[Durachko]

A to Z Tweaks . . . and other useful stuff. A work in progress . . .

Striving to be your ONE STOP SHOP for everything (well . . . almost everything) in LumenLab!

Hyperlinks in boldface are generally links to other topics. I use this page for my own reference and find it handy to have all this stuff in one place.

This topic is a place for successful, experienced builders to submit their secrets for optimizing projector functions - brightness, illumination uniformity, cooling, whatever. Submit your ideas singly or even as an ordered checklist of things to do to get everything in tip-top shape. Tell us what things you feel are critical for getting the most from a projector. Point us to useful stuff in the forums for our review for including into this topic. Feel free to critique and make suggestions for additions/alterations. PM or email me with suggestions if you want. And by all means tell me I'm a butthead if that's what you think. Corrections and differing opinions are welcome.

Original topic conception by members Durachko and cpsubrian.

As of April 2006 I've curtailed major edits to this topic but will revisit it as new products and methods come to light and whenever I uncover another gem in the forums. I've still got a LOT to learn too!!!

Building Essentials & Guidelines:

• A must-read: Help Me Help You by ozstang65.
  
• Useful tools
  
• Paint/cover all reflective surfaces between your fresnel/LCD and projection lens (triplet) with a non-reflective material (flat-black, high-temperature, spray paint is commonly used). A number of builders also do this to the rest of their projection box internals but there is some debate as to whether it's necessary or helpful; however, one may find it simply aesthetically appealing to do so. SonicWonder2000's argument for blacking out your projector.
  
• Build CLEAN. A good idea is to wrap your optical components in clear plastic wrap during handling and construction. It can always be torn and/or trimmed away when everything is in place. Zug say "Clean good, dust bad!" Fresnels are a bear to clean once dirty. Good optics typically have special coatings so don't just assume you can spit-shine your projection lens (triplet) with toilet paper. Even though it feels soft on your bum doesn't mean it's okay for the lens! I work in a lab and we use honest-to-gosh lens cloth slightly moistened with chloroform for cleaning glass optics. Lens paper is readily available at drug stores.
  
• Plan well. Make scale drawings (example). Understand and use the Throw Calculator and Focal Calculator in Build and Calibration Tools. Measure twice, cut once.
  
  
• Layout your design using the Focal Calculator and allow for one inch (2.5 centimeters) of movement of your triplet fore and aft for final tweaking.
  
• Familiarize yourself with electrical safety! This cannot be emphasized enough. You can't enjoy your projector from your grave.
  
• Don't "paint yourself into a corner". While a beautiful projector CAN be made with everything "fixed" in place, if you keep in mind you may want to make future modifications, additions, substitutions, and/or adjustments your system will be much easier to "tweak". Check this topic: What parts of a projector should be adjustable?
  
• Keep your wiring organized and SAFE. Experiencing electrical noise in your picture? Do some searching for "ferrite choke". Radio Shack sells them as do many other vendors. Shielding cables and components from radio frequency interference can make or break some designs.
  
• Read the wiki.
  
• Helpful Wiring Diagrams, Control Your Projector
  
• Lamp Wiring, Timers and Other Control Circuits, Easy lamp wiring diagram inside.
  
• Using the Lumenlab eBallast? You simply must read this post from Brainchild. Here's another bit of eballast wisdom.
  
• Find and read some plogs that correspond to your planned build style. You'll likely make some friends and get some chuckles along the way and before you know it you'll find you know what everyone is talking about.
  
• The LCD panel is sensitive to pressure. Push your finger against yours to see what I mean. When you mount the panel do not use a method that forcefully clamps the panel in place or you will get projection artifacts.
  
• A safety message from member spugnoid.
  
• Cutting fresnels (by member JackyChan): Fresnels should be cut (if you are cutting them) 20mm to 30mm larger than the viewable LCD because on the edge of the cut you get some kind of optical anomaly. TESCORP's guide to cutting them.

Brighter is Better:

• Member Arizonavideo's "sun in a box" projector simply must go here! Check it out.
  
• Various reflectors have been used to great effect. The new (as of this writing) pro reflector is probably the single most cost-effective reflector. In a perfect world, a reflector will double your brightness. The pro reflector doesn't work with ALL lamps though. Other commonly used reflectors are the Ikea Soare napkin ring/holder and the Norpro. Much research is being done on reflectors of sophisticated shapes and also pre-condenser lenses toward the desirable goal of increasing brightness and illumination uniformity. LumenLab is researching having yet another (or perhaps several) reflectors custom manufactured specifically for use by this community.
  
• The most commonly used lamps are metal halide types. Research is being done on utilizing lamps of much higher wattage and lumen output than those stocked by LumenLab but, at present, one would do well to stick with what LumenLab sells - unless you are an experimenter above all else. The color of light produced by a lamp is also to be taken into consideration as it affects projected results quite drastically. LumenLab is working on a new lamp as of this writing.
  
• FACT: Every component through which light passes dims your projected image. As I type this, dedicated LumenLab members are comparing various LCD panels to determine the best (most transmissive) models. Check out LCD Transmission Measurements, a new winner....
  
• I'm led to believe that long-axis orientation of the T15 Pulse Strike with respect to the long axis of the LCD may have an interesting effect on overall picture illumination quality. See this thread.
  
• A precondenser lens placed between the rear fresnel and lamp can also greatly enhance brightness. As of this writing precondensers are still somewhat experimental in nature but are a modification within reach of any accomplished builder. The thread linked immediately above is an excellent source of precondenser info. Watch for Lumenlab to come out with a precondenser someday. A precondenser also helps to even out the light distribution across your entire screen. Almost everyone agrees this really makes your projection much more pleasing.
  
• Ansi Lumen And Vignetting Calculator Excel spreadsheet with 4:3 and 16:9 images

Contrast, Brightness, Gamma, CRI, Lumens, etc. (What's it all mean?):

• Well . . . see the wiki glossary for answers to most or all of the above.
  
• And this: Glossary of terms, More than you wanted to know
  
• Another glossary pointed out by member Me2!
  
• Heard of THX Optimizer? Here's a pdf document outlining a procedure for using it. In short, it's a process for optimizing your monitor settings so you see what you're supposed to see.
  
• Offical Diy Pj Calibration Discussion With programs, methodology, tips and tricks!

Cooling:

• Not getting enough cooling? Samuraijack found that simply reversing his fan helped a tremendous amount. Eventually you should browse his entire plog - It's an experience in and of itself.
  
• More fan info than you (probably) want to know.
  
• COOLING THE BOX, Don't melt that plastic!
  
• Plenty of folks are experimenting with assorted fans. See pun15her's plog for some thoughts on fans.
  
• Running 12VDC fans at a lower voltage has been found - in some instances - to provide sufficient cooling with less annoying noise. See these cooling ideas.
  
• Remember - when something gets hot it expands. To avoid bowing and possible breakage of components allow for thermal expansion. 1/8" or a couple of millimeters seems to be the accepted amount to allow for fresnel lens expansion.

Advanced Modifications & Methods:

• Anti-glare Removal: This entails the somewhat delicate and risky procedure of removing a layer of diffusive material from your LCD. A synopsis of member experiences. A "strip" video. Note: If you think you'll remove the antiglare it may be best to remove it while your monitor is brand new. There is some evidence that it gets "baked on" with use and becomes much harder to remove. Check out this picture of light spillage at the triplet before and after antiglare removal (courtesy GadgetSmith). Member elken's advice on antiglare removal.
  
• Lens Shift: samuraijack found this explanation. It's similar to keystone correction (see below).
  
• Keystone Correction: Probably one of the more common "tricks" to pull with your projector. Instead of reinventing the wheel I'll simply redirect you: Keystoning, Information, calculation, correction
  
• Polarizer Removal: The LCD panel has a polarization layer. Some people remove this and replace it with a polarizer of higher transmissivity in their quest for a brighter image.
  
• Overclocking/overdriving: This involves modification of ballast circuitry to push a lamp harder than its nominal design parameters. This must be considered a risky and warranty-voiding procedure but has shown promise as a method for getting that little bit extra out of your build. Read and understand methods and risks before proceeding with anything of this nature! Thanks to member ArizonaVideo for his extensive efforts regarding overclocking. A newer summary by ArizonaVideo: Overdriving Lamps And Ballast The short list.
  
• Adding a pre-condenser: This is an extra lens between your lamp and rear fresnel. This has been shown to improve light distribution across the projection screen and may or may not result in a modest increase in brightness to your whole projected image. Research into this is ongoing.
  
• Ceramic lamps are in the lime-light right now. Watch for developments in the forums.
  
• It is possible that some pro lenses have issues whereby they might be made even better than they already are. See this topic for further info.
  

Software:

• ffdshow: benchun's experiences with his build are a great place to learn about ffdshow.
  
• ATI's Catalyst Control Center
  
• Great resource for setting up FFDshow, etc.

HTPC Info:

• keyboards: Seems a lot of people go the wireless route. Makes sense, huh? I mean, what could be more satisfying than reclining in a cozy chair and surfing a GIANT Internet, playing a HUGE game, or simply controlling your movie with a remote? Well, there's a lot to consider and a some things you may not know. Check this topic for example.
  
• Calibrating your display

Buying Guidelines:

• Proven strippable LCD panels.
  
• Link to online, editable, strippable LCD database. Thanks to SamuraiJack!!!
  
  
• ebay is a great source for all sorts of stuff for a projector build. Use common sense and check those seller ratings! Check for LCD panels that specify a broken backlight. We don't use the backlight for our PJ's. Just watch out for other Lumenlab members bidding against ya!

Hints & Kinks:

• Which fresnel is which? In case you can't tell one from the other.
  
• Another way to tell which fresnel is which.
  
• Always install your fresnels with their grooves facing each other.
  
• Which way does the LCD go in? In what orientation? For "straight" (LumenLab guide, slusher, Haas) designs the triplet "flips" the image going through it BOTH vertically and horizontally - at least that's the way you need to conceptualize it. For "folded" designs it gets slightly more complicated. A mirror flips the image along the axis of the bend only. This visual aid should help. Just want an answer? For "straight" designs the LCD goes in upside down with the side you would face normally (while using it with a computer) toward the lamp. Chew on this awhile too - the triplet's double-axis image flip is topologically the same as rotating the LCD 180 degrees about a skewer stuck straight through it. Wow - where'd I come up with that image? For a floor-based, vertical, single-fold design, the so-called "front" of the LCD faces away from the lamp with the normally top edge furthest from the projection screen/wall. Okay, you can hate me now if I've simply confused you or typed this wrong! An awesome visual aid regarding vertical folded LCD orientation by Mordeth. See this topic if you're folding horizontally.
  
  
• Electrical questions frequently arise on the forum. Suffice it to say if you are not absolutely comfortable working with and fairly knowledgable of electrical wiring then find someone who is or ask for detailed help on the forums. Make sure everything is properly grounded.
  
• Relative placement of lamp to rear fresnel.
  
• SupraGuy's ideas on optimizing his projected image. He describes moving the lamp farther away from the rear fresnel and the triplet closer to the front fresnel to even out the illumination of his projected image at some cost in total brightness.
  
• A suggestion I remember reading somewhere to aid in fresnel alignment is to put a tiny, round, opaque, sticky dot (sticky part of a Post-It Note colored in w/black marker?) on the center of one fresnel and one of those tiny, donut-shaped, notebook-paper reinforcement rings at the center of the other. Once you're all aligned you can remove them. They'll show up on your projected image to help verify and assist in alignment. Of course, you gotta beware of "sticking" stuff onto your fresnels. Another member described his method of stretching black string from opposite corners of each fresnel to make sort of a cross-hair effect like you would see through a rifle scope. The strings will cross precisely at the center of the fresnels and can be used for alignment. I figure the fresnels are (hopefully) manufactured sensibly and the center of each lens will be at the geometric center of the rectangle formed by the perimeter of the fresnel so simply carefully building and aligning the frames in which the fresnels rest should suffice for extremely precise alignment.
  
• The Ushio T15 Pulse Strike has a metal rod within the lamp housing and a glass nipple on the arc tube 180 degrees rotationally opposed along the lamp's long axis to said rod. Ever wonder where to position those to avoid projection artifacts? Check this post.
  
• What's all the discussion about "lamp burn-in" anyway? Personally, I am a proponent of burning-in a projector lamp. Burning-in refers to the procedure of firing up your lamp for the very first time and leaving it on for a few hours to as long as overnight. There is - and will continue to be - some debate as to the necessity of this procedure. A couple of facts: 1) A metal halide bulb will only produce its highest brightness level and best color after burning for a number of hours of its total lifetime. 2) Short duty cycles will decrease a metal halide bulbs longevity. 3) It doesn't "hurt" to burn-in your bulb so why not just do it? Member Tank posted a thought about burning-in that I hadn't previously thought of (see here). He said to burn in your bulb in the precise orientation you intend to use the bulb. Very sensible idea. I've recently learned that most lamp specifications are obtained after a 100 hour burn so it's safe to assume that it takes tens of hours to achieve those specs.
  
• It's perfectly normal for a metal halide lamp to look defective and sound broken. There are salts in the arc tube and some of the metal in the lamp can bang around a bit. Almost sounds like a jar of marbles! See this post.
  
• The lamp puts out a LOT of light and heat and that can be harsh to the guts of your projector. Exposed wiring might become brittle. Plastics might degrade. If at all possible, it's best to keep as much wire and plastic out of your light chamber as you can. Alternatively, you can shield things with some inexpensive aluminum flashing from the hardware store - painted flat black of course.
  
• It has come to light that for folded designs it is critical that the mirror(s) be PERFECTLY aligned. Even a toothpick-width misalignment might result in the inability to achieve optimum focus. See this post by DAZZZLA.
  
• So, how do I adjust my reflector? Member DAZZZLA described this method to me for a spherical reflector. When properly adjusted if you look toward the lamp/reflector (with the lamp off, of course) you shouldn't be able to see the arc chamber reflection. Position your head straight-on looking at the lamp/reflector and note the arc chamber image in the mirror. Bob your head around (left, right, up, down) and the arc chamber reflection should remain "hidden" in the reflector. If you can see the arc chamber that means the reflector isn't in the sweet spot. There are tiny exceptions to this rule (sometimes you may want your arc chamber slightly closer to or further from the reflector along the line of projection) but this will get you very accurately centered. Also, DAZZZLA relates you can determine how well the reflector is aligned by taking note of the sharpness of the edge shadow your lamp/reflector casts when you position an iris appropriately for the light to shine through. If the reflected arc isn't aligned with the real arc you'll get a double shadow.
  
• To determine the sweet spot for your arc (lamp) +/- reflector +/- precondensor move them as a unit fore/aft until you see bluish/yellowish corners. Use the centerpoint as your optimal placement. Some minor tweaking off that spot may or may not produce your favorite projection. {from DAZZZLA}
  

Member Contributions to This Topic & Stuff I Found While Forum Surfing:

• ozstang65's suggestions
  
• voovoov's thoughts
  
• A post by MJames describing his alignment technique
  
• An elegant pro reflector mount
  
• Align your projector by "looking down the barrel of the gun"
  
• All you ever wanted to know about LCD's
  
• Invaluable search info from Quasi_Mojo: http://www.google.co...cheatsheet.html & http://www.google.co.../operators.html. Sometimes a little searching solves a lot of trouble.

Common Component Dimensions:

• LumenLab Standard Lens (triplet)
  
• LumenLab Standard Fresnels: 12 9/16" (319mm) x 9 15/16" (252.4mm) x 2mm
  
• LumenLab Pro Lens (triplet)
  
• LumenLab Pro Fresnels: 431 x 406 x 2mm (approximately 17 x 16 x 5/64 inches)
  
• LumenLab Pro Reflector: 74mm diameter (a little under 3 inches diameter x 1 inch deep)
  
• LumenLab eBallast: 7lbs; 8.75" x 4" x 3"

Odds 'n Ends:

• Test Image Creation Program courtesy of paladin. Sweet little utility!!! THIS ROCKS!!!
  
• Calibrating your projector: http://www.geocities.com/tvdarekz/. This is a sweet little utility that "can guide you in setting and adjusting the parameters and controls of your monitor. You can test and adjust the picture size and position, color convergence and purity, white balance, brightness and contrast, focus, moiré and interference, and high-voltage regulation." If this link comes up dead PM me for a copy of the utility. If I come up dead - good luck!
  
• AVIA, Digital Video Essentials, and Sound & Vision are three popular packages that can help you fine tune your projector. Here's a review.
  
• Test Patterns
  
• More Test Patterns - That blue-haired girl, Strawberries 'n water, & more . . .
  
• Still more test patterns - mostly B&W gradients
  
• And more test patterns
  
• Holy cow! Even more test patterns. Found by member Fulcrum.
  
• Links to the beautiful, hot, stacked, indian, squaw woman in the headress images and animations you may have seen/heard about . . . or not.
  
• Free CAD software (limited license/functionality) - www.cadstd.com
  
• Free 3D software from Google! Google SketchUp
  
• Really powerful CAD software with generous evaluation period - http://www.rhino3d.com/
  
• Some neat info including a graphical ray tracing tutorial are at http://www.anchoroptics.com/documents/
  
• Free ray tracing software (limited license/functionality) - members.ozemail.com.au/~imesoft/
  
• A nice synopsis on reflectors.
  
• Neat program for dead pixel determination - Do a Google search for "Dead Pixel Buddy".
  
• Some nice HD images
  
• 720p, 1080i, 1080p. Confused? This will help: Hd Explained 480p,1080i,720p,1080p
  
• LCD's come in a lot of shapes and sizes. See these threads:

• Official 10.6 Wxga Q&a's Thread
  
• 7" Simple LumenLab Projector, Build a 7" quick and easy
  
• The Official 15.4" Wuxga Q&a Thread

Conclusion:

• Made it this far and still don't want to DIY? Check out the prebuilt projector from Lumenlab and the following topics.
  
• The eVo Projector
  
• New Ht Evo Projector, User Discussion

Read the pinned topics. They're pinned for a reason. Well . . . except for THIS topic. You've just WASTED a lot of your valuable time reading my garbage.

Last, but not least, enjoy the Lumenlab experience. This is a great group of diverse and helpful people.

Use common sense and courtesy and you'll be rewarded immensely.

This post has been edited by Durachko: 27 March 2008 - 04:59 PM

[cpsubrian]

Bump, this would be very usefull to us new-wavers coming in on the first few Pro Lense shipments.

[ArchibaldTuttle]

There is no real check list, the big thing is making sure all you elements are centered and oriented correctly, eliminating all light leaks, and then in terms of tweaking playing around with the distances between elements to see if that improves the projection.

This post has been edited by ArchibaldTuttle: 26 January 2006 - 02:37 AM

[Litherish]

ArchibaldTuttle, on Jan 25 2006, 08:37 PM, said:

There is no real check list, the big thing is making sure all you elements are centered and oriented correctly, eliminating all light leaks, and then in terms of tweaking playing around with the distances between elements to see if that improves the projection.

All these "elements" are giving me a headache

Maybe one of you guys should sift through the forums and create a big guide, newer members have less bias to certain techniques and methods. I bet Brain might even make it a sticky!

This post has been edited by Litherish: 26 January 2006 - 03:25 AM

[cpsubrian]

ArchibaldTuttle, on Jan 25 2006, 05:37 PM, said:

There is no real check list, the big thing is making sure all you elements are centered and oriented correctly, eliminating all light leaks, and then in terms of tweaking playing around with the distances between elements to see if that improves the projection.

Excuse me if Im wrong but are items seperated by commas a list. Sounds like what u just said. In all serisouness though, thanks for the info and you are right, from what ive read each PJ has its own tweaks, im just saying that a centralized thread of what works and what doesnt would be helpful.

Litherish, on Jan 25 2006, 06:23 PM, said:

All these "elements" are giving me a headache

Maybe one of you guys should sift through the forums and create a big guide, newer members have less bias to certain techniques and methods. I bet Brain might even make it a sticky!

You sir, are on the money. This type of info is something that an excited newbie can do and is not nessesarily the responsibiliy of the LL "gods". If i get some time this weekend i may contribute to the cause.

[elbeghast]

I've found ATI's "Catalyst Control Center" software to be extremely useful for tweaking the projection..i.e.-Gamma,brightness,hue,saturation,contrast etc. and it works with most video cards,not just ati's.Though,you must have your projector connected to a PC.

ATI Catalyst control center:
http://www.ati.com/p...nter/index.html

This post has been edited by elbeghast: 26 January 2006 - 08:18 AM

[DAZZZLA]

Litherish, on Jan 26 2006, 01:23 PM, said:

All these "elements" are giving me a headache

Maybe one of you guys should sift through the forums and create a big guide, newer members have less bias to certain techniques and methods. I bet Brain might even make it a sticky!

Are you putting your hand up?

DJ

[Durachko]

elbeghast: Thanks for the input. It's what I had in mind.

cpsubrian, on Jan 25 2006, 10:57 PM, said:

Excuse me if Im wrong but are items seperated by commas a list. Sounds like what u just said. In all serisouness though, thanks for the info and you are right, from what ive read each PJ has its own tweaks, im just saying that a centralized thread of what works and what doesnt would be helpful.

Commas are helpful. It's too bad that so many find abbreviations soooo attractive (hard on newbies and there's that search limitation for short "words") and poor grammar/punctuation can make following a thread difficult, annoying, and bothersome.

cpsubrian, on Jan 25 2006, 10:57 PM, said:

You sir, are on the money. This type of info is something that an excited newbie can do and is not nessesarily the responsibiliy of the LL "gods". If i get some time this weekend i may contribute to the cause.

I wasn't intending LL "gods" (you know who you are) to compile a list but rather contribute tid-bits of info in this thread so one wouldn't have to surf through all the forums to get a handle on things.

Also, I would be very happy to collaborate with someone in compiling such a list. cpsubrian - PM me if you want to work together on such a project.

I'm still in the pre-build stage so can't contribute from experience - only from reading the forums - and I don't retain info well by reading forums - I seem to need hands-on experience to really absorb stuff.

Anyway, maybe this topic will live on and maybe it'll fade away but I still think it's a good idea and would prove useful to many. I almost daily see posts asking very basic questions and I'm sure it's because sifting through the forums can be so frustrating and imposing.

[Durachko]

I've been editing and adding to the first post in this topic for awhile now and feel I've reached the point where I'd like to ask whether sufficient people will find this useful to make it worth continuing. I don't think edits bring a topic back into the "View New Posts" page - do they? So, this has been a dead topic for awhile. And I'll bet a lot of people are like me and they click on View New Posts mostly and skip the old stuff.

So, anyway, re-read the first post and please chime in with your comments.

Critique the format, make suggestions for additions, provide specific links to useful tid-bits, whatever.

What I envision is a nice, big page full of basic info and hyperlinks to specific points, methods, and pictures.

I only wish I'd done this from the first time I started combing through the forums. It takes a lot of time to wade through the forums and find the info - even when I know where I'm going or what I'm looking for. That's why I'm inviting everyone to post to this topic and I'll copy stuff and paste it back into the first post. Somehow, I'm reminded of a dork I knew in college who was a computer science major. He actually wrote on his resume that his goal was "To be a user friendly programmer." He never lived that down. In retrospect, I kind of feel bad for all the grief we gave him over that. (Nah . . . not really! )

[cpsubrian]

I definitly think this thread should live and grow. We need to be careful to keep it focused (no pun intended). There are already some good starting points for newbs such as the LL guide. If I am correct the point of this thread is to compile post-build tweaks and upgrades into a managable checklist. I will be contributing to this as often as time allows. As soon as my pro kit comes in I will be starting my PJ and I am going to try and document everything. I too hope that someday this will be finished enough to sticky it.

P.S. PM sent Durachko

[Litherish]

Durachko, that is looking nice! I'd suggest going into buying an LCD panel, the types of LCD panels you can get, such as buying an LCD Tv which has all the nice inputs, component, composite, s-video, cable, analog audio, etc...but to be warned that their is no guarentee as to whether the LCD Tv will work considering it may have FFC issues, and few LCD tvs have been stripped.

Mention good places to buy LCD's, like eBay, tell them to search for "dead backlight" or "no sound" to get good deals on perfectly working LCD panels, again warn that theirs no guarentee the LCD will work considering its eBay. Other good places to buy from are www.newegg.com www.tigerdirect.com (theirs definately more can't remember)

I know these aren't necessarily "tweaks" but the topic shows "hints"

[Litherish]

DAZZZLA, on Jan 26 2006, 05:41 AM, said:

Are you putting your hand up?

DJ

Actually I am!....(stretches).....Alright its down.

[cpsubrian]

Good idea Lith,

Feel free to start this and reply it in more of a list type format, me and Dur need all the help we can get. If you dont have a lot of time just get it started and we can run with it, plus people can add with their own experiences.

Brian

[Durachko]

Litherish, on Jan 27 2006, 08:59 PM, said:

Durachko, that is looking nice! I'd suggest going into buying an LCD panel, the types of LCD panels you can get, such as buying an LCD Tv which has all the nice inputs, component, composite, s-video, cable, analog audio, etc...but to be warned that their is no guarentee as to whether the LCD Tv will work considering it may have FFC issues, and few LCD tvs have been stripped.

Mention good places to buy LCD's, like eBay, tell them to search for "dead backlight" or "no sound" to get good deals on perfectly working LCD panels, again warn that theirs no guarentee the LCD will work considering its eBay. Other good places to buy from are www.newegg.com www.tigerdirect.com (theirs definately more can't remember)

I know these aren't necessarily "tweaks" but the topic shows "hints"

I actually was going to edit the title to narrow the suggested scope of this topic but I guess now I won't. After all, so long as it's well written (big IF! ) and heavily linked there's no harm - I suppose - in providing as much info as possible. We'll (me and cpsubrian) keep at it and see what develops. Thanks for the suggestions!

[ozstang65]

Ok, the original post asks for tweaking instructions and it looks as though it's growing into a general info cache so here's my $0.02 (Edit: once you start writing you realise how many things there are to take into consideration!)

Firstly, to be able to 'tweak', you must have built some 'tweakability' into your system in the first place. This is heavily dependent on your initial design and it begins as soon as you have said "Wow, that looks great, I'm going to build me one of these things!"

Ok, so here's some tips from my (on-going) building experience.

Step 1: Basic Design Phase

Start with your goal - "What do you want to achieve?". High Definition or Standard Definition? PC or AV to drive it? This will determine your panel size and connection componentry, with a general rule of thumb being SD <= 15", HD >=17" (or 15.4" WUXGA).

Don't be too egotistical - "Bigger isn't necessarily better": You don't have to have a 120" picture to enjoy bigscreen TV! My livingroom pretty much dictated a 72" 16:9 screen size, but I don't find myself saying "Gee, I wish I could go bigger", even if I had the room. A smaller picture will be brighter and you don't have to turn your head to follow the action when you're sitting in the front row. It's down to personal preference however, but don't paint yourself into a corner with screen size.

Location, Location: "Where are you gonna stick it all?": Do scale drawings of your room and make sure you can see all of your screen without anything getting in the way, including the PJ itself!. You will probably have to compromise between screen size and PJ location. It is supposedly good to design your screen location so that your eyes, when looking straight forward, are looking at 1/3 of the way up the screen. Use the focal length calculator, as a guide to help you locate the PJ in your room.

Research: "Read 'dem forums!" Once you have done some preliminary design and figured out the basic layout you want to aim for, spend a few hours checking out other PLogs of those who have built something similar.

Flexibility is the key. Design everything ultra-adjustable using the guide as a basic starting point for component location, remember, it's a guide, not gospel.


Step 2: Basic Construction Phase

IMHO I think it is ideal if you can make a mock-up on a basic frame first. That way you can adjust component location until you get a picture you are happy with then build it into a housing. If you have chosen the basic 'dog coffin' desing then you can probably feel pretty safe in putting everything straight to 'the box', however, adjustability with this design has it's benefits too.

In your construction allow for adjustability for these items:

Lamp location - Up/Down/Forward/Backward/Tilt
Reflector Location relative to lamp - Up/Down/Left/Right/Forward/Backward/Tilt
Lamp to rear fres distance
Rear Fres to LCD distance (rumor has it that the closer the rear fres is to the LCD, the more chance you'll have of fresnel rings in the projection)
Front Fres to LCD distance
Front Fres angle (keystone)
Front Fres - Up/Down if you've got oversized fresnels and are going to play with lens-shift
Triplet location - Up/Down/Forward/Backward/Tilt

Keystone and Lens-Shift can be combined to get your picture where you want it on the wall. Some put figures on how much of each you can get away with, my advice is make it all adjustable then you can come up with a configuration that is acceptable to you.

Step 3: Initial Tweaking Phase

Place the PJ in it's designed resting place in your room. Move the components (including the PJ as a whole!) about until you are getting a picture close to what you're after. Doesn't have to be 100% at this stage. I found it helpful to hold the triplet by hand and play with different orientations until I got it close to what I wanted. I remembered it's location and made a frame to hold it there (adjustable of course)


Step 4: Final Construction Phase

Transfer your mock-up into it's 'box', retaining all the component locations. It may be necessary to build in some fine-tuning adjusters at this point in time.

Step 4: Fine Tweaking Phase

Things to Tweak: Everything that's adjustable!

Tweaking tools:

Luxmeter - can be used to check for even lighting across the fresnels/lcd/screen. All the readings will not be the same, but if they are symmetrical along both axes then that's a good start. A 9-point pattern can be used to check light distribution on your projection screen. Measure the Lux at the 9 points, Make a mod, check your readings again again, if it's worse - go back! Only stop adjusting things when the last change made makes it worse.

Thermometer - Don't melt the expensive bits! Fan noise can be minimised with temperature monitoring and using circuits to control fan speed (manual or automatic).

Step 5: Final Tidy up

When all the optics are in their desired locations it may be beneficial to enclose the light path within the box to minimise stray light. Make the outside presentable and, unless you're making a work of art, try to make it blend in with the surrounds as much as possible - WAF.



Note: I'm not going in-depth on lighting or cooling circuits (as well as other things) - there are way too many different designs here! Ancilliary component location (ballasts/controllers etc) is up to the individual designer and it usually bears no influence on the projected image.

[Durachko]

Thanks much ozstang65! I've linked your post from my first page. I'll continue to do so with other contributions. This is what I had in mind!

[Durachko]

Straight versus vertical design ray trace visual aid.

 straight_versus_vertical.gif (12.44K)
Number of downloads: 559

Scale reference drawing of pro reflector, lamp, and rear pro fresnel diagonal: (Notes: Actual fresnel diagonal is slightly larger. Dots represent a 10 mm grid.)

 scale_max_rear_fresnel.gif (7.57K)
Number of downloads: 316

This post has been edited by Durachko: 02 February 2006 - 10:09 PM

[sctele]

Awesome thread, very helpful! Thanks!

[voovoov]

HDTV via HTPC is much better than other video sources.
One side of LCD affords better result than another, which is a drawback to lumenlab design. (some people don't believe me or are reluctant to admit this.)
The tempered glass is not necessary when the room temperature is below 80F.
A precondensor lens may help the brightness and even lighting.
Keep things simple, vertical, parallel, alligned. Don't use your eyes only, use tools.
Only use first surface mirror.
The distance between lenses, glasses needs to be adjusted, don't get it fixed according to calculations.
These are I learned from building two projectors.

[jonjandran]

voovoov, on Feb 5 2006, 01:33 AM, said:

HDTV via HTPC is much better than other video sources.
One side of LCD affords better result than another, which is a drawback to lumenlab design. (some people don't believe me or are reluctant to admit this.)
The tempered glass is not necessary when the room temperature is below 80F.
A precondensor lens may help the brightness and even lighting.
Keep things simple, vertical, parallel, alligned. Don't use your eyes only, use tools.
Only use first surface mirror.
The distance between lenses, glasses needs to be adjusted, don't get it fixed according to calculations.
These are I learned from building two projectors.

Well allow me.

"HDTV via HTPC is much better than other video sources." Not for me . My 15.4" Wuxga Projector looks MUCH better with an upconverting Samsung at 1080i than it does with my Htpc with ANY Dvd Software and FFDShow.

"The tempered glass is not necessary when the room temperature is below 80F." This is entirely dependant on the cooling system in your box. Not enough fans or good airflow and you will end up with a melted rear fresnel and a cooked Lcd .

[dajyn]

voovoov, on Feb 5 2006, 12:33 AM, said:

One side of LCD affords better result than another, which is a drawback to lumenlab design. (some people don't believe me or are reluctant to admit this.)

voovoov - can you elaborate on this? Is it based on your own experiences?

[Durachko]

voovoov, on Feb 5 2006, 01:33 AM, said:

One side of LCD affords better result than another, which is a drawback to lumenlab design. (some people don't believe me or are reluctant to admit this.)

voovoov: I'd really like to hear more about this as well. Thanks for your contributions.

[Durachko]

sctele, on Feb 3 2006, 07:54 PM, said:

Awesome thread, very helpful! Thanks!

Awww . . . shucks. Flattery will get you more edits and additions to this topic!

[voovoov]

Durachko, on Feb 6 2006, 09:16 AM, said:

voovoov: I'd really like to hear more about this as well. Thanks for your contributions.

My first projector is based on DPC, which used a mirror in the setup and the LCD was in normal position. When tried the LL's design, the projected image is with a tint of black compared with another side of LCD. This is a Dell 15 LCD. My second is based on Samsung 15" LCd. I removed the antiglare film in order to get a normal image, but I found that one side is still worse than another one.
To surpasss the problem, you can use some video card or some software to flip the image. It works for DVD, However, it doesn't work my me. My HDTV card must use overlay and it can not be flipped.

[voovoov]

jonjandran, on Feb 5 2006, 08:26 AM, said:

Well allow me.

"HDTV via HTPC is much better than other video sources." Not for me . My 15.4" Wuxga Projector looks MUCH better with an upconverting Samsung at 1080i than it does with my Htpc with ANY Dvd Software and FFDShow.

"The tempered glass is not necessary when the room temperature is below 80F." This is entirely dependant on the cooling system in your box. Not enough fans or good airflow and you will end up with a melted rear fresnel and a cooked Lcd .

Fisrt, what I said is HDTV. I don't think your Samsung can match OTA HDTV. I seldom watch TV until I saw HDTV. Nowdays, OTA HDTV furnishs the best PQ.

Second, my point is that you can increase brightness by not using IR tempered glass. Of course you need sufficent cooling.