State Of The Diy Projector, One place to stay up to date Options

[Dergrin]

I have been a member here since January 05, and have seen many posts discussing the idea of having one post that keeps people up to date with the Lumenlab DIY projector. I thought I would take this time to take a shot at it.

This post will be very simple at first just stating a few things, but I encourage everyone to help me. I know everyone does not agree on what they think should be the components to build the best projector, but that is not what this post is about. This post is going to show an unbiased summary to compare the most popular components and help new builders.


The State of the DIY Projector Updated 7-24-06


The Box:
Many first time builders like to stick with the original Lumenlab rectangular box design. Others like to test their craftsmanship and try to build a Haas Box or Puni5sher's vertical design. Still others like to show their ingenuity and come up with their own design. This section will discuss the most popular box designs currently used.

The Lumenlab Box: This box is probably the most popular box of Lumenlab members. The reason for its popularity is its ease of construction and alignment for first time builders. This box can be summed up as the quick and somewhat dirty way of building a projector. The two big disadvantages of this box are size and appearance. This box is probably the maximum size possible for a Lumenlab projector given the same size monitor. Also, having a big box in your living room is not always going to be the most attractive thing. The most common construction material for this box is MDF or plywood.
Fly CRJ's PLOG

The Haas Box: To overcome the appearance and size of the standard Lumenlab box, Haas man designed the Haas box. First of all, it really isn’t much of a box, but resembles a concave lens lying on its side. The Haas box is almost always made from real wood and stained to match ones furniture in the house. With the nice curved design and stain, the box is much more aesthetically pleasing. This box is harder to construct and has plans which can be used on a CNC machine.
Haas man's PLOG

The Vertical or folded Box: The vertical and folded designs can be box shaped or curved in outside appearance. What differs with these boxes is the use of mirrors. By bending the light path there is less wasted space, sometime significantly reducing the size of the box. The box itself may not be hard to construct but depending on the number of mirrors used (usually one) can make aligning the optics very tedious.
Pun15er's PLOG




The Monitor and Cables
The monitor is most likely going to be the largest single investment in the projector; therefore, you are probably going to want to decide what is best for your application. When choosing a monitor you may want to first check for its compatibility. You can do so at the Compatible monitor list. There are several other things to look at when looking at monitors: contrast ratio, resolution, response time, and inputs.

• The contrast ratio is the difference between the brightest whites and the darkest black. The contrast ratio is important to some and not so much to others. Some people cannot stand a washed out image to where the blacks appears a dark gray and the white a light gray. Although the contrast ratios stated by different monitor manufacturers can be subjective, a contrast ratio of 500:1 is good, below 300:1 is poor, and above 700:1 is great.
• Most everyone here knows what the resolution of a monitor is. It is how many pixels a monitor is able to display. The higher the resolution is, the higher the image quality will be. Most monitors have a native resolution associated with them, and any other resolution displayed on it isn’t as clear. If you want your projector to have an image quality of 720p you must have a monitor with 1280 pixels across (1280x1024 or 1280x768)
• The response time of a monitor is the time it takes for a pixel to go between on and off. For watching movies the response time is not very critical. Movies are typically done at 30 frames per second. Response times become more critical for gamers when playing first person shooters. When objects move quickly across a screen with a slow response time they tend to slightly blur. A monitor with a response time of 12ms is good, 16ms is average, and less than 8ms is great.
• The most common inputs are VGA and DVI. Some people want composite or component inputs on their monitor so they can connect common home entertainment equipment directly to the projector with out having to use a converter or computer.

15in: 15in monitors are the most commonly used size with the standard lenses. With the introduction of the Pro lenses, and the decrease in price of 17in monitors, more people are building with 17in monitors. 15in monitors usually have a native resolution of 1024x768 which is higher than most entry level commercial projectors. A lot of builders use the Westinghouse brand from Best Buy.

17in: The most inexpensive and readily available monitor to produce 720p is a 17in monitor. There are other smaller monitors that will accomplish this, but they are more expensive and hard to find. Because of its ability to display HD (High Definition) content, some builders are starting to use 17in monitors. Builders use a variety of brands and models of 17in monitors.

<15in: Because of the large size of high resolution LCD monitors, the box for the projector has to be very large. The best way to reduce the size of the box is to use a smaller monitor. The monitor that seems to have the most success is the Hami 8” monitor. It has a resolution of 800x600 and is much smaller than a 15” monitor.

Cables: To connect your projector to your HTPC or TV box you are most likely going to need an extension cable. VGA and DVI are the most common cables leaving the box besides a common power cable. These cables can be found for a very low price at Monoprice. Monoprice’s cables are high quality and sometimes 1/5 the price of competitors.


Antiglare
Almost all LCD monitors on the market, except the Sony X-brite and a few others, have a layer on the front of the display called antiglare. The antiglare diffuses the light that hits the front of the monitor, reducing the glare that bounces back. This helps to see your desktop monitor in well lit environments. Although the antiglare may be beneficial in a desktop environment, it is detrimental in the projector. The antiglare scatters the light causing it to reach the collector fresnel at a different angle than intended. This scattered light does not make it to the triplet, and reduces the brightness, sharpness, and color quality of the image.

Stripping the antiglare: Stripping refers to the method of removing the antiglare from an LCD monitor. This procedure is risky and requires the utmost care and patience. All monitors are different, and one member’s ease of removal may differ from yours even if you own the same monitor. It is important to search the forums regarding you monitor and the ease of stripping its antiglare. The water strip or “rag” method is the most common method for removing the antiglare. There are several threads that outline which monitors have been successful with this method and include a step by step description on how to use the water strip method to remove the antiglare.
This outlines the removal process: Antiglare, Removal Revised
This thread shows attempts that have been documented: Antiglare Removal Attempts]
This outlines the discovery of the removal process: Antiglare Story


The Light
When choosing a bulb there are several factors that are considered including: color temperature, lumen output, arc chamber size, wattage, life expectancy, and ballast.

• The color temperature of a light describes what color light is being produced. Having a color temperature around 6000k means the bulb produces the closest to white. If a bulb has a color temperature less than this, it produces a yellowish light, and if a bulb has a color temperature greater than this, it produces a bluish light. The closer to white the light is, the more vibrant the colors.
• Lumen output is very important. This is how much light the bulb produces. Usually the higher the lumen output the better. Most people weight color temperature and lumen output against each other to find which bulb they want.
• The optics of the projector expects the light to come from a point source which it isn’t. The arc of the bulb usually spans a couple centimeters. Having a bulb with an arc larger than a couple centimeters is impractical because the extra light it may produce is wasted because the optics can’t focus it.
• As most know, wattage is the power the bulb consumes. The higher the wattage the brighter the bulb is and the more heat it produces. Most people use a 400W metal halide bulb although a few use 250W HQI double ended bulbs.
• The main advantage Lumenlab projectors have over commercial projectors is bulb life. Most bulbs used in these projectors have a life of 10,000-20,000 hours while most commercial projector bulbs only last 200-2,000 hours. Also, Lumenlab bulbs only cost $30-$50 while commercial bulbs cost $250-$500.
• Finally, depending on which bulb is used depends on which ballast must be paired with it. Some of the community uses electronic ballasts while others use coil and core ballasts. The electronic ballasts are slightly more expensive, but are much lighter and smaller. The coil and core are cheaper, but weigh around 15 lbs and take up a little more space.

S400DD: The Ushio S400DD 400W bulb is probably the most common light used today by builders. This is only because this is the bulb Lumenlab used to stock. Builders are now starting to use the LL65K T15 bulb. The color temperature of this bulb is 5200k. The lumen output is 33,000 and life expectancy of 15,000 hours. This bulb requires a HPS S51 400W coil and core ballast or electronic ballast

LL65K T15: The LL65K T15 400W bulb is now the bulb sold by Lumenlab. The color temperature of this bulb is 6500k. This bulb has a color rendering of 91 meaning it produces the most accurate colors. The lumen output is 38, 000 and life expectancy of 10,000 hours. This bulb requires a M59 or M135 coil and core ballast or electronic ballast.


The Lenses
The lenses of the Lumenlab projector, also referred to as optics, are responsible for making the projected image show up crisp and clear. Every projector has the two fresnel lenses to direct the light to the triplet. The triplet is responsible for projecting the image. Some builders are now starting to add precondensers lenses in the projectors.

Standard: The standard Lumenlab lens set comes with 2 fresnel lenses and an 80mm triplet. This lens set is recommended for all monitors 15” and below. The standard triplet has been proven to work with 17” monitors but the standard fresnel lenses are too small and must be purchases somewhere else. The triplet lens has a 1:1 ratio, meaning that the projector must be the same distance away from the wall as the projected diagonal.

Pro: The pro lens set comes with two larger fresnel lenses and a 100mm triplet. This lens set is recommended for 17” monitors and above. Although, if this lens set is used with smaller monitors it will increase the throw distance of the projector. This allows the projector to be positioned further back while still projecting the same size image. This triplet allows more light making the projection brighter. This triplet lens has a 1.6:1 ratio allowing the distance from the projection to the projector to be 1.6 times the projected diagonal.

Precondensers: A precondenser lens is a special convex lens that collects more of the light right next to the bulb and bends it towards the fresnel. Many builders are starting to do this because it adds brightness and uniformity to the projected image. Condensers come in many diameters and focal lengths. Mikyd has started the Precondenser Experimentation thread to compile all the information that has been collected so far.


Cooling
Cooling the monitor in the Lumenlab box is very important. Without it the monitor will degrade and eventually expire. To overcome the heat produced fans are installed.

EverCool PCAC: Up until recently these fans were the most recommended, but are now rivaled by 120mm case fans. The EverCool is a cross flow fan which resembles the paddle on a paddleboat. These fans look very good on paper (23dB and 100cfm) but in reality produce a slight whine and have difficultly pulling air with restricted air paths. One of the biggest advantages of the cross flow design is very little light escapes through the fan.

120mm case fans: Slowly, builders are exchanging their EverCool PCACs for a 120mm fans from either Lumenlab or computer part retailers. Although these fan state a higher noise level, builders have stated it is a little quieter than their EverCool. This fan can also move up to 100cfm of air. The only problem with these fans is that they let a lot of light out the box, unless you position it in a way that allows air flow but no light to escape.

80mm case fans:Some builders like to salvage what they have around the house. Most Lumenlab builders have a couple 80mm fans lying around from computers that they have tinkered with. Depending on the fan, these are usually adequate but can sometimes be noisy. As with the 120mm fan, light leaks can be a problem and must be taken into consideration.


Mounting
Because the DIY projector has less of a throw distance than the optimal viewing distance, the projector must be in front of the viewer. To keep the projector out of the way of the viewer it is usually placed on the floor, ceiling or to the side. Of course with all of these methods, some form of keystoning or screen tilt must be applied for the image to appear undistorted and clear.

Ceiling: Most commercial projectors are ceiling mounted, so why not mount your DIY projector from the ceiling. The biggest disadvantage with this route is that these projectors are big and can be quite heavy. If you are going to ceiling mount your projector it is recommended that you know what you are doing, because no one wants a 40lb object falling on an unsuspecting victim. Some builders have made nice rail systems to slide the projector back and forth. This allows them to change the size of the projected image if need be.

Floor: Many that do not want to deal with the hassles of hanging a projector and/or it doesn’t work for their situation. Most builders position their projector on the floor, or not far from it. Some have even gone as far as designing furniture (such as a coffee table) to hide the projector and make it more appealing.

Side: For some, the ceiling and the floor are not an option. These builders place their projector to the side of the screen. Just keep in mind that if you use this option and keystone by pivoting the field fresnel, you must pivot the fresnel vertically.


The Screen
Now you have your projector built and you need something to watch it on. Projection screens can sometimes vastly increase the contrast and gain of your projection, depending on what you are currently projecting on. Most common features of screens are gain, contrast, viewing angle, and hot spotting. Methods are currently being tested to make screens that reflect ambient light but not projected light.

Blackout cloth: Probably the most common screen among Lumenlab builders. Blackout cloth can be bought from almost any fabric store in 54” widths but Lumenlab sell this material in 110” widths. Blackout cloth is the heavy, white, cloth used in combination curtains to block the light from entering your house. The aspect of blocking light makes it better than a standard white fabric. This material is usually stretched over a wooden frame, keeping wrinkles from distorting your image. Some advantages of this screen are that it is cheap, easily acquired, wide viewing angle, and no hot spotting.

White Paint: Some builders have a nice bare wall they would like to project their image on instead of building or buying a screen. There have been many debates if a white wall or blackout cloth make a better screen, and the outcome is that they are about the same. The paint used is usually a flat white, but some have used silver to increase gain brightness and make blacks come out better. Flat white paint has no hot spotting while the silver usually does. Some have stated that the disadvantage of using a painted wall is that it brings out the imperfections in the wall in the projected image.


UV, IR, Reflectors and Heat Shields
So you have figured out what light kit you are going to use. Now you need to make sure that light gets to the monitor, but the heat doesn't.

Heat Shields These are an important component of every projector. Heat shields are installed between the bulb and the first fresnel lens to help block heat from getting to the fresnel and monitor.

• XL10: This is a UV blocking lexan. This is probably the most common method for blocking UV light from the bulb and providing a heat shield for the rear fresnel and monitor. Most people get this from their local Home Depot and it usually costs around $10. The main advantages of XL10 are that is cheap, blocks UV, and can easily be cut to the needed dimensions at your own home. Just make sure when framing the lexan to leave a little expansion room for when the lexan is heated.
  
• Tempered Glass: Other members use tempered glass as their heat shield. Since the tempered glass doesn’t block UV, a filter must be purchased from Lumenlab to block UV. Another hassle is you have to go to the glass store and have them cut it to size for you, so you better know the exact dimensions of your box. The advantages of tempered glass are that it doesn’t bow when heated, and it blocks heat a little better.

Reflectors: The reflector is used to get more usable light to triplet to brighten the projection. The most common method is by using a spherical reflector so the light is reflected straight back through the arc of the bulb. Two of the most common reflectors are:

• IKEA Soaré napkin holder: This reflector works with all the bulbs stated above and most all other bulbs. If you do not have an IKEA store near by we have members who will help you get a hold of one.
  
• Pro Reflector: This reflector is designed by Lumenlab to work well with tubular style bulbs. It is extremely reflective and coated with an IR pass filter to allow the heat to pass through the reflector instead of being bounced back towards the fresnel and monitor. Note: Be careful when handling this reflector as to not rub any of the IR filter off.

Hot Mirrors: These are special mirrors that reflect IR light and transmit visible light. Most of the heat that reaches the monitor is caused by the IR light being absorbed into the monitor itself. A few builders use them in their projectors. These tend to be pretty expensive but when used, you may be able to get away with not having any active cooling in your box at all.


TV Boxes and HTPCs
Now that your projector is built you might need something to plug it into. Three of the most common things used to drive the projector are an HTPC (Home Theater Personal Computer), TV box, or transcoders.

TV Boxes: TV Boxes are usually a small box that have various inputs and outputs including composite, component, VGA, coaxial and much more. These are mostly used if you want to hook up most of your existing AV equipment to the projector. Although this method works and is an inexpensive alternative, by not using a HTPC you will be sacrificing image quality. The most common TV Box is the Viewsonic N6.

HTPCs: HTPCs are used by most Lumenlab members to drive their projector. By using a computer, you open up thousands of possibilities to tweak every last aspect of your projected image. Based upon your hardware and software you use you can drastically improve your image quality compared to using a TV box. If you do not already own a computer that you can run your projector off of than this method could be more expensive. Some common programs to look into are: WinDVD6, Zoomplayer, FDDShow, Dscaler, and Powerstrip. There are many more out their but these are some of the most common and essential programs.

Transcoders: Transcoders are a toned down version of a TV box. Transcoders allow you to convert component to VGA for your monitor with very little loss in image quality. One of the most common transcoders is the VDigi VD-Z3.


Useful Tools
Here you can find a thread that lists useful ways to help build your projector.


Tips
Add a list of helpful tips that we would have all loved to know before building.

• Monitor Stripping:
  Typically there are row drivers and column drivers that burnout and cause a given row or column not to be addressed - simply stated, it is not connected electrically any more to the display. If a block of lines goes out, the entire driver has probably been damaged. One possibility is that the TAB driver has disconnected from the surface. The TAB driver is connected to the transparent traces on the glass using an anisotropic conductive film (ACF). Sometimes that film will be damaged and a particular connection between a row and a column in the driver can be destroyed. If you have a row or a column driver damaged, the driver needs to be replaced. In a CG silicon display where the driver is on the glass there is no repair. Chip-on-film drivers can be replaced in their entirety.
  
  The real issue is what causes these failures. They are typically caused by electrostatic discharge. You should make sure that your manufacturing area is properly handling displays especially before they are connected to a ground. Make sure that personnel handling displays are working with wrist straps and are working on a conductive floor. An ionized air flow environment with a slightly elevated humidity is recommended for handling displays that are not yet grounded in a system. When removing protective plastic film, remove in the direction away from the drivers and should remove it at a relatively slow rate to eliminate the build up of a strong static charge on the display. When these precautions are taken, you should see minimal or no damage to row or column drivers and most line-out problems will be eliminated.

Troubleshooting
Common problems and their solutions.

• One common problem is mixing up the field fresnel with the collector fresnel. This will cause an effect of looking at the projected image through a narrow round tube.

Useful Links
"Tweaking" Your Projector From A to Z

This is just a preliminary listing of topics that I thought would be good to include. Please if you have suggestions let me know. If you have content you think should be added or removed, let me know. I want this post to be a compilation of the entire Lumenlab community. I also want it to be a quick reference for those that are new to the community or have not checked up in a couple months and want to read up on the new discoveries.

[Dergrin]

If any members would like to help me keep this post up to date I would greatly appreciate it. With the new influx of members, and it being my senior year in college, it is really hard to keep up to date with all the new experiments.

The main thing I would need help with is updating the post with what most members are using when it comes to the ceramic lamps. Maybe something on a commonly used complete light engine setup and the triplet mod.

PM me if you would like to help.

[Frying]

Isn't it about time to give this post a proper update ?

I have only been into this whole DIY thing for ~12 hours straight now so I don't know that much yet, but some key things I bumbed up so far, compared to the above post:

- refreshrates gone down like crazy; 8ms isn't special anymore, 4~5ms is the standard now on new screens
- everything and everybody on display is about HD these days; maybe there could be said a bit more about HD and (real) 1080p
- screen paint; I have been reading about this -quite expensive really...- special screen paint, there's lot of them out there, something that could be pointed out a bit more
- LED backlighting; it's time to make a note on using LED as backlight, information on this subject seems to be really scattered (on this forum) so far and only a few brave really tried there best on it.. mosts posts on LED's seem to end in people mixing up terms like 'mcd', 'lux', 'lumen', 'angle of the light' and comparing them to bulbs without really knowing what they can compare, or how to compare (how much lumen does a LED produce compared to a bulb? how much lumen do these sources send out in which direction? how much do both sources really deliver to the panel? etc.)
- controllers; I don't see anything mentioned about controllers, although I read about them quite a lot on the forum, ppl trying to boost their resolution? getting better connections

Fry.

This post has been edited by Frying: Jan 27 2008, 09:16 AM

[SupraGuy]

I'd agree, however, Dergrin hasn't been around in over a year, so it'll be up to someone else to "take over" for him.

Anyone who has the time and knowledge to do so is invited to.

I don't have the time to keep something like this up to date, but I'd be more than willing to transfer ownership of this to someone who does. PM me if you want to volunteer.

[Frying]

I'd agree, however, Dergrin hasn't been around in over a year, so it'll be up to someone else to "take over" for him.

Anyone who has the time and knowledge to do so is invited to.

I don't have the time to keep something like this up to date, but I'd be more than willing to transfer ownership of this to someone who does. PM me if you want to volunteer.

Now I'm getting all into this DIY projector stuff I would love to update this in my crappy english. To bad I start with my final internship next week, meaning it's probably bye bye precious lifetime. Yet I will try to write some updated pieces. Whenever I got something I'll post it down here.

Fry.

[Dergrin]

If someone would like to take this over for me go right ahead. I dont have the time to stay up to date here as much as I would like. I only stop by once every couple of months to see what new is happening.

[joesin]

Hey all,
Just wanted to take a moment to thank everyone who posts here at the Lumen lab forums. In two weeks of intense reading I went from a guy who didnt know his @$$ from a hole in the ground to the proud owner of an 7800 Lumen OHP that greatly exceeded my expectations. Ground up these forums where my Bible. From selecting an OHP to stripping the Anti glare I was getting all my info here. Thank you.

JOE S

This post has been edited by joesin: Apr 28 2009, 04:03 PM

[misieso]

Hello,
I have a Torpedo video projector, made by Senario. I'm trying to upgrade the resolution of its LCD tft panel (2.5 inches) and change it for a new one.
Where can I buy a LCD TFT panel, same size (2.5 inches), with a higher resolution in USA?.
Thank you.