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Alcheringa

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About Alcheringa

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  1. Nice scientific terms those: "impression" and "image quality". They make me wonder why I spend so much time designing, building and calibrating down to less than 1/100th of a degree cumulative, and getting all those expensive lens elements built on million dollar machines, when two glass wedges in a nice box are just as good They give a good "impression" . They have "image quality" - however that's defined. The problem with a lot of this stuff is that it's mostly anecdotal. Someone went through a few stores and came away with a good "impression". Panamorph run the line with their el cheapo sub-$1000 model (Cine-Vista, I think it's called) that because it has no color aberration correction, and no focusability - none of that snake oil cylindrical lens designers use to jack up the price - it's somehow "clearer" and sort-of closer to how Mother Nature meant lenses to be made. "Sharpest image on the planet", was the phrase used, I think. When quizzed, the spruiker for Panamorph replied that, well, it was sharp in a strip about 4" wide down the middle of a 12-foot wide image, and that it did need users to lobby the projector makers to include sub-pixel color channel correction (because the rainbow patterns the lens produced outside this 4" strip looked like an illustration of Isaac Newton's prism experiment), and anyway, it was cheap, and whaddaya want for 2-bits? Sleigh bells? Suddenly "sharpest on the planet" became "only an entry level device after all". It only took 2 personal messages to get him begging me to stop being so truthy. No mention of gross distortion, ghosting, astigmatism, beam displacement and sheer unadulterated weight, unsealed optics, low ANSI contrast and expensive add-ons just to get the image focused. And these limitations apply as much to the upper end of the scale as the lower end of the prism field, which is severely llimited in design degrees of freedom by the fact that prisms by definition emobdy nothing but flat surfaces. You can usually tell when a lens maker is fudging it. They rely on "impressions", not hard specifications. I mean, feel the love, baby. Why go to all the hassle of producing a precision intstrument to exacting standards when you can just "impress" punters and rely on "wow" factors like "sharpest on the planet" and "best image quality" from checking out lenses in store demo rooms with light streaming in from all over the place? Never mind that prism lenses were dropped in 1953 as a viable means of top quality commercial cinema projection. What does Panavision - who junked their prism design for all-cylindrical lenses - know about "image quality"? I bet you can't quantify that 5%. Which parameters are you referring to?
  2. The problem with prism lenses is that they distort so much,most noticeably towards (although not restricted to) the edges where the image can elongate quite significantly. It's quite common to see a 1.25 expansion in the center and 1.45 at the edges. The average is around 1.33, but only the average. Single air-gap cylindricals have this problem, too. On my web site there's a comparison between an Isco and a Xeit lens, clearly showing the Isco stretches the image far more unevenly than the Xeit. Prism are also susceptible to ghosting, more readily than cylindricals. And of course they can't be focused, plus they displace the image a couple of inches due to the light path passing through an optical "chicane" as it passes through the prisms. And this is for a GOOD prism lens. Simple ones - with no correction for astigmatism or color aberration - are just plain awful. It's easy to think something is "the best image you have ever seen". That is simply because you haven't seen anything better. Many of our own customers who have upgraded from a prism system (and in some cases from a single air gap cylindrical) can tell the difference straightaway when they install a Xeit lens. Specifications here: http://xeitoptics.com/specifications/
  3. Who ARE all these people who have a Xeit lens? I 'm so busy making them - each one takes a full day to put together, five hours in a clean room and the rest calibrating - that I don't get to meet the punters. The process involves cleaning, rinsing, drying, more cleaning and then mechanical assembly. When the parts are together we have more cleaning and assembly of the glass. Finally an hour of calibration, then final assembly into the stand. THEN packaging. You really need a drink after all this. It all has to be done to high standards and can get very intense when the pressure's on. As to meeting customers, I hardly ever get to meet the installers either, for that matter. The lenses just leave here and I rarely hear back. Hey, no news is usually good new in this business, sort-of... Anyway, the good vibes are much appreciated. Thanks guys. In answer to the "stock" questions... stock levels are pretty good at the moment.
  4. Yeah, Xeit is still going strong. The dollar drop has re-opened America to us with trans-Pacific orders forming about 30% of sales. We are doing a roaring trade in import replacement too. Everyone seems to have hiked their prices, except us (well, up only a little). Thanks for all the nice things said about Xeit lenses here. Youse know who you are (even if I don't!). Gosh... I'm blushing. We're in the happiness business. Nothing personally rewards us more than satisfied customers.
  5. Hey, it wasn't me who said it. It was the political genius, Campbell Newman. Right up there on a par with Gerry Harvey declaring no-one was coming into his shops because they were too expensive!
  6. You want pizza AND charity? It's a business they run, and a tough one at the moment what with the local boss man claiming Queensland is the new Greece and sacking 20,000 potential customers for Christmas, Sheesh.Give 'em a break.
  7. Hardly a fair comparison, but I'll take the compliment anyway!
  8. Nice to know the "best quality picture combination", exhibiting "such clarity" with "momentary sensations of 3D" was achieved with the JVC projector using a Xeit CM-5E anamorphic lens to faithfully pass all that wonderful quality. Good to hear too that even Mark was "especially... impressed" with the cinema. Why wouldn't he be? While I couldn't be there in person, I was there in spirit. So much for the "Lens v. Zoom" argument. 5 elements really do rule. Merry Xmas to all.
  9. I've seen some dreadful installations in my time. Projector out of skew, unfocused, not level. Maybe some of the patterns provided can help right a few big wrongs. These patterns are used by me to calibrate lenses to less than 1/100th of a degree. They work. The projector manufacturers provide almost useless focus patterns (in particular). They are usually a broad grid with one or two-pixel thick lines that almost hinder focus, rather than help. Some manufacturers only provide focus patterns in the middle of the screen, leaving open the suspicion that centre focus is about the best you can hope to achieve. Anyway... try them out and see for yourselves. The link again: http://www.xeitoptic...m/test-patterns
  10. Just a note for members interested in the Test Patterns I have offered for download... thanks for all the support,but already (after two days) it's getting to be too much of a chore to send them out. I originally thought I could distribute them via PM, followed by an email exchange, but found too many problems with either my own or the target email ISP regarding file sizes allowed. So... consequently I have uploaded the patterns to my web site and you can find them all there. http://www.xeitoptic.../test-patterns/ There's some explanatory stuff there on how to download and use them, both for anamorphic and non-anamorphic purposes. Don't worry... nothing too complicated. All straightforward, standard browser stuff. I have plenty more but the patterns on the web site are the one I most often use myself. Download whatever you want to, they're still free. Happy Patterning! Alcheringa.
  11. Anyone wanting test patterns, please be aware of the following. >>>>> THEY ARE NOW AVAILABLE ONLY FROM MY WEB SITE <<<<< I was having too much trouble with the size of the email attachments being rejected either by my ISP or the recipient's. Go to http://xeitoptics.com/test-patterns/ They're all there. Take your pick. Thanks, Alcheringa.
  12. Test Patterns Just a note re. Test patterns while I'm posting.... I've decided to offer FREE OF CHARGE emailed test patterns that I use for calibrating projectors and anamorphic lenses. The patterns projectors provide for focusing are awful, nearly useless. These patterns have been designed by myself to show the true state of focus of any system. They are 1080 x 1920, lossless JPG format. The test patterns are as follows: 1. 30 pixel grid plus single pixel checkerboard test pattern This consists of 30 pixel grid squares with single pixels checkerboarded throughout (i.e. Nyquist frequency), The test pattern comes in green channel only and white. Each pattern has vertical and horizontal center marks along the edges, as well as a cross in the exact center of the screen. 2. Single Pixel "Wickerwork" pattern (Green channel only) This is a variation on the single pixel theme, except that the pixels are in a squared format, rather than checkerboarded. When you look at pixel tiling the effect is of "wickerwork", hence the name. 3. Single Pixel "Black Dots" (Green channel only) The inverse of pattern "2" above. Very useful for overall focus inspection. 4. All purpose Anamorphic Test Pattern (Full color and gray scale) Contains a grid, single pixel pitched dots, checkerboard pattern, random colors as well as a model's face for skin tones, plus greys and alignment marks. Circles in this pattern are "egg-shaped" - 3 wide by 4 deep - and should anamorphose out to "circular" circles. 5. Aspect ratio test pattern Shows all aspect ratios to the nearest pixel, from 4:3 to 2.76:1. Useful for setting up zoom extents on a screen. 6. ANSI Test Pattern - 16 checkerboarded rectangles Note: you need proper gear for this, to measure contrast. Anyone wanting to obtain these should send me a PM. You must have a way of displaying JPG files. Many players, plus Play Stations have this capability straight off a memory stick. Don't forget: FREE OF CHARGE.
  13. SIM2 + XEIT + CINESLIDE DEMO Australian Hi-Fi & Audio Show, Sydney 2012 . Having just finished a stint on the Audio Active stand at the Australian Hi-Fi and Audio Show (held at the Sheraton On The Park hotel in Sydney), demonstrating my CM-5E lens with the featured Sim2 Lumis, (the first time an Isco has not been used for this purpose, I believe), Audio Active is the new Sim2 distributor for Australia. Let me offer a couple of thoughts on the projector and its attachments themselves. Brightness You don't need any more. This Lumis is a light cannon. When you're setting up and aligning an anamorphic lens, be careful not to look to directly back down the barrel of the optics. You'll be seeing spots for the next half an hour. Presentation It looks like a Ferrari, and at circa $60k is priced like one. But like a Ferrari, this projector delivers great, indeed the best performance I have ever witnessed in its chosen field. Bells & Whistles For such a costly projector, the Sim2 Lumis does not have some of the bells and whistles that much cheaper projectors almost routinely include nowadays. Surprisingly there is no motorized offset capability, for example. This is due to the complexity of the optics required to squeeze such a brilliant image-producing projection machine into the surprisingly small and light Lumis package. Unless the projector was to get much larger, this feature needed to be left out to make room. There IS a bewildering array of options as far as digital processing is concerned. This projector is designed to be set up professionally and everything's there for the serious 6500k devotee (plus a few things you've never thought of). Even when calibrated, this image was BRIGHT. Image quality Absolutely superb. The throw ratio was 2.23 onto a 150", 2.35:1 aspect ratio screen. At this Throw Ratio anamorphic grid distortion and pincushion on the flat screen were practically nil, It was a truly cinematic presentation, with the rich blacks and detailed highlights that Sim2 units provide as standard. Make that better than cinematic. You don't get this quality for $20 admission at the local complex. This is how projectors SHOULD be demo'd at shows: huge big screens, plus ample seating for interested parties and lots of room to move around in, not the pet carrier sized "theaters" enclosed by black curtains that we are so used to having to put up with. Many were seated only three metres from the screen, and were clearly "immersing" themselves into the various movies shown. I am pleased to say the XEIT CM-5E did not let the Sim2 side down, requiring no adjustments at all to the Sim2's color output, preserving its sharpness and clarity exactly. Sound With a 10,000 watt sound system - $35k Paradigm Home Theatre surround sound speakers and a rack full of audio and video processing equipment (Anthem M1 power plants, Primare Blu-Ray player) - "submersion" may have been a better word than "immersion". You could have heard the sound in an Auckland swimming pool, on a good day, I reckon. Perfect. And LOUD. Mounting We used a custom mounting plate for the Lumis and a CineSlide motorized sled. This was a Sim2 product designed specifically for use with an Isco-III with the Lumis, but as the CM-5E is CineSlide compatible,and roughtly the same dimensions as the Isco, there were no problems with the fit. Having the sled there was good for demonstrating how an image is built up from letterbox to full 'scope and back again. Some of the punters I spoke to were puzzled at just what was involved in the process. It was easy to show them by using the CineSlide to just render the image back and forth from 'scope to 16:9. Overall This is where anamorphic really comes into its own. There is no substitute for it, only excuses for not having it. 'Scope cinema as it was meant to be seen. Tiny, tight pixels, using all the DLP panel, a bright sharp image with great depth, and a sound system that made you feel you were in movie heaven. Which, of course, you were. Sorry Owen and you other anamorphic doubters, but this was an inspiring set-up. Sell the kids.
  14. Black Diamond Screens About a year ago I posted this: There had been some discussion about these screens. Well, I finally went and had a good look at the Black Diamond screen (1.4x gain) at Network Audio Visual in Manly Vale (Sydney) and came away very impressed after an hour's intensive examination in a one-on-one scenario (no vulgar crowds!) Network Audio Visual demo'd the Black Diamond using a very impressive calibrated Runco LS-1 (Network are Runco importers). This screen does everything its publicity claims. The difference between "House lights ON" and "House lights OFF" is very little. With lights "ON" contrast is still excellent. Viewing angle is very good. You can stand well to the side of the screen and observe very little hot-spotting or (conversely) dimming. "Speckling" - color flecks when your viewing angle is incident to the projection angle - is very low, about what you'd expect with a greater than unity gain plain white screen. I would assume that the 0.8x gain model of this screen would be even better (although one was not available for demo yesterday). With no light projected onto it the screen looks approximately like an LCD flat panel monitor turned off: a dark, warm grey look that suits a room more than a bare white screen. Quite sexy, actually. With an image on it the contrast jumps out at you. Perhaps a better word than "contrast" would be "richness". The image is seriously enhanced by the screen multiple layers of reflective material without affecting either shadow or highlight detail adversely. I can see a screen like this being ultra useful in a mixed viewing environment, perhaps one where the Home Cinema has stray light from, say, a bar (we all have built-in bars don't we?) or in a family room (i.e. where you don't have either the opportunity or the inclination to build a bat cave). That is not to say that it wouldn't look completely in place in a formal, dedicated cinema. In fact I think it would look pretty sensational. What should also be remembered is that the screen not only rejects much of the ambient light in the room, but it also does not spill light from the screen out to the room. That is, it works in reverse as well. This is a great feature where you don't want to paint your Home Cinema black or in dark tones. It gives you a much wider gamut of choices in room decoration without the downside of having to account for reduction of contrast due to light spillage. These are not inexpensive screens, but neither are they all that expensive either. Won't get into price talk here, but it does seem that inflation has not affected last year's indicated price, and (for once) the high dollar has helped. Scope screen come in sizes up to 140", and there are curved models available. I was very impressed indeed. It would make any light loss from the 1.33x expansion of the anamorphic image quite negligible. You wouldn't need a light cannon to light this screen up to the point where you almost need sunglasses (useful for 3D active too). You really have to see this screen in action to believe it. VERY well worth a look.
  15. I can't find a way to edit the original post, so for the moment I thought I'd put in a rough index of topics covered here for the moment: Some topics, like Lens v. Zoom and Owen v. The Rest permeate throughout this seminar. Owen's contributions have been superb. While you might not agree with all his conclusions (or perhaps, assumptions) he certainly brings a depth of knowledge and clarity of reasoning to this thread. I'd like to personally thank "The Big O" for his erudite contributions and the links he has supplied to back up his thinking. I learned a lot from them, and continue to do so. Other contributors - Blade and Hi-Jinx come especially to mind - have given us the benefit of their experience and thinking on the subject. But there are many others who have taken the time to pen thoughtful mini-essays and commentary. To all of you I extend my sincere thanks and appreciation. You've all helped make this thread well-behaved, on-topic and informative. The Index (topic followed by page): Throw Ratio 1 Pincushion 1 Prism v. Cylindrical Lenses 1 Vignetting 1 Quality Loss through Anamorphic Lenses 1 Owen on the importance of MTF 2 Human Angular Resolution Discussion (HAR) 2 Grid Distortion and what can be done about it 5 ANSI Contrast considerations 5 Curved Screens: not always a panacaea 5 Bottle Distortion 5 THX Specifications and whether we need them 6 Advantages of anamorphic lenses 7 Focus and Astigmatism Issues 7 More MTF Links (Owen) 7 "What the director intended" 8 The lens design rocess 10 Virtues of the Scope format 10 Early Scope 12 Matching Camera and Projection viewing angles 14 Lens stand and mounts - fixed and motorized 17 Differential distortion across the screen 19 Scope Aspect Ratios 20 HTPCs (Owen) 21 Media Players 22 Special Screens 28 The Future of Anamorphic 29 Not an exhaustive index, nor 100% accurate, in that some topics pop up at all kinds of times as late posters wade into the debate.
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