DIY anamorphic lens

[morkys]

So Bud, which prisms did you buy and from where? How do you make sure they are the right size and angles etc? Just making sure I know what I need to do myself.

[TwisterZ]

Mark
Any good ideas for an LD scaler. I have access to a couple for testing but will need to find something I can afford.

[Bud Bray]

Originally posted by morkys
So Bud, which prisms did you buy and from where? How do you make sure they are the right size and angles etc? Just making sure I know what I need to do myself.

I got 4 of the medium ones from Massillon Plaque. The right size depends on the light beam of your projector, try the paper test Mark described a few posts back. As for angle, I 'm doing the mount & turn till it looks good method, then marking the positions.

Bud

[Mark Techer]

Originally posted by TwisterZ
Mark
Any good ideas for an LD scaler. I have access to a couple for testing but will need to find something I can afford.

Not sure what you call "affordable" with scalers. I want one too, but the prices of these units in Australia are a touch much - The VP 30 has a RRP of $3499 here...

The cheapest one I have found converts all signals to 480P (perfect for my current projector) and is less than $1000. Problem is, I am left thinking that would be great if I didn't want to upgradde to 720P any time soon...

Mark

[mfeidler]

I got my 2 small prisms by UPS today! Set them them infront of the lense and played with the angle and they loooked awesome. The picture was soooo good. I cant wait to find the time to build the enclosure for them. I'm using a Panasonic AE900U with the Zoom all most all the way out as I have a long throw room. The prisms are plenty big for this setup.

Can't sleep!

Mike

[Mark Techer]

Mike,

Can you post a picture?

Mark

[mfeidler]

It will be few days before I post pictures. I really want to build the enclosure and black out the end of the lenses. I think this made a huge diference in the quality of picture. I used the stretch (zoom) aspect on the ae900 and was watching my super bit DVD of the Fifth Element. I love the way the Panasonic shows no pixels and this lens just gave it an awesome smooth detailed picture that was plenty bright in my darkened room.

I love it!
Mike

[Mark Techer]

Cool Mike, Zoom 1 on the Panny 900 works well

What did you use to blacken out the ends of the prisms?

Mark

[Steve Scherrer]

I have been slowly building my enclosure, and got things pretty much together last night. I epoxied some pivot points on the bottoms of the prisms, and epoxied posts on the tops of the prisms. The posts extend through the roof of the enclosure and allow me to spin the prisms. Right now, the prisms swing fairly freely, so they are difficult to maintain at this point in time. I do have to shorten the posts a little bit (should have thought of that before I epoxied them to the prisms) in order to fit the dial cap on them.

Again, I am truly impressed by these prisms. The picture it displays is just phenomenal. Very clear, no apparent focussing problems from side to side. Very little chromatic aberration--really none that I could see (but I am slightly colorblind, so maybe I'm not the best judge of that...). DISCLAIMER--I have not tested the prisms with a grid to test focus or CA--in reality, we don't watch test patterns, but I played "Madagascar" last night (nice bright colorful movie) and it looked phenomenal!

However, with the pj moved to a table in front of my screen, and even with the housing tilted up into the light path, I am still battling some geometry problems--but really only across the top--pincushioning. The sides are pretty straight and the bottom is pretty much perfectly straight across.

I would also like to shorten the housing a little bit--it turns out that the way I have set the prisms gives a couple of inches of clear space in the front of the housing that would allow me more ability to move the housing around and try different angles without cutting off the image due to the housing. I am also thinking about changing the shape of the housing a little bit--narrowing up the entrance hole because of reflections I get from the back prism that I can see on my back wall. Man, I wish I had more time to spend on this...

[z2895]

Originally posted by Mark Techer


Not sure what you call "affordable" with scalers. I want one too, but the prices of these units in Australia are a touch much - The VP 30 has a RRP of $3499 here...

The cheapest one I have found converts all signals to 480P (perfect for my current projector) and is less than $1000. Problem is, I am left thinking that would be great if I didn't want to upgradde to 720P any time soon...

Mark

Man, at that price you might as well just buy a All In Wonder ATI card for your computer, a 9800 would probably do, you can route the signal in to the card, scale it to whatever you want via a TV window, then route it back out.

I did some grid tests the other night and took some measurements to measure the CA of each color band, green looked like the worst, but it seems read measures the worst. I'll post some pics later when I get some more time, here are the results.

R 37% G 29% B 7%

How I measured this is I displayed a test pattern with 3 lines with each color, then measured how big it was on the wall without the lenses M, then with the lenses L. CA% = (L - M*1.33) / (M*1.33) All of the CA observed was outward from the center as expected. (AE900 at 13' w/ 80" to 106" HE)

I still haven't been able to fix my blurry splotches problem, what are you guys using to clean your lenses?