know that due to this post I have gotten many Rude E-Mails from people connected to this theatre ie:Your mama is so fat... Sorry mym mother abadoned me and is in florida

and my email account has boon "Spoofed" my e-mail adress has been added to hundreds of mailing lists however AOL has a block and sorry it didnt work!

I am so glad that this forum attracts so many intelligent and mature people but the few who arent bring the whole place down! Over one persons opinion of a theatre! HEY YOU KNOW WHAT? 2 screens in my theatre have top masing and a small scope picture! my theatre 7 has ashort throw distance and the lamp focusing is bad! all our platter decks are scratched,some of our policies, and moviephones are dirty! OH MYGOD! maybe I should sent nasty emails to myself! and put my name on 100+ mailing lists! give me a break! im sorry for the rant but this is sooo childish! and to the gloucester cinema I AM SORRY! but everyone elso on the forum seems to share my opinion!

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I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

Posted by Randy Stankey (Member # 64) on 12-02-2000, 01:48 PM:

Just ignore the bastards!

Posted by John Walsh (Member # 168) on 12-02-2000, 01:52 PM:

Oh, I get it... they run a little too cheaply, but it's your fault for noticing it...

If that theater is reading this.......You're supposed to use aperture plates on projectors. That's why they make them. They are not "extra parts" that you can do without.

Posted by Gordon McLeod (Member # 33) on 12-02-2000, 02:19 PM:

Since they obviously lurk here then post the email addresses of the people who sent you the hate mail and all the pros

can send them directly their comments on taped appertures

Posted by Evans A Criswell (Member # 381) on 12-02-2000, 07:05 PM:

If the employees at that theatre sent abusive email messages to you or in any way violated the policies that most ISPs have in place, send email to abuse@ the ISP's domain that they sent the mail from. I would also suggest writing a letter to the theatre company's home office concerning the matter and enclose printed copies of the abusive email messages.

Just because people do not agree with you does not give them the right to abuse you through email or inconvenience you by playing games with your email address (like putting you on mailing lists). It seems to me that this particular theatre you mentioned has a concentration of computer geeks, which I find rare around here in Huntsville.

Evans A Criswell
http://home.hiwaay.net/~criswell/theatre/

Posted by Sean McKinnon (Member # 612) on 12-03-2000, 11:06 PM:

Well it seems Ive made quite a mistake! The gloucester cinema does have aperture plates. They are just worn. They are waiting for replacements and new equipment. It is really a nice theatre. They do a great job of providing the people of the gloucester area a place to ge see movies inexpensivley. The staff and ownership do take great pride in the work they do and they try very hard to be the best they can. Its too bad not all theatres have the commitment and dedication that the gloucester cinema does then maybe the industry wouldnt be in all this trouble! also its not anyone with the theatre that had been sending me harrasing mail it was an ex employee! so my apologies to the gloucester cinema!

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I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

Posted by Brad Miller (Member # 2) on 12-03-2000, 11:11 PM:

Perhaps after they get their new apertures installed, they will send us in some pictures to add to our warehouse.

Posted by Randy Stankey (Member # 64) on 12-03-2000, 11:19 PM:

Yeah, that hard steel file against the soft brass aperture plate DOES tend to wear them out after a while!