Ace_3000....pictures of Projector?

[Dazzzla]

Because I’m using a 17’ LCD the Fresnel’s have to be large so here is an alternative. It’s a compromise but I think with some fine-tuning I should be able to get it to work. If you look at the ray trace I deliberately raised and placed the lamp closer to the rear fresnel to spread the light slightly to compensate for the ring shadow in the second fresnel. As an added bonus this config actually improves Spherical aberration.

now the light only goes through the condenser and it seems fine so that has to be it,

What did you do to fix it?

DJ

[ace3000_1]

heya dazzla, hmmm i dont know where you got some of those drawings from but they dont look too right, tilting the lcd ones do but the frensesl ones arnt too correct.

The light that goes along a axis wont change its axis from a lens, only a prisim or a mirror can change the axis, and thats what give us lens shift, maybe you mixed that up with keystone, who knows but however with a top frensel tilted it wont alter the lights axial path, what it does alter is the magnifacation and thats what gives us the keystone.

The reason for the rings as ive stated in an earlier post is from the light traveling in a single given direction, if you could change the light rays to match the angle on the rings of the top frensel then you wouldnt get the ring shadow, although not impossible, in our diy world it is on the cheap, and honestly i wouldnt be too fussed about it.

A rule of thumb to follow is to always have the lcd panel perpendicular to the lcd, thats a must, i saw a drawing in there that wont work as it was out of paralelle.

Trev

[ace3000_1]

A small notice, for anyone who has emailed me in the last 2 weeks and wonderd why i havnt replied, is because my email has currently screwed up and all of them are gone, i have changed my email addy since, so those who would like to email me back feel free.

Trev

[Dazzzla]

heya dazzla, hmmm i dont know where you got some of those drawings from but they dont look too right, tilting the lcd ones do but the frensesl ones arnt too correct.

I drew them, what do ya mean not, to, correct
Just joking and you’re correct they are not 100%. The software I used is meant for drawing house plans so it's a real pain to use for ray traces. The rear fresnel is right out of wack, I rushed it hoping you wouldn't notice, Bugga.

A rule of thumb to follow is to always have the lcd panel perpendicular to the lcd, thats a must, i saw a drawing in there that wont work as it was out of paralelle.

If you mean the LCD and lens, then I have to disagree. Tilting the lens with regards to the lcd will compensate for spherical aberration intoduced by the tilted second fresnel.

DJ

[cohort36]

I've been away from the boards for awhile, so I don't know the latest developments, but are your plans available for sale yet?

[Dazzzla]

With a lcd of 381mm and fresnel fl of 220mm, the beam angle required by the fresnel would be about 81 degrees and the angle of incidence would be half this, 40.5 degrees. When light strikes a lens it can do two main things, refract or reflect. The thing that determines how much reflection and how much refraction that will occur, is called the angle of incidence. As the angle of incidence becomes bigger, more light is reflected and less refracted until a point is reached where total reflection takes over, this is called the critical angle and its value is about 41 degrees. So in this situation you’re at about the most efficient position without using a condenser. Condensers a good for improving the situation when the fresnel fl is larger than half the its dimensions, as in Ace’s setup.

I have to make a correction to a post I made a few pages back. Most of it is correct exept for the part about total reflection and critical angles. This only acures when the light leaves a high density material to a low density one, in other words when it leaves a lens as opposed to entering it.

oops sorry
DJ

[botcolon]

I know this has been posted before but are the plans available ACE? Really wish to start my new project.

botcolon

[ace3000_1]

I know this has been posted before but are the plans available ACE? Really wish to start my new project.

Heya buddy, put it this way, they are done in a way lol, they are done on paper but not on the comp, i just have to draw them on the comp and then their done, ( not all just the lcd unit), the guide will be in a forum im making up some time this week, the drawing wont take long to do its just a matter of free time on my behalf, i want to get you guys going asap, like now! but ive had a real lack of time in the last month, work is catching upto me.

Im going to try and get the waiting lot of you guys going altogether in the one hit, so atleast that way i can show you what to do as you go along all together, to make it a breaze for you guys to construct it. Ill have the forum up before the plans with guides telling you how to bend the alloy so you can get some practise in before the comming days of the plans, about 2 days or so beforehand.

Trev

EDIT along with the materials list

[ace3000_1]

Dazzla, im onto you tommorrow, i havnt forgoten.

Trev

[botcolon]

Originally posted by ace3000_1


Heya buddy, put it this way, they are done in a way lol, they are done on paper but not on the comp, i just have to draw them on the comp and then their done, ( not all just the lcd unit), the guide will be in a forum im making up some time this week, the drawing wont take long to do its just a matter of free time on my behalf, i want to get you guys going asap, like now! but ive had a real lack of time in the last month, work is catching upto me.

Im going to try and get the waiting lot of you guys going altogether in the one hit, so atleast that way i can show you what to do as you go along all together, to make it a breaze for you guys to construct it. Ill have the forum up before the plans with guides telling you how to bend the alloy so you can get some practise in before the comming days of the plans, about 2 days or so beforehand.

Trev

EDIT along with the materials list

should I buy my 7" xga lilliput now then? its AUD299 + AUD50 postage. I assume I will need to pay oz import duty (10% isn't it?)


in anticipation...botcolon