I pose this question because I would like to explain to people that see my dIY PJ
why I chose to build one when I could "buy one" for not too much more $$....
I would like to explain why, in REALITY, my DIY Resolution is so much more
for the dollar......... Here is my point and my question:


Ive read here on LL forums that the commercial PJ's stated resolutions are
not realistic...... example:

One poster says:

Today I found this pj: NEC Projector (commercial)
The cost is not that high (roughly 700 Euros) and it comes with a res of 1280x1024.

Answer:
Its not a 1280x1024 it is a 800x600 that will down sample a 1280x1024 to 800x600.
17" gets you 1280x1024, there really isn't any benifit to going with a 19". 15" are only 1024x768.


SO, WHAT ARE THE COMMERCIALS USING TO BE ABLE TO QUOTE SUCH HIGH RES., when what
is on the screen is not such High res ???

They obviously quote these high resolutions....... My guess is that they DO have these resolutions,
just not at the screen like ours..........what gives? Are they hitting these resolutions somewhere
INSIDE the projector??

Yes, I realize the main diffrence is brightness........but we are working that out........ So,
back to the point, How are they quoting such high res when it is not true???

Anyone know ?

To put it simply. The native resolution of the commercial PJ is 800*600, the actual number of pixels it has. It can however accept a resolution of 1280*1024 but an algorithm in the electronics selectively removes or modifies the resolution so that the actual Pixel count to the display is only 800*600. This equates to a poorer quality image.

DJ

So, tell me if this is right:

800X600 = 480,000 pixels.
1024X768 = 786,432 pixels.
1280X1024 = 1,310,720 pixels.

AND, 1024 x 768 pixels has 64 % more pixels than the 800X600
AND, 1280 X 1024 pixels has 109 % more pixels than the 800X600.


Question: Is that Linear to the human eye? ie, does 1280X1024 look
109 % better "or double" as good as the 800X600 ?? WOW!

ALSO, WHY do they have to downscale it ? for focus ? Why cant
the commercials display the 1280 x 1024 ??


Thanks a bunch !

I think that is because the hardware in that specific commercial commercial pj is not capable of outputting anything more than 800x600. They probably quote resolutions like 1280x1024 because they can accept that resolution from the source.

I may have put it too simply. A DIY or commercial PJ is limited to how much information it can display by the physical number of pixels in its display device. If for example the DIY PJ had a native resolution of 800*600 then that is all it can display. The same goes for an 800*600 native commercial PJ. When we feed a higher resolution, 1280*1024 or some other non native resolution, into either of these PJs there is a problem, there are simply too many pieces of information to fit on the 800*600 native pixels. So an algorithm is used to get rid of the excess information and it is lost. So it is better to use a PJ with a higher native resolution you get more information on the screen. So in your example above where the manufacture says it can display a 1280*1024 resolution image, they are only saying that it can accept this resolution but it is still only able to display 800*600 and the algorithm discards the excess.

DJ

I've just had a look through our supplier's catalog and by far the most available are native XGA res (1024x768). The first one I came across to have a native High Definition res (1280x720) is a DLP at $6000.00 RRP, it has a lamp life of 3000 hrs (in standard mode) with a replacement cost of $690RRP

If you make your PJ properly and have the room to place it optimally then you can make a HD projector for about the cost of a replacement bulb, or not much more. Brightness might be the only thing that you lack, although with all the improvements going on these days here that may not be a problem for long.

I hope the brightness is not an issue for long, but it certainly makes a huge difference now. I have both an 800*600 commercial pj, and a LL 15" pj. The commercial is so much more useable because of the brightness. The difference is so huge between the two in brightness, that I can not imagine it changing that easily. It makes such a difference that I use the 800*600 commercial more often than the LL. With regular tv, the difference in image quality is not noticeable as far as resolution. The LL does give a slightly smoother image with DVD movies, as long as the movie does not have dark scenes. The other trouble I have is with the lack of adjustable throw. That will be improved if I do a ceiling mount though. Right now I figure the 15" xga LL pj to be about $650-$700. Very useable xga commerial pj's are around $1100-1200, so the 15" still has some value to it. If you go to the 17" you really increase the cost in lenses, as well as the size. Hopefully folded designs will help this. There is an LCD 1280*720 commercial pj available for $2000. Obviously the cost of the bulb will be more than with the LL. I have found them to average around $350 for about a 3000 hour bulb. I am happy with the idea of the 15" LL pj because it has good value still. However, I think that an xga commercial pj will give a better image and useability than a 17" LL due to differences in brightness, adjustability of throw and ease of keystoning, size, and much closer cost. Also, with what I have seen, an HD image compressed to xga res will not look much different if at all than with true 720p in any picture up to 120". Its like putting HD on a 21" tv. It is too small to tell much of a difference. Then you add tha fact that a commercial is so much easier to use, and there is no external ballast present, and it has some added inherent value. Of course the bulb cost difference still remains. However, two bulbs used 3 hours every day will last around 6 yrs, and that is a lot to use a pj. My point: simply that the 15" LL is still the way to go. You will get a res that when compressed will show excellent HD, looks good for the size picture our brightness will allow, and is still a strong value compared to commercial. I would wait until the brightness issues are vastly improved before I spent anymore than a 15" LL costs on a DIY. After that, the 17" may then be a worth while project. This is all of course what fits my useage for a pj, which is for movies, tv while shooting pool (which requires that some light be on), and for xbox.

Two bulbs cost $600-$1400 dollars. That averages out to $100 to $230 a year...just to watch your projector 3 hours a day. I don't know about you, but my family watches our pj constantly. We use it for TV and movies and games. And we watch it with the lights on in the room.

Keep in mind that your DIY pj may not be optimized. The problem with DIY is that the quality is very susceptable to individual builds. With commercial you don't have this problem.

Personally, I have to agree that if you are not a very good DIY person and you only plan on watching an occasional movie with it then you may want to seriousely consider a commericial pj.

My pj is fully adjustable for lens position and bulb position. It has been tweaked and adjusted considerably, with good improvements from the original result. However, it still does not compare in brightness to that of the commercial pj. I am not trying to say that it lacks value completely, but if brightness was not an issue acrossed the board, it would not be a constant topic in the forums. Just look at the DIY screen threads that say our pj's are "lumen challenged" and that certain screens won't work because of it. I simply think people should be well informed to the benefits and negatives of the LL pj before spending this much money and time on the pj, as well as when trying to decide to go with a 15" or 17" as the cost differes quite a bit.

After much research into commercial bulbs, I would say that the avg is $150 to $600 with the $150 and $600 being much more rare cases. That does still leave the cost of a bulb at $350. However, I got my pj for $500 brand new. That plus a new bulb for mine is $800 (replacement bulb for mine is obviously $300). That is $800 for 6 yrs worth of pj.

For me, with little kids, it is easier to ceiling mount the commercial pj and shelter it from their activities. For others who have a problem with the couple hundred dollars cost difference between LL and commercial, a room setup with good light control, and no worries about the size of the pj, than I think the 15" LL pj is a great option.

Heh. I have kids too.

In part, the one chunk outlay on a commercial projector isn't going to happen for me. I can buy parts here and there, and get the same.

The 800X600 res on a commercial projector that would come in the same total cost range isn't acceptable to me. I use my projector from my computer all the time, and an 800X600 desktop would make me insane. Downsampling text isn't an option, that would make me crazy too.

Did I mention that I use my projector all the time? The lamp cost would prohibit me from doing that. If I had to replace the lamp every year (About right for my regular usage)

I use my projector for TV, movies, PC games, and just generally as a PC monitor. It can get up to 60 hours' use in a week. The kids get to watch stuff on it as a treat. It's big enough that they can't lift it, so it doesn't need to be out of their way. About the only time they come near it is when I'm letting them watch something on it.

So for me, DIY was the only viable option. If not for DIY, I would not have a projector.

Supra,
For those reasons, and those situations, LL is a great site. It works great in certain situations. It does, however, have its limitations. I just saw a commercial xga with a 5000 hour lamp for $1100. For some people, that will be a great option, for others it will not. You do not have to convince me that the LL has significant value. While I do not like to see people down play the value of LL, I also don't like to see people ignore its short comings, so everyone who does it knows what they are getting into.

Rumple,
By the way, to further answer your question, all of the makers of the LCD's that we use to make our pj's also state both a native and a max resolution, just like the commercial pj's.

LL is an excellent site, and the DIY pj is constantly improving. Hopefully that trend will continue, and the DIY pj will become the ultimate pj overall. For now though, know your needs, the strengths and weaknesses of each, and make a decision that works the best for you.

I think one of the things that seems to be missing from this conversation is the value of the "DIY" part of the project. Ever seen a Heathkit? They cost more than a quality component of roughly the same make, but you can say you did it yourself. Thats a hell of a thing in my book.
My family is a video oriented family, so we use a considerable amount of time witht he TV on. I actually built the PJ as a substitute for the smaller TV we had. Then my wife surprised me with a big screen. Nice. The bulbs however are a seperate matter. Even with one of the lowest cost consumable ratios, I would still rather have the PJ on. They both use about the same wattage but I can get a whole wall full of resolution like that of my TV. 20,000 hours for 45.00 compared to 3000 for 280.00 ( that .002 cents an hour versus 10.7 cents for the commercial) the LL PJ uses less electricity as well.
But the best thing is, I built it ergo, I can fix it, service it and upgrade. I cant quite put a measure of value on being able to do that. The WOW factor with the friends doesnt hurt either.

Yes, the LL design still has lots of bugs to work out, but its not a static design and it can be upgraded, rebuilt whatever. Possibly it might not be a bad thing to have a Pros and Cons section in either the public forums or the write up. I am ultimately happy with my design and I didnt feel LL left anything out.
Im with you on the evolution of the PJ. New developments are happening all the time. The new reflector seems to make a huge difference in lighted room viewing and Im sure other developments will crop up.

Basically the way I look at it is like the difference between a condo and a house. With a house you can do anything you want with it, with a condo you are chained to someone else to fix things. I kinda like the house.

SJ.

Just wanted to point out that all these calculations of bulb costs per years used seem to be not factoring in the bulb you get with the PJ. So if you have 3000 hours bulb life and you think you will use 1000 a year (whic I would guess is average) you don't need to buy 2 bulbs for 6 years, you only need to buy if that.

Remember that while your bulb may last 20,000 hours you probably won't get more than 6-8,000 on it before the technology is old and or you decide to upgrade to something else. Yes a car might be so solid that it lasts 800,000 miles, but most people will be buying something to replace it long before that mark. Unless your projector is replacing a 19 inch CRT from the mid 90's or earlier you probably aren't the kind to have technology long after is current. And when it comes time to upgrade I think it will be easier to sell a "used but great condition SP4805" than a "LCD projector I made myself and comes in a heavy MDF box".

I wanted a projector years ago and I would say about 3-5 years ago retail projectors were simply too expensive for what they offered. But with very good HT projectors like the SP 4805 comming along at as low as $500 for a refurb or $700 brand new it's hard to say no.

I was originally looking into making a small pj from a PSone screen (since my throw is only 12 feet) but the 4805 caught my eye and some things about commercial PJs just made it too hard to go the DIY route:

1 Inputs - I have a lot of things I want to plug in and they very in terms of input, I have component, DVI, svideo stuff and the convenience of having all the inputs and control them all via remote is great. Getting that to work on a DIY one seemed like it was going to be a lot of trouble and cost.

2 Simplicity - I love DIY as much as the next guy, but my house is literally cluttered with projects that are always a work in progress. One big problem with DIY is there is never really a finished... it could alwyas get better. When I factor in the large amount of time I would have to put into it all (especially considering I live in an apt without access to many big tools or much space) it would probably increase cost and if I figured I paid myself $7.25 an hour (minimum wage) plus travel expenses it would greatly cut into my savings...

3 Size - I have very limited space to work with and one major seller of the PJ method to me was that it took so little size. A wall mount for me was made out of an old tv wall mount and my screen is a piece of vinyl coated mdf. My whole room is opened up, I don't have room for an MDF box conveniently anywhere.

4 DLP - LCD contrast ratios in retail PJs are getting close to what DLP offers, but in DIY Pjs I think it leaves something to be desired. I am a sticker for detail so a sharp high contrast DLP is what I am looking for (since I can't afford CRT) and I just know I would always be a little annoyed at the LCD picture in comparison (I am like that). Rainbow effect and whatnot I have looked at lots of DLP vs LCD projectors (obviously retail since I don't think DIY dlp is really an option) and I just couldn't take the washed out blacks, especially when watching anamorphic movies where the black bars were grey.

The main downside of commerical pj?

Cost obviously.

Yes the $350 bulb does put me off quite a bit, but I figured it out, at 3000 hours rated (I use low power so expect probably 4000 hours actually assuming my GF doens't keep striking the hot bulb >:( ) that's about $.10 an hour... not really that much when you look at it that way. Sure if you use the pj a LOT it might add up faster but you still are getting decent value for your money.

So options were:

DIY - source parts, take on DIY project with limited supplies and probably end up spending pretty near what I would have for the retail PJ, have great learning experiences that are also frustrating mistakes and proably not have a really good working PJ for days, weeks, months even...

Buy a retail - pick it up today, plug it in, turn it on and good to go for about 3 years (my useage dictates it should go about 3 years for me if the bulb lasts it's expected life) have a nice widescreen DLP.

And even more so with HD advancing as fast as it is and prices for true (720p/1080i) projectors dropping as fast as they are and the promise of LED projectors increasing bulb life and decreasing cost I don't think I will be holding on to this PJ any more than it's initial life. I think probalby in 3 years or so if my bulb is still running I will try to sell off this PJ somewhere on ebay or something, recover a few hundred bucks and put it towards a new super uber whatever that is out then. Sure it cost money but I figure $1000 every 3 years for great home entertainment ease and value is well worth it. After all it comes out to $330 a year which is about what I spend on haircuts!

So you can look at the numbers very statically:

Absolute cost of material vs cost of retail pj

or you can look at it factoring in how much work there is involved (yes it's often fun but it's still work and it is almost garaunteed to come with some frustrating pitfalls) and the fact that especially those that DIY are always looking at the newest and next best thing and just take it as sort of renting entertainment value over years or leasing or something like that.

4 years ago I bought a 36 inch CRT HDTV and 5.1 surround sound system on employee discount for about $1500. Just sold it for $1000 and bought my 4805, Onkyo LR552 and a set of Onkyo HKS SP240 speakers for that same $1000 and this will all last me at least 2-3 years.

So for $1500 I have got myself 6 years of home entertainment which wows all my guests (the 36 inch HDTV got a lot of wows and now when peopel come over I hear about how my living room is like my own movie theater - which it pretty much is) and keeps me very happy. I figure when I am getting bored of this setup a nice 1080i (maybe p) LED projector with 20,000 hour bulb life will be under the grand mark and maybe if I can score some deals I can get it for only a few hundred as an upgrade.

Oh and as for the original questino of resolution, some HDTV (or HDTV Ready sets) are really EDTV and don't handle higher resolutions at all (not so much teh case nowadays) and it was a bummer to get home and find out you couldn't play 720p xbox games becuse your tv didn't support that res.

Actually making more pixels of course costs more (that's why an 800x600 lcd will cost less than a 1024x768 of the same size) as you simply have more dots to account for and there is a greater chance there will be a flaw rendering the whole screen useless, more dots means more chances to go wrong.

So instead of upping costs they simply downscale the higher res image, you can still view it, it does look slightly degraded (however 1080i and 720p HD cable still looks stunning to me) they simply put in scalers to make it work with the cheaper hardware. I have seen some 720p projectors next to a 4805 (which is a 480p) and to be honest they looked about the same with the 4805 even pulling ahead of some due to a really good quality scaler.

Not trying to fault anyone for going DIY but there are a lot of aspects to consider.

Dev,
I agree with you on a lot of levels. A lot of what you said is what I have stated in other threads. However, the LL will fit some people better than commercial, and just the opposite. I do also agree with samurai that the DIY part of it is very COOL. I do have to say though, that when I showed a lot of people my finished product, the common response was, wow thats cool, but i didn't realize it was going to be so big.

One other thought. Everyone talks about resolution, but you have to remember that an LCD shows the screen door effect much worse than a DLP. My 800*600 commercial pj shows less screen door at the same size as my LL LCD pj at 1024 * 768. Just know what your purposes are, and make a good decision before deciding which way to go. They each have their own positives and negatives.

With my theater room done now, I have had a lot of people over for movies.

And all they want to talk about is my projector, how I did it, how I got the picture to look so good, etc, etc.

I don't think I would be having this much fun with a hobby if I said , "Hey look at my $2000 projector from Best Buy...

Sometimes with things like this it matters who your audience is. I used to do a lot of work in video compression, other engineers knew how hard it was to compress video, and still have it look pretty good when transmitted over a modem (33.6Kbuad), but regular people (nonengineers) expected to see regular ole TV quality and had no concept of bandwidth and why couldn't it be as good as a 10 year old TV. If you have friends and family that like to create they will see the work involved and be impressed others who just buy everything don't see the difference in working for months or running to BestBuy to swipe thier card and bring back a 60" plasma. Its the same difference as people who would rather buy a new BMW than rebuild an 69 Mustang. Not that either one is better tahn the older just some people have different values.

DIY is best for some and commercial is better for others.

There are significant opportunities to build exactly what you want with DIY, higher res, match furniture, place the box exactly where you want etc... but if you are happy with the commerical and all the extra features then maybe thats even better. I like the challenge and wouldn't be happy with even a standard LL PJ so I've been trying to make something different and maybe even a little bit better.

Well put pagercam.

I have done both the LL PJ and commercial Sanyo Z1. I was pretty happy with my LL PJ but situations changed and I didn't have the space. I needed something small and I only use my PJ to watch movies so the bulb expense really doesn't matter to me. It was fun to build the LL PJ and I still lurk the forums daily even though I don't currently have a DIY PJ because it is interesting and I like to see what discoveries are being made.

In my opinion anyone that says the other is an idiot for their decision(commercial or DIY) is probably either jealous or just bullheaded. The pros and cons of each have been laid out on the table several times. If you weigh them to your needs and decide then you made the correct decision.

Again, I agree with BB. Just make sure you know your needs, your future setup, the pros and cons of each, and make an unbiased decision.

For me the LL experience has been great. I spend countless hours lurking these forumns.

Wouldn't trade the experience for the world

For me though what truly seperates great home theater experience from mediocre isn't LL vs commerical.
As stated I think both have their advantages.


It is the quality of your AUDIO!! That's where DIY truly has a HUGE advantage. YOu can make a $2000 dollar system with a sub-woofer that will blow your doors off for like 600 bucks.

Mantis,

Just a quick question. Have you removed the anit-glare from your 15". If so do you think it vastly improved the brightness, or only made a slight difference?

Thanks

I removed my antiglare. I would say it improved the brightness a little because the light goes thru the panel easier. The real difference is in the clairity and color saturation. In this area it makes a very noticable difference. I think it is a good mod.

I have not yet tried removing the antiglare.

Ok I have to say I haven't posted on here, but the brightness issue has me puzzled. I didn't have a LL projector although I'm working on one now, but I did make one with a 2600 lumen OH projector, and I've seen commercial projectors and they weren't that much brighter than my OH projector design.

So I just don't get how even a DLP commercial can be THAT much brighter than a LL when the LL is starting with a 36000 lumen BULB!!!!

I mean if a 360 watt OH projector bulb that produces 2600 lumens can give me the quality of projection that it did, I can't see the LL design not rocking the socks off of anything else..

Jaden,
The LL starts with a 36000 lumen bulb, but much of the light is lost before it hits the screen. Only the light going forward or reflected can be used and the lenses and LCD filter out light. Most 15" LL pj's are getting somewhere around 200 lumens, which is about what I would say mine gets. My commercial pj is rated at 1800 lumens at high power, and 1100 at low power. If I turn on my LL and my commercial, the LL picture can't even be seen because the extra light from the commercial washes the LL image out. I am not sure what commercial unit you compared the OHP to, but many older models only have 200-500 lumens. Most LL's are propbably at least as bright as the OHP models, but no where near as bright as currrent commercial units. No one really argues that here. A commercial is definately brighter. That doesn't mean that the LL can't give a good picture, it just needs a more light controlled room, and sometimes suffers with dark scenes. This does vary with build quality though. Good luck.

I hope I'm not straying off-topic with this. I've been lurking these (and other) forums for quite a while. Can you share your opinion on the resolution subject?

Is it possible and/or feasible to make a DIY HD (720) projector with short throw - around 10-15ft and screen size of around 60-70"? The reason for short throw is obviously small room dimensions (as a student I don't get to live in large ones) and reason for small screen is the same plus hoping it would be brighter than 100" image. Or is this all just a pipe dream and I should spend my time earning extra money in hopes of being able to afford a decent commercial projector that could display 1280X720 image without much deterioration?

A 17" LL pj displays 1280 x 1024, making 720 p entirely possible. This will of course require a larger box than the 15". The 15" is 1024 x 768, so 720p would have to be compressed to this, although it would still look very good. The lens for the 15" is an approx 1:1 ratio for distance away from the wall to actual screen size, so those dimensions would not be possible. I believe the pro lens is 1.6:1, so that would be better, but still not able to do 60" at 15'. That is a limitation of these pj's.