DIY anamorphic lens

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#1,722
iseealiens said:
Sorry Mark I should have been clearer; nelliekins is correct I am planning on making mines’ liquid filled for the reason that I think it would be to hard to find someone that will do AR coating on these trophy wedges in the UK.

JB1061 is the 6” plaque number and if you Google it will show other company’s in the UK that sell them. JB1062 is the 7” and JB1063 is the 7.5”.

Let me know if anyone finds a company that can do AR coating in the UK for a reasonable price.

I have one question? Is it better to use these trophy wedges rather then constructing ones liquid filled? And why?

Cheers
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Hi iseealiens,

I think you are right regarding finding AR coating for a reasonable price. Which glass are you thinking of using? I've seen something called Mirogard Waterwhite AR - quite expensive, but supposed to be just about as transparent (and perhaps more importantly, colour-neutral) as commercial glass is going to get.

In terms of whether DIY liquid-filled prisms or trophies are better, I would guess that, if done right, the liquid-filled prisms would give the best possible results. However, the marginal gains (in terms of correcting / reducing chromatic aberration, for example) might well be offset by the complexity of the job (sourcing the perfect liquids, manufacturing geometrically perfect prisms, etc).

On the other hand, if a job is worth doing... 😉

Mark Techer said:
Hi Neil,

Email returned. I would try and see if you can get that coated glass bonded to the faces of the prisms.

My prisms have a 14.5(?) angle too, so a bit steeper than the 8 degree angles some used. The steeper the angle, the less displacment, but the more material the light has to pass through...

Mark
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Hi Mark,

Thanks for the email. I wonder if crystal-to-crystal glue would suffice for this? I've found somewhere that sells 6"x4" crystal wedges for about 5GBP(!) (but have a minimum order of quantity of 50GBP for first orders) - they sell crystal glue as well. Here's a link:

http://www.xpres.co.uk/shoppingcart/acatalog/Versacamm_Accessories.html

Perhaps this would work for attaching the AR glass to the trophies...

As for 14.5 degree angle - is that right? Assuming the trophies are right-angle triangles (in profile), that makes the adjacent 150mm and the opposite 30mm. atan(30/150) = 11.3 degrees (unless I am missing something??) 😕

Neil.
 
#1,724
Hi Guys,

this is my first posting here and i have to apologize for my bad english...sorry, i'm writing from germany and unfortunately i'm not an english native speaker 🙁

My equipment until now:
Epson EMP-TW 700 projector
Sony PS3 (40GB)
Cinescreen V5

At first, the most important question for me is, where i should buy the prisms for a DIY anamorphic lens? I don't have problems to pay higher shipping costs, if i would buy them in the USA, Canada, Australia or whereever else...

Furthermore, i suppose that neither the ps3, nor the epson projector are able to stretch the image vertically, right?
So, i need a dvd-player with this function or a HTPC.
But i would prefer a dvd player, because in my opinion, a dvd player looks more elegant like a "huge" htpc 😉

I think the Samsung DVD-HD 850/950 players are able for doing this job.

Do you have any other propositions how it is possible to stretch the image by using the ps3?

Regards from germany 🙂
Karol
 
#1,725
Okay, after a long while, (and unfortunately selling my pair of J25 glass prisms), I'm back and ready for a constant height set up again!!!

I just bought an Optoma HD65 projector and I'm tired of watching the 16x9 aspect ratio.

Where can I get the 5x7" glass prisms these days? Anyone have a pair for sale in the USA?

Any help would be appreciated...I'm ready to go WIDE again!!!!

Thanks!
Paul
 
#1,728
artbypaul said:
Thanks Mark! I got my screen set up again and watched "Empire Strikes Back" (anamorphic vertically stretched) and I just need to get prisms again.

It's nice to be back...I really missed my home theater and the quest for the best inexpensive anamorphic lenses! 🙂

Paul
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Hey Paul, from memory, your prisms were not as steep an angle as mine. Do you remember the angle by change?

I am moving into cylindricals, but these are hardly DIY any more...

Mark
 
#1,730
Cylindrical lenses are not cheap - even building this my self will still cost me a few thousand dollars. I am no longer selling my prism based lenses anymore, so am happy to assist those wanting to achieve a prism lens once again.

I have unlocked the secret to CA correction now too 🙂 but from a DIY perspective, may introduce more problems as well as an addional cost...

Mark
 
#1,731
I was always under the impression that BLU-RAY could not be used with a Constant Height set up. However, my new Optoma projector vertically stretches 2.35:1 or wider (letterboxed) movies! It looks just like my old DVD player when I used it for constant height. So I'm guessing it CAN work with Blu-Ray now?

I do realize that TRUE Anamorphic encoding means all of the pixels are used to begin with in the 16:9 native aspect (1920x1080). So I'd be actually stretching a 1920x800 pixel image, correct?

Please let me know if you think this will actually look okay. I'm figuring my old 480p or 780p constant height looked awesome, so the 1920x800 should look just as good if not better.

Any input would be appreciated.

THANKS!
Paul
 
#1,732
artbypaul said:
I was always under the impression that BLU-RAY could not be used with a Constant Height set up. However, my new Optoma projector vertically stretches 2.35:1 or wider (letterboxed) movies! It looks just like my old DVD player when I used it for constant height. So I'm guessing it CAN work with Blu-Ray now?
Click to expand...


I bought the BenqW5000 because the "letter box" and "4x3" modes are the 2 that are needed for CIH. This works for HD over HDMI. The are a few projectors that now do this and I have started on a list on my site of units that I have actually tested for CIH...

I do realize that TRUE Anamorphic encoding means all of the pixels are used to begin with in the 16:9 native aspect (1920x1080). So I'd be actually stretching a 1920x800 pixel image, correct?
Click to expand...

With a TRUE anamorphic title, your image is made from 1920 x 1080 and is "tall and thin" - usually horizontally squeezed like film but at 25% not 50%. You NEED an anamorphic lens to view this program or it will be geometry incorrect - sorry 16:9 crowd 😛

So instead of wasting 25% on black bars and having to vertically stretch as we do now (we actually zoom in a 4 x 3 mode, but that is another story), we would actualy use the 16:9 mode and have to use an anamorphic lens to optically correct the geometry...

Please let me know if you think this will actually look okay. I'm figuring my old 480p or 780p constant height looked awesome, so the 1920x800 should look just as good if not better.

Any input would be appreciated.

THANKS!
Paul
Click to expand...

CIH at 1080 with HD as the source needs to be seen to be believed - I love mine and why I am wanting an even better lens...

I've been using HD DVD up until now, but will get a BD player this month sometime - I thinking the Samsung BD1500...

Mark
 
#1,734
artbypaul said:
Awesome! Thanks so much for the detailed answers, Mark! I now have decide which lens to go with. I may wait and see how much the cylindrical type ends up being. I was really happy with my old set up but after watching movies with the Blu-Ray player I think I may notice the lack of focus and uniformality in the 2 lens set up.

Paul
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You may, but I found the increase in sharpness from the source to counter the effects. It was not until I got to compare cylindrical to prisms lenes that saw the real benifits of edge to edge "focus"...

Mark
 
#1,735
Sounds good, Mark.

My lenses should be here today, I had them shipped overnight. 🙂

This will be the biggest 2.37:1 screen I've had since my new projector projects a larger image from the same throw distance as my old one. It's right at 12 feet diagonal.

700cinemaWide.jpg


I hope to have actual screen shots later today... 🙂

Paul
 
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