Film-Tech Forum ARCHIVE: Light on Screens (DRIVE-In)

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Posted by Ron Funderburg (Member # 4561) on 05-27-2008, 03:58 PM:

One of my Drive-In accounts didn't have enough light on their screen. They were running 3000 watt bulb in a Century Projector and pretty old lenses. After many, many discussions we at last changed the power supply, the lamp house and upped the bulb to 4500 watts. They at first were not very happy with the outlay of cash but once the customers starting telling them what a nice picture they had now they came around.

I guess my question is how many Drive-Ins or for that matter indoor theaters are running to dim a picture to save money on the bulb and electricity. Don't you guys agree you get more back from the paying customer if you do it right?

(Edited to correct Drive-Inn to Drive-In)

[ 05-28-2008, 10:36 AM: Message edited by: Ron Funderburg ]

Posted by Brad Miller (Member # 2) on 05-27-2008, 06:47 PM:

4500 is still not enough. Any drive-in not running at least a 6000 watt bulb isn't set up properly.

Posted by Louis Bornwasser (Member # 3063) on 05-27-2008, 06:50 PM:

In a drive in, it's all about the light! No light, no picture. Anything below 4500 watts with a top grade lamphouse; water cooled projector, and new, excellent lenses is criminal. Screen size is not relevant, since 4500 watts on a small screen will allow an even earlier start.

Double the light, start 1 hour earlier; 2x the gate and 4x on concessions. The average result of 10 drive ins.

In the 60's & 70's we had 2 sets of lenses to allow an even earlier start. Louis

Posted by John Wilson (Member # 269) on 05-27-2008, 10:25 PM:

Only one 'n' in 'in'. (unless you're staying overnight).

Posted by Tim Reed (Member # 137) on 05-28-2008, 12:03 AM:

Thanks, John! [Wink]

FWIW, the single best thing you can do for any drive-in is get new lenses. Even with existing lamphouses, that difference alone can be phenomenal.

Posted by Monte L Fullmer (Member # 2797) on 05-28-2008, 02:44 AM:

Dang, same setup that I work with at this drive-in in my area...

..and with a 3k bulb in that XENEX hitting a 45x90 screen 400ft away..and can't get the owner to do some serious upgrade with this setup.

..least the lenses are Schneiders...

Posted by Louis Bornwasser (Member # 3063) on 05-28-2008, 05:57 AM:

He must be allergic to money! Louis

Posted by Paul Gordon (Member # 3320) on 05-28-2008, 07:09 AM:

If its about saving electricity "technalight" could be an option... basically its a retrofit lamphouse that greatly increases your light.

We had our 2000watt lampghouses done (indoor cinema) and now they act like 3000 watts. with large drive in lamps the increase is even greater, 4000watts acting like 7000watts etc.. with a very even and great contrast..very punchy

http://www.robertfilm.com/english.html

Posted by Scott Norwood (Member # 30) on 05-28-2008, 08:18 AM:

quote:
He must be allergic to money!

Aren't all theatre owners? [Frown]

So, does the Technilight thing really work? As in, does it give more light per watt without damaging film? Are there any issues with the quality or evenness of the light?

Posted by Ron Funderburg (Member # 4561) on 05-28-2008, 09:31 AM:

We are working on new lenses and yes technalight does work, no he hasn't got technalight but it is an upgrade we are looking at. The lamp house does have a glass reflector.

This guy will spend money unlike many drive-in owners and sorry for the double n I was tried maybe that had something to do with it. They also already figured out they can start earlier than before.

The projector isn't water cooled now but it was in the past and we are looking to set it back up that way in the near future. The previous owner didn't throw anything away he just took the stuff off and put in storage! But there is a lot of stuff in storage!

Monte I like the footstool to be able to get up high enough to do the tread work! I have seen that booth set up before.

Posted by Mark Gulbrandsen (Member # 72) on 05-28-2008, 09:48 AM:

With a technilite conversion and 5kw lamp its very possible to hit the 20 footlambert level on many a drive inn screen.

Mark

Posted by Ron Funderburg (Member # 4561) on 05-28-2008, 10:38 AM:

Brad it is there drive-in and I can't make them spend the money to have everything perfect. All I can do is get them to spend what I can and get the picture and sound as good as I can.

Posted by Jack Ondracek (Member # 1466) on 05-28-2008, 10:42 AM:

I don't know of any drive-in that intentionally under-powers their lamps. Anyone who keeps his head above ground level has at least heard that this can be about as hard on a bulb as overpowering it.

It's more likely a problem of not having updated their lamphouses or lenses since the theatre was built (or converted to xenon). There are LOTS of drive-ins that are using old ORC lamphouses. Their 4,000 watt boxes are about as efficient as a 1,800 watt Super Lume-X, and their consoles are worse. Going through some of the online tours, I'm still seeing Panavision and those old B&L anamorphic adapters... light hogs.

There are also a few out there that don't have 3-phase power. I've seen a couple with Xenex lamps, but they have no ambient light problems and their owners think they're just fine.

I have 7kW Big Sky lamps here. So far, I haven't seen anything that beats them... at least not in this application. Switching to Schneider lenses on our big screen made a noticeable difference as well.

This kind of stuff costs money that a lot of drive-in operators can't see putting back into that part of their business. Having done it though, I'm a big believer. There are other drive-ins in our state that our customers can go to, so comparison is possible. If anyone were to tell me that one of those places had a picture that came anywhere close to mine, I'd be going over there to see why pretty fast.

Posted by Ron Funderburg (Member # 4561) on 05-28-2008, 10:50 AM:

Jack the lamp house isn't underpowered the old one was just to small to get the job done. The 4500 is putting out much better light and it is probable not bright enough but we are working with the limits of the budget they set for me.

Posted by Jack Ondracek (Member # 1466) on 05-28-2008, 10:52 AM:

4500 watts is nothing to sneeze at, Ron, though others here rightly point out you might not be happy with a dark movie.

I didn't see it in your original post... How big is your screen, and what lamphouse are you presently using? Are you fighting light incursions from nearby parking lots?

Posted by Monte L Fullmer (Member # 2797) on 05-28-2008, 12:19 PM:

quote:
I like the footstool to be able to get up high enough to do the tread work!

I just use the stool to hit the upper roller, then I can thread up the machine standing on the floor.

With threading where the machine is rather higher than me since I thread standing on the floor, I put black spots on the frameboss of the machine with a marker so I can match up framelines that way without having to use the framebox.

I have a spot down on the INT assembly underneath the trap to line up a frameline and a matching arrow on the dowser cover with it's corresonding spot on the assembly for assembly frame center.

Doing this, I can thread in frame every time.

No, the lady that owns this drive-in isn't too afraid to spend money, just that the expenditures to get more light out - to get this Century to handle a larger bulb with a watercel and a larger lamphouse/rectifier assembly, just isn't in her budget right now.

Place only operates a few months of the year and only on wknds. And last year wasn't a good year with a lot of the junk that came out. This year, as soon as the hot movies drop to discount levels (she runs discount films out there), then she'll get some serious business.

Posted by Ron Funderburg (Member # 4561) on 05-28-2008, 01:21 PM:

We have little light coming from other areas in fact there are no lights to the non screen side at all and what is to the screen side is a long way off with a lot of trees between us and them. The drive in outside of city limits and well off the highway so we are covered there. The width of the screen is 75 feet. I can't remember the height but I think it is 32 feet. I also can't remember the throw and my note book is not with me but I think that is 300 feet.

Monte keep up the good work even with the reduced care of the owner man. There are far to few drive-ins around!

The scope picture looks best I think we have enough light for what we are doing but certainly no extra we still discussing moving up in bulb size we can go up to 5,000 with the power supply easily.

The Lamp house is a Kin-Tron Xenex one of the larger ones I can't remember the amp and volt capacity but we aren't at the top so we can go larger. Glass reflector so that helps. Not having my note book here keeps me from giving exact numbers sorry. I left it at the drive-in have to go back in a day or so and retrieve it!

This place is very much a work in progress! The previous owner was one of those owners that doesn't put back in that Mark is so fond of! A big windstorm with 75 mile an hour gust took out there marquee the other night so they are trying to get it looked at now.

Posted by Mark Gulbrandsen (Member # 72) on 05-28-2008, 03:37 PM:

quote: Jack Ondracek
I have 7kW Big Sky lamps here. So far, I haven't seen anything that beats them... at least not in this application.

Jack,
The Technilite will give you the same light as your 7kw Big Sky whilst only running a 4200 watt lamp. So thats about 30% more light equivelent than the Big Sky. There is also ALOT less heat on the aperature because of the glass mirror. Nothing I've seen out there will beat a Technilite conversion including Kinoton's stuff. I didn't believe the stuff about thei eitherr gear until I saw a conversion and had the chance to measure the light. We have six of them here in Utah.

Mark

Posted by Monte L Fullmer (Member # 2797) on 05-28-2008, 03:54 PM:

quote: Ron Funderburg
There are far too few drive-ins around

THX for the comment! [thumbsup]

Sadly, there were scads of DrIns in this area, but all were knocked down for businesses.

(in 1969, I started at this Drive-In and began my crazy association with this industry here.Interestingly enough, this Drive-In is still in operation.)

From the good dozen in this area at one time, now there are only two standing - the one I work at, and the one close to the Ida/Ore border, which the latter is in prime/mint condition and really draws the crowds in the three days it's opened. That small 250 car yard is always full during the summer.

I also do service work for both Drive-Ins. The other one has a water cooled XL/4star setup mounted in front of a CFS4500 console, 4200w bulb inside, with an AW3 for their film transport.

Luckilly, her scope pictures looks pretty good - thank goodness for full open apertures...lol

Posted by Ron Funderburg (Member # 4561) on 05-28-2008, 08:05 PM:

Keep them drive-ins going! I have two drive-ins right now that I'm consulting on and doing the service for with another one that I may pick up later on; however, the third one is a long way off (5 hours) and may be to far for me to do the service work on very easy since I'm rather tied to the indoor I run. Just have to see.

Posted by John Wilson (Member # 269) on 05-29-2008, 05:16 AM:

quote: Mark Gulbrandsen
With a technilite conversion and 5kw lamp its very possible to hit the 20 footlambert level on many a drive inn screen.

Tim?

What size screens are they lighting to get these results Mark?

Posted by Mark Gulbrandsen (Member # 72) on 05-29-2008, 07:40 AM:

quote: John Wilson
What size screens are they lighting to get these results Mark?

Off the top of my head I don't remember but I will find out for you today. The projectionist there is one of our techs so thats an easy one. I do know that one screen there has an 800 foot throw and requires a 21" focal length flat lens . Also no lenses were replaced out there, all that was done was the lamphouse upgrades. Their outdoor images look better than most indoor images!!

Mark

Posted by Robert Throop (Member # 61) on 05-29-2008, 08:43 AM:

quote: Mark Gulbrandsen
800 foot throw and requires a 21" focal length flat lens .

Man, that would give about a 17 ft. high picture. No wonder they're getting 20 fl.
Bob

Posted by Steve Guttag (Member # 268) on 05-29-2008, 10:12 AM:

Yeah, I want to see that 21" lens. Presumming no lens barrel and just magically suspended glass, a 4" OD lens would effectively be stopped down to f/5.5. For a standard 70.6 OD barrel, you are pretty close to f/8.

I presume this thing flares out oat the end to get "some" light out of it.

As to light...I've done a fair amount of experimenting with it, myself.

The lamp, reflector, shutter, and Lens ALL play into the light the system puts out.

The shutter is easiest to conceptualize. The more opening it has, the more light, as a percentage it will let through. Most mechanial shutters have an effective 50% efficientcy. Simplex is closer to 53% if you tweek it just right but is safer at 50%. Kinoton also is better than 50%. The current Kinoton FP30E Premiere, at 57% efficient will increase your light about 14% over a typical projector, all else being equal

As for the light itself, different lamps work better/worse with different reflectors. It isn't just about creating the lumens at the arc but how the reflector collects that light and focuses it to the lens. It is also about how the reflector mates with the lens to efficiently get as much light as possible though the lens.

I have tested 5K lamps that, in the same lamphouse, same lens put out 8% LESS light than the 4K lamp, both running at their respective powers!

I have also tested 4200-watt lamps that will put out 20% more light than their 4KW counter parts. Or the absolute kicker...a 4500 watt lamp that put out nearly 40% more light than the 4KW counterpart!! All without changing anything but the lamp.

I'm also finding that the evenness of the illumination, not just the center, varies based on reflector/lens characteristics.

I have no doubt that Technolite has specific lamps they have you use with their optics and they would also be wise to specify lenses too as they do play into it.

The bulk of my testing has been with Kinoton projectors/lamps with ISCO and Schneider lenses. These results may not apply to other combinations.

The 4200-watt lamp in question was ASL's XM4202. The 4500-watt lamp is still under test.

The 4KW lamp (reference used for all of the above) was Christie's CXL-40SC.

The 5KWs were Christie's CXL-50SC AND the ASL XM5000HS...both dogged. I suspect the arc was too big and or the anode was too large for efficient light transmission though a 1.85 aperture.

Steve

Posted by Ron Funderburg (Member # 4561) on 05-29-2008, 10:21 AM:

Steve,

Technolite does have a specific bulb that you have to use for it to work right. It isn't not any more expensive than any others and I don't remember the exact one that they tell you!

Again we haven't switched to Technolite for this drive in yet. Not sure they will even do it but I think they would be happy with the results.

I'm working on getting them to upgrade the lenses at this point.

Ron

Posted by Mark Gulbrandsen (Member # 72) on 05-29-2008, 11:14 AM:

quote: Ron Funderburg
Technolite does have a specific bulb that you have to use for it to work right.

Yes, the 4.2 kw Osram is what they reccomend. The 21" focal length lens is a 4" Kollmorgen Gold Series that was gotten from Glenn Bergren himself. It is a lens of which just a few were hand made and Glenn had one left. I believe it's an f2.8 on the speed and no it doesn't flare out at the end. I have a picture of it somewhere .

quote: Ron Funderburg
I'm working on getting them to upgrade the lenses at this point.

Actually you'd see more impressive results by doing the lamp coversion first and it will cost you less. The 6 screen D.I. here didn't and isn't going to bother with new lenses. If you want some input from the projectionist at the Drive in here that has six of them just give us a call. Just wait till about 11:00 to call since he doesn't come in till then... he's up usually till 4am.

Mark

CLACO Equipment
801-355-1250

Posted by Steve Guttag (Member # 268) on 05-29-2008, 11:42 AM:

A 21" EF with a nominal 4" OD? It is an f/5.25 at best...that is the physical facts.

The BX265 series (4" diameter) topped out at 7" from all of the literature I could find.

I'm most curious.

Steve

Posted by Ron Funderburg (Member # 4561) on 05-29-2008, 11:51 AM:

Mark they are using lenses manufactured in late 50's or early 60's it is time for new lenses.

Posted by Mark Gulbrandsen (Member # 72) on 05-29-2008, 12:27 PM:

Ron,

I wish I could agree. The images are sharp as a tack there. About all they might gain is a bit better contrast ratio. Indeed, the lenses they have are more then satisfactory and as I said the image quality is better than many indoor theaters in this area. Earl just came in and I checked with him on the lens and throw just to be sure... I was wrong on the lens focal length... its a 22" NOT A 21" and the throw is not 800 feet, its 690 feet.

Mark

Posted by Steve Guttag (Member # 268) on 05-29-2008, 12:34 PM:

I too have seen Super-Cinefore (B&L) as well as Kollmorgan 4" lenses look VERY impressive for their age.

Most, if not all of the development in lenses in the last 3 decades have been on focal lengths 100mm (4") and below. The 100-150mm Cinelux designs go back to the '70s and the 160-180mm go back to the '80s from Schneider. Anything in a Kiptar design is going back into the '60s...which were the only "modern" lenses that went above 180mm.

A big advantage to using the 4" diameter lenses is you can get more light through them. But at 22", you are still maxed out at an f/5.5. Which is tons better than a max of f/8 on a 2-25/32 lens barrel.

Posted by Jack Ondracek (Member # 1466) on 05-29-2008, 01:00 PM:

quote: Mark Gulbrandsen
Jack,
The Technilite will give you the same light as your 7kw Big Sky whilst only running a 4200 watt lamp. So thats about 30% more light equivelent than the Big Sky. There is also ALOT less heat on the aperature because of the glass mirror.

The Big Sky boxes I have do use glass reflectors, and an additonal heat filter in the front. You can put your hand on top of my XL heads... they're almost cool to the touch... just a little warm.

On the Technilites: I really don't want to start this war again, but I'm still somewhat leery about it. I watched this, and other forums around the time I was looking to upgrade my booth. What bothered me was the secretive nature of the owners about their system, as well as the lack of long-term positive comments from actual users. I heard comments ranging from problems getting parts, peeling reflectors, and proprietary components. Seems bulb life comes into my recollection, but that may be getting mixed in with the digital stuff.

In any case, I found it disturbing that nobody who's had Technilite over the long haul is uniformly positive about it. Most of the comments come from early adopters, who probably had other issues with their projectors to begin with. The users who put the system in are very impressed at the start, then get strangely quiet. I do know one owner who'll gladly work himself into a rabid lather over the problems he's had with his installation.

Technilite is said to use a "systems" approach to acquire their light gain. I'm pretty happy with my "system" as it is. About the only issue I hear is whether you could get a little more light from a Century... maybe, maybe not... I don't know.

What I do know is that there's nothing particularly special about my lamphouses. Everything pretty much makes sense, and I understand what I have.

Maybe I could get the same light from a smaller bulb. I'd sure like to hear that from a drive-in that's had the system for 8 or 10 years.

In the meantime, I'm having more trouble from the Scotch Broom around the perimeter of my fields! [Roll Eyes]

Posted by Chris Slycord (Member # 4239) on 05-29-2008, 03:58 PM:

That's one thing I won't miss about the Seattle area... Scotch Broom when it goes into it's flowering stage gives off some sort of super-pollen that somehow creates allergy responses many times stronger than other sources (at least for me and a good portion of friends back there).