I'm still waiting for my replacement ushio to arrive. But in the meantime I've been using a 22,000 lumen home depot bulb which seems to be similar to the old mh400 bulbs.
Anyway, the brightness is adequete though not spectacular. Especially on darker scenes.
However I've noticed something strange about my bulb. My fresnels appear to be projecting TWO brightspot onto the front of the projector kind of shaped like a figure 8. What in the world? It looks like the bright spot of the bulb is sort of long but that should produce more of an oval, or a square, not two brightspots. Brightness seems to appear slightly better on the right bright spot but I wonder how bright it would be if I could get both of them in the lens.
My old Ushio didn't have this problem, so I probably won't have to deal with it much longer. Also I had to forego my bulb adjustment system to fit the bulb in my projector, (which I will put back once I get my new ushio) so maybe its just a bulb distance problem.
The projection is still nice, and like I said it probably will be gone once I get my new ushio.
But isn't that just a little wierd?
Full Version: wierd bulb I've got here
QUOTE (Mikau @ Jun 25 2005, 06:11 PM)
I'm still waiting for my replacement ushio to arrive. But in the meantime I've been using a 22,000 lumen home depot bulb which seems to be similar to the old mh400 bulbs.
Anyway, the brightness is adequete though not spectacular. Especially on darker scenes.
However I've noticed something strange about my bulb. My fresnels appear to be projecting TWO brightspot onto the front of the projector kind of shaped like a figure 8. What in the world? It looks like the bright spot of the bulb is sort of long but that should produce more of an oval, or a square, not two brightspots. Brightness seems to appear slightly better on the right bright spot but I wonder how bright it would be if I could get both of them in the lens.
My old Ushio didn't have this problem, so I probably won't have to deal with it much longer. Also I had to forego my bulb adjustment system to fit the bulb in my projector, (which I will put back once I get my new ushio) so maybe its just a bulb distance problem.
The projection is still nice, and like I said it probably will be gone once I get my new ushio.
But isn't that just a little wierd?
Anyway, the brightness is adequete though not spectacular. Especially on darker scenes.
However I've noticed something strange about my bulb. My fresnels appear to be projecting TWO brightspot onto the front of the projector kind of shaped like a figure 8. What in the world? It looks like the bright spot of the bulb is sort of long but that should produce more of an oval, or a square, not two brightspots. Brightness seems to appear slightly better on the right bright spot but I wonder how bright it would be if I could get both of them in the lens.
My old Ushio didn't have this problem, so I probably won't have to deal with it much longer. Also I had to forego my bulb adjustment system to fit the bulb in my projector, (which I will put back once I get my new ushio) so maybe its just a bulb distance problem.
The projection is still nice, and like I said it probably will be gone once I get my new ushio.
But isn't that just a little wierd?
I have yet to build my project but just for the heck of it maybe you could try using a mirror to direct the light and create one sold beam???
mirrors just redirect. Compressing the light after the triplet would distort the image.
If you mean a spherical reflector behind the bulb, this bulb is kind of big for a reflector. I do intend to use one with my ushio once I get it and make a trip up to ikea, but the ushio doesn't have this problem anyways.
If you mean a spherical reflector behind the bulb, this bulb is kind of big for a reflector. I do intend to use one with my ushio once I get it and make a trip up to ikea, but the ushio doesn't have this problem anyways.
QUOTE (Mikau @ Jun 25 2005, 09:19 PM)
mirrors just redirect. Compressing the light after the triplet would distort the image.
If you mean a spherical reflector behind the bulb, this bulb is kind of big for a reflector. I do intend to use one with my ushio once I get it and make a trip up to ikea, but the ushio doesn't have this problem anyways.
If you mean a spherical reflector behind the bulb, this bulb is kind of big for a reflector. I do intend to use one with my ushio once I get it and make a trip up to ikea, but the ushio doesn't have this problem anyways.
Thats what i'm talking about... If you get 2 spots on your screen maybe the light isn't getting directed right and you could use a mirror to direct the light how you want it... But since your getting a new bulb this might just be a waste of time..
I’ve heard that some MH lamps produce most of their light output at the two ends of the arc. Maybe this is what you are seeing. If you have an arc-welding mask you might be able to look directly at the arc. I’ve done this with my HQI but its light appears constant right across the arc. Maybe a cheaper lamp has this effect?
It’s actually very interesting to watch the arc form, with the HQI you can see it start at one electrode and travel to the other over about a second.
DJ
It’s actually very interesting to watch the arc form, with the HQI you can see it start at one electrode and travel to the other over about a second.
DJ
I believe that you've said you don't have a good camera, but we would really need to see a picture of the PJ to help with this. I'm not sure if you have painted the inside of the PJ balck or not but many people have reported strange "hot spots" or unevenness that turns out to be reflections from unwanted angles and paintin to monimize reflections has corrected this.
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