OK this is a portascribe G-100 by dalite 10 bucks from a local school, I will attach pics of it. My questions are 1 it has this knob on it that raises and lowers the light/ reflector assembly and I wanted to know what the use of that for? I dont have a bulb to test it out( Im gonna get a HQI) however the fan works without the light installed. @nd question, the overhead projection head( above the stage) has the old style closed head with the 2 convex glass lenses and the mirror, whats the purpose of the 2nd convex lens on the front after the mirror? Oh and one more thing the reflector is a Little dirty, gow should I clean it windex? I will attach some more pics so you know what Im talking about. Thanks for any further help on this issue.
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19 lookers and no talkers C mon people help a bro out, I know at least 1 other person here has this projector I remember hearing it spoken of.
I don't know other things, but I do recommend you to put a condensor lens just above the bulb. mikekniner has purchased a box of 3M optics. you may ask one from him 😀
hey VF, I had an old OHP just liek that but it was a Bell and Howell. It had that knob but it was for switching bulbs (DYS)
u paid 10$ hehe i got mine for free😎 i may ask the principle for more OHPs since no one ever uses em...
any ways my Apollo 1000 has the option of lowering or raising the light. But i've nevr tried it fearing the heat would be too much...but i think raising it would make a huge difference in lumens, maybe we can try this with cooler HQIs.
the old bell and howell also had 2 convexes i think this emulates a doublet.
u paid 10$ hehe i got mine for free😎 i may ask the principle for more OHPs since no one ever uses em...
any ways my Apollo 1000 has the option of lowering or raising the light. But i've nevr tried it fearing the heat would be too much...but i think raising it would make a huge difference in lumens, maybe we can try this with cooler HQIs.
the old bell and howell also had 2 convexes i think this emulates a doublet.
18 why a condencer above the light, even new projectors with FXL lights dont have a after light condenser within the projector. Also negative you lucky bastard LOL Yea I tried calling my local HS to see if they had any old OHP's in the basement( when I was In HS i ventured into the basement and swa tons......before I even had the notion of diy lcd) anyways as to the 2 convex lenses, how does My apollo with its one concave( or convex lens depends on how you want to look at it) get by with just the 1 lens and the mirror? Im confuced am I missing something basic on the OHP and its lenses?
Video Freak said:
FXL bulbs use a-spherical reflector, so light is 'collected' as a corn-shape beam toward fresnel lens, which minimize the light loss. I think the reflector in your OHP is spherical, which reflects light back to the 'burn point' of the bulb. Using a condensor can collect more spreaded light into the fresnel. well, if MH bulb can be as small as a halogen one day ( and cheap enough, not like those in the commercial projectors ), we can use aspherical reflector and eliminate the need for a condensor.
Edit: just saw a picture. it can give you some idea:
An externally hosted image should be here but it was not working when we last tested it.
yeah i did get lucky but its nothing...i threw away that OHP a long time ago i only took a condensor lens and some other stuff from it.But i am lucky for gettin a free tripod 70x70 screen though😎 lol, if u want i can give u an OHP if my skool gives me one more.but it'll be an old Piece of crap though....lol
well Negative keep me posted on it if you can get a few more, I think tomorrow Im gonna call the maintanence Dept of the schools, they would know if there was old OHP's in the HS basement..................talk to My gal shirly the janitor wonder if she remembers me from 3 years ago LOL prob not but hey worth a shot
lol good luck with that 🙂
as for me theres no skool 2morrow 😀 🙂 brooklyn and queens day! ahahah they make anything to keep us out of skool lol
I'll let u know if they give me the OHP(s)
as for me theres no skool 2morrow 😀 🙂 brooklyn and queens day! ahahah they make anything to keep us out of skool lol
I'll let u know if they give me the OHP(s)
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