Film-Tech Forum ARCHIVE: Is common width sometimes better?

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Posted by Lyle Romer (Member # 1266) on 12-02-2005, 12:25 PM:

I know that if an auditorium is properly designed, common height screens are absolutely the way to go. What if the auditorium is not properly designed? There was a trend for a while of very narrow auditoriums. In this situation, with a common height screen, flat films look like they are being projected on a little postage stamp.

When there is a situation where an auditorium isn't wide enough to have a properly sized common height screen, is it better to maximize size for both formats and go with common width?

Posted by Louis Bornwasser (Member # 3063) on 12-02-2005, 12:35 PM:

Tear it down......really!

We lose in two ways:

1. Assuming you actually project the full flat and scope images, you will have a situation I call "inverted reality." Flat usually allows plenty of cropped framing and tight closeups. Scope does not. Inasmuch as the high grossing films are mostly scope (more flat movies; but most leave quickly.) The result is that the scope image seems small and distant, while the flat image is overly large, compounded by the tight close ups.

2. Image quality on flat is reduced (light, grain, & stability.) Naturally we make it bigger; therefore more noticeable. Louis

Posted by Monte L Fullmer (Member # 2797) on 12-02-2005, 01:00 PM:

..then what really kill flat presentations is the usage of the 2.00/1 aperture - like I know of one theatre that uses this ratio since they wanted BIG FLAT pictures instead of optimizing the screen for scope.

Results is of the horribly cramped flat presentation.

..then,there are the ones who crop the crap out of scope features for the same BIG FLAT presentations....

-Monte

Posted by John Pytlak (Member # 331) on 12-02-2005, 01:07 PM:

Been there, done that. I wrote about it years ago:

Kodak: Caring About Composition

quote:
"Scope" Is Meant to be Wider than "Flat"
Filling the full width of the screen for both 2.39:1 scope pictures and 1.85:1
flat pictures is almost as bad as "one size fits all" screens. This poor practice
has become a popular trend in modern theatre designs, especially those with
stadium seating. The misguided idea is to fill the front wall of the theatre with
the biggest image possible, regardless of the intended format. So instead of
maintaining the same image height for the scope and flat formats by using
adjustable side masking, both formats are projected with the same width. The
top and bottom masking are adjusted to letterbox the scope format, and
actually project a much smaller image than the flat format.
What's wrong with this picture? Plenty! First, the wider 2.39:1 scope format is
usually chosen to give pictures greater impact, than the more intimate 1.85:1
aspect ratio. Letterboxing it to a smaller image often violates the intent of the
cinematographer and director in telling a big story.
Image quality of the flat format suffers in comparison to the scope format,
especially when common width screens are used. The projectable image area
of the 1.85:1 flat format is only 65 percent of the much larger and efficient
scope format. It makes no sense to project the much smaller flat film image
area on the print to a much larger picture than scope on the screen. It simply
magnifies the grain and greatly reduces the light level. For example, a theatre
that is getting the SMPTE aim of 16 footlamberts for scope on a 25 x 60 foot
screen, will typically get only about 13 footlamberts for the less efficient flat
format on a 25 x 46 foot screen, which is still within the tolerances allowed by
the standard. But if they try to magnify the flat image to fill a 32 x 60 foot screen, they will only get a sub-standard 8 footlamberts, since the light must
be spread over a much larger screen area. When you project flat and scope
films to the same width on the screen, bigger is definitely not better!

Posted by Lyle Romer (Member # 1266) on 12-02-2005, 01:10 PM:

If tearing down walls is not an option, the scope picture will be the same size either way. It will be as wide as possible and the height will be width/2.39. The issue is with flat.

For example, lets say a 6-6, 180 seat auditorium. So we're talking about 27 feet wide, and 55 or so feet long. Let's assume the widest screen that can be put in is 25 feet.

With common height, the scope image will be 10'5.5" x 25' and the flat image will be 10'5.5" x 19'4.2". This image will appear tiny because you have people (improperly) sitting over 5 screen heights away that will have a lot of black in their field of view.

The scope image will be too small either way but if you made the screen common width, the flat image would be 13'6" x 25'. Now for flat images, people will only be around 4 screen heights back which is more ideal.

Contrast this to a properly designed 180 seat auditoruim. Scope of 17' x 40'7.56" and Flat of 17' x 31'5.4".

So, if knocking down walls isn't an option, is it better to go common width and at least present flat at the right screen to seating ratios?

Edit:
John, I was writing this post when you posted yours. I'll leave this post and see if there is any comment to it with my more specific example.

Posted by John Pytlak (Member # 331) on 12-02-2005, 01:21 PM:

The issues I discussed are due to the physics of projection. The aesthetics in a long, narrow theatre are a subjective decision, but I prefer common image height, and just sit closer (best seats are 2 to 4 image heights from the screen. If you sit 5 to 6 image heights away, you might as well be watching television. [Razz]

Posted by Louis Bornwasser (Member # 3063) on 12-02-2005, 01:34 PM:

Monte: In the South it is 2:1 flat and then crop scope to 2:1. Thankfully the "lens changers" are gone. Someone was using reverse anamorphics and minimizers with even more cropping.

To me 445 x 825 is holy..I never crop that. Scope width I do sometimes play a few games; but only in problem houses. Louis

Posted by Frank Angel (Member # 248) on 12-02-2005, 01:45 PM:

There's a building that is long and narrow. You want to put in an upscale restaurant. Once you put in the kitchen, the only room left is narrow swath of space that can only accommodate bar stools and a narrow bar on which a full size dinner plate will barely fit. Do you say, "Yah, that's great---no one will notice that that we can't fit any tables in there and waiters bump into patrons as they pass them carrying the trays"? NO. You say this place simply WON'T WORK. If you are planning to rent, you find another place to put your restaurant; if you own that long narrow building, you sell it for use as a bowling alley or as Louis says, you TEAR IT DOWN.

Does a curator hang huge Monet paintings in a gallery only 3ft wide so people have to stand 2 feet in front of them to view them? Do you build a car wash that is not wide enough for cars to fit? Do you make donuts with no holes?

How does compromising the very thing that a theatre owner expects to make his livelihood at (selling the movie going experience), ever make an sense? You think The Four Seasons would substitute horse meat for prime rib and no one would notice? Or anyone would come back? How can serious, extreme compromises ever be "OK" in any business, theatres included? To think that it would some how be "better" is a serious, extreme error. Can it be done physically? Sure; then again, lots of businesses are run badly -- thing is, everyone knows which they are and everyone avoids them. Just because a business is run by imbeciles doesn't mean it's OK or that it will even survive. Besides, who wants to have to tell his friends, "Hey guys, come on over to my restaurant; the meal's on me....but I wouldn't recommend ordering the prime rib."

Posted by John Pytlak (Member # 331) on 12-02-2005, 01:47 PM:

quote:
To me 445 x 824 is holy..I never crop that.

Standard SMPTE 195 specifies 0.446 x 0.825 inches as the projectable image area for 1.85:1 "flat". But what's a "mil" among friends??? [Wink]

Posted by Louis Bornwasser (Member # 3063) on 12-02-2005, 02:24 PM:

John: you are right.

Frank: I agree; why handicap a new business (or put an old one on life support) if you can avoid it? The narrow hall is just not an acceptable cinema. Times have changed enough that mere "playback" is no longer acceptable especially in any competitive environment. Poorly split thatres have "been dropping like flies" lately. Louis

Posted by David Stambaugh (Member # 1102) on 12-02-2005, 02:24 PM:

In this town (Eugene & Springfield), there's Cinemark 17 and Regal Cinema World 8.

Regal has a mixed bag. The old/better houses are common-height. Funny thing is though the 2 largest houses with ~480 seats have relatively small screens. I measure them at about 24' flat and 30' scope (going by ceiling tiles). The newer houses have either common width or both top & side masking is movable. Those screens are 40'+ even though they have far fewer seats. In a couple of them the throw is so short and the screens so large that only the back row is acceptable to me. They also crop the sides of scope images in those short-throw houses too much, titles are cut off sometimes.

Most of Cinemark's screens (but not all) are common width. So scope is smaller than the flat. A few screens (4?) have movable side and top masking. Screens there range from about 34' to a little over 40'. They can look good in either flat or scope and even though in perfect world scope should be wider than flat, as long as they get the aspect ratio right I don't think it makes a huge difference, at least not in their setup. I know that's heresy though. [Wink]

Posted by John Pytlak (Member # 331) on 12-02-2005, 02:40 PM:

Most important to show the standardized image area (per SMPTE 195). You can always move to a different seat to be at the correct viewing distance. But with common width, "scope" will be MUCH brighter than "flat", unless attention is paid to matching the light level.

Posted by Brad Miller (Member # 2) on 12-02-2005, 03:04 PM:

quote: Lyle Romer
With common height, the scope image will be 10'5.5" x 25' and the flat image will be 10'5.5" x 19'4.2". This image will appear tiny because you have people (improperly) sitting over 5 screen heights away that will have a lot of black in their field of view.

Well there's your problem. You have the screen on the wrong wall!!! [Razz]

Posted by Monte L Fullmer (Member # 2797) on 12-02-2005, 03:06 PM:

I've seen auditoriums with those Christie SLC (and Reference) with autofocus adjusters on those consoles. Are these for to compensate the reduced light using the flat lens on a big screen to get the lamberts up to a reasonable level..automatically?

thx-Monte

Posted by Brad Miller (Member # 2) on 12-02-2005, 03:08 PM:

Yup.

Posted by Monte L Fullmer (Member # 2797) on 12-02-2005, 03:17 PM:

Now, next question if possible: with the autofocus feature on these consoles, isn't there the danger of overheating the film, especially if one is cooking a 4.2 to 6k bulbs inside when projecting such a big flat presentation ( on a 35 x 62 ft screen) , or is an area that is pretty well under a controlled operation where this isn't too much of a concern?

thx-Monte

Posted by John Pytlak (Member # 331) on 12-02-2005, 03:24 PM:

Yes, with a large lamp, you do need to be careful not to "hot spot" to the extent you might cause heat damage to the print. Be especially careful with silver image B&W prints and prints with deliberate silver retention processes.

Posted by Louis Bornwasser (Member # 3063) on 12-02-2005, 03:43 PM:

Brightness-wise scope will take care of itself even if misaligned. Flat however will forevermore be dark.

Remember if flat height is 35 ft, then the scope width the lamp thinks it is illuminating is 82.25 ft; a VERY large screen. Flat light level will be appropriate for an 82 ft screen....6k?

Louis

Posted by Robert E. Allen (Member # 1351) on 12-02-2005, 04:22 PM:

quote:
"Scope" Is Meant to be Wider than "Flat"
Filling the full width of the screen for both 2.39:1 scope pictures and 1.85:1
flat pictures is almost as bad as "one size fits all" screens.

Way to go John!!!!!

For too long some exhibitors have been cheating the moving going public out of the effect of "scope", stereo surround sound process with the "one size fits all" presentation.

Ya know what I miss? The Fox CinemaScope logo. One of the theatres I owned was equipped with Panatar variable anamorphic lenses and I would hit the screen with the image compressed and as the theme played I would slowly expand it to its full width. It never failed to impress the audience.

Posted by Brian Guckian (Member # 1678) on 12-02-2005, 05:33 PM:

Remember too that a long narrow auditorium is bad acoustically, and you're often into using very long focal length lenses as well, which can sometimes be awkward in terms of getting ones which closely fit the required image sizes.

Why not shorten the auditorium? Moving the stage area forward is probably the easiest way, and would create room at the rear which could be used for other purposes, e.g. an additional foyer area perhaps.

Worth thinking about; sure you lose seating capacity, but as has been pointed out, they're not good seats at the back anyway!

Posted by Monte L Fullmer (Member # 2797) on 12-02-2005, 06:32 PM:

Yes, I miss that "CinemaScope" logo as well. It was great to see it on the screen again last year with the movie (I forget the name and it kinda flopped some) that had E. Magregor in it.

Panatars variables were an interesting set of anamorphics. I ran a "hole-in-the-wall" buck house theatre that had a set of these hanging on the front of a pair of SuperSimplexes. During kid shows and with the cartoons, I'd do the same-set the attachment so the cartoon would play full-frame (even though a small picture) then reset it for the feature...

-Monte

Posted by Mark Hajducki (Member # 1732) on 12-03-2005, 11:56 AM:

One of the worst features (from a non-projection trained audiances perspective) is the reduction in screen size from the flat adverts to the scope feature.

Posted by Robert Harrison (Member # 3202) on 12-03-2005, 05:42 PM:

Hey, Monte,

That movie you are thinking of was "Down With Love." I, too, appreciated that CinemaScope logo, even if it was only a joke to put you in the mood. The end credits list Panavision.

Posted by Daryl C. W. O'Shea (Member # 1303) on 12-03-2005, 09:32 PM:

quote: John Pytlak
But with common width, "scope" will be MUCH brighter than "flat", unless attention is paid to matching the light level.

That's the one great thing about common width screens. If the flat image is at least close to being properly lit, the scope image will be nice and bright.

Posted by Stephen Furley (Member # 1277) on 12-04-2005, 03:46 AM:

About the only advantage I can think of is that if you run a lot of Academy ratio films you will have a nice large screen size for them. [Smile]

I suppose it could be said that if you're using something like Kalee Varamorphs (there are still a few places) that lose a lot of light, then your scope picture will not be dim, but buying new anamorphics would be a better idea.

Of course, when Cinemascope came in a lot of cinemas were running very old equipment, and gettng enough light on the screen was a serious problem. Many places had to replace their arcs, or even completely re-equip. It's odd that today, with better lenses, and common width, it's the Scope picture that's brighter.

Posted by William Hooper (Member # 71) on 12-05-2005, 01:22 AM:

This is the problem that killed a lot of successful "storefront" theaters several years after cinemascope arrived. With a screen 20' wide, the picture was 14.5' tall & worked OK in the room.

As scope titles became more numerous & it was neccessary to install Cinemascope equipment to remain competitive in booking (after holding out as long as possible running just Academy), the scope picture was just 8' tall & completely unacceptable.

That's why those theatres are gone; they couldn't compete because they were unsuccessful at running the scope format.

If it's an historic theatre with a small front end & you've got to run scope & flat, you must have *not* common width or height, but adjustable side & top masking so that the image size for both formats can be maximized. Obviously, the wider the screen is to begin with, the more acceptable this is to an audience.

At 25' wide, the scope picture will be only 10.5' tall. That's screening room size. The room really can't be very long or the folks that get the seats in the rear won't be coming back.

Cute, but I don't think it'll do a lot of repeat business these days.

If you're stuck with the room, I'd go with shortening it, & also adding a small balcony a few rows deep. Balconies are popular, & the Prytania in New Orleans often rents the entire balcony out for birthday groups, etc. I mean often; almost every weekend I visit they've had a balcony rental. If you're adding a balcony today, you'd need an elevator too as well as other considerations for satisfying ADA.

Posted by Mark Hajducki (Member # 1732) on 12-05-2005, 07:07 AM:

The Electric Cinema London has a screen that 'folds' out from the proscenium arch for widescreen films and 'folds' back afterwards so the curtains can close.

Posted by Steven J Hart (Member # 2340) on 12-05-2005, 07:28 PM:

Many of you would really hate my theater!

This theater was built in 1936 with the auditorium only 23'6" wide with seating area extending back about 80 feet. (This picture was taken from the front of the balcony) The seating area used to go back 114 feet. The reason the building is so narrow must have been because the original business district lots were only 25' wide.

As you can see by the image above we have tons of headroom so when I installed a new screen I thought it made sense to install a fixed-width screen 23' wide by 12' 5" high to maximize the image area for flat features. My Scope picture is still as large as possible so whats been lost? My audience may not be very discerning, but I've never had a complaint about the Scope image being "too small" in comparison with the Flat image. The nearest competing theater is about an hour away so I guess my customers are just happy to have a theater in town. I think most of our customers would be pretty upset if we had bulldozed the theater "because it was too narrow" instead of restoring it. [Wink]

Steve

Posted by William Hooper (Member # 71) on 12-06-2005, 12:57 AM:

quote: Mark Hajducki
The Electric Cinema London has a screen that 'folds' out from the proscenium arch for widescreen films

Neat idea if the room is wider than the proscenium; in theatres like Steven Hart's, though, the room is no wider than the 'proscenium'.

I wonder how they avoid visual evidence of folds on the screen when it's folded out.

There should be 4 or 6 ranks of theatre organ located on top of the exit vestibule at left. Someone needs to be fired.

quote:
Many of you would really hate my theater!

If it works, it works, & it's working for me!

It's also a good example of how a center aisle is neccessary in a narrow room. Especially since the width must be 36" to comply with ADA. Stick 2 aisles on the sides, & you lose too many seats.

The sconces are GREAT! I know you had to expose the pictures for other features in the auditiorium & blow out the light from the sconces, but I can tell the shapes of light cast by them are cool!

I demand a movie theatre deco valance or even a rudimentary proscenium in that sleek room with the cool sconces!

edit:

There's your valance.

Also, if you can't make it work, turn it into a bit: make that speaker cabinet at center work for you by getting a grille for it & sticking your logo in the middle of it. Heck, make an acoustically transparent cartouche out of chicken wire & fabric & stick it on there. Shine a special on it. Front & center is your space, not JBL's!

edit again:

Those white HVAC grilles over the screen are hurting. Get some cheap scrim material, stretch it over a frame, staple it in folds radiating in a pattern from the bottom center (a classic movie theatre deco shape), & screw the panel of scrim material over the panel with the HVAC vents.

The house lights hitting it & the folds will make it more fascinating than the diagram. Get some scrim material with some metallic threads in it & it will pop. You'd need someone like Bobby Henderson to do the colors. I'm a mechanic, not an artist.

It's the old gag with a lot of horizontal lines & surfaces over the screen de-emphasizing a large area above it.

[ 12-06-2005, 03:12 AM: Message edited by: William Hooper ]

Posted by Steven J Hart (Member # 2340) on 12-06-2005, 07:02 AM:

William, Thanks for the advice. I've been looking for ideas on dressing stage area of the theater. I have almost no sense of "design", but can fix the boiler or the projector in a snap. I'll be trying some of your ideas in the future.
Steve

Posted by Dave Macaulay (Member # 813) on 12-06-2005, 03:57 PM:

"Are these for to compensate the reduced light using the flat lens on a big screen to get the lamberts up to a reasonable level..automatically?"
Being, as usual, too technical...
The lamp would be specified to light the flat image to whatever spec the owner wants; hopefully 14-16 ft-L if they're doing it right.
So actually the automatic lamp focus shifter is there to reduce the brightness of the scope image. Too bright changes the "look" of the film as much as too dim does, and bright scenes will have annoying flicker.

Posted by Bobby Henderson (Member # 840) on 12-06-2005, 04:11 PM:

I have a pretty strong dislike against common height screens. But there is something even worse: fixed aspect ratio screens.

For example, the Sikes Ten theater in Wichita Falls, TX has some smaller, narrow theaters with screens that only do 1.85:1. Even worse, the auditorium's emergency exit is off to the side of the screen. That makes the screen appear off center in the auditorium. Add to this the even worse problem of the projector throwing the image at an angle from a port that is off toward a corner of the small room. What you get is one edge of the film frame lined up properly with the edge of the screen -but then a bunch of the other end of the frame is lopped off!
[Roll Eyes]

This sort of thing is one major reason why movie theater companies should avoid building new theaters inside shopping malls.

Posted by John Pytlak (Member # 331) on 12-06-2005, 10:15 PM:

quote: Dave Macaulay
Too bright changes the "look" of the film as much as too dim does, and bright scenes will have annoying flicker.

Standard SMPTE 196M allows up to 22 footlamberts for theatres, with an aim of 16 footlamberts screen luminance. With a two blade shutter (48 interruptions per second), most people start to perceive the shutter flicker in bright scenes if the open gate luminance exceeds 22 footlamberts. You can go brighter at higher frame rates or with a three-blade shutter, and in most cases, the images look very good, but not necessarily what the director and cinematographer intended. (e.g., you might see something in the shadows they don't want you to see).

Posted by David Stambaugh (Member # 1102) on 12-06-2005, 10:50 PM:

quote:
You can go brighter. . . with a three-blade shutter, and in most cases, the images look very good, but not necessarily what the director and cinematographer intended. (e.g., you might see something in the shadows they don't want you to see).

I don't understand. How would using a 3-blade shutter cause that? [Confused]

Posted by John Pytlak (Member # 331) on 12-06-2005, 11:18 PM:

quote:
I don't understand. How would using a 3-blade shutter cause that? [Confused]

Going too high in screen luminance may let the audience see too much detail in the shadows. With an underexposed negative, the blacks in the print may look "milky" and you will notice the grain more. But a really well exposed scene and good print will usually look very good at higher screen luminance.

Posted by Monte L Fullmer (Member # 2797) on 12-07-2005, 01:25 AM:

..silent speed projectors (16fps) also used that 3 bladed shutter to have that same 48 pulses of light.

Posted by Carl Martin (Member # 1146) on 12-07-2005, 03:20 AM:

what open gate luminance would allow most people to perceive flicker if the shutter has two 100 degree blades?

Posted by William Hooper (Member # 71) on 12-07-2005, 04:32 AM:

quote: Steven J Hart
I've been looking for ideas on dressing stage area of the theater. I have almost no sense of "design"

Same here, I just have gotten to notice what's missing from the pipe batten, & why it was there by the way it looks when it's gone.

If you do it, you need to sort out how all the components work at the same time, & the only other component that may be missing is if you use top masking only for scope. Only the leading 6" or so of the side or top masking is black, the rest is something else that goes with the house decoration. Otherwise, the screen does look small & awkwardly thrown in:

Fortunately, top masking is usually a panel, so it's easy to just apply above the leading black edge whatever fabric or whatever is going to be used. This is technically a lambrequin: a panel with fabric on top of it that sort of impersonates a drape.

This panel is the only one where you can use vertical folds (pleats here, really, since they're flat). A "straight valance" with vertical folds really looks lowball over a screen because the lines run in the wrong direction. However, if you've got a valance or pseudo-prosc above it with lines running horizontally or radiating, you can go with vertical lines on a short lambrequin beneath it to get eye-busying variety & to de-empahsize the sliveriness of the lambrequin. There must be some sort of demarcation at the bottom of the decorative panel where the black edge starts; not a fringe (which is wrong for deco), I forget what they're called at the fabric store. It's just a fabric border-y thing in a roll, sometimes it looks like a few-inch-wide fabric thing, some are like soft cloth rope.

The audience manipulation part about reducing the screen size with the top masking is to tart it up somehow with some eye candy so that it becomes something new to stare at & wonder what the hell that's all about when it comes in. I personally would enoy an RCA meatball stuck in the middle of the lambrequin on the top masking, but if you'll be disguising the speaker with a single, central element already, you'll need something more horizontal in layout. In a frenchy-looking movie palace, you could put a silhouette of Phaeton joyriding or something, but in a deco house, it's all about geometric shapes. You don't want something else out of left field adding to the clutter, so I always look around to find some existing element that might can be utilized there in the star position. Just from the photo, the only shape that pops out is the silhouette of the sconces, so they could be a candidate somehow:

If that works for you, go to Home Depot, buy 4 panels of sheet metal, cut them in silhouettes of the nested bowls of the sconces, spray them dark gold, & stick them on the lambrequin. I've noticed in deco houses with cast metal figures of some sort that they're almost always just silhouettes with a small bit of geometric relief: you could do the same by taking each cutout and giving it a soft vertical bend no more than 1" up the center. Don't shine a light on it, the two slightly differently facing sides will have sufficient eye-candy action in the houselight scatter.

Someone else will really need to work out the design with you, these are just the components & how they're laid out, especially considering that it must be something that works visually with your grand drape.

The missing components:
False prosc/valance thing
Lambrequin panel on top masking
(in your case) panel or something over the AC ducts

The neat thing here is that in your case, you might be able to do it all just by getting enough scrim material for all 3 components. They're all basically lambrequins, just stapling fabric to a panel & then hanging the panel. Radial pleats on the AC panel, horizontal pleats (with maybe a sort of swirly thing in the center) on the valance, vertical pleats on the top masking.

Hopefully, you & someone else can work out colors & maybe work out something better for the top masking design which isn't really setting me on fire.

All right, this is starting to work for me.

Posted by John Pytlak (Member # 331) on 12-07-2005, 05:33 AM:

quote: Carl Martin
what open gate luminance would allow most people to perceive flicker if the shutter has two 100 degree blades?

You still should stay in the standard SMPTE 196M range of 12 to 22 footlamberts, and aim for 16 footlamberts. Whether the blades of a two-blade shutter are 90 or 100 degrees, it's still a two-blade shutter with 48 interruptions per second.

Posted by Ken Lackner (Member # 1002) on 12-07-2005, 01:57 PM:

quote: John Pytlak
Standard SMPTE 196M allows up to 22 footlamberts for theatres, with an aim of 16 footlamberts screen luminance.

I thought the standard was 16 +/- 2 foot lamberts. [Confused]

Posted by John Pytlak (Member # 331) on 12-07-2005, 10:10 PM:

quote:
I thought the standard was 16 +/- 2 foot lamberts. [Confused]

Screening rooms (e.g., where color timing decisions are made) have a tighter tolerance than theatres.

Posted by Carl Martin (Member # 1146) on 12-08-2005, 01:44 AM:

quote: John Pytlak
You still should stay in the standard SMPTE 196M range of 12 to 22 footlamberts, and aim for 16 footlamberts. Whether the blades of a two-blade shutter are 90 or 100 degrees, it's still a two-blade shutter with 48 interruptions per second.

well, we do have a flickery screen with 100 degree shutter blades. i'm pretty certain it's not anywhere near 22 ftlamberts even in scope, though i haven't measured it. apparently the flicker is not in the lamp itself, either.

carl

Posted by Dustin Mitchell (Member # 372) on 12-08-2005, 03:23 AM:

Diode?

Posted by John Pytlak (Member # 331) on 12-08-2005, 05:39 AM:

If you have too much current ripple in the DC supplying the xenon lamp, the 60 Hz ripple will "beat" with the 48 Hz or 72 Hz shutter frequency, producing a very visible 12 Hz. flicker. Check for current ripple and possible causes (e.g., a bad diode, deteriorated filter capacitor, or missing leg on 3-phase).

Posted by Carl Martin (Member # 1146) on 12-10-2005, 03:01 AM:

that was what i had suspected, but our union guy looked at the light (briefly) without the shutter running and said it was steady. i was surprised that a ripple would have been visually discernable without interference from the shutter.

Posted by System Notices (Member # 2357) on 12-15-2013, 01:01 AM:

It has been 2926 days since the last post.

Posted by Ron Curran (Member # 3631) on 12-15-2013, 01:01 AM:

I assume that Tim Winton's The Turning DCP was designed for common width presentation.
This feature is based on the author's book of short stories, each story has a different director for the movie version.
Some directors prefer the expanse of the Scope format, while others prefer the more intimate flat format.
The DCP is 1.85, so the Scope sequences are letterboxed.
Frankly, I am embarrased by this presentation on our common-height screen but there is no easy fix. If the DCP had been Scope, we could have plotted the automation to adjust masking accordingly - the flat portions would have been just the same but the Scope portions would have been correct.

Posted by Jim Cassedy (Member # 4115) on 12-15-2013, 10:37 AM:

quote: Carl Martin
that was what i had suspected, but our union guy looked at the light (briefly) without the shutter running and said it was steady. i was surprised that a ripple would have been visually discernable without interference from the shutter

Carl, YOU are right, and in this case your 'union guy' is a bit off base.
I recently dealt with a similar situation last year.

Yes, you'd be able to see a large amount of ripple when viewing a light source
sans shutter; but often, small amounts of ripple or phase unbalance can only
be seen when viewed on screen with the shutter running.

At one time, I made an inductive scope probe using an old coil of wire to
detect a tricky ripple on the DC line.

I had an electronic scope with storage capibility so I was able to compare
the ripple wave-form with that from a known 'good' power supply to help
track down the problem.

In my case, I traced the problem to a failing filter cap in an old (well, actually, ANCIENT!)
carbon arc rectifier power supply that had been badly bastardized to work with the Xenon.

Posted by Jason Metcalfe (Member # 5739) on 12-22-2013, 04:41 PM:

I know this is the wrong forum but what do you guys think of common width screens for digital projection since the screen size would more closely imitate the amount of LCOS/DLP panel that's being used?

Posted by Marcel Birgelen (Member # 6801) on 12-22-2013, 05:29 PM:

My personal, unbalanced opinion: [fu]

Look in the mirror, what do you see? Two eyes, horizontally aligned.

Scope should be wider than flat and scope is by far the best format if you want to make an impact.

Why should we all collectively bend over for some stupid "industry standards" that are only there, because that happens to be the gold standard for home entertainment?