I had some free time so I decided to make this panoramic image (only two images combined) of the room where the projector will go. As you can see I want to place the projector on the floor where the lamp is located. Therefore, the some work will have to be done to insure that the image looks alright on the wall.

1) With these lengths, do you think a 15" or 17" lcd would be better choice?
2) If I use the HYUNDAI L72S 17" monitor, will I be able to use its built in controls to make image look correct on the wall? Or will I have to actually adjust the lcd/fresnel angles inside?

Thanks

honestly i think you should got 19 inch, I did and you get a higher res at decent price there comming down fast, you can get a widescreen from newegg for 180 now, tigerdirect.com had a 19inch 1200x yad 8ms for 140 after rebate and my dewoo 19 inch works great!

when it comes to pricing its like oh buy a 15 for 100, 17 for 150 and 19 for 150-200 so might as get the most res for less money, might need a little bigger box but oh well right, anyway thats what i would do, I would go witha tower in your position as a box is about 3 feet long and you only have 10 and projectrs seem to really focus in at 7.5 feet so you will most likely need a somewhat upright model

-and paint that entire wall as your screen will take up pretty much all of it!

Using the throw calc, the pro lense has a focal length of 500mm-->19.6850394 inches
size of lcd: 17"
I want a size of image to be 120"

The calc says distance from projector lens to screen in inches: 158.64-->13.22 feet
As you can see in the above image, I only have 128 inches from screen to lense.

Am I inputing the correct focal length? Is there anything else I can do to get 120" on this wall?
It seems from the throw calc, that I can get a much larger image on the wall with the 15" and standard lense...Is this true?

Yup, your numbers look correct.

Basically two things control the throw (for any given screen size). The LCD size and the triplet FL. The smaller the focal length of the triplet, the smaller the throw for a given size screen, and the smaller the LCD, the longer the throw for a given screen size. For an example: 17" screen, 500mmFL triplet, and 120" screen gives a throw of 158"... if you change the triplet to the 320mm, the throw becomes 101" (158-101 = 57" shorter throw). If you now change the LCD size to 15" (using the 320mm triplet) the throw becomes 113" (113-101 = 12" longer) for the same 120" screen.

The 17" LCD with the 320mm FL triplet is probably pretty good for your setup as you'll need the 27" between the triplet and wall for your PJ... a vertical folded design would take up a bit less space.... the only problem is that you won't get perfect focus on a 17" LCD from the standard 320mm triplet... not good for web browsing, but OK for movies.

Something to think about...
I know you said you'd like a large screen (120"), but for your viewing position the screen size using the 1.6 rule, would be 128"/1.6 = 80" screen. Using a 17" panel, 500mmFL triplet and a throw of 112" will give you an 80" screen. You could hit a 112" throw using a vertical folded design, with the PJ tower sitting between the two seats. This would also give you a brighter image to combat the large sliding glass doors off to the left of the screen. Just something to think about...


cheers,
gs

I know for sure I don't want to do a vertical folded design.

It would be nice to stay with the 17" lcd plus it looks like if I plan on doing that, I won't be able to use the pro lense with my setup. Although, if I go with a 17" with standard lense, if I ever have more room, I could buy a pro lense. I plan on using the projector for everything, including gaming, movies, standard things like web browsing...so I worry that the only thing I will be able to use this for is movies if I go with the 17"+standard.

Couldn't I fix this temporarily by using the lcd controls to make the image on the lcd smaller? ...So it doesn't lose its edges..
Or would it be easier to just go with a 15" lcd (I really would like to avoid if possible)?

If you use a PC with your projector you can re-size the active area of the LCD to use only 1024x768 of the pixles on a 17" (1280x1024) monitor using a program called powerstrip. For an active 1024x768 area on a 17" LCD, the equivalent montior would be 13.3" diagonal. If you did this, using the standard triplet would be possible. Assuming you need 28" from the wall for the required box length a a couple of inches of "breathing room", you would have a 13.3" LCD, 320mm triplet, and a throw of 100".... this would give you a 92" projection. I'm not sure how you planned to mount the PJ, but floor mounting will require split fresnels to correct for keystoning. This will increase the image size (good), but it will also effect focus (bad for web browsing, ok for movies). This would allow you to upgrade your optics at a later date without having to change LCD's to get a higher resolution.

I didn't do it, but you could also calculate an equivalent resolution for a 15" LCD on the 17" monitor. (using powerstrip to run that custom resolution). The resolution would be higher than 1024x768, and your image would be larger.

cheers,
gs

I may build or buy a table to hold the projector so it wouldn't have to sit on the floor.

1) What fresnels should I be using with the 17" + standard lense? Will the standard frensels work from LL?

I see comp_atkins used some from 3dlens.com.

2) I need find a ballast (anything but the LL eBallast) for the LL65K T15 Lamp that will be safe. I wasn't able to find anything on the forums. It would be nice if it was around $70. Can anyone recommend one?

Yep, the 3dlens are the only ones that will fit. LL Standard only covers the 15"

anyone?

look into the M135 coil and core ballast.. $66.85 from hidirect.com. is the LL65K T15 a 135 or 155 bulb?

This one correct?
V90D7612K - 400 - M135 - 120 / 208 / 240 / 277 - CWA $66.85

Are you 100% positive? Do you know of someone that has used it with the LL65K T15 lamp? I need to be completely sure because I will be ordering soon.

I'm not sure if the LL65K T15 is a 135 or 155..
thanks

no I'm not 100% sure. The LL65K T15 would have to be an m135 or 155 pulse strike bulb. The only ballast I can be sure that this bulb works in in the LL eBallast.. but that ballast can operate a variety of bulbs

I know people are using the V90D7612K ballast on here with success, but I didn't come across anyone using it with the T15. I'm sure someone will comment on the compatability.. I'm curious as well.

The LL 65K T15 Lamp will run on an M59 ballast (probe start type). It has been discussed that an M59 lamp will also run on an M135/155 ballast (pulse start type), although there may be some difficulties starting the M59 lamp on an M135/155 ballast. I can't recall anyone doing this at the moment, although there have been recent discussions about doing it. The LL eballast will also run this lamp.

cheers,
gs

ok so a quick search returned that the T15 is in fact an m59 bulb as mentioned above, so you can use the V90D6413K ballast from hidirect.. keep in mind though, this is a probe start ballast, an old design. it will result in a less efficient system and shorter bulb life compared to a pulse start or electronic ballast.

What kind of difficulties? Seems to me something like this would either work or not work.



Well, I know I don't want the electronic ballast. I do want something I know that will be safe and efficient.

Looks to me like this is a job for a 15"/standard lens projector, like Pun15her's verticle design.

Why SupraGuy, why? Right when I think I have everything decided, I hear, "go with the 15"" AHH

The past few days I've decided, I don't want a 15" projector. I also don't like the veritcal design.

I can get Samsung 730b for a great price + it support Sync on green. I have plenty of space for a 17" with standard lense. Unless you can convince me otherwise, I will probably be ordering sometime in the next 2 weeks.

People are getting great results with the 17" with standard lense.

If I go with the pro lense, my screen will be much smaller. For now, I want a 17" with standard, so it will be easy to upgrade to the pro when I have more room. What do you think?

Electronic ballasts are the most efficent, and argueably safer as all components are self contained. But, you've indicated you don't want to use one of them, which is fine, I'm just pointing out the effeciency and safety aspects.

If you get the LL 65K T15 lamp, it is an M59 lamp (probe start), so my suggestion is to use a probe start ballast (M59). Tameone is correct in that probe start is an older technology, and pulse start is a new, more efficient design, but it has little to do with the ballast, and everything to do with the way in which the lamps are made. This means you won't see any benefits from using a pulse start (M135/155) ballast with a probe start (M59) lamp. Basically the difference in ballasts is the electronics required for lamp ignition are located outside the lamp for pulse start technology, while the ignitor is located inside the lamp on probe start. A quick goolge on probe start and pulse start will bring a plethora of information on the subject.


cheers,
gs

only if you build your box big enough. The pro lense will work best with a long FL front fresnel. the kit comes with a 650mm, but some have used 550mm.. this will require a box length of 40+ inches for a straight design.

I was in a similar situation as you are. The room I wanted to put the PJ in was only ~166 inches long. With a pro setup and a 42-44 inch PJ, I would only get 10-10.5ft of throw which would give an 85-90" image (my initial goal was 100"+). I was toying with the idea of a folded design, but after seeing all the problems with the mirrors, I decided to bite the bullet, order the full pro lense setup for a straight design.. Then when I move it to a larger room, I can increase the throw with no problem and get a giant image. 85-90" image is pretty f'n big when youre sitting 9 ft away

Why ? Because a 15" LCD using 320mm FL triplet @ 100" throw with unsplit fresnels will give you a 104" projection; and using a split fresnel design with 30mm between LCD and field fresnel will give you a 115" projection... which is pretty much what you want.

You seemed pretty convinced that you wanted a 17" LCD. If you use a PC and the powerstrip program you can run a 17" LCD with a special resolution of 1156x867, which is equates to a 15" active area on a 17" LCD... giving you the same numbers as I just mentioned above.

The question is, do you want to run a 15" LCD, or a 17" LCD ? ... and why ?

There are many ways to "skin the cat" ... at some point it comes down to your preferences.

cheers,
gs

I planned on using this projector for many things...games, movies, web browsing, using it like I use my own monitor right now, everything. I wanted a 17" (Samsung 730b) because I felt it provided the best response time plus I could get it for a great price. Also, I will be watching a lot of hd content 720 and 1080. I have a Dvico Fusion HDTV Lite in which I will be displaying a lot of over the air HD content.
1) I can get a lot better results with HD content if I go with a 17" over a 15", correct? AND, it will be better for gaming.



I'm somewhat confused now, if I were to build a projector much like comp_atkins:
He used the Hyundai L72S 17" monitor, external box dimensions are 30" long, 16" wide, and 14.5" high made out of 1/2" MDF, standard lense.

2) So...I wouldn't be able to use that same box size if I decided to upgrade to a pro lense someday in the future?

I believe he is using the standard triplet with fresnels from 3dlens.com. As long as the fresnels are large enough, you can use a 17" screen without scaling down the image.

The pro triplet and fresnels would require a longer box. like I said before, I decided to go with the pro off the bat and just take a bite on screen size (edit: projection size). I don't know if anyone is using the pro triplet with short focal length fresnels, such as a 330/330 setup.

I would be using the fresnels from 3dlens.com if I went with the standard lense + 17".


17" Samsung 17" 730b, Venture ballast, T15 lamp
Choice 1) standard lense, I will be in this apartment for atleast 2 years, so in 2 years if I have more room, I build a new box and put a pro in there.
Choice 2) pro lense, I have a smaller screen, I pay more, I don't have to upgrade in 2 years.

I cannot decide. Its too difficult.

1) TV and DVD with a 17" displaying through your Dvico will look better than a 15" due to more pixles. Assuming you are basing this on the 320mm triplet; surfing the web may be difficult/annoying/immpossible as text will not be in clear focus at the corners and center of the screen simulaneously. What do you mean by gaming. PC based games or Console based games ? PC based games run at fixed resolutions such as 800x600, 1024x768, 1280x1024, etc... this will all depend on the games being played. Console based games need a way to be input into your PC, does the Dvico have that capability ? Best results will come from a straigh through design with the center of the PJ aligned to the center of the screen with unsplit fresnels. Ceiling mount with split fresnels (for keystone correction) is a possibility, but your focus will not only suffer from using the standard triplet with a 17" LCD, the keystone correction will make web browsing (IMHO) impossible.

2) No. Upgrading to pro lenses will require the box to be lenghened by approximately 7.5-8". This is due to the larger FL of the triplet (500 vs. 320)... 500-320 = 180mm/25.4 = 7.1" longer focal length.

cheers,
gs

I only play computer games. If I ever want to run a console system, I will buy a comonenet to vga cable. The Dvico does not have svideo or composite input, although my Happauge 150 does.

It seems to me that if I go with the pro lense, I'm not going to get the size of screen I want. If I go with the standard lense, and I want to browse the web, couldn't I just use that program to scale it down to 15" on the 17" monitor? Wouldn't this take care of all the problems of annoying web browsing, etc?

I suggest you use tape and mask out a 90" screen, then a 110" screen on the wall. If you don't mind spending the extra money now, and you think you will be satisfied with the 90" screen, go with the pro setup now.

Gee, I think I've seen that advise somewhere before... Can't put my finger on it...

With the dimensions as you posted them, the 17" LCD still doesn't QUITE work with the standard lens. I also think that you don't really wasn as big a screen as you think that you want, but that's another issue altogether.

17" LCD + Pro setup will seem a bit small, after all it's just not possible in that room to put the projector behind the intended seating position.

17" + standard lens is going to be very large with the projector in the location that you indicated. While large is okay, there really does exist such a thing as too large. Seriously spend some time with the focal calculator, particularly throw/screen calculations, and go through the permutations.

What I came up with is that a standard 15" projector with standard lenses is going to be as close to optimal as I could ask for. Then again, I know people who do go sit in the 'pit' area at the movie theaters by prefrence...

haha maybe your wise words are permanently imprinted on the back of my brain

SupraGuy,
I normally do not go sit in the pit at the movies. I don't mind it though.

I really would like to stay away from a 15" monitor.

"17" LCD + Pro setup will seem a bit small"
If I had 120" from screen to lense, that would leave 40 inches for the length of the projector. I would get itleast 80" on the wall.
Is 80" considered small? 80" seems small to me.

"With the dimensions as you posted them, the 17" LCD still doesn't QUITE work with the standard lens."

I've seen people use the standard lense with a 17". If I want to use it for something other than movies, I can use that powerstip software and shrink the 17" to 15" resolution so the corners are clear...and if the image is too large on the wall, I can move the cart I'm building for the projector a little closer to the screen, right?

How doesn't it work?

Anyway..sorry I'm rambling on and on...its just too difficult to decide. The price of the pro lense keeps jumping out at me too. AHH

120" from triplet to wall will give you an 86.63" projection with pro lense, 17".. not small by any standard other than projector standards I will be getting between 86.63 and 91.81" depending on how far back I shove my pro-lense PJ when it's finished (120-126"). I can live with a 90" image knowing that when I move it to another room, I can make the projection huge.

refer to post #26. "You can do it" (The Waterboy reference) using painters tape. Look at it and decide. As reference: a 17" LCD with Pro Optics @ 120" throw (40" left for PJ postioning) gives a screen of ~87" for unsplit fresnels and ~91" for split fresnels with 30mm spacing (if keystoning).



As i've stated above the reasons why 17" doesn't quite work. Mainly it's focus issues. Once you have the PJ and screen dialed in you won't want to be moving it back and forth, you'll just want to turn it on and go... no messing around because you want to surf the web, then play some games. (IMHO)




I feel for ya man... all these decisions to make. An extra $200 may seem like a lot now, but it's well worth it in the end.

Good Luck !
gs