This blog is intended to be a meeting place for HT projection enthusiasts interested in my new cylindrical lens design for Constant Image Height (CIH) applications.
If you don't know what "CIH" means and how it works then you probably need to visit one or more of the several excellent net forums that deal with this area of HT projection. You could try the AV Science Forum which has extensive information on CIH, Mark Techer's excellent CIH-based Australian site, or perhaps the DTV Forum from Australia which covers CIH issues from time to time.
The "working title" of my lens design is "Horizon". Since early 2007, I have been testing and evaluating the prototype Horizon with a variety of HT and cinema projectors, screens and optical systems to make sure it performs as well as modelled by my Zemax optical design software, the world standard for advanced optical design.
The aim of the design is to produce an optically advanced 1.33x horizontal expansion anamorphic lens that is bright, focusable, has low astigmatism, low grid distortion, maintains its 2.37:1 image geometry over a sizeable range of throw ratios and is compatible with 1920 x 1080 HT projectors, all in a moderately-priced, easy to use package.
In many ways, the optical design is the easy part. When you're doing your computer modelling, you don't have to worry about dust, or faulty glass, or trying to get engineers (who'd rather be making door knobs) to turn out your precise mechanics sometime within the next year. You don't need to worry about unreal price expectations of users, kibbitzers who only want to criticise, or potential customers who know far too little about far too much and take every opportunity to tell you about it. Most of all you don't have to worry about the money, as in "lots of it", which is necessary to go into production so that your product can be appreciated, as much for its external appearance as its critical function.
But first, a couple of things that always get asked about any new product.
When?
If there is sufficient serious demand, I am hoping to produce an initial "advanced prototype" run of from 25 to 50 units before the end of 2008. These will be most likely sold direct off the net to keep marketing and distribution costs down, and to enable me to have direct feedback from customers on the performance and quality of the design .
Price
I know I said "moderate" but I haven't decided on a firm price yet. Suffice it say that I intend the Horizon to be very competitive in the market. By this I don't mean just $10 short of the price of some of the European cylindrical anamorphics available today. I mean a lot less expensive.
On the other hand, I can't give the Horizon away and there are no shortcuts in quality optics. The initial product will probably be a little less expensive than subsequent production runs in order to get it out there in the marketplace and to garner some feedback. So please keep these thoughts in mind.
Quality
When I use the term "advanced prototype" I don't mean something held together with chewing gum and Durex tape. But, until full production jigs and tooling are fully on line, I'm going to have to put these lenses together one-by-one in a sort of "mass customization" manufacturing process.
However, there will be no compromise on the optics. I believe performance is already optically first-class. Optical quality will not be sacrificed to pressure of cost. Berlow are some screen shots of a recent test, using test patterns of my own design (click to enlarge to 100%).
The features to notice in this series of screen shots are the clear separation between pixels and lines. "Fundamental Frequency" demonstrates alternating single pixel lines or dots: black-white-black-white etc. "Fundamental" indicates the finest resoution available in the display device, in this case a Sony 1920 x 1080 pixel full High Definition projector. In these shots, the fundamental frequency is clearly displayed with very good separation between pixels.
Design Outline
The design uses four lenses - two singlets and two doublets - in two groups: and anamorphic group and a focusing group. As a result of the functional separation between the two groups, image size will not change as focusing proceeds. You'll set your zoom, focus your projector and then focus the Horizon... all without any change in image geometry. Remove the Horizon from the light path and your 16:9 image will be exactly the same height, and still as perfectly focused as your anamorphic image was. That is what genuine "Constant Image Height" performance is all about.
Any other questions... please ask them. I don't guarantee to give answers to all of them (for example, I'm not publishing the curvatures of the individual lenses or similar cinfidential details, and I'll be trying to avoid directly comparing my lens with any other similar product... let others do that), but I'll try my best to be frank and upfront as this project continues.
The design uses four lenses - two singlets and two doublets - in two groups: and anamorphic group and a focusing group. As a result of the functional separation between the two groups, image size will not change as focusing proceeds. You'll set your zoom, focus your projector and then focus the Horizon... all without any change in image geometry. Remove the Horizon from the light path and your 16:9 image will be exactly the same height, and still as perfectly focused as your anamorphic image was. That is what genuine "Constant Image Height" performance is all about.
Any other questions... please ask them. I don't guarantee to give answers to all of them (for example, I'm not publishing the curvatures of the individual lenses or similar cinfidential details, and I'll be trying to avoid directly comparing my lens with any other similar product... let others do that), but I'll try my best to be frank and upfront as this project continues.
