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Author Topic: Proper Lamp Alignment/Bulb Focus Procedure Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 07-08-2009 09:29 PM                     I was doing a search on this site but could not find a procedure for properly aligning and focusing a bulb. So, what are the proper steps?  |  IP: Logged Jarret Chessell Master Film Handler Posts: 288 From: London, Ontario, Canada Registered: Jan 2009 posted 07-08-2009 11:29 PM                     Assuming your lamp house is in good order.... Put your new lamp in, and manually start the projector without any film in it. You're about to put white light on the screen. WARNING: Too much white light will wreck your lenses, if you're playing for too long close your dowser for a few minutes to let the lenses cool down. You'll need the manual for your lamp house to see how you adjust it. I usually start with scope format. With white light on the screen you want to back off the focus so that you have a bright ball of light. You want to do the best you can to use the horizontal and vertical controls to get the ball of light into the center of your screen. Once centered start using the focus control to expand the light evenly around the screen. While you're expanding the light you'll likely need to constantly adjust the horizontal and vertical controls to keep the light centered (it's fairly normal to have it try to drift out of center when backing it out). Some projectionists like the light to be even right into the corners, others prefer having it dimmer in the corners and around the sides (because the black masking provides contrast for the eye). I'm sure lots of people on here have opinions, you can try it both ways if you like... once you're happy with how even the light is flip to flat, you may feel you need to adjust it a little more... flip back and forth between your flat and scope until you're happy with how they both look. Also... I usually find that after a few days when the new lamp has settled in a bit it's worth aligning it again. I hope that helped.  |  IP: Logged Galen Murphy-Fahlgren Master Film Handler Posts: 405 From: Canton, MI, USA Registered: Oct 2007 posted 07-08-2009 11:57 PM                     Jarret's instructions are pretty good. The only things I would add are, I start focusing the lamp in the format that has the largest screen area in that auditorium (scope in fixed height, flat in fixed width), and that I don't shine the direct light through the lens for more than 10-15 seconds at a time. I follow up the alignment procedure by running a looped green band in the format with the bigger screen size, and make my final adjudication based on that. Also, check to make sure that the lamp isn't running too hot and causing buckling in your loop, which indicates too aggressive a focus.  |  IP: Logged Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 07-08-2009 11:57 PM                     Thanks for the info. However, I was referring to the method used where no lenses are in the projector during focus/alignment. What is the procedure for this method?  |  IP: Logged Scott Christopher Film Handler Posts: 69 From: Adelaide, South Australia Registered: Apr 2001 posted 07-09-2009 12:49 AM                     I think the Christie manuals explain the method you're after  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 07-09-2009 04:50 AM                     quote: Tom Wienholt However, I was referring to the method used where no lenses are in the projector during focus/alignment. What is the procedure for this method? We call that doing the "Looney Tunes" alignment - due to the fact of the rings that shows up on the screen when we get the bulb in focus - which is called the "coarse focus": With lens and aperture out of the projector, you start the projector motor,strike the bulb and open dowser. You'll notice the dark spot in the middle of the screen which is the bulb itself. First you do focus which the dark spot will decrease in size along with creating the "looney tunes" ring around this dark spot. You don't want to decrease this spot too much, but back it up where the rings really show. Then, on the dark spot, you might see "blisters" around this dark spot. This is the cathode part of the bulb coming from behind. the goal is to hide the "blisters" which means that the bulb is square with the center of the projector. To rid of the "blisters" is to do the lateral and vertical bulb alignments. When you're done with this "coarse" focus, leave bulb and motor on and close dowser. Then throw in the "scope" aperture plate and "scope" lens. Then, open dowser and you should have an even field of light over the entire screen. If you got dark edges or a "hot spot" in the center of the screen, adjust bulb focus until the edges brighten up, or the "hot spot" is gone.. This is called "fine focus". ..BUT, be quick at this for the naked light through a lens will cook and could destroy the lens in seconds. And if using a large wattage of bulb, do this step in 15 second intervals, with having dowser closed good minute between the 15 second intervals so the lens can cool down Good luck-Monte  |  IP: Logged Jonathan Worthing Master Film Handler Posts: 384 From: Hereford, UK Registered: Apr 2001 posted 07-09-2009 07:07 AM                     "Looney Tunes" alignment is the way I do it & it works fine  |  IP: Logged Dan Reiter Film Handler Posts: 74 From: Easton PA Registered: Jul 2002 posted 07-09-2009 07:14 AM                     I too have used the concentric circles to align for years, the best way, bar none. I wrote a procedure on this, with pictures, when I worked for Big Sky, I think it's still on thier website. I was taught by one of the old greats, Jim Ezell.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 07-09-2009 07:30 AM                     Even on constant width screens one must use the scope format for final alignment as this has the largest hole in the apperture per se and as such requires the flatest of field  |  IP: Logged Dennis M Dow Jr Expert Film Handler Posts: 141 From: Bloomfield NJ USA Registered: Oct 2003 posted 07-09-2009 10:12 AM                       Dan is correct that we still have it on our website. Here is the link to the page: Optical alignment  |  IP: Logged Victor Liorentas Jedi Master Film Handler Posts: 800 From: london ontario canada Registered: May 2009 posted 07-09-2009 01:55 PM                     My problem is a port hole too small to get the concentric rings on screen! . I end up with much of it on the booth wall around the porthole. I also worry my reflector sits off set,how can this be verified?  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 07-09-2009 06:42 PM                     Gordon is right, always use Scope. I agree with Jarret, but a small note: do not turn the focus knob too much, I prefer to just darken the corners and center the light this way. Marco  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 07-09-2009 06:56 PM                        I just read the Big Sky alignment procedure. While the overall thrust of this procedure is about right, it leaves out many small details. (such as critical alignment of the projector lens to the RP-40 centers and critically framing the image.) I worked many times with the late Jim Ezell (who worked for RCA service back in the 40s-50s & 60s.) The devil is in the details; yes, it CAN be perfect. (I'm so old, I serviced equipment for Jim Ezell's FATHER in Danville, KY. I was new and he was 86 years old back in the early 70s.) Louis  |  IP: Logged Tony Ratcliff Expert Film Handler Posts: 216 From: Madison, IN, USA Registered: Mar 2002 posted 07-09-2009 08:09 PM                     I usually run the RP40 looping using the scope lens for the fine adjustment, so as not to risk damaging the lens. I've also used a loop of the green "The Following Preview" since it is a solid color on the whole screen.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 07-09-2009 08:17 PM                     Gordon is right, always use the scope format. If scope is right, flat will be too. The type of masking has nothing to do with it. Also, if you have to keep readjusting the horizontal and vertical adjustments as you back off on the focus, you have a physical alignment problem and are losing light. The "Looney Tunes" method (of which I have never heard it called that before today) will also give you a good idea if your optics are properly aligned. If you can't get good circles, you need to get your tech in there. Regardless of the port window size, if you focus the lamp down enough, you will see the circles.  |  IP: Logged

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