Hi all, I have been reading though the old thead regarding building an anamorphic lens--I have been thinking of build on myself. I am just woundering how many people have in fact tried this and the results.
Those prism type anamorphic lenses seem to be more work than they are worth
I got some lexan glass, and some mineral oil, and im going to heat one of the pieces of lexan glass, bend it, and make a cylindrical lens, with magnification power of 1.33333 in the horizontal direction.
That will stretch a 4:3 image to 16:9
It will be much easier to do this, and if I'm clever, I will totally eliminate the screen door effect in the process.
I got some lexan glass, and some mineral oil, and im going to heat one of the pieces of lexan glass, bend it, and make a cylindrical lens, with magnification power of 1.33333 in the horizontal direction.
That will stretch a 4:3 image to 16:9
It will be much easier to do this, and if I'm clever, I will totally eliminate the screen door effect in the process.
wouldnt that distort the picture when you stretch a 4:3 screen to 16:9 ? im sure you are going to have short fat stubby people on your screen, along with everything else.
rethink your strategy.
ap0
rethink your strategy.
ap0
rethink my strategy??
Do you even know what anamorphic encoding is??
Of course its going to distort the image, that is what anamorphic lenses do!
If your theory is right, i think psionic is right, however the bending should be done perfectly otherwise the whole image will be messed up.
Hmm anamorphic lenses... nice idea but not as easy as i wish they were
Hmm anamorphic lenses... nice idea but not as easy as i wish they were
I just finished building a prototype of the DIY anamorphic prism project using glycerine, glass panes and a fence post as discussed in the later part of the original thread.
Initial Impressions: Yes, it compresses the image to 16:9, eliminating any screen door from my seating position of 1.3 screen widths. It also dims the image noticably (seems like 30% loss?), and reflects a significant amount of light on the back wall and ceiling. This is probably because I used normal window glass, which is fairly reflective. Even though the brightness is reduced from the reflections, I am lossing contrast, the blacks are noticeably brighter also. The image seems to have been somewhat defocused. The price in PQ seems too high to pay to get rid of the screendoor, and so I will not be continuing this project. It seems like I can get most of the screen door reduction benefit from a slight pj defocus without any of the brightness and contrast loss.
If anyone in Northeast Indiana wants some free glycerine or part of a 5" fence post, let me know.
Initial Impressions: Yes, it compresses the image to 16:9, eliminating any screen door from my seating position of 1.3 screen widths. It also dims the image noticably (seems like 30% loss?), and reflects a significant amount of light on the back wall and ceiling. This is probably because I used normal window glass, which is fairly reflective. Even though the brightness is reduced from the reflections, I am lossing contrast, the blacks are noticeably brighter also. The image seems to have been somewhat defocused. The price in PQ seems too high to pay to get rid of the screendoor, and so I will not be continuing this project. It seems like I can get most of the screen door reduction benefit from a slight pj defocus without any of the brightness and contrast loss.
If anyone in Northeast Indiana wants some free glycerine or part of a 5" fence post, let me know.
psionic
psionic when u go to bend your lexan put it in some hot water to get it soft its the best way and it is a even temp on the whole proposed lens till it cures but dont put it in boiling water cos the outside will get too hot for the temp of the center, u will need to fool around to get the best temp to center to outside temp, its abit like cooking a roast lol even temp on the inside as the out.
Trev
buy the way dont use the ot u are putting it in again as this stuff is poisonous, also another way is putting it in a small pie oven for 5mins.
psionic when u go to bend your lexan put it in some hot water to get it soft its the best way and it is a even temp on the whole proposed lens till it cures but dont put it in boiling water cos the outside will get too hot for the temp of the center, u will need to fool around to get the best temp to center to outside temp, its abit like cooking a roast lol even temp on the inside as the out.
Trev
buy the way dont use the ot u are putting it in again as this stuff is poisonous, also another way is putting it in a small pie oven for 5mins.
Actually I'm doing it on my gas stove
This stuff gets pretty flexible when you add a small amount of heat. You can put a 90 degree angle in it with no problems.
This stuff gets pretty flexible when you add a small amount of heat. You can put a 90 degree angle in it with no problems.
Assayer said:
You can totally eliminate screen door if you have some dichroic filters. I have dichroic filters, but I dont have a light to use, so I don't have a projector right now.
I will post how this works when I get everything going.
EDIT: Sweet, avatars are the way of the future!
psionic
hey bro i meant to say dont use the pot again that u used to heat the plastex in for cooking cos its poisonous **** lol, as for the 90 deg bends u can make a small line heater ie a halogen bulb so u only heat the area that u want to bend, that way the flat surface that is meant to be flat either side of the bend stays flat
Trev
hey bro i meant to say dont use the pot again that u used to heat the plastex in for cooking cos its poisonous **** lol, as for the 90 deg bends u can make a small line heater ie a halogen bulb so u only heat the area that u want to bend, that way the flat surface that is meant to be flat either side of the bend stays flat
Trev
A couple of points:
1. Assayer commented on losing 30% light while having the benefit of some screen door loss at 1.3. My opinion is a little different. In my situation, on my projector, is more like 5% light loss, subtle difference in screendoor. However, the other benefits which were not mentioned include no more light spill above and below the screen. Also, if your eyes pick up the LCD scanline effect for vertically moving objects, this can go away depending on your seating distance.
NOTE: Assayer, other than the reflected light on your ceiling, you should not be getting any if your lenses are at exactly the correct angles relative to the surface they sit on and to one another. If your projector is brihgt enough you can get reflections from the screen itself back to the front of the lense and back again onto the screen. This means your angles weren't setup correctly.
2. Once you bend lexan if you try to project through it I've found that the image is blurred. I tried to design my first model w/ bent lexan to eliminate one or more sides to seal. The sharp edges of the material don't appreciate being bent. I'm really interested in the results Psionic achieves! Great to have new ideas flowing! I had to trash my lexan piece after it was built and moved to lexan + glass.
3. I'm just starting my design w/ fenceposts. My goal is to design one which can easily be adjustable for 1.85 and 2.35 films. I will post my results in the other DIY anamorphic lense thread.
1. Assayer commented on losing 30% light while having the benefit of some screen door loss at 1.3. My opinion is a little different. In my situation, on my projector, is more like 5% light loss, subtle difference in screendoor. However, the other benefits which were not mentioned include no more light spill above and below the screen. Also, if your eyes pick up the LCD scanline effect for vertically moving objects, this can go away depending on your seating distance.
NOTE: Assayer, other than the reflected light on your ceiling, you should not be getting any if your lenses are at exactly the correct angles relative to the surface they sit on and to one another. If your projector is brihgt enough you can get reflections from the screen itself back to the front of the lense and back again onto the screen. This means your angles weren't setup correctly.
2. Once you bend lexan if you try to project through it I've found that the image is blurred. I tried to design my first model w/ bent lexan to eliminate one or more sides to seal. The sharp edges of the material don't appreciate being bent. I'm really interested in the results Psionic achieves! Great to have new ideas flowing! I had to trash my lexan piece after it was built and moved to lexan + glass.
3. I'm just starting my design w/ fenceposts. My goal is to design one which can easily be adjustable for 1.85 and 2.35 films. I will post my results in the other DIY anamorphic lense thread.
Jude, you tried to bend the lexan, like making a cylindrical lens instead of the prism setup?
I can't see why the image would be blurred, unless you messed up the curvature in the glass, but then it wouldn't be blurred, it would just be distorted in the wrong places.
My setup isn't going to be just a cylindrical lens though, I'm going to use dichroic filters to project the red green and blue portion of the images ontop of eachother
Then the cylindrical lens is going to be out of focus slightly to blur the image horizontally.
I asked a physics teacher about this and he said it was possible.
I've got the lexan, I've got a machine shop, and i've got the dichroic glass. I just don't have a light for my PJ right now so I can't test
I had a post about this a while ago, and people kinda told me i was crazy.
I can't see why the image would be blurred, unless you messed up the curvature in the glass, but then it wouldn't be blurred, it would just be distorted in the wrong places.
My setup isn't going to be just a cylindrical lens though, I'm going to use dichroic filters to project the red green and blue portion of the images ontop of eachother
Then the cylindrical lens is going to be out of focus slightly to blur the image horizontally.
I asked a physics teacher about this and he said it was possible.
I've got the lexan, I've got a machine shop, and i've got the dichroic glass. I just don't have a light for my PJ right now so I can't test
I had a post about this a while ago, and people kinda told me i was crazy.
Hey Psionic + co,
I've been kinda reading this post casually, as I'm interested in the results.. but I just had to say..
**** man thats hardcore.. I could never imagine trying to make my own lens 😱
How do you shape it so it's exactly just right?? -_-
Anyway.. are you gonna make more if it works eh eh? 🙂
Good luck with your lens,
-rep
P.S. Happy Canuck Day
I've been kinda reading this post casually, as I'm interested in the results.. but I just had to say..
**** man thats hardcore.. I could never imagine trying to make my own lens 😱
How do you shape it so it's exactly just right?? -_-
Anyway.. are you gonna make more if it works eh eh? 🙂
Good luck with your lens,
-rep
P.S. Happy Canuck Day
I've got access to a machine shop
im going to make a cylindrical mount for the glass that will look something like what i've attached
I won't really have to heat the glass very much, because there isn't much of a curvature
i will then screw the lexan onto the metal, so that the lexan stays intact with that mold.
Then i will fill everything up with mineral oil, and but another piece of lexan on the back of the mount
im going to make a cylindrical mount for the glass that will look something like what i've attached
I won't really have to heat the glass very much, because there isn't much of a curvature
i will then screw the lexan onto the metal, so that the lexan stays intact with that mold.
Then i will fill everything up with mineral oil, and but another piece of lexan on the back of the mount
Attachments
But that isn't 1/2 as hardcore as what my other lens project is
Im going to find a way to machine a mold like what I've attached. How this one will work is I will put the piece of lexan ontop of this mold, and then use a torch from a distance to heat the lexan, and let it melt down to form this mold.
Then i will:
a) cut a piece of lexan that spans bigger than the hole
b) fill the glass hole up with mineral oil
c) machine a gasket for the glass hold and the bottom piece
d) attact everything together
This is my design for a fresnelless projector. There is a chance that I may have quite a bit of money coming in in the future, so if that happens I will be moving to a large high resolution LCD.
Im still working out the logistics of this, its going to be alot of work to get it right.
Im going to find a way to machine a mold like what I've attached. How this one will work is I will put the piece of lexan ontop of this mold, and then use a torch from a distance to heat the lexan, and let it melt down to form this mold.
Then i will:
a) cut a piece of lexan that spans bigger than the hole
b) fill the glass hole up with mineral oil
c) machine a gasket for the glass hold and the bottom piece
d) attact everything together
This is my design for a fresnelless projector. There is a chance that I may have quite a bit of money coming in in the future, so if that happens I will be moving to a large high resolution LCD.
Im still working out the logistics of this, its going to be alot of work to get it right.
Attachments
Psionic can you attach some graphics onto that bracket on how the cyclindrical lense would attach to it and how the light would pass through (like, does the light pass through the long side of the lense or through each end -- may be a dumb question, but ??)
As far as my experience with bending lexan, it may be the way I heated it, which was just very bluntly over a stove! But yes, after I did this and bent the lexan to the appropriate angle, and dilled w/ mineral oil, I didn't get a very clean looking image. Even though prior to bending the lexan the image seemed unaffected passing through the material.
One other comment about these lenses in particular, keep in mind there are quite a few folks out there who bought the commercial version of this lense in the past few years who are tickled pink to get it. I had the two of the commercial versions at my house so I was able to compare visually the differences, and the DIY version I made provided basically the same results, although I think the glass they use on the commercial version is the anti-reflective.
As far as my experience with bending lexan, it may be the way I heated it, which was just very bluntly over a stove! But yes, after I did this and bent the lexan to the appropriate angle, and dilled w/ mineral oil, I didn't get a very clean looking image. Even though prior to bending the lexan the image seemed unaffected passing through the material.
One other comment about these lenses in particular, keep in mind there are quite a few folks out there who bought the commercial version of this lense in the past few years who are tickled pink to get it. I had the two of the commercial versions at my house so I was able to compare visually the differences, and the DIY version I made provided basically the same results, although I think the glass they use on the commercial version is the anti-reflective.
JudeBarnes said:
yep dumb question 🙂
it passes through the bottom hole and travels throught the top.
What did you use to mount the glass?
And did you take the glass paper off before you cut it?
How did you know you had the curvature correct?
Are you saying the image passes through the bottom hole on your BRACKET with the cylinder in place? Which would mean the image actually passes through the SIDES of the cylinder? Or, do you mean it passes through the bottom and top of the cylinder itself, as well as, or instead of the bracket. Send an updated graphic w/ the cylinder in place so we can see how it's mounted in the bracket, and a simple arrow where the image passes through, your project sounds very interesting!
In my lexan version of the standard anamorphic lense project (two prisms filled with liquids), there was no glass whatsoever. I "mounted" two pieces together with E6000 compound, and had no leaks on my first try. I knew I had the angle (not curvature per say) correct because I had a piece of wood cut to the appropriate angle which I used as a template to wrap the heated lexan around.
This model was the one unforunately that didn't provide a very good image so it was trashed right away.
On my glass version, there was no glass paper on the glass I got, which was scrap picked up at a frame shop for free. The pieces were also "mounted" with the same E6000 compound.
Glass cutting is very simple once you try it. It sounds like your expirment isn't going to include glass at all though, correct?, only a lexan cylinder and your bracket?
In my lexan version of the standard anamorphic lense project (two prisms filled with liquids), there was no glass whatsoever. I "mounted" two pieces together with E6000 compound, and had no leaks on my first try. I knew I had the angle (not curvature per say) correct because I had a piece of wood cut to the appropriate angle which I used as a template to wrap the heated lexan around.
This model was the one unforunately that didn't provide a very good image so it was trashed right away.
On my glass version, there was no glass paper on the glass I got, which was scrap picked up at a frame shop for free. The pieces were also "mounted" with the same E6000 compound.
Glass cutting is very simple once you try it. It sounds like your expirment isn't going to include glass at all though, correct?, only a lexan cylinder and your bracket?
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