While I was shopping for a mixing bowl reflector, I happened to come across something else that could be used as a reflector today, and I was wondering if anybody would be interested in one. I'm using one myself, but I can get more. Check out the pictures and e-mail me at carl_of_et@yahoo.com.
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Nope. I was planning on buying a mixing bowl, but I wasn't happy with the shapes I was finding. I found this dealy and I figured the shape was much better. It's *almost* an actual sphere.
How well did that focus the light for you? Do you have any pics of a spot on a screen or the wall?
stainless steel hemispheres
This is a source for stainless steel hemispheres, in the form of quiche molds:
http://www.dr.ca/e_pcercle.html
Look down the page for "Stainless steel half sphere moulds". They have 11 different sizes, so you can pick one to fit your needs. I used the 12 cm version. After I cut the top inch off with a Dremel cutting wheel (actually about 12 of them), it made a perfect spherical reflector. I tested mine with a very tiny flashlight bulb running at 2/3 voltage. If I put the filament at the center of curvature, then I could see it reflect right back through the bulb from every angle. With the top inch cut off, it fits my lamp optics and still gives me lots of airflow around the bulb.
They come with a mirror polished finish. If you want to make them even better, you can get them silver plated at a local plating shop. Just be sure to tell the platers you want a bright mirror finish, so they don't do it with a matte finish.
Only problem: Though the prices are great, the shipping to the US cost me about $12 US, which more than doubled the price. Should be MUCH less if you are in Canada. Elsewhere, you might want to find some nearby buying-buddies to split the shipping cost. They told me they could have shipped several for that minimum shipping charge.
This is a source for stainless steel hemispheres, in the form of quiche molds:
http://www.dr.ca/e_pcercle.html
Look down the page for "Stainless steel half sphere moulds". They have 11 different sizes, so you can pick one to fit your needs. I used the 12 cm version. After I cut the top inch off with a Dremel cutting wheel (actually about 12 of them), it made a perfect spherical reflector. I tested mine with a very tiny flashlight bulb running at 2/3 voltage. If I put the filament at the center of curvature, then I could see it reflect right back through the bulb from every angle. With the top inch cut off, it fits my lamp optics and still gives me lots of airflow around the bulb.
They come with a mirror polished finish. If you want to make them even better, you can get them silver plated at a local plating shop. Just be sure to tell the platers you want a bright mirror finish, so they don't do it with a matte finish.
Only problem: Though the prices are great, the shipping to the US cost me about $12 US, which more than doubled the price. Should be MUCH less if you are in Canada. Elsewhere, you might want to find some nearby buying-buddies to split the shipping cost. They told me they could have shipped several for that minimum shipping charge.
Guy - do you think youd be able to notch two sides of those and use them for the Ushio 400W MH retrofit bulb you pointed out?
quiche mold hemisphere
The center of curvature on the 12 cm diameter mold is right in line with the rim, but the top inch of it is a bit straighter than the nice smooth curve of the rest. But you don't need that part of it in your reflector anyway. I cut the top inch off, but left a small tab remaining on each side for mounting.
With the one inch removed, it fits my Ushio retrofit bulb perfectly. These bulbs are T15, so they are 15/8" in diameter. Half that is 15/16", so it is mounted 1/16" above the rim of the reflector.
I think it is important to cut most of that top inch away, instead of just making a small cutout for the bulb on one side. This way I get lots of cooling air flowing around all sides of the bulb, instead of making a little oven for it to sit in.
The center of curvature on the 12 cm diameter mold is right in line with the rim, but the top inch of it is a bit straighter than the nice smooth curve of the rest. But you don't need that part of it in your reflector anyway. I cut the top inch off, but left a small tab remaining on each side for mounting.
With the one inch removed, it fits my Ushio retrofit bulb perfectly. These bulbs are T15, so they are 15/8" in diameter. Half that is 15/16", so it is mounted 1/16" above the rim of the reflector.
I think it is important to cut most of that top inch away, instead of just making a small cutout for the bulb on one side. This way I get lots of cooling air flowing around all sides of the bulb, instead of making a little oven for it to sit in.
Very nice! Just out of curiosity, how much did you pay to plate it? Did you then use that 100x200mm condensor?
reflector
This was the very last thing I needed to get my PJ together, so I confess I ran out of patience and went to a local plater well known for being overpriced. So I paid $48 US and picked it up the next day. They actually would have done in in just a few hours for that price, but I live about 50 miles away and couldn't wait around.
I found other platers on the web who have a $28 charge for something that size. And of course, the price for some quantity of them would drop.
Another option for plating a bunch of them would be to setup a plating operation: Some of the latest plating solutions are non-toxic and suitable for home use.
I had to give up using the condensor lens for now. My hot mirror mounting doesn't let me get it close enough to my 2" diameter lamp arc. But I really do like the results. And tests with the reflector covered show that it makes the image much brighter.
Even if you just leave it stainless steel, it has a better size and shape than most soup ladels.
This was the very last thing I needed to get my PJ together, so I confess I ran out of patience and went to a local plater well known for being overpriced. So I paid $48 US and picked it up the next day. They actually would have done in in just a few hours for that price, but I live about 50 miles away and couldn't wait around.
I found other platers on the web who have a $28 charge for something that size. And of course, the price for some quantity of them would drop.
Another option for plating a bunch of them would be to setup a plating operation: Some of the latest plating solutions are non-toxic and suitable for home use.
I had to give up using the condensor lens for now. My hot mirror mounting doesn't let me get it close enough to my 2" diameter lamp arc. But I really do like the results. And tests with the reflector covered show that it makes the image much brighter.
Even if you just leave it stainless steel, it has a better size and shape than most soup ladels.
Reflector still working?
It's been a few months since anyone posted something to this page, I was wondering, CarlofE / Guy Grotke , are you both still using the reflector that you described on this page, one of you said you had it silver plated, are there any signs of the silver tarnishing yet due to the heat from the bulb? CarlofE has yours trrnished yet, or is it still nice and shiny?
Does it still work well, it seems a good option for a 400w MH bulb and 15" screen.
Anyone any opinions who has used this reflector.
Thanks.
James
It's been a few months since anyone posted something to this page, I was wondering, CarlofE / Guy Grotke , are you both still using the reflector that you described on this page, one of you said you had it silver plated, are there any signs of the silver tarnishing yet due to the heat from the bulb? CarlofE has yours trrnished yet, or is it still nice and shiny?
Does it still work well, it seems a good option for a 400w MH bulb and 15" screen.
Anyone any opinions who has used this reflector.
Thanks.
James
silver plating
I've only been using it for a couple of months, but I have not seen any tarnishing yet. Ask me again in a year! 😀
I've only been using it for a couple of months, but I have not seen any tarnishing yet. Ask me again in a year! 😀
Many thanks for the info...........seems like my quest for a good reflector is over (hopefully).
James
James
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