DIY anamorphic lens

[MikeP]

klemsaba: is that blue tint on the edges of your screen an artifact of your camera? Or does it really look like that?

I'm finally on vacation and am getting started on building my prism enclosure. I'm charging the battery for my camera and hopefully will get some good pictures over the next couple of days on the construction. It's going to be a combination of various ideas from this forum.

Yesterday I cut some plexiglass that I glued to the top and bottom of each prism with a bolt sticking out. I'll use this like several other people have to adjust the angle of the prisms in the box.

One tip: just go ahead and glue the plexiglass to the prism using normal epoxy. I tried some fancy "all purpose" cement that was supposed to bond *anything* including glass, plastic and metal. Well, apparently companies are now allowed to sell products that don't actually work and are allowed to falsely advertise on their product boxes. This cement didn't work at all! I followed the instructions and after 12 hours (the set time was supposed to be one hour) all I had was a sticky mess on my hands.

Fortunately, I was easily able to separate the plexiglass from the prism. And then I was able to use something called "Goof Off" which is a wonderful adhesive remover. It all came off pretty easily and I didn't get anything on the prism faces. But I was worried for a while. Then I used normal epoxy and it worked great. The bolts are well attached to the prisms now.

I hope to have the enclosure ready later today. I got my 7205 mounted to the ceiling on Friday and now I'm dying to watch movies with proper geometry.

Oh, and does anyone else think it's a crime that companies are hyping this whole "Cinema-Scope" concept and charging thousands of dollars for it? I just got my latest Widescreen Review and was pretty dismayed looking at some of the ads for this stuff. Not only am I amazed what we've been able to do with a couple of inexpensive prisms, but I'm equally amazed at the marketing that has gone into trying to make people believe that "cinema-scope" is somehow hard and expensive (and anything new).

[morkys]

klemsaba,

Do you have any reflections? If not, do you have any sort of anti-reflective coating on those prisms or are they just regular prisms from the same source as the rest of the folks here?

[klemsaba]

Originally posted by MikeP
[B]klemsaba: is that blue tint on the edges of your screen an artifact of your camera? Or does it really look like that?

Well the camera gives photos a blue tint and I always have to run my images through some kind of process. I think I over did the processing though so I went back to the raw images out of the camera.

[klemsaba]

Originally posted by morkys
klemsaba,

Do you have any reflections? If not, do you have any sort of anti-reflective coating on those prisms or are they just regular prisms from the same source as the rest of the folks here?

I haven't spent much time watching in detail, but during the credits of Cars I didn't see any (and some reported that this was a tough scene). My wife thought she saw some during King Kong, but I didn't notice any.

They are regular prisms without any anti-reflective coatings. I don't even have them in an enclosure yet. Hopefully tomorrow or Tuesday I'll have one built (thanks to my brother-in-law).

[stevodude]

Originally posted by Mark Techer


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

Interesting... I doubt they have a leg to stand on, unless the have a world patent on spherical geometry.

this link tells you what a torus is, http://en.wikipedia.org/wiki/Torus
And thats not what I'm basing my curve on.

the basic dual curved screen is based on a 'section' of a sphere, and so is not classed as a torus, but even so, no one can patent 1+1=2, it's a given, so it sounds like to me just bully tactics so they can make a bucket load of money for nothing....

Just my observation, as I won't be building anymore than one for myself, but if I have mates that like the screen and want one, no one can stop me building my own dual curve screen's to sell, just the masking technology he's using can probably be patented and protected.

BTW did you notice much difference between dual curve and horizontal curve? is the difference perceptable, ie more than %5 increase in picture clarity? If the difference is not perceptable I will probably build just the horizontal curve, and maybe dual curve down the track if I'm feeling the need.

[Mark Techer]

Apart from being difficult to set, it hotspotted worse than the vertical flat screen (TORUS's are supposed to be one big hot spot) and I found this distracting as with 1400 ansi, and 1.2gain screen, my image is alread bright and didn't need any further gain.

So I went back to a conventional "curved" screen and with the exception of slight bowing at the sides, generally I find it more exceptable. Tilting the lens helps here.

The reason I still curve the screen is becuase of the really short throw of ust 1.3:1. When I tested my lens on a system at 2.2:1, there was no need to curve the screen...

Mark

[eXa]

Okay, i want CIH too.

Forgive me for asking questions wich already has been answered but 137 pages is just too much!

So where can i but prisms? i need to get it to Norway. Does someone sell complete diy sets or something?

Btw, it could be smart to just make a "technical" thread wich only lists where to get, how to bulid, links and stuff. And keep it closed for posting so that just the thread starter can change it. the discussion can be done in this thread!

[stevodude]

try to find a local trophy house, and ask for their catalogue. probably %90 chance of getting them to order the crystal wedges if they don't already have them in stock.
I also found a local supplier of the pvc foam filled boards for a screen :-) woot 2850x1220 screen here I come.

[Mark Techer]

Originally posted by stevodude
:-) woot 2850x1220 screen here I come.

Hey Steve, that stuff also comes in 3600 x 1500 too...

Mark

[torsteinvh]

Originally posted by eXa
Okay, i want CIH too.

Forgive me for asking questions wich already has been answered but 137 pages is just too much!

So where can i but prisms? i need to get it to Norway. Does someone sell complete diy sets or something?

I also live in Norway, and I ordered prisms from a supplier in Australia. They should get back to me with the shipping cost, I'll let you know when I get it.

There is a link to the supplier somewhere around page 60 in this thread I think.

As for suppliers in Norway I have looked around a bit, but haven't found any.

-Torstein