Film-Tech Forum ARCHIVE: Suggestions for small lamp for 35mm home projector setup

This is topic Suggestions for small lamp for 35mm home projector setup in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=012456

Posted by Steve R Pike (Member # 6238) on 07-13-2019, 02:14 PM:

Hi

Following my post a few weeks ago, I have successfully moved our Kinoton FP25D and Westrex Tower to our garage for my future home cinema.

The original projector obviously came with a xenon lamp and lamphouse but I don't want to use that as it's too powerful.

I have seen a small lamp house (500w) attached to a projector on eBay which would be perfect. Just wondered if anyone knows where something like this could be sourced (UK). For the meantime I'm going to be using my super 8 projector running with just lamp on (obviously a temporary solution)

The lamphouse I've seen is attached to the projector for sale here:

egad!

Thanks in advance

[Post edited to remove obnoxious length URL as well as quote below]

[ 07-18-2019, 11:22 PM: Message edited by: Brad Miller ]

Posted by Dave Macaulay (Member # 813) on 07-13-2019, 02:26 PM:

I made one with reasonable success by chopping the lamphouse part out of an Ektagraphic slide projector. Not at all pretty but it worked. This had an 83V lamp, the projector's motor was used as a transformer apparently. I wired in a 36V transformer I had lying around to buck line voltage down.

Posted by Helmut Maripuu (Member # 2281) on 07-13-2019, 03:33 PM:

Parts from an office video projector work well but can be dangerous. Have respect for high voltage.

https://www.youtube.com/watch?v=BaeBD5rdFvI

https://www.walmart.com/ip/Epson-ELPLP12-Epson-Replacement-Lamp-200W-UHE-1500-Hour/10928662

Posted by Emiel De Jong (Member # 4225) on 07-14-2019, 02:13 AM:

Or you can use a small xenon lamp for home use; see this Ebay item from the same seller. This 500w xenon lamphouse was built by Philips / Kinoton for 16mm and 35mm use. The units I have seen installed on FP20 / FP30 projectors had a sort of condenser lens between lamp and gate though, I don't see that lens in this auction.

https://www.ebay.co.uk/itm/Kinoton-500w-Xenon-lamp-And-Irem-Solid-State-Small-rectifier-single-phase/123762539395?hash=item1cd0d27b83:g:BVkAAOSwmlZcrOgc

Posted by Steve R Pike (Member # 6238) on 07-14-2019, 03:54 PM:

Thanks for your replies.

As it's only going into a garage, maybe I don't need anything too powerful anyway like a xenon.

I found the following lamp (basically a security light) very cheap, which may help just shine some light and I could screw it to the back of the projector using the frame it comes on. Thoughts?

https://www.toolstation.com/halogen-floodlight/p13443

Posted by Phillip Grace (Member # 2262) on 07-17-2019, 06:48 AM:

I dont think a halogen floodlight is going to do you much good. As much light as possible from the lamp must be focused onto the film and pass through to the projection lens. I would follow Dave's suggestion and look at slide projector lamps, and optical systems. The 24 volt 250 watt system in a Kodak carousel or similar projector can do quite useful work and is compact. It is also possible to adjust the spot size with a condenser optical system to optimise the light for the smaller aperture.

Posted by Jim Cassedy (Member # 4115) on 07-17-2019, 09:26 AM:

AGGGAAAAHHH!
A URL shortener can be your friend!
Also, I have a feeling the "URL" button on the message compose page, is there for a reason.
I wish people would learn to use it instead of posting insanely long URL's [Wink]

(Sorry, it's nothing personal, but I haven't had my morning coffee yet so I guess I'm a bit
cranky, and this is one of my pet peeves.)

[ 07-18-2019, 11:21 PM: Message edited by: Brad Miller ]

Posted by Steve R Pike (Member # 6238) on 07-18-2019, 08:55 AM:

Yup, I agree - horrific URL! I did try and use the URL button but it didn't work (possibly because I'm using a phone rather than a PC), and then when I realised that it was a horrificly long and ugly URL on display I apparently ran out of time to edit it.

Posted by David Ferguson (Member # 10588) on 07-18-2019, 08:46 PM:

The URLs ebay's "share" button gives are horrible. You can actually condense them down quite a bit to just http://ebay.com/itm/<item-number>, so in this case it would be: http://ebay.com/itm/123778452420 and http://ebay.com/itm/123762539395

Posted by Jonathan Wood (Member # 4614) on 08-06-2019, 04:40 AM:

Hi Steve,
I’ve experimented a lot with this and the security lamp , although 400w , will give quite poor results as most of the light will be lost within whatever lamphouse you use. The small Phillips lamphouse Emiel suggests is an excellent choice . If you don’t want to use xenon you can cannibalise the innards of a slide projector or an OHP that uses the 36vdc 400watt lamp. The important thing is that you use some sort of condenser or reflector to harness the power of the lamp or all you will do is nicely heat up your lamphouse. Also consider LED .( I got my small Phillips lamphouse in a trade with the PPT.) Best wishes , Jon

Posted by Steve R Pike (Member # 6238) on 08-07-2019, 02:44 PM:

Hi Jon

Thanks for your message. Do you use a Xenon for your setup?

With the Xenon lamp-house that came with the projector I have removed the Xenon bulb and I plan on doing the following;

- Remove all wiring for Xenon power and connections
- Re-wire the existing extractor fan to a mains plug
- Install a lamp holder on a separate plug for a 500w bulb within the existing lamphouse mirror so that the light can be concentrated down through the gate

For the lamp holder, I have been looking at a simple screw-in fitting like the following:
FoxHunter Photography E27 Bulb Holder Socket

This can then be screwed into place, with the lamp fitting going through the hold in the back of the lamp house mirror and by replicating the position of a Xenon bulb, I could use one of the following:

Photolux P2/1 ES 240v 500w Photoflood Lamp

or, for an LED alternative:

ONIVIB 54W Super Bright LED Corn Lamp Bulb, E27

Here is what the projected image looks like at the moment with just the 500w halogen security light up against the gate:

So I'm hoping that with a 500w bulb, as above, with the existing mirror in the lamp-house, I should be able to project a decent image … hopefully!

Steve

Posted by Steve McAndrew (Member # 8865) on 08-13-2019, 02:03 PM:

I believe some have had success with small halogen lamps mounted in lamp houses. I think it is a A1/239 lamp. You would need to get the filament in the same position as the arc in the xenon lamp but should be quite effective although the colour temperature of the lamp would be wrong.

Hope this helps

Posted by Ed Inman (Member # 2583) on 08-18-2019, 12:58 PM:

Vintage Navitar or Elmo xenon slide projectors can often be found for $200 or less on ebay. They can be a bit awkward to mount behind a 35mm projector head but are adequate for projecting up to about a 4 to 6-foot wide picture. I used a Navitar 750 with a 5-inch f.2.8 lens for a while for my indoor movie projector until I got my ORC 1000 repaired.

Posted by Steve R Pike (Member # 6238) on 09-09-2019, 03:23 PM:

Hi All

Still not having much luck with this.

Recently, I have tried an LED corn bulb (this one from Amazon) which seems to produces a huge amount of light!

So I inserted it into the lamp house, into the middle of the mirror in the same position as where the Xenon lamp would have been, but the output through the gate was terrible onto the screen. In fact, it was pretty much nil!

I know its not the most conventional way of doing it, but for something like this using this type of bulb, should the lamp house mirror be as close to the gate as possible for it to have maximum light efficiency through the gate?

I also purchased a couple of A1/239 lamps in another fitting, but they blew straight away!

I may have a look at purchasing a high powered slide projector for this, however I don't want to spend much more money on this if it's going to fail.

So far, the only thing that gives a decent(ish) light is the halogen 500w security light pressed up against the gate!

My early Christmas wish list is a small lamp house with a powerful lamp for a 12 foot throw!

Posted by Gordon McLeod (Member # 33) on 09-09-2019, 04:01 PM:

The reflector is designed to focus a spot of light on the aperture from a light source that is a point source
The point of light of a xenon arc is very small

Posted by Randy Stankey (Member # 64) on 09-09-2019, 05:32 PM:

What if you cannibalized the head from an old, unused photographic enlarger?

Something like a Simmons Omega D2 that has a fairly large reflector and a long-ish focal distance.

The Omega has swappable columator units to focus the light down to different aperture sizes. I have columators for my Omega for use with 4x5, 120 and 35mm film.

The down sides that I can think of would be how to get a bright enough lamp and how to get enough cooling for said lamp.

Maybe you could fabri-cobble together the lamp from a slide projector and a columator from an enlarger.

I dunno’. Just spitballing.

Posted by Jonathan Wood (Member # 4614) on 09-10-2019, 02:50 PM:

Hi Steve, sorry for the late reply . Yes , I use xenon . I did try a few halogen alternatives but I gave up as the output wasn’t good enough , plus all non faded colour prints are timed for a xenon light source and I didn’t like the colour rendition from a halogen source. Some people have had success using the 36vdc/400w (EVD?)bulb but if you use a cannibalised OHP projector as your donor then you’ll need a modified condenser as the one in the OHP is designed to spread light over a wide area with minimum throw. If you think about the size of the 35mm aperture, then this is where you need to focus all the light energy of the bulb. So you need a optical system that will do this rather than let all that light stray around inside the lamphouse. There is an 800w/230vac bulb commonly used in a ‘Red head ‘ tungsten lamp which although not the same length as a xenon , it does share a similar tubular construction, it might be possible to mount this within a xenon lamphouse mirror along the same axis as a xenon and het a reasonable output. You should t have any flicker issues as the filament never really dims enough on the ac cycle to cause a problem . Ive never tried it , but it was the next thing I was going to try before I went with xenon. Do you have a lamphouse with a mirror ?