I've got this idea to put together a folded 15" pj that can project toward the ceiling or the wall depending on mirror placement. it's still in the preliminary planning stage any constructive input will be greatly appreciated as I'm still grasping at all the theory.

Edit: I've taken a step back. going to keep it simple next time though....

Hi,justinstar77.
Nice to see some interesting thinking going on there.I think that I should mention at this point,one problem you may have...
To introduce a mirror into the light path,for the 90 degree bend,the lcd orientation needs to be reversed.To get a straight lightpath,you will need to remove the mirror from the lightpath.this will require the lcd orientation to be the opposite of when the mirror is in place.I cant think of an easy way to achieve an easily reversible lcd.Hpe this doesn't dampen your spirits!You have the folded lightpath diagram spot.I think,if I remember rightly,the projection lens should be 20mm? further back into the lightpath,and then have the ability to move an inch or so in either direction for fine focussing.(the 20mm is from memory,so don't quote me!)
Good work though.I hope you find a way of getting both lightpaths to work,it sounds like a great idea.
Cheers P

Thanks your pj was a source of inspiration. I think i'll use software for the screen flip.

Ive looked for software for this exact reason. Ive built my projector from day 1 with the ability to be stood upright and have a mirror placed after teh triplet. The problem I found was sourcing the software to do this. Let me know if you find anything.

Hmm good point. You'd think somebody would have written something like that as a practical joke already, or as a way to show off a video card.

Nvidia drivers have a function to do exactly this - rotate and flip the image. Just a few mouse clicks to do what you wish. I am pretty sure someone posted that he ATI drivers would do the same, so it should be no real problem.

Cheers,

Chris

Ah Ha! Good thinking.If the nvidia software is anything like the nvidia keystone software,beware of image quality,as soon as you activate the nv keystone s/w the quality drops noticeably!
I wuld check it out first if you can.
Cheers P (Thanks for the kind words!)

Here's another attempt at a folded 2 way without software.

Edit: Umm. that wasn't going to fly, atleast not with me at the wheel

Just had a look at my nvidia drivers, could only find rotate, not flip. Without looking at it in too much detail, I think a 180 rotate may work for you. Just tried this on my monitor and there was no decrease in image quality that I could detect. I suspect that the problem Pun15er found with the keystoning software is that the driver/card would have to effectively rescale each line of the displayed image and that the amount of rescaling would progressively change with each displayed line. As you are no doubt aware, as soon as you are not displaying an LCDs native resolution you will get a reduction in image quality. I suspect that the rotate function of the display driver is a different animal than keystone adjust and should not have the same problem, but I would share Pun15ers caution and say that if I were you, I would test the monitor/card/driver before committing to the design.

Good luck!!!

Chris

This shouldn't be a problem, flip and rotate and just that showing the pixels in another order. Image warping is modifying the pixels to show them somewhere else so there are less pixels and a lot of averaging so yes the image quality drops.

Sounds fair enough.I have no knowledge of the exact s/w,I was just going on my (very limited) experience.Pagercam knows his stuff.
Its all gravy! Go for it,justinstar77

The more I think about it it would probably be simpler for my first attempt at this if I went with an unfolded design and incorporated the 2 way idea mechanically. Like with a crank that rotates the whole box 90 degrees or better yet an electric motor with a push button for up and down. I'll still use aluminum if I can get my boss at work to help me out with the project since we make light boxes for back lit displays hopefully i'll only have to pay cost...or less

Here's the part list I'll be using
1- CMV520D 15" LCD from newegg.com $200
2- the lumen lab fresnel kit $35
3- a 290mm fujinon copy lens from surplushed.com $8
4- 89mm dia, 116mm FL PCX lens from anchoroptics.com $15
5- 250 hqi 5100k $ not yet purchased
6- Matching 250w ballast $ not yet purchased ---electric or magnetic / what's the deal with "flicker"?
7- A good reflector (not a bowl) $ not yet purchased ---any suggestions?
8- uv/ir glass shield $ not yet purchased
9- misc wiring $ not yet purchased
10-Did I forget something?

well i've emailed a couple folks about the horizontal flip feature that would make my pj a success and I think it should be easy to implement if they haven't already and we just don't know about it. I know it's an easily achievable goal in linux but i'd like to stick with a windows solution so more people can benefit. It would be so nice to be able to switch back and forth from watching on a wall to watching on the ceiling.....

My Ati Radeon card had a tab feature under the video properties called rotate, However the problem you will run into you also need to flip the image left to right.

Joe

I'm aware of the issue. Horizontal flip means left to right, like in a mirror. 180 rotate is pretty standard on vid cards. I know there's an API for this feature in OpenGL and DirectX, but how to turn it on is another matter, and i think it's an avenue that needs to be explored so finding a program to tweak vid card settings with this feature is one of my priorities. In linux it's easy because all you have to do is edit some config files like this link

Well I just spent an hour on the phone with ATI's tech support... they said i should look for a 3rd party product... yeah like I hadn't already tried google. and that they have no plans to implement this feature in future releases of the catalyst control center. oh well at least they know someone wants it. I'll have to start posting on the rage3d forums for an answer.

I found a filter in VLC for horizontal flip, and I think that's good enough since i'll mostly be watching movies on the ceiling and using a dual display setup, so once i have the $$ for the remaining parts I should be set.

I think i may go with a linux htpc setup there's a nifty program for the x window system called xflip that does just what i need.

Hmm... this piece of software looks promising for mirroring

Edit: It works but the video overlay will get sluggish on an older machine (read: my PIII 550mhz)

w00t!!!
I just got an email from their tech support and it will work in a dual monitor setup!!!

Dont think that software will do it. That mirror system they talk about is a alternative to clone......

finally decided to test out my lcd so I hooked it in to the dvi on my radeon 7000 and it boots up through the second win2k screen and then goes out of range :angry: vga works fine at least so i could test a little. No dead pixels! Luckily this isn't the card I'll be using in my final setup. Anybody experienced the same dvi issue? It's running on an asus p3bf mobo and a radeon 7000 pci and yes I know it's old but hey it was free

You should be happy to know that it actually does work!! I'm running it right now and I can confirm everything is backwards and upside down just the way it should be!!!

Well ATI's catalyst drivers are &^@$%# I decided to test out Media Center Edition on my pc and the M$ included driver locks on to the DVI from my CT-520d with no problems! Right now I have it running on my TV through s-video and on the LCD (which I'm still a little nervous about stripping) and I'm using UltraMon to mirror and rotate the screen. It works great and I should give credit to the french DIY site Allinbox for listing it as a useful utility. I also went to the Home Depot and bought a dremel and a riveter as well as some aluminum so i can practice before I attempt the real thing. I still need a good work table, some clamps and a better tape measure. Among other things

Edit: Decided to go back to basics. you know Icarus and all..

Well now i'm starting to rethink the design because I just picked up this lens. It looks promising here's the description: The first of two lenses is a multi-element assembly with an iris that has an adjustment from f/8.5 to f/30. There is a dichroic coating on an internal element. There are some small spots on the first element. Not certain if they will come off or not. Same for all the assemblies we have. Doesn't seem to affect the image. Focal length is 400mm. Black metal housing has two 3/8" diameter by 8-1/2" long shafts attached with linear ball bearings to provide an adjustable distance between first and second lens. Second lens is a beauty and easily worth our price for the whole assembly. It's a 5-3/4" diameter meniscus lens mounted in a 6-1/2" diameter black metal housing 1-5/8" thick. First lens assembly is 4-9/16" diameter by 5-3/8" front to back. Includes complete mounting and motors and gears. You can hand rotate one of the gears to make the lens assembly move up and down the shafts. Should give you hours of interesting experiments. Limited supply.

F8.5 mmm slow lens IE: it doesn't let alot of light though it.
I am willing to bet you won't like the light loss, but have fun playing with it! you never know what results you will get until you try.

I'd be suspicious of the Field of View of this lens....But have fun and good luck!

Hopefully it came from a copy machine capable of 11x17... FOV might not be a problem after all ??

I'll probably need that 550 fl from 3dlens.com now that i think about it... and if it doesn't work i'll just take it apart for fun

Wow, well then it just might work, providing it allows enough light to pass through.
Does anyone know what the aperture measurement is on the LL lens?

of course I suppose it's possible that the aperture could be removed from the lens
allowing it to pass more light, that depends entirely on how much light the lens can
"pass through".


I'm intrigued!

I should have it in a couple days I'll keep you posted and see if i can take a couple of quick pics.

this one looks like it might do the trick too 80mm dia & 400mm fl

I guess it must be ok the french diy store izzotek.com sells them with a better picture. and for more $$

The color temp and cri on this bulb look very attractive. Anyone who uses this bulb care to comment?

I was interested in this but is not that bright. Its listed there a 26,500 but I've seen it else where listed as 29,000 (Horizontal) 32,000 vertical. The big problem is that the arc length is 37mm. Data sheets are avialable here and here
One is Horizontal and the other is vertical (Bottom Up/Down (BUD)) Horizontal bulb is bigger and not as bright, vertical is longer. Both are bigger than the S400DD which is brighter.

There is a theory that light from the ends of a longer arc won't make it to the triplet, S400DD is 27mm so more of the light should be usable. What we really need is a short arc bulb with at least reasonable life.

Thanks PC, I'm assuming you've tried this bulb? I'm fairly sure all those specs are right. They're for different bulbs though. Here are specs from the manufacturer for the s400dd and the Iwasaki Eye I'm using the 400 t15 as a comparison.
I work in the print industry in a color critical calibrated icc workflow environment so when I see familiar color temps like 6500k which is a printing standard I get a little excited, so I guess that's my bias. 6500k is also the native color temp of my soon to be stripped 520d. So I feel like it would be a good thing to shine the same color light through the monitor and I'm still a little cloudy on how much the arc length is going to effects the output. I'll probably just end up buying both

Well I'm on my 6th design revision now. It looks like I might go with a bellows setup from the triplet to the fresnel so can experiment with all manner of lenses/focal length combinations. I'll update soon with some "new and improved" specs and some pics of what I have so far, If I can borrow the digital camera from work over the weekend I'm also fairly certain I'll just use a small fs mirror after the triplet like the plain old OHP to satisfy my 2 way 90° ceiling projection fixation. I still need more practice at riveting though, perhaps I'll just screw it together using L brackets instead.

I think they are the right specs but Eye/Iwasaki isn't very good about providing info I'v seen them called Clean Arc, Clean Arc, Color Arc etc... and the people selling bulbs just say 400W or similar dont give an actual part number.

No I haven't used the bulb I was planning to do so, but my simulations on light paths suggested that I'd get less light throu the triplet with a longer arc. The basic theory is that the 220/330 fresnel combination increases the effective arc by their ratio which is 1.5. So a 37mm arc ends up generating a 55 effictive arc at the triplet. I made a series of posts demonstating this but noone seemed interestedlink

So that along with looking at the bulb size suggested to me that the s400dd is indeed a beter choice overall. 6500K does sound good but example images even on bulbs with poor color temps always look good, brightness seems to be a bigger problem than color. The only complaints I've seen about color are for bulbs that remain green after burning and they are just defective. Many have reported better colors after switching to the S400DD.

I was also attracted by 6500K, and tried playing with the color temp settings in the powerstrip program. 6500K was my clear choice for my desktop but when watching movies 4700K seems more vibrant (personal preference dependant). Try powerstrip for desktop and movies and see which temps look best to you. One other issue is the LCD filter gap that I discussed link
I'm not sure how much the color temp means after the light has been seperated by th R G and B filters. I'm think CRI may be more important than color temp because it generally generates a fuller spectrum.

Well here's a gigantic lens I found at work. I wonder if it would work well for projection.

and here's another

I've made progress in the parts department. All I need now is the bulb, wiring, fans, some paint and a screen. Then all I have to do is actually put it together.

grrr

i got the box together and i was sanding down an edge that wasn't square with my dremel and I let the bad smell out of the dremel... :angry: it's toasted, it overheated and died. I'm really wishing I'd kept the receipt from the HD, I remember throwing it out thinking "what a great tool, it's a real keeper" sheesh I dunno I had it for like 3 weeks and used it for less than 20 hours I'm very disappointed.

That's a bummer

I'd try returning it for an exchange, the HD is very good with their return policy. They have taken stuff from me in the past without a receipt (they require a valid picture ID). Hope that you get that sorted out.

That is a factory defect right there. If you have problems with HD I would try the dremel corporation themselves. Tell them how disappointed you are with its performance and make sure to mention how many people know that it died at an early age. I have seen better results when a company knows that it is not just one consumer that is hearing about the problem.

I got a replacement Dremel from the HD, my lamp arrived yesterday and I gave it a test burn for a couple hours. One thing I noticed was that for the first half an hour or so the bulb intensity flickered a bit but then it calmed down. I'll be able to commence with construction now that I have all the parts to get it rolling. Being that all I've got to work with in the power tools department is my Dremel I'll have to make a jig so I can cut straight grooves for the slots in the sled. Hopefully an uninterrupted weekend should get that part done maybe even the LCD stripping too. I don't foresee a problem with the electrical. I still need a screen and a stand but I'll concentrate on on the pj for now.

if you used a credit card, they can look it up.

read the stuff on the wall once in a while. ;-)

Back when I sold retail electronics, we had what we call a 30/90 rule. There is a 90% chance that, if a component is going to fail, it will do so in the first 30 days of use. Early death = full refund because the source company eats it.

Remember also, that any company in the US who brokes with credit cards must keep a minimum of 3 years of transaction records. If you cant find your slip, then ask them to look it up by credit card number history. As a matter of pattern buying, most companies keep as much history as they can.

"Not having your slip" as an excuse to not give you back money, or at the very least store credit or replacement, went out with the 90's

Finished my pj this evening and wouldn't you know it I was putting it together in such a frenzy this weekend that I built my sled backwards Do'h! well i guess i'll be rebuilding the sled next weekend...

I'm glad that you got a new Dremel, however it is a light duty tool made for small jobs. If you are careful not to overload it, it should last you for many years. I got mine in the '70's and it is still going strong. If it gets hot, take a break so it can cool down. Speed selection is critical for the job you are doing... if it starts to bog down, give it more speed or back off on the pressure. Also too much speed can be a problem ...use just enough so that the bit cuts well.

If you know it's limits it can be a very durable tool.

Agreed, the dremel is a light duty tool. I overestimated it's power. I was just juiced about the purchase of my very first power tool and worked it a bit to hard. I guess the XPR doesn't stand for eXtreme PoweR It would've been nice if the documentation had stated that if the tool starts to get hot stop using it or it will break. It does say not to use it in a dusty environment but at the same time they give you sanding drums so WTF? Ya know?