Re: My anamorphic lens setup
Hey! I was going to try that exact idea, have the parts but was worried the weight would be too much. I'm using a 4 prism set so it's twice as heavy...didn't think the slide would hold that much weight hanging down instead of on the side. Do you notice any weight problem or strain?
Bud
dvarma said:
Hey! I was going to try that exact idea, have the parts but was worried the weight would be too much. I'm using a 4 prism set so it's twice as heavy...didn't think the slide would hold that much weight hanging down instead of on the side. Do you notice any weight problem or strain?
Bud
Holey moley, I think thats the first thread I've read end to end 🙂 whew...😀
SO now I'm hunting for Optical Crystals...
anyone else in Aussie found the cheapest wedges in AU, or cheaper to import your own from the good old US of A ?...
I'm looking at 2 sites, once has them for $90aud, the other for $50us + international postage...
Woot, got an email from Aussie distributor 🙂 much cheaper now.
SO now I'm hunting for Optical Crystals...
anyone else in Aussie found the cheapest wedges in AU, or cheaper to import your own from the good old US of A ?...
I'm looking at 2 sites, once has them for $90aud, the other for $50us + international postage...
Woot, got an email from Aussie distributor 🙂 much cheaper now.
Strike one. The vikuiti films just won't work--at least these screen protectors that you can buy. The AR capability is due to their haziness. Firstly, they are very difficult to get on the face of the prisms without bubbles. Any dirt, lint, fingerprint, etc., and a bubble forms directly on that spot.
Secondly, once I put them on, it was obvious that they wouldn't work. They make the surface of the prisms hazy, scattering the light. This would be devastating for a projected image. I didn't even bother setting them up in my projector light path.
At this point, I'm not sure I want to spend the cash to get the AR coating from L&L Optical that I posted before. For the MgF2, it's $40 per prism. I would think the best bet would be the broadband AR coating, but that is $80 per prism. I'm not sure the benefit is worth it. Aehhh, but give me a few days--I'm just feeling the sting of having paid for these vikuiti films...
Secondly, once I put them on, it was obvious that they wouldn't work. They make the surface of the prisms hazy, scattering the light. This would be devastating for a projected image. I didn't even bother setting them up in my projector light path.
At this point, I'm not sure I want to spend the cash to get the AR coating from L&L Optical that I posted before. For the MgF2, it's $40 per prism. I would think the best bet would be the broadband AR coating, but that is $80 per prism. I'm not sure the benefit is worth it. Aehhh, but give me a few days--I'm just feeling the sting of having paid for these vikuiti films...
Hi Steve,
That's what I imagined they would do - like the protective coating you can get for a mobile phone screen...
Hey Stevedude send me a email cavx01@bigpond.com
Mark
That's what I imagined they would do - like the protective coating you can get for a mobile phone screen...
Hey Stevedude send me a email cavx01@bigpond.com
Mark
Well I have emailed them to see what is available on this side of the world. Even if it cost $200 per prism, that would be better than the $1500/prism quotes I have been given so far...
Mark
Mark
Re: prism
lxjoe,
The two different prism sizes would be ok if their small angles are identical, but I don't know if this is true of the J24 and J25. It probably would have been safer to buy two J25's just to make sure they have the same wedge shapes, but I guess worst case you may just have to buy another J25 if it doesn't work out.
I also have a new pani 100axu and am going to order a couple of J25's. My experiment with water prisms worked out well, so I'm curious to see how the glass prisms compare to the homemade version.
As far as your last question, there are a few good screen calculators out there that you may want to play with. Here's one of them that will do calculations for 2.35 ratio screens. It basically will show you that for a 120" diagonal screen, you'll want a 110.4" width.
http://www.4tn.net/HomeCinema/AspectRatioCalculator.aspx
Hope this helps,
Ed
lxjoe said:
lxjoe,
The two different prism sizes would be ok if their small angles are identical, but I don't know if this is true of the J24 and J25. It probably would have been safer to buy two J25's just to make sure they have the same wedge shapes, but I guess worst case you may just have to buy another J25 if it doesn't work out.
I also have a new pani 100axu and am going to order a couple of J25's. My experiment with water prisms worked out well, so I'm curious to see how the glass prisms compare to the homemade version.
As far as your last question, there are a few good screen calculators out there that you may want to play with. Here's one of them that will do calculations for 2.35 ratio screens. It basically will show you that for a 120" diagonal screen, you'll want a 110.4" width.
http://www.4tn.net/HomeCinema/AspectRatioCalculator.aspx
Hope this helps,
Ed
Steve Scherrer said:
What angle did you get? Mark reported the angle as 10º but looking at the top down picture from dvarma (in PDF) it looks to be right about 8º to me. The picture may have gotten stretched or some thing to change the angle. The easiest way to test this would be to know the top and bottom thickness and the angle could be calculated easily.
Pagercam said:
I actually measured 5 degrees, but it might not have been entirely accurate. They were identical, though. I have them both at home, I will take some measurements and calculate it more accurately.
(OK brain, got to bust out the high school trig!)
I have to accurately measure, anyway, because I received another response from an optical coating company that wanted to know the precise dimensions of the prisms.
I probably should post this in a new thread about anamorphic screens or something, but thought I'd wak it in here....
I got some info off avs forums about what to do once I have some lenses functiontion, and like your screen Mark, creating a curved screen in both horizontal and vertical planes.
seems a lot of info has been removed, or 'filtered' on specifications on 3d curved screens.
I have no idea why as a mathmatical formula derived from simple geometry I thought could not be patented, but who knows in America they do anything...
Anyway my thoughts on a screen once you get the a lense and try it out it seems there is a lot of barreling? or something it's called, but anyway, the idea is the screen should be based on a cut out section of a sphere to get the perfect image with minimal distortion, and the formula for a sphere is
&^2=z^2 - x^2 - y^2
z=r (radius)
from that
z = distance from projector to center of screen
x = width or distance from center of screen
y = width or distance from center of screen
rise = r(or z) - &
so from that you can throw it into an excel spreadsheet and calculate whatever points from the flat plane you need for making the spherecal section.
I have a spread sheet I can post, currently it will calculate a 100 point screen with XY curves (10 x and 10 y), but I will modify first I think to allow input of how many points you want X & Y directions.
hopefully should work for perfect screen curvature 🙂
and I've ordered a few prisms and next will be to see how far out the pincusioning or barrelling effect there is, and get some more screen material and make up a 'spherical screen', or I'd like to call it a Sphereen?... hahaha
I checked my xcel against the flat vertical, curved horizontal formula posted on avs, and the centre horixontal numbers are exactly the same, so should be spot on.
xcel to follow, if anyones interested.
BTW I think I might have my projector a bit close @ 3.2meters, means my outside corners are going to be 225mm away from the 0,0 point center ( or wall) ...
If Bring the projector back to 5 meters I almost half the rise to 141mm.
so I'd check your room dimensions before embarking on extra lenses 🙂 I have 9 meters to play with, so not a problem for me hehehe
I got some info off avs forums about what to do once I have some lenses functiontion, and like your screen Mark, creating a curved screen in both horizontal and vertical planes.
seems a lot of info has been removed, or 'filtered' on specifications on 3d curved screens.
I have no idea why as a mathmatical formula derived from simple geometry I thought could not be patented, but who knows in America they do anything...
Anyway my thoughts on a screen once you get the a lense and try it out it seems there is a lot of barreling? or something it's called, but anyway, the idea is the screen should be based on a cut out section of a sphere to get the perfect image with minimal distortion, and the formula for a sphere is
&^2=z^2 - x^2 - y^2
z=r (radius)
from that
z = distance from projector to center of screen
x = width or distance from center of screen
y = width or distance from center of screen
rise = r(or z) - &
so from that you can throw it into an excel spreadsheet and calculate whatever points from the flat plane you need for making the spherecal section.
I have a spread sheet I can post, currently it will calculate a 100 point screen with XY curves (10 x and 10 y), but I will modify first I think to allow input of how many points you want X & Y directions.
hopefully should work for perfect screen curvature 🙂
and I've ordered a few prisms and next will be to see how far out the pincusioning or barrelling effect there is, and get some more screen material and make up a 'spherical screen', or I'd like to call it a Sphereen?... hahaha
I checked my xcel against the flat vertical, curved horizontal formula posted on avs, and the centre horixontal numbers are exactly the same, so should be spot on.
xcel to follow, if anyones interested.
BTW I think I might have my projector a bit close @ 3.2meters, means my outside corners are going to be 225mm away from the 0,0 point center ( or wall) ...
If Bring the projector back to 5 meters I almost half the rise to 141mm.
so I'd check your room dimensions before embarking on extra lenses 🙂 I have 9 meters to play with, so not a problem for me hehehe
Steve, the L&L AR glasses (5x7 sizes) are what I tried, and as I mentioned i do see a reduction in reflection, as seen by the reduced scatter and reflection strength on the Z4 projector. However, I don't know how to measure the reduction.Steve Scherrer said:
Also, since all I did was tape the AR glass (by the edge) to teh prism face of the beam receiving face(s), I am sure there is some air gap, however minute would be causing issues, as at the wavelength distance even a spec of dust must be causing problems.
I am waiting for someone to try the AR coating!
Re: Re: My anamorphic lens setup
Bud, I was worried about the weight issue as well, though I have a two prism setup. Besides, I have a habit of sitting right underneath the projector (it happens to be the sweetspot!). I gave it the "pull really hard" test and it didn't even budge, These are heavy duty ball bearing slides rated very high (130 lbs I think, but that is for two when mounted horizontally, so the weight rating is for shear strength not for pulling it apart). There are a large number of balls (bearings) that are between the two separating slides, and while slides super easy, I could not pull them apart once slid on.
I don't think there is any chance of it coming apart. However, my lens was not centered on the slide, which I need to correct by moving the slide forward a bit. I am worried that if the lens is not centered geometrically (weight center) it might twist it and pull it off (again not likely).
For real peace of mind on a 4 prism set what I would try is the dual set of ball bearing slides that are often used for mounting underneath slide out kitchen cabinets (and underneath slide out trash cans). These come in pairs and are mounted with the ball bearing and slides vertically. You can use normal slidesa nd a vertical adapter, which is better than mounting it like I did with the flat face horizontal, the flat face vertical would be far stronger of course, since the weight of the lens will be supported by the slides in its normal slide position (vertical) rather than horizontal as I have.
I had this one with me so didn't shop around. If I were looking for slides more suitable for this purpose, I would look at ww.rockler.com and part numbers like 51692 or 31915 or 30818. I think I used the Accuride 9301 series, which are very heavy duty. These are not cheap, but there may be a cheaper source for similar slides.
What I also liked about them is that they are so smooth, I should have no trouble adding an electric remote controlled system to move it in or out, using a cheap X-10 controlled drapery controller (the one that uses a cord) with limit switches (I have one bought from Smarthome for well under $100 a while ago).
I had the slides lying around for a while and I was thinking of trying it but didn't bother. Then I read a post by you where you were thinking of trying it, so that got me moving. Thanks!
Bud Bray said:
Bud, I was worried about the weight issue as well, though I have a two prism setup. Besides, I have a habit of sitting right underneath the projector (it happens to be the sweetspot!). I gave it the "pull really hard" test and it didn't even budge, These are heavy duty ball bearing slides rated very high (130 lbs I think, but that is for two when mounted horizontally, so the weight rating is for shear strength not for pulling it apart). There are a large number of balls (bearings) that are between the two separating slides, and while slides super easy, I could not pull them apart once slid on.
I don't think there is any chance of it coming apart. However, my lens was not centered on the slide, which I need to correct by moving the slide forward a bit. I am worried that if the lens is not centered geometrically (weight center) it might twist it and pull it off (again not likely).
For real peace of mind on a 4 prism set what I would try is the dual set of ball bearing slides that are often used for mounting underneath slide out kitchen cabinets (and underneath slide out trash cans). These come in pairs and are mounted with the ball bearing and slides vertically. You can use normal slidesa nd a vertical adapter, which is better than mounting it like I did with the flat face horizontal, the flat face vertical would be far stronger of course, since the weight of the lens will be supported by the slides in its normal slide position (vertical) rather than horizontal as I have.
I had this one with me so didn't shop around. If I were looking for slides more suitable for this purpose, I would look at ww.rockler.com and part numbers like 51692 or 31915 or 30818. I think I used the Accuride 9301 series, which are very heavy duty. These are not cheap, but there may be a cheaper source for similar slides.
What I also liked about them is that they are so smooth, I should have no trouble adding an electric remote controlled system to move it in or out, using a cheap X-10 controlled drapery controller (the one that uses a cord) with limit switches (I have one bought from Smarthome for well under $100 a while ago).
I had the slides lying around for a while and I was thinking of trying it but didn't bother. Then I read a post by you where you were thinking of trying it, so that got me moving. Thanks!
Re: Re: Re: My anamorphic lens setup
Thanks for the ideas...I have Home depot here & bought 2 of what look like your type. Right now I have a cylindrical bar mounted on the ceiling with large eyelet bolts hanging from it, then the bolts mount to the housing...I went to IKEA and bought a kitchen utensil bar for a better looking bar in the future. I'll give the slide a try though...I have the parts...why not. I'll keep U posted.
Bud
dvarma said:
Thanks for the ideas...I have Home depot here & bought 2 of what look like your type. Right now I have a cylindrical bar mounted on the ceiling with large eyelet bolts hanging from it, then the bolts mount to the housing...I went to IKEA and bought a kitchen utensil bar for a better looking bar in the future. I'll give the slide a try though...I have the parts...why not. I'll keep U posted.
Bud
Here's an update on prism availability from massillonplaque.com:
The J25 glass wedges (medium size) are currently on backorder until the beginning of January. Their customer service rep (Suzanne) said that their glass supplier is out of stock because they have been getting tons of orders for these. (We can only hope it is due to all of us who are crazy enough to make our own anamorphic lenses).
The J24 (small) and J26 (large) are currently in stock, and the pricing for all the wedges is still the same as what was posted previously.
The J25 glass wedges (medium size) are currently on backorder until the beginning of January. Their customer service rep (Suzanne) said that their glass supplier is out of stock because they have been getting tons of orders for these. (We can only hope it is due to all of us who are crazy enough to make our own anamorphic lenses).
The J24 (small) and J26 (large) are currently in stock, and the pricing for all the wedges is still the same as what was posted previously.
Has anybody asked that optical prism manufacturer if they have any advice for people wanting to coat the prisms with anti-reflective coating?
🙂
🙂
stevodude said:
Just for the record, I now have gone back to a curved screen where the screen bends only in the horizontal plain.
Steward screens are quite protective about their TORUS and on AVS my project was dubbed "the rouge TORUS". Basically the measage I got was that they will tollerate one offs, but will take leagal action against anyone found selling dual curved screens...
Mark
Mark Techer said:
Do they have a patent on it??? (Just wondering, as I am a patent attorney, and wouldn't mind looking into it.)
Steve Scherrer said:
I'n not sure Steve, but whist your there, what does Shawn Kelly's Patent for a prisms lens cover?
Mark
I've been following this thread for a while now and finally have some time to actually build my enclosure. I bought 2 4x6 prisms and just set it up with some crazy ladder contraption to test the prisms out. I am really excited by what I see.
Here are some test pattern shots...
I have pretty good geometry but sometimes it's hard for me to tell because of my Coke bottle glasses. 😉 Focus is pretty uniform but it is a tad off on the left. I have a slight bow across the bottom.
King Kong HD-DVD using the 360 addon (which is really nice btw)
Cars DVD using a Sony S75 upconverting player via HDMI
And Star Wars using a Sony S75 upconverting player via HDMI
My projector is a Sanyo Z4 and the screen is a Carada 135" 2.35:1 screen. On thing that is obvious is that I need to recalibrate the projector. My wife even commented on the difference in color and light levels. I have been using my projector on economy mode but I may need to turn it up to full power when using the prisms. I have about 1300 hours on the lamp. I still have my freebie lamp from when i bought the Z4 last May so no worries on lamp life.
I am going to be working on my prism box this week! Thanks everyone for your pioneering work... it makes easy for me! 🙂
Here are some test pattern shots...
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I have pretty good geometry but sometimes it's hard for me to tell because of my Coke bottle glasses. 😉 Focus is pretty uniform but it is a tad off on the left. I have a slight bow across the bottom.
King Kong HD-DVD using the 360 addon (which is really nice btw)
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Cars DVD using a Sony S75 upconverting player via HDMI
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
And Star Wars using a Sony S75 upconverting player via HDMI
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
My projector is a Sanyo Z4 and the screen is a Carada 135" 2.35:1 screen. On thing that is obvious is that I need to recalibrate the projector. My wife even commented on the difference in color and light levels. I have been using my projector on economy mode but I may need to turn it up to full power when using the prisms. I have about 1300 hours on the lamp. I still have my freebie lamp from when i bought the Z4 last May so no worries on lamp life.
I am going to be working on my prism box this week! Thanks everyone for your pioneering work... it makes easy for me! 🙂