Now it is time for me to start with my first projector. I'm thinking about having this setup:
A Philips CDM150/T6/942 for lighting. (150W, 4200K, uv filter)
A homebuild ballast and ignitor as in this thread
An ashtray that I found on IKEA as reflector. It is spherical with a diameter of around 8-9 cm. (I think)
Maby I'll join in on the group buy for the ellipsodal cold reflector and use that instead.
I'v got an old 10.4" projection lcd from sharp that I'm planning on using (lq10ps21) 800x600 resolution. I can get a picture on it using my fpga and think I'm easily able to build a vga interface for it.
For rear and front fresnel I have got two of them 100" projection-tv lenses. They are 7x10" with fl = 300mm.
I'll use this condensor lense (76mm diam. 112mm fl)
and this projection lense (265mm fl).
I want a 6' image from a 10' distance and according to my calculations the distance between projection lense and lcd should be 290mm. Do I put the fresnels together then and the lcd 10mm closer to the projection lense?
would this setup be ok?
If later on I decide to build a smaller one using maby the 7" lilliput. Would this stuff be useful or would I need other things for that?
A Philips CDM150/T6/942 for lighting. (150W, 4200K, uv filter)
A homebuild ballast and ignitor as in this thread
An ashtray that I found on IKEA as reflector. It is spherical with a diameter of around 8-9 cm. (I think)
Maby I'll join in on the group buy for the ellipsodal cold reflector and use that instead.
I'v got an old 10.4" projection lcd from sharp that I'm planning on using (lq10ps21) 800x600 resolution. I can get a picture on it using my fpga and think I'm easily able to build a vga interface for it.
For rear and front fresnel I have got two of them 100" projection-tv lenses. They are 7x10" with fl = 300mm.
I'll use this condensor lense (76mm diam. 112mm fl)
and this projection lense (265mm fl).
I want a 6' image from a 10' distance and according to my calculations the distance between projection lense and lcd should be 290mm. Do I put the fresnels together then and the lcd 10mm closer to the projection lense?
would this setup be ok?
If later on I decide to build a smaller one using maby the 7" lilliput. Would this stuff be useful or would I need other things for that?
I'v changed my plan a bit for the projector.
Lcd: 8" Hami which I'll receive in a week or so.
Bulb: HQI-T 150W / 4200K with UV-filter
Ballast: Not yet. Hopefully I'll build one during easter.
Reflector: Not sure. I'm in on the elliptical reflector group buy, but I don't know if it will be useful since it will be cone-axis elliptical. (Looks like this )
Maby I'll just use my Ikea ashtray instead but that elliptical would give me more light output.
Condensor: Don't know what will be needed.
Fresnel: Maby this, or this.
The first have fl 210/310 and the second one 165/305. Would the second be more suitable concidering the shorter rear fl?
Objective: I'd like a zoom-lens thinking about the one in that lens-pack with the second fresnel. Will the aperture of that thing be enough?
All comments on this are welcome!
Lcd: 8" Hami which I'll receive in a week or so.
Bulb: HQI-T 150W / 4200K with UV-filter
Ballast: Not yet. Hopefully I'll build one during easter.
Reflector: Not sure. I'm in on the elliptical reflector group buy, but I don't know if it will be useful since it will be cone-axis elliptical. (Looks like this )
Maby I'll just use my Ikea ashtray instead but that elliptical would give me more light output.
Condensor: Don't know what will be needed.
Fresnel: Maby this, or this.
The first have fl 210/310 and the second one 165/305. Would the second be more suitable concidering the shorter rear fl?
Objective: I'd like a zoom-lens thinking about the one in that lens-pack with the second fresnel. Will the aperture of that thing be enough?
All comments on this are welcome!
Things are starting to get going here. I'v received my hami display and started taking it apart. Too bad I have to do that though, I'v just started to like it, it is really nice. Well I guess I will enjoy it more when it sits in my projector anyway.
I'v goten the homebuild ballast and ignitor for my bulbs to work. Not quite as good as it should though. Hopefully I'll fix it soon.
I'v ordered a 290mm fl Fujinon copylens from surplus shed and should receive it any day now. I also got two fs mirrors that is 19x7.5cm. Now that I think about it and have got a fullscale drawing of the optics, I think that 7.5cm in height is not enough, that means I have to put the mirror so far from the fresnel. I'll look around for a larger one.
I'm really eager to get started with actually building this thing now. I need fresnels though. I'll probably order that from Gadaffy's.
I'v goten the homebuild ballast and ignitor for my bulbs to work. Not quite as good as it should though. Hopefully I'll fix it soon.
I'v ordered a 290mm fl Fujinon copylens from surplus shed and should receive it any day now. I also got two fs mirrors that is 19x7.5cm. Now that I think about it and have got a fullscale drawing of the optics, I think that 7.5cm in height is not enough, that means I have to put the mirror so far from the fresnel. I'll look around for a larger one.
I'm really eager to get started with actually building this thing now. I need fresnels though. I'll probably order that from Gadaffy's.
Bulb problem
I have a slight discoloring of my bulb (HQI-T). Is this normal or has it got something to do with my ballast and/or under powering the bulb or something.
As you can see in the picture there is red spots on the bottom side or the bulb. (It will move to the bottom by gravity when the bulb is on.) This causes a miss coloring (yellow dots/areas) of the image and it can be seen in the next picture. Both of my bulbs have the same problem.
I have a slight discoloring of my bulb (HQI-T). Is this normal or has it got something to do with my ballast and/or under powering the bulb or something.
As you can see in the picture there is red spots on the bottom side or the bulb. (It will move to the bottom by gravity when the bulb is on.) This causes a miss coloring (yellow dots/areas) of the image and it can be seen in the next picture. Both of my bulbs have the same problem.
Attachments
Reflector
Some pics of the reflector setup. I'v got a cone-axis ellipsoidal reflector which means that instead of directing the light to a point it will be directed to a ring. The hole for the bulb were not large enough so I had to grind it up using a dremel. Took a long time, damn that glass is hard. I used som old leftover pcbs to hold the reflector and bulb.
When I was playing around with positioning of the bulb and lenses I had no fan on the bulb so the reflector cracked after a while, although it is still useable, just have to be more carefull next time. Got a fan on it now.
Some pics of the reflector setup. I'v got a cone-axis ellipsoidal reflector which means that instead of directing the light to a point it will be directed to a ring. The hole for the bulb were not large enough so I had to grind it up using a dremel. Took a long time, damn that glass is hard. I used som old leftover pcbs to hold the reflector and bulb.
When I was playing around with positioning of the bulb and lenses I had no fan on the bulb so the reflector cracked after a while, although it is still useable, just have to be more carefull next time. Got a fan on it now.
Attachments
Some results. The image is not as bright as I thought it should be and the colors are wrong. Although messing around with some adjustmens in the lcd might help to at least improve on that. (Colors looks like taken from some old 70's movie.) A better screen will also help a bit, both on brightness and color. I'm using an bed sheet right now.
Windows background image through a/v input.
Windows background image through a/v input.
Attachments
iguess you mean that when you reduce the throw, the projection lens needs to move farther from the lcd and the image gets smaller, but then you losse some light out of the projection lens;
well, have you ever tried this short trhow setup and moving the lamp closer to the rear fresnell, that should help not loosing the light.
well, have you ever tried this short trhow setup and moving the lamp closer to the rear fresnell, that should help not loosing the light.
Youre frying it!!!
Only use the proper recomended running gear on HID lamps. Using the incorect running gear will give unpredictible results, including the potentional of bulb rupture which pose a serious health/fire hazzard!!! Trev
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