Hey Guys, I'm getting back into the swing of things and being able to use a large LCD now is great. One thing though, I figure you have to use the new optics with a 17-19" LCD does this mean that your projector has to be long throw? My next projector would be great with just larger optics but same distance. I'm putting this one on the ground and it's going to be closer (8 feet instead of 12). If anything I would want shorter throw than last time so I can get the picture to be the same size.

Thanks,
Jeremy

i believe the triplet will only view up to a reg. 17" monitor.

Hey Joe, yeah that's fine, I want it to be a 17". But the Long throw is a problem for me. Can I use the new optics without making it long throw?

And since I'm posting... This projector is on the floor so using a FS mirror to projector at a 90 degree, how does this change the keystone adjustment?

Thanks again,
Jeremy

you need the optics to match, on the new lens the focal length is 450mm to 500mm and the old field lens in 330mm which will be to short for it.

Also here is a simple design i did for using a mirror after the projection lens and will allow for better keystone control if placed on the floor. Let me know what ya think.

I'm sure that would work for some, But I need to use the mirror not only to make the projector project at a 90 degree angle but also to make the box alot smaller.

Basically I need the distance from back of the light to the middle point of the triplet to be no more than 25 inches. I reformatted my computer and will post a sketch of what I'm talking about when I get macromedia MX installed.

The new optics would give you a 74" picture from 8'.

So in other words, 59.2" W x 44.4" H to yield a 74" Diagonal 4:3 picture? That makes a worthless ~68" Widescreen. That isn't that big (to what I'm used to ). I have a 4' W x 3' H dry erase board that I use for studying. That makes a 60" 4:3, so I know how small a 74" would be.
So is this the best I can do? I would like at least 7-8' 4:3. Does this mean I can't use the new optics or a 17" LCD?

(BTW: can't find my MX cd :angry: )

What you have to keep in mind is that the 74" screen is the proper size for the throw. The lens is designed to make the perfect screen size to seating ratio. If you are sitting at 8' from the screen the largest you'd really want the screen is 74". If you used a 19" panel it would be bigger. If you built a vertical design you could get the projector farther back. The regular triplet has barely enough FOV for a 17" but you'd have to get the field lens somewhere else.

okay, now I'm confused... Okay I understand how most people wouldn't mind a small 74" screen but I've been watching 12' of heavenly goodness too long to cut that picture in half. The other thing is that I will have a 12' screen for a picture that is 6'2". Another, I am making basically an entertainment table. Half of it will be for all of my components (reciever, sat rcvr, xbox, ps1,N6,DVD player) and all my DVDs/Games with the other half being for the projector (or less than half). I'm cutting down on the length of the table by making the projector project at a 90 degree angle. However the end of the table will be approximately 8' away from the wall (triplet). How much bigger are we talking for a 19" LCD?

So to recap, I'm not going to build a vertical design. I will be sitting the same 12-14' away that I was before (might add a sectional) so I need something bigger.

As for this --^ Are you talking about the triplet I already have? Are you saying that I can get 74" out of the one I have or the new one? Also, what are you talking about by finding the field lens somewhere else?

I don't mean to be offensive with my comments, I'm just frustrated that there is no way to get the size I would prefer.

Thanks,
Jeremy

I don't have MX but I do have Autocad!!
Here is a ruff sketch:

[edit] the two measurments are 16.25'' and 48.5" and this is a overhead view

blue squares are legs and the red are divider walls

Wow looks like a cool project. A 19" panel would give you about 84". The regular triplet with a 17" panel will give you 112". If you need a field lens let me know with a PM.

i thought 10' was a relatively normal achievable size with the 15" lcd, yet you say the 17" lcd only yeilds a 112" projection? maybe im just getting confused with all the info ive read over the past 2 days, or maybe yall are talking about something other than regular projectors that im thinking of, but i was under the impression that a 15' projection is achievable using the new expensive optics and a nice 17" lcd

That screen size he stated was based on the throw distance that wqas given in that post. If you have the projector further back you will get a bigger screen. The idea of the new lens is to have a good viewable screen size based on your seating distance. Right now with the old triplet you would have a 10" diagonal screen with the projector lens 10' from the wall. The pro lens will give you a smaller screen size from the same distance with a 15" lcd. You could use a larger lcd and get a bigger screen if you like and take advantage of the higher resolution of a 17" or 19" lcd.

I was planning on using a 17" lcd to take advantage of the higher resolution. From what i've read, I understand the neccessity of purchasing the "pro" fresnals for the larger lcd, however, if i plan to place the projector roughly 7' from the wall would i run into any problems using the standard "old" triplet? Aside from the longer throw distance, i'm am failing to understand any other advantages that the new "pro" triplet has to offer. Could anyone kindly clarify the pro's of the new triplet and the cons of the old. Is having to place the projector closer to the wall the only drawback to the old triplet? Do i loose picture quality using the old triplet?

thanks a lot,
jesuspicture

was very much hoping for a response

With the new fresnels, you will need the new bigger triplet. It is varifocal at 450:500mm where the other triplet is 330mm. The old one is too small and you would basically lose alot of the image. This is why I'm just going to reused my 15" LV and old optics in my new projector.

Read Brainchild's second post on this page. The answer to your question is there.

Hi Brain,

So you're saying the current Triplet and Fresnel (if cut to correct size) will be enough for a 17" 4:3 LCD? Also, I didn't understand your comment about "requiring a field lens" - why would I need this? What does it do?

Thanks,
Neel

Field lens is the proper name for the front fresnel.

Thanks pagercam, got it!