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Making A DIY Anamorphic Lens

162K views 169 replies 20 participants last post by  Prof. 
#1 ·
If anyone has ever considered making their own lens, but felt it would be beyond their capabilities, this DIY article that was published sometime ago might just change your mind..

It's a very straight forward description of what's required to produce a very reasonable Anamorphic lens..
Anyone with any Carpentry skills should be able to make up the lens box..and the method of setting up the prisms is clearly explained and shown..

http://www.zuggsoft.com/theater/prism.htm
 
#55 · (Edited)
I have a small problem the picture lines up ok on the sides of the screen but i cant get the picture to fill the screen top and bottom i have a grey bar top and bottom and the bottom line has a slight arc (Curve) How can i get it to fill the top and bottom ie the whole screen? i have played with the prisms but i cant get it to fill the screen.

When the projector is on i get the blue screen it fills the screen but it goes off the screen at the bottom on an angle greater on one side. I need help please Prof.
 
#56 ·
OK..To set up the lens correctly, you need to do the following...
You may have done some of this already, but I'll just go through the whole procedure in the correct sequence..

Anamorphic lens removed..

1. Firstly, set the zoom on the projector to minimum..
2. Play a 16:9 movie and make sure that the image is centred on the screen and fills the height of the screen..
If it doesn't, you can do one of two things..
Zoom the image to fill the screen height, or don't zoom and move the projector back to fill the screen..
The latter is preferable but not always possible..
A small amount of zoom will be ok..

Anamorphic lens in position..

Once you have the 16:9 image filling the screen, move the lens into position, making sure that the projector lens is centred within the prisms, and the anamorphic lens is square to the projector..

Adjust the tilt of lens so that you have a small amount of overspill top and bottom..
If the prisms have been positioned correctly, you will also have a small amount of overspill at the sides..Otherwise, you will need to adjust the front and back prisms until you have the image filling the width of the screen..
If you have overspill on one side and not the other, don't move the lens left or right to compensate..The prisms need adjusting if that's the case..

The curved image at the top and bottom is known as "pincushion" and cannot be avoided..
The longer the throw ratio, the less pincushion you will have..
Providing you have good light absorbing black borders on your screen, you won't notice it..

I hope that fixes your problem..
 
#59 ·
It sounds like the lens needs to be tilted up or down, so that you get the same curved part of the image equidistant top and bottom..
If your projector is tilting slightly up or down, you might have to adjust the tilt on the projector to line it up parallel to the lens..
It is most critical that every thing is perfectly aligned..
It sounds like you're almost there..Just a little more adjustment needed
 
#60 ·
Problem fixed. I moved the projector closer ( i thought this but i hoped i could fix it without re positioning the lens and pj) Now the problem i got tonight when iwas about to watch a movie for the first time, the pj powered up then when off with the power light RED and the temp light on RED then after a minute turns off.

I had this problem last year i simply blew compressed air through the front to remove dust and it worked. Tried to do it again with air and no go. I am dying to watch a movie with my new screen set up
 
#64 ·
Hi All,

I'm a completely new to this excisting world of home theatre.

I have dedicated home theatre room, size is 3855 long x 4280 wide.

Planning on using JVC HD550 projector.

I would like to embark on the journey of building my own Anamorphic Lens as well documented by the professor. My question is would anamorphic setup work in a room of this size with 100" Screen???

Your help is very much apprciated.
Thanking you in advance.

Abe
 
#65 ·
Hi Abe and welcome..

Are you projecting down the length of the room or across the width?
I can only presume that it would be the length, unless there is a reason why you can't do that..
If it's the length then 14' with a 100" screen will be fine for anamorphic projection..

My room is 15' long and I'm projecting onto a 106" Scope screen..sitting 9'6" back from the screen..so you should be fine..
Nice projector choice!.:T
 
#66 ·
Hi ya, Thanks for the quick reply. I will be projecting down the room, 3855mm which I believe equals
12.64 feet. This doesn't take into account the length of the projector. Do you believe 100" Ananmorphic projection will still work in a room of this size.

Best Regards,
Abe
 
#67 ·
Abe,

If your projection length is approx.12' then the projector you're proposing to use won't be suitable..
The HD550 is a long throw projector and according to the projectorcentral calculator, probably wouldn't fill a 100" scope image in that length..
To use a 100" scope screen in that length, you're going to need a shorter throw projector..
Why can't you project down the 14' dimension of that room? Then you would be able to use the JVC..
 
#68 ·
Hi There, Apprciate the help however I'm now more confused than ever before. Getting conflicting information from different sources.

I looked into buying a LP Morgan Lens for use with HD500 projector.
Seller said they physically setup in a room of my size 3855mm (12.64 ft) and fit to 100" screen using this projector. This is a big investment for me, obviously need to be carefull & don't want to buy just because they say it will work.

I cannot change config of room due to location of door & window.

Apprciate your thoughts on this.

Kind Regards,
Abe
 
#69 ·
Abe,

According to the projectorcentral calculator (which most people use to calculate projection distance) the HD550 set at 12' back from the screen, will require a scope screen with a height of 44"..That would mean having your screen width at 105".. and that calculates to a 114" diagonal screen..
Here are the details..http://www.projectorcentral.com/JVC-DLA-HD550-projection-calculator.htm
 
#72 ·
[commercial post] Mods please remove if inappropriate.

The topic of making a 4 prism DIY lens has once again come to my attention. In short, you need two prisms of different angles that are made of different materials that once bonded (with opposing apexes), form a new doublet prism. The use of 4 identical prisms does not correct CA.

If I was able to get enough interest, I might be able to produce a short order run.
 
#74 ·
The prisms from SS are the same prisms also known as "the French" prisms. Whilst they are made from BK7 and do feature optic coatings, they are not corrected for CA or astigmatism. They are actually quite small as well at about 80mm tall, so your throw needs to be quite long.
 
#82 ·
So after my introduction I started reading through the
Anamorphic Projection section and who do I find but my friend
Mark Techer!

For those of you that want to jump down to the reason I am
posting in this thread and skip the flashback, go to the
bottom of the text in italics

For those who care about the backstory read on....

**flashback music begins....screens fades away in waves.....**

I met Mark in 2004 on another HT forum.
Not too long after, he started talking about Scope and lost me in a blur of fuzzy math....but caught my attention back when I realized what in the he was talking about.
Mark had already moved way down the path of his own solution when in 2006 I won an MK1 in a competition on that other forum. (No, not the one you are thinking of....this was a much smaller forum)

We have stayed in touch via email over the years.

In 2009, My wife, son and I went to Australia on vacation
(holiday for the Aussies here).
We spent about a month in Brisbane and I got to see several
really nice Home Theaters (Alot of which had added some
version of the MK lens to their HT)

Jump to 2010, we caught up again at CEDIA in Atlanta. My wife
and I drove down for the weekend just to catch up and I
started talking to Mark about my new house and my new
plans....

**flashback music fades......screen fades in waves back to the

high definition clarity of the present.....**


Now it's 2011 and my new HT is getting ready to become a
reality and I approached Mark about a possible DIY version of
the MK4. I wasn't sure how he would take my asking about
taking the lens he worked so hard to get just right and putting it in a case I would make....but he was very supportive.
He mentioned a special offer that he was able to get in January for glass only for the MK4.
Just about a week ago I received an awesome package in the
mail!!!

Woohooo :bigsmile:My glass is here and I am ready to start designing my
case.

I have some great ideas and this looks like the perfect thread to log my progress.
 

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#83 ·
Welcome to the forum..

By all means post your details and progress with making up the MK.4..I for one will be most interested to see how it works out as I'm sure others will be as well..

If Mark is making a kit type lens available for the MK.4, then others may be interested in takiing this up as well..
 
#84 ·
If Mark is making a kit type lens available for the MK.4, then others may be interested in takiing this up as well..
It had been on the "to do" list for some time. The challenge to making a DIY cylindrical is that the alignment of the two lenses is critical. Whilst a DIY prism lens allows for a fair amount of hit and miss, near enough is not good enough when you are using cylindrical lenes, and so I need to be mindful of this when designing the DIY case parts as well or no one will be able to assemble the lens.

The ONLY way to align the two lenses is to use single display lines mapped at 1:1 with the projector and you need to ensure the glass is 100% vertically aligned.
 
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