DIY anamorphic lens

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#221
slize

When I was working for an engineering company we called the plastic you use for your end plates "UHMW" (ultra high molecular weight) plastic, at least from your pictures it looks the same 😉
If it is it's great stuff to work with! It's very easy to machine and it's a stable plastic. Thinking of machining slots for the glass to fit into on 2 of the sides, then recessing the third piece.

Good information, thanks for showing us.

zardoz
 
#222
the reason the pictures are not sharp is not because i have focus problems.

that comes from the image is moving, it is a normal tv movie.
i took a picture without the flash (because the flash would reflect on the glass and you would see nothing).

And if you take a picture without flash the light time is very high, so the picture looks unsharp but it isn't. it is a normal tv picture and believe me it is sharp... may be i should have taken a freezed picture... may be i'll post that as soon as get the digi cam back from a friend...
 
#223
to the picture at the beginning of the page:

i didn't cut the edges out.

i bought a plastic plate at 3mm (0.16" ?) thick

(polysterol it is called)

and a second plate at 10mm (1,6"?) thick.

I cut the first outer triangle (the 3mm) and the inner smaller triangle (10mm). then i glued them together with pattex glue gel. That's how i got the edges... look at the sketch...

In that picture i press the two triangles for each side left and right together...
 
#224
hi jude,

the reason i would say two holes are better:

if you have just one hole and you use that hole to fill in the oil, with an injector, and your prism is thight (that means no air comes out anywhere), then the oil won't get in...

believe me i tried it.

imagine you would blow into a bottle. Now we take your breath; the air and imagine it is oil, your breath/the oil won't get in.

you need a second hole for the filling process of the prism, where the air inside the prism comes out... just for the filling process.
 
#226
The lens filled with "Glycerin" can be made smaller than the other because of the smaller angles of the prisms. I have received my NEC HT1000 and it's a cracking projector! 🙂 I might make a lens for it.

Do you have a picture of the glyserin-bottle? What is the chemical name?

EDIT:
After searching a little I think it's called Glycerin in Norway too. 😀


Tor Arne
 
#229
It helps in so much that you use ALL of your pixels on your 4:3 projector, and gain picture detail as a result. You also lose annoying light spill on the top and bottom of your image if you use a 16:9 screen.

You merely need to set your DVD player or HTPC to use the FULL 4:3 resolution and let the lense do the work of squeezing the resulting tall & skinny looking images and detail into their proper ratio.

Speaking for my own personal experience and my projector, I can't tell you how invaluable this lens is to me -- gone are many distracting artifacts and instead I'm left with a more film-like image. No more light spill on the top and bottom of the screen (so, no masking required). Even screendoor is less noticable, because the pixels appear smaller vertically. The only downside I noticed was a very subtle loss in brightness, plus time it takes to setup the lens for every movie.
 
#231
can this be done with any dvd? it sounds like there is actually more resolution on the dvd than is normally used?! so for example if i have a 16:9 screen and watch a 16:9 dvd and there are 480 lines of available resolution... but only 350 are used because the top and bottom are "black", and there are 640 pixels horizontally... what you are saying is that i would set the dvd to run as 4:3 which would still have only 640 pixels horizontally but this time the previously downsampled 350 lines will become 480... but the problem is that the image would look "tall and skinny"... which is where the anamorphic lens comes in... and when the lens stretches then image back out, you have the correct ratio again but this time with the full 640x480 resolution? i guess this would work with a 4:3 screen too (which is what I have) but you will still get black top and bottoms... only this time the image will have more resolution. did i get it right?

would an anamorphic lens also amplify the screen door effect? this idea sounds intriguing... but out of my league since it sounds very complicated to build a lens of this type and i would likely have to throw away the first couple of tries... and the commercial variety are about $1-2k from what I've seen... I would go for one if it was more like $100-200 🙂
 
#232
#233
I'll be looking for Glycerine at Walgreens for my next revision. Tor great pictures of your HTPC concept/WIP. What software combination will you be using on it?
If you haven't kept up to date in the HTPC forum at avsforum.com, the latest and greatest "best PQ winner" seems to be using the combination of zoomplayer + ffdshow + sonic cinemaster video filters, I saw a remarkable improvement on my LCD projector using this software.
 
#234
to kl899: I think you described the process well. Except, it wouldn't amplify screendoor, if anything, it makes it less noticable because it "squashes" the pixels into a flatter shape. And yes, if you have a 4:3 screen you'd have empty whitespace unused on your screen, however, it wouldn't be projected onto.

Yes this process works with ANY material -- DVD or not -- if you can get it scaled into the "tall & skinny" 4:3 ratio. As far as the resolution of the DVD, I don't think it's so much you are pulling more resolution out of the dvd you are re-scaling the existing detail in the DVD such that the images are "tall & skinny". When you squish the detail back down, it provides a more detailed looking picture because you are compressing the space between pixels & lines and, at least for me, got rid of a lot of the little annoying artifacts that went along w/ LCD movie viewing.

Just as you need to re-scale the aspect ratio of 16:9 or 2.35 content, if you watch 4:3 material a lot, and want to keep the lense in front of the projector and not move it around, you need to be able to set your 4:3 material into "anamorphic" mode, which squeezes the 4:3 material horizontally, making the images "tall & skinny" again. This gives you black bars (unused pixels) on the left and right, but allows you to watch your 4:3 material in the same aspect ratio without having to move the lense. You most likely need an HTPC to do this work, unless standalone DVD players can do this, I am not aware of any that can.
 
#235
JudeBarnes said:
I'll be looking for Glycerine at Walgreens for my next revision. Tor great pictures of your HTPC concept/WIP. What software combination will you be using on it?
If you haven't kept up to date in the HTPC forum at avsforum.com, the latest and greatest "best PQ winner" seems to be using the combination of zoomplayer + ffdshow + sonic cinemaster video filters, I saw a remarkable improvement on my LCD projector using this software.
Click to expand...

I will be using Theatertek. I won't use ffdshow because I don't want the hassle of changing the registry every time I change between PAL/NTSC.

I bought the 100ml Glycerin-bottle today. It's called Glyserol but it's the same stuff. I ordered more for later. The 100ml bottle is enough for one lens.

Glyserin=Glyserol: http://ptcl.chem.ox.ac.uk/MSDS/GL/glycerol.html

BTW, I made the front for the HTPC today: http://home.c2i.net/ahustvedt/images/htpc01.jpg


Tor Arne
 
#236
this is my first post so be gentle. ive been following the anamorphic lense thread and like the idea of using more of the screen for projection. while surfing i found a small program that changes the aspect ratio of such programs as windvd. its called yxy and is free. i donot have a dvd rom drive and i was wondering if someone with windvd could give it a try and post results . ive tried it with mediaplayer but it just changes the windows size not the actual video . im hoping it works with windvd like it claims you can find it here http://www.keohi.com/keohihdtv/htpc/yxy/yxy.html thanks in advance
 
#237
Remember that with these lenses you are actually making your total image size SMALLER (from 4:3 compressing vertically to 16:9), unless you use it to do the opposite (expand horizontally from 4:3 to 16:9) which I think yields less satisfactory results. (You mentioned something about being interested in using MORE screen.)

YXY was a very popular HTPC application in it's day, but most recently, zoomplayer has been available (free dvd player software) which has all of those features built in and much, much more. I use zoomplayer's aspect ratio controls for everything I need, it handles basically every combination of aspect ratios you'd need depending on your source material.

I suppose if you didn't want to use zoomplayer for whatever reason, yxy might still be a necessity if the dvd player software you were using didn't have very good support for aspect ratio settings.
 
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