Home made projector!

[Gizmo]

Originally Posted by Chernobyl

Any help on using the spray gun will be gratefully accepted

Umm...........make sure the nozzle points away from you?

[danrok]

You'll still get some wastage using a spray gun, the paint will stick to the internals and has to be cleaned out after use. Needless to say!

I used to make projection screens which would be part of a stage set for conferences.

This is the stuff I used:
http://www.rosco.com/uk/screens/roscoscreen.asp

They have offices around the world:
http://www.rosco.com/

"Front White" would be most suitable for a home projector using front projection.

You can buy a simple roll of it, or get them to cut it to size. They can put eyelets around the edges. That way you can attach the material to the rear of a wooden frame using elastic, so the screen will stay taught and the eyes and elastic will be hidden.

I had a little preview theater at work. In there we had some silver screen. That's the best stuff, it has tiny particles of silver which reflect the light. Expensive stuff though. No longer used that much since projectors are more powerful now.

[Chernobyl]

Thanks for the useful (lol @ Gizmo) info.
It didnt go very well!

It seems the spray gun I was given is erm, not very good.
At first, under test, I couldnt get a steady spray of water to come out, it was constantly pulsing. After taking it apart and cleaning it thoroughly, it gave a nice water spray but only if using a narrow spray beam.
Turning the spray beam wider resulted in very little water coming out.
This was despite trying to use over twice the recommended pressure (26 psi recommended, I tried up to 50psi).

I thinned the paint to 10% water, the max recommended, and no paint came out just air. Seeing as the tub of paint was already opened I had to keep trying.
I gradually thinned it more and more until it was 20% water and a fine paint spray came out with a very small paint spot of a few cm's. I cleaned the gun again and it made no difference. In all it took 1 hour of spraying to use 1/4 of the paint from one of the 3 tubs!
It was impossible to see where i had sprayed despite keeping the gun only 4" away from the surface (the recommended is 6 to 8 inches).

My screen looks a bit blotchy now which I imagine will settle over the next 6 weeks but I'm finished with spraying.
I would roller the paint on but I have no flat walls so wont be able to get even pressure.

Hopefully the shop will take the remaining 2 tubs of paint back and then I can get one of those high gain screens

[Chernobyl]

I have done a bit of research to see if I'm really doing the right thing getting a glass beaded screen.

High Gain screens
All of the higher gain screens (above 2.0 gain) have a cone of visibility.
A flat matte white screen (gain 1.0) has a viewing cone of 180 degrees, whereas the glass beaded designs (gain around 2.3) have a cone of 30 degrees or less.
There some very expensive screens that have a slightly larger viewing cone but is this really needed?
(note: the centre angle of zero degrees is the direction of light coming from the projector This hits a glass bead and reflects back to the viewer to give the viewing angle)

Many screen reviews only concentrate on using a ceiling mount projector.
Often the angle from the projector to the screen then to where you sit is on the boundary of the viewing cone and as such projectors mounted this way do not get the best from directional screens.
The best way to use the high gain directional screens is from a desktop projector which is exactly the height of my projector, superb!!
(Because the home made projector has no keystone adjust functions, the lense is pretty much at exactly the centre of the screen)

So a glass bead screen is perfect with my projector for the person sat in the centre of the seats but is it good enough for people sat at the side or on the floor?
A common mistake I have made is to imagine the centre of the screen or the perpendicular (90 degrees straight out) as the zero degree angle but this is not correct.
To go over an earlier point:
Zero angle must be taken as a straight line from the projector lense to the point/bead on the screen you wish to know about.
So the angle between where you are sitting and the projector lense (to any part of the screen) is what matters.

Lets take for example an extreme position, the person sat opposite the far left of the screen:
looking at the far right of the screen, the projector lense angle is quite close to the viewing angle so there will be no problem there.
looking at the left of the screen (straight ahead) gives the largest angle between the projector lense and the viewer, this must not exceed 15 degrees to give optimal gain and indeed it is under, magic!
The viewing angle for people sat on the floor in front of the sofa to the sides of the projector is easily within the 30 degree arc so it looks like this screen will be good for all my uses.

An added bonus of using a directional screen will be the ability to use it during the day with curtains open. The light will be reflected back towards the window in a 30 degree arc, nowhere near the optimal angle to see it.
That will be a huge bonus!

So how itchy is my buying finger going to get, can I hold out ordering a screen before I send the paint back?
They have stock of a screen even bigger (3.0m) than mine (2.5m).
hmmmmmm

[Chernobyl]

Had to do it!
I ordered this
http://62.75.177.102/shop2/index.php...oid=67&skat=28
120", 4:3, radio controlled, glass beaded screen!

Translate the page with this (German to English)
http://babelfish.altavista.com/



cant wait

total price was £150 (216 Euros) with insured delivery, what a bargain!
(they contact you to let you know the quoted delivery price is incorrect, wait for an email before paying)

[Daniel ~]

I hope it comes through for you! YOU EARNED IT! ":O}|

[Chernobyl]

Cheers

I realised something today that has taught me why its bad to work when tired.
My angles are a bit out, I mistook 90 degrees to be 45 degrees so the screen may not be viewable at high gain from all seat positions.

I have discovered a nice picture showing the gain curves for some screens on sale (see picture).
The Glass bead graph shows that with a 40 degree cone (20 degrees left/right) the gain is still 1.0 (higher than my current big screen!) and drops off quite slowly so the screen should still be pretty good. I'm dead eager to see how it performs.
The screen should be here next Thursday fingers crossed.

I took a some photos in last last few days of the current big screen before I made it blotchy
I'll load them off the camera and post em...

[Chernobyl]

The first picture was taken with a flash, you can just see snooker on the screen.

The second one is the screen in use and is a perfect demo of why i havent bothered taking photos of it. It doesnt look at all impressive on photo, yet in use its not bad at all !

The last one looks great with the flash.
Its how badly the spraying went. While spraying I had no idea where I had already sprayed and am surprised it was that good lol.

Edit:
the writing on the screen in the last picture is from the projector which was still on in the vain hope it would light up where it was already sprayed.
For reference I am sat 4 metres away from the screen.

[ibanBCN86]

Hi! This is my first projector, I've purchased a iiyama prolite E380S for 46€ (I thik it's a good price), I've read that this is a good monitor and easy to strip but what about the OHP?, do you think it worths paying money for a OHP with triplet lenses? or single lenses are enough good. how many watts I need to have the best results with my iiyama? what kind of bulbs? thanks!!

[ibanBCN86]

Hi , it's me again, what kind of cooling system do you recommend? thanks and sorry for all the questions, xD I'm newby on this

[Chernobyl]

Hi Iban, welcome to the project.
the LCD you have is the same as mine, I like it
Damn good price you got too!

Which OHP you get depends on quite a few factors.
Are you going to replace the bulb with a 250W Metal Halide as I have?
(ps you must get a decent rear reflector too if changing the bulb)
If not, standard 250W OHP bulbs are not really powerful enough so you would really need a 400W OHP.
The original bulbs generally dont last long and dont do the colour blue justice but can still be quite presentable.

If you dont have a triplet lense system then light will be wasted.
The extra lense on a triplet (over a doublet) sits just above the bulb and gathers radiant light that would otherwise not go toward the screen.
You can add a triplet lense yourself as long as you can make a heatproof mount for it and have enough airflow to keep the original bulb cool (they run much hotter than metal halide - in fact even with a metal halide I use an extra fan inside the OHP to circulate air).
The site I mentioned a few posts earlier sells the lenses quite cheaply. In fact they sell most of the kit to build your own without the use of an OHP. I dont recommend the 8" screens they use though as they are low res.

It is essential to keep the LCD from getting too warm.
The warmer the LCD is, the more it is affected by the light passing through it. The LCD gets a temporary burnin from static pictures that on cold days is unnoticable but in the summer can take a whole day to go away.
A normal 400W OHP bulb does run very hot (unless it has a cooling layer) so you must provide decent cooling to the LCD.
I have 2x80mm fans running at 5V blowing onto the top of the LCD.
You must filter the air or you will be cleaning it quite often. I use a wire mesh with ladies tights stretched over it.

I bought a 400W triplet lense OHP and after replacing the bulb, temperatures dropped a lot. Thats the method i would recommend but if you have decent DIY skills, theres no reason to go that route.
You can get a singlet lense OHP and add the other lenses in yourself, but you WILL need the other lenses if you dont want to waste light and have a more unform looking picture.

Another thing to watch for is the quality of the lenses on some OHPs seem to suck, ie, you cannot get uniform focus across the screen.
I cannot give any advice on what will be a good OHP to get good lenses as it seems there is a bit of pot luck involved.
My OHP can focus very sharply on either the middle or the top/bottom.
I use a focal point between the two so the whole screen looks the same. Its easily good enough for 1024x768 res but might struggle to look good with higher res (not that it matters with the LCDs we have).
Ultimately you can change the focal lense to fix the problem, that site again sells decent focal lenses.

You would also be wise to get an OHP that has colour tone adjustment. This raises the bulb platform up/down so that the colour of the edges of the screen can be matched to the centre.
If you are changing the bulb to metal halide, this platform is extremely convenient to find the postion for the new bulb and also provides a nice easy way to mount the bulb too (they are very different from the standard bulbs).

Good luck
feel free to ask more if needed.

[Chernobyl]

The screen arrived today yippeeee
But it is broken!
The screen lowers down but wont go back up.
At the moment its sat way too low for correct use and I darent open it up to raise it manually until I hear from the supplier.

I can give an appraisal of the screen and its really good and effective
The surface is made of glass beads that are so tiny I'm not really sure that I can see an individual one. When looking closely at the screen surface, it looks like its made of tiny flakes and this may be what it really is made from.

The claims for its gain are misleading.
There is a claimed 30 degree arc where it gives a gain of 2.3
The arc is literally a couple of degrees only and can therefore be completely ignored as nowhere I sit allows me to get that gain.
Going beyone those few degrees though gives a gain of about 1.5, I would say, that is uniform over the whole screen. Light from the window affects the picture just as much as the other screen so the glass bead advantage doesnt appear to be there.

The screen has a slightly blue-er tint to it which is great to be honest
Colours look bright and vibrant and the image quality is superb.
It is a lovely screen!
The screen size has been taken to about 2.7 metres diagonal which is about the maximum to keep the picture bright enough.

So the screen is good
I'm waiting for the supplier to reply about it being broken.

[Daniel ~]

grrr I just hate it when that happens! But at lest you know your on the right track!

[Chernobyl]

Hiya
its taken a while to get back here as I've re-installed Windows and have been playing Oblivion on my new X1800XT

I got a reply from the chap who supplied the screen the very next day and he sent a picture of a screw to turn. Having turned the screw just 1mm, the screen now works perfectly, wahooo!!

I am sooooo happy with the projector.
The screen does indeed have an optimal viewing angle but the transition into/outside it is so smooth its hard to notice. Sitting anywhere on the Sofa is abolutely ace (techy term), outside that it still looks very good just a little darker but very watchable.

I still use a little brightness tweaking simply because I want as big a screen as possible
Ideally, with this screen I should have a max picture size of 2.5metres with no tweaks but I really like a 2.7metre screen so a very small boost to brightness in games and watching video is used.
I think thats great for a 250W bulb.


Now you probably spotted that I swore earlier lol.
I have bought an ATI card!!!
Having been a devout NVidia card user, it took a lot to make me try ATI.
What swayed me was the amazing performance and overclockers selling the X1800XT for £180 delivered!!! Incredible.
So for the price of an AGP 7800GS I got the X1800XT, an Asus PCI-e motherboard and a pretty decent Ebuyer 600W PSU (£20 unbelievable value).

Either the PSU or the motherboard has allowed me to get higher clocks on the CPU with air cooling (ditched the water cooler for now as I plan on water cooling the GPU instead later ). Previously I could get 2.6GHz stable, I can now get 2.7GHz stable with default 1.4V, fantastic!

The new ATI card has made a difference to the projector as it seems to favour brighter blue and not so bright red. At first I missed the nice glowing red from the NVidia card but am now accustomed to it. Blues do look smashing tho
The speed of the card is awesome but boy is it a trauma to overclock compared to NVidia.

With Nvidia, install coolbits2 and tell the software to find the max 3D speeds and you are pretty much home and dry. On reboot, your preferences are kept.
With ATI you can either use the CCC software to give you either no clocking or a limited clocking experience (thats what has been reported) . I didnt install this as ATI have deliberately made it hell to use but went straight to NGO and got their version of the 6.4 Catalyst and some overclocking tools.

The main tool I use is ATItool which allows you to set the fan speed, voltages for memory and GPU core and GPU/memory clock speeds.
Now this sounds great but each time you reboot or play a game you need to reset the clock speeds, fans speeds and voltages.
Also using the automated tools to find the max GPU/memory speeds will crash your PC and then remind you after you reboot what speed it crashed at lol.

I used ATI tray tools for a while to set the fan speed but its awfully untrustworthy. The fan speed profile I made has suffered from being replaced with something I didnt create after reboot and in mid game Oblivion, the profile was discarded and replaced with something entirely dangerous (50% fan speed at very high temps). I couldnt get my original profile to load and stay loaded until I rebooted.
For those interested, I set VGPU to 1.4V, left the memory at 2.097V and clocked the card from 600/700 to 700/800. Max GPU temp is 80C at 70% fan speed (ambient 22C).

Another point of interest for the projector is using the SVHS in on the graphics card so I discarded my WinTV card and merrily plugged my video recorder (my TV tuner) into the X1800XT.
After setting up DScaler to the highest resolution, I wasnt too impressed.
It looks like its about 1/2 the vertical resolution which could mean that somewhere it is discarding the odd or even fields of the TV signal.
When viewing the picture in a small window, it does look fantastic but when full screen, TV looks low resolution and is not good enough.
So I plugged in the WinTV card and am back to top quality.

When using windows/watching TV, the card doesnt get at all hot and is truly silent. While gaming, the fan needs to be set to at least 70% speed which isnt so bad tbh. 80 to 100% speed is a little annoying if you want to overclock more but you soon forget about it as you get lost in the game.

The X1800XT is a great card but boy do ATI's drivers/methods suck!

[Gizmo]

Originally Posted by Chernobyl

hi Admins,
I have forgotten to come here for some time as it hasnt been so easy to get here.
I use Blocklist Manager and Protowall as protection. Unfortunately the standard blocklists from Blutack block your Website.
This is the message:

BLOCKED [!] - Destination is Everyones Internet, www.neededware.com, roings.c... (67.15.20.6) [Protocol: TCP - src: 2615 / dst: 80]

The blocklists are used on some gateways as well as on personal computers.
No doubt you will be getting less visitors due to this so thought you should know. I stop Protowall to visit here then turn it back on when finished.
It would be nice to press one shortcut to come here, I hope you can get yourself removed from the list

I am still working with the folks at BluTack to try to get us unblocked from their list. So far, the last response I have gotten from them was on the 13th of April, to the effect of "We will look into this when we get a chance". I have started a thread with them, here, and you can see the correspondence. I would encourage you (and anyone else with this problem) to post a very polite message there asking them to remove us from the blocklist. In the mean time, you should be able to add us to your exclusion list, without having to shut down the software.

[Chernobyl]

Hi Gizmo
super, I'm glad you are sorting it out, you deserve your internet freedom
I left a message supporting your request.

[Chernobyl]

They replied...

"Thanks for the reminder , should be out of the lists in the next update."


Looks like you will be home and dry

[dsio]

Tell you what, I would be extremely carefull with that 20 GBP 600W PSU.

[Favu]

Originally Posted by Chernobyl

They replied...

"Thanks for the reminder , should be out of the lists in the next update."


Looks like you will be home and dry

Hooray! Now that is good news

Originally Posted by dsio

Tell you what, I would be extremely carefull with that 20 GBP 600W PSU.

I have to agree on this one.

[Chernobyl]

Originally Posted by dsio

Tell you what, I would be extremely carefull with that 20 GBP 600W PSU.

yeah completely understood, I too am an evangelist of quality power supplies to prevent killing everything when it dies!
My last PSU is an Enermax 400W (now 3 years old) which annoyingly doesnt have enough juice on the 12V rail.
I havent found any statistics or information regarding how expensive power supplies die and how often which leads me to wonder if care is taken, can a cheaper psu be just as good?

Something about this one made me buy it.
You can check it for yourself here
http://www.ebuyer.com/UK/product/102587
Its £24 my bad

At a minimum I wanted certain protection standards which this one is advertised as providing:

# Power off component protection
# Over voltage protection circuitry
# Over current protection circuitry
# Short circuit protection circuitry

Also I have checked my max power consumption is 420W when heavily overclocked with the new kit so this PSU at 600W has a lot of headroom. This does reduce the chance of PSU component failure.
It must not be allowed to overheat which can happen easily with silent PSU's so I am maintaining decent case airflow and keeping the PC away from heat sources.
The PSU is quite heavy and has decent heatsinks inside which is a relief.

There is also the quality/stability of the voltage rails to be considered, especially as you near a rails max current. You dont know how good that will be until you get the PSU so I took a chance there. However given the higher overclock achieved with my CPU (and power draining overclocked ATI card!), I am happy that this PSU can supply a stable working environment.

My intention is to use this PSU for 2 years and then bin it regardless of its condition. At some time it will fail (as with anything) and the chance of that increases with time. Its fair to assume a cheaper PSU will die earlier so this is a safeguard.

What you dont get with a cheap PSU is peace of mind. If you want that I advise getting a "quality" PSU with a decent warranty.
Thing is, does the warranty on a PSU cover any other parts or just the PSU? If only the PSU is covered it doesnt inspire much confidence.

So yes, I have taken a little chance here but its an informed one