Slize, thank you for sharing all this with us. I'm really interested most of all in your results once you actually set your prisms up next to a projector. (I saw your pictures of the effect on the proportions of your TV)
These are new angles than the prisms that were originally posted on the german site of 30 degrees and 24 degrees.
Even more interesting to me is this concept of the "water getting dirty", AND, that using two filled with oil does not cause --or compensate for -- "chromatic abberation". For example, if you look at the projector image through JUST the water prism, the colors aren't aligned, there is a slight "rainbow" effect until you place the oil prism in place as well. Are you saying that the two glycerine-filled don't have such an effect, or, not sure until you try it on your own projector?
These are new angles than the prisms that were originally posted on the german site of 30 degrees and 24 degrees.
Even more interesting to me is this concept of the "water getting dirty", AND, that using two filled with oil does not cause --or compensate for -- "chromatic abberation". For example, if you look at the projector image through JUST the water prism, the colors aren't aligned, there is a slight "rainbow" effect until you place the oil prism in place as well. Are you saying that the two glycerine-filled don't have such an effect, or, not sure until you try it on your own projector?
Slize we must have been writing at the exact same time, because you seem to have answered my questions already with your most recent post. Great information!!!!!!!!!!!! Please post more as you collect more information and results!!!
"These are new angles than the prisms that were originally posted on the german site of 30 degrees and 24 degrees."
Yes these are new angles, but they were posted on that site too; under actual stuff the last point. It was just mentioned in two or three lines. but i think it is very important...
"Even more interesting to me is this concept of the "water getting dirty","
Do you have an aquarium? It is quite the same with the water prism. I don't know the english word for "Algen"... that's what will happen to the water. There will be "Algen" in it... and if you don't change it or do air in it, like in an aquarium it will get dirty...
"that using two filled with oil does not cause --or compensate for -- "chromatic abberation". For example, if you look at the projector image through JUST the water prism, the colors aren't aligned, there is a slight "rainbow" effect until you place the oil prism in place as well. Are you saying that the two glycerine-filled don't have such an effect, or, not sure until you try it on your own projector?"
I say they have the same effect. That's why you need 2 of them.
If you take just one prism filled with oil. you have the same thing as if you would take just the water prism. the rainbow effect...
You always need 2 prisms to re-aligne the colors. And i know it, because i saw it, that the 2 prisms filled with oil will do the same as two prisms one filled with water and the other filled with terpentine oil...
and the silicon inside the the prism is important too.
I have pictures of the building of the two prisms. anybody whos interested send me an e-mail to der_jojojo@yahoo.de and i will send it.
Yes these are new angles, but they were posted on that site too; under actual stuff the last point. It was just mentioned in two or three lines. but i think it is very important...
"Even more interesting to me is this concept of the "water getting dirty","
Do you have an aquarium? It is quite the same with the water prism. I don't know the english word for "Algen"... that's what will happen to the water. There will be "Algen" in it... and if you don't change it or do air in it, like in an aquarium it will get dirty...
"that using two filled with oil does not cause --or compensate for -- "chromatic abberation". For example, if you look at the projector image through JUST the water prism, the colors aren't aligned, there is a slight "rainbow" effect until you place the oil prism in place as well. Are you saying that the two glycerine-filled don't have such an effect, or, not sure until you try it on your own projector?"
I say they have the same effect. That's why you need 2 of them.
If you take just one prism filled with oil. you have the same thing as if you would take just the water prism. the rainbow effect...
You always need 2 prisms to re-aligne the colors. And i know it, because i saw it, that the 2 prisms filled with oil will do the same as two prisms one filled with water and the other filled with terpentine oil...
and the silicon inside the the prism is important too.
I have pictures of the building of the two prisms. anybody whos interested send me an e-mail to der_jojojo@yahoo.de and i will send it.
Again, great information.. thanks again slize!
I think "Algen" must mean "Algae" and I had hoped that if the water prism was sealed well enough, that the water would never get cloudy (?) Assuming it does eventually cloud up, I like your design better with both being filled with oil.
Slize, any comments/thoughts about making two prisms compress 4:3 to 2.35 ? Are your thoughts the same as those posted in general, that you use the same prisms, just tilt them more (therefore creating more barrell distortion) ?? Or is there a different set of prism angles that you can use when you actually contruct them that works better to compress to 2.35 ?
Thanks!
I think "Algen" must mean "Algae" and I had hoped that if the water prism was sealed well enough, that the water would never get cloudy (?) Assuming it does eventually cloud up, I like your design better with both being filled with oil.
Slize, any comments/thoughts about making two prisms compress 4:3 to 2.35 ? Are your thoughts the same as those posted in general, that you use the same prisms, just tilt them more (therefore creating more barrell distortion) ?? Or is there a different set of prism angles that you can use when you actually contruct them that works better to compress to 2.35 ?
Thanks!
Yup, I think it's "Algae".
I don't think a sealed water prism would have the problem of a fishtank. Fishtanks
a) Have aerated water. This provides both oxygen for algae and a source for algae contamination.
b) Algae = plants. Fish urine = fertilizer
Still, the glycerine is a neat idea. I think I'll try two glycerine prisms once I get my projector back up and running.
BTW, just as a correction for the future, since Slize probably wants to improve his English: The sealant is silicone, not silicon. They're different things. (Don't worry, even people in this country who speak native English get that one wrong pretty often!)
Also, you have to worry about water coming out, not cumming - Cumming is a word you'll only see on porn sites. 🙂
I don't think a sealed water prism would have the problem of a fishtank. Fishtanks
a) Have aerated water. This provides both oxygen for algae and a source for algae contamination.
b) Algae = plants. Fish urine = fertilizer
Still, the glycerine is a neat idea. I think I'll try two glycerine prisms once I get my projector back up and running.
BTW, just as a correction for the future, since Slize probably wants to improve his English: The sealant is silicone, not silicon. They're different things. (Don't worry, even people in this country who speak native English get that one wrong pretty often!)
Also, you have to worry about water coming out, not cumming - Cumming is a word you'll only see on porn sites. 🙂
I'm prety sure that water will grow algae in a prism. Where there's light, air and biological matter there is algae. There must be some air(any) inside the prism, this will be enough I'm certain. Using the finest distilled water would help slow the process, but any "biological matter" whatsoever would be enough to contaminate the best water.
It's motion dampening qualities aren't the only reason merium oil is used in the cockpit compass of a yacht. A friend of mine foolishly drained his compass and couldn't find merium oil for it...he bought a new compass $$$ I'm betting he could have used glycerine.
I've been following this thread and looking deeper for a while now.. and to be honest the single thing that has stopped me from just going for it was the water prism. I'm building one as soon as I know what my final lens will be in my design. This use of glycerine has convinced me.
zardoz
It's motion dampening qualities aren't the only reason merium oil is used in the cockpit compass of a yacht. A friend of mine foolishly drained his compass and couldn't find merium oil for it...he bought a new compass $$$ I'm betting he could have used glycerine.
I've been following this thread and looking deeper for a while now.. and to be honest the single thing that has stopped me from just going for it was the water prism. I'm building one as soon as I know what my final lens will be in my design. This use of glycerine has convinced me.
zardoz
If you use distilled water and seal it completely I am not sure how fungi can grow since distilled water is distilled no fungi or bacteria in it and if it is sealed nothin should grow in it.
Any how I have my NEC VT540 on way now got it on E bay and I am excited about building this lens
Slize I have a few questions for you
What is the size of both your prisims and are they of same size or have u built different size prisims like tor.
For sides of prisims I have a idea buy some cheap plastic tissue holders from walmart and cut it with dremel and stick glass on front and back I checked size it is about 7 inch square
I attached the bathroom set which has picture of tissue holder in there
Any how I have my NEC VT540 on way now got it on E bay and I am excited about building this lens
Slize I have a few questions for you
What is the size of both your prisims and are they of same size or have u built different size prisims like tor.
For sides of prisims I have a idea buy some cheap plastic tissue holders from walmart and cut it with dremel and stick glass on front and back I checked size it is about 7 inch square
I attached the bathroom set which has picture of tissue holder in there
Attachments
hi shiv,
the reason why i built such big prisms in the lenght (the second one) is because i use an ohp lense for my diy projector. there the picture goes wide on a short way.
For a regular projector i would say you should use the mesaruments of tor arnes prisms. one small and on big prism both filled with the glycerine oil and both with the angles i mentioned above. i will post a picture of the angles for better understanding later.
For the sides i used a self designed plastic sides. I will post pictures of that this afternoon too.
the reason why i built such big prisms in the lenght (the second one) is because i use an ohp lense for my diy projector. there the picture goes wide on a short way.
For a regular projector i would say you should use the mesaruments of tor arnes prisms. one small and on big prism both filled with the glycerine oil and both with the angles i mentioned above. i will post a picture of the angles for better understanding later.
For the sides i used a self designed plastic sides. I will post pictures of that this afternoon too.
here are the plastic sides: you see the edges, there i fixed the glas with glas glue from pattex:
this is the bottom side:
you see the 2 holes. I think this is the best solution. one you fill in the oil the other is for the air to come out. once the prism is full the air will go automatically to the upper hole because you know the physic of water. i closed the holes with two with screw. Before i rotatet threads in it. That's the advantage of plastic. easy to work with.
you see the 2 holes. I think this is the best solution. one you fill in the oil the other is for the air to come out. once the prism is full the air will go automatically to the upper hole because you know the physic of water. i closed the holes with two with screw. Before i rotatet threads in it. That's the advantage of plastic. easy to work with.
Attachments
Couple of thoughts:
1. I don't think it's that important to get all the air out, as long as your lens is large enough to let the image pass through just liquid. And, as long the air itself doesn't potentially contribute to algea inside the prism. For my model I just had one 1/8 wide fill hole in which I poured water or oil, no other holes necessary?
2. I like the idea about the tissue holder (I think I'll look at those next time I'm in Walmart), however, I'm skeptical that using a dremel tool will do the job. I think the best tool is a large electrical saw that has the ability to cut at specific angles in one quick cut. If you use a cutter with which you only cut one side at a time, I'd worry that one side would end up JUST a small bit out of alignment/angle and it seems that subtle problems w/ the angles can cause big focus problems on your image.
1. I don't think it's that important to get all the air out, as long as your lens is large enough to let the image pass through just liquid. And, as long the air itself doesn't potentially contribute to algea inside the prism. For my model I just had one 1/8 wide fill hole in which I poured water or oil, no other holes necessary?
2. I like the idea about the tissue holder (I think I'll look at those next time I'm in Walmart), however, I'm skeptical that using a dremel tool will do the job. I think the best tool is a large electrical saw that has the ability to cut at specific angles in one quick cut. If you use a cutter with which you only cut one side at a time, I'd worry that one side would end up JUST a small bit out of alignment/angle and it seems that subtle problems w/ the angles can cause big focus problems on your image.