mikep, thats a very good setup... similar to how mine is going to be when finished with the vertical twist adjustment, but with turning the lenses to get straight through mode, as the projector/lense are hanging from a beam holding the ceiling, top floor up, so sliders sticking out into free air would look silly.
but great work, and will push a few more ppl to building their own cih projections 🙂
😉 😀 😀
but great work, and will push a few more ppl to building their own cih projections 🙂
😉 😀 😀Got mine up and running last night. I took my projector down from its ceiling mount, and had it table mounted. with my lens housing, with the adjustable knobs on top, I was able to easily fill my 4:3 image to 21:9. There is some pincushioning issues that I still have to deal with, but the masking does a good job of hiding that. The only real issue I had was on the stretch on the right hand side of the image. Having the prisms in "pass through mode", and the stretched 4:3 image centered directly on the screen, I first rotated the front prism, which easily stretched the left side of the image to fill the screen, but the right side of the image only mostly got there, because the back prism bumped into the front prism, and kept me attaining the full stretch. Overall, though, it was pretty cool.
There's no way to combine the Panamorph with the DIY lens, because the image is too large from the first lens to be useful in the second lens, and I get serious vignetting problems.
So ceiling mounting the projector where I had it still poses the problem for me, that the image is too large, even optically zooming out to the fullest extent possible, to fit my screen. So I either have to increase the size of my screen--which is doable, but will take a bit more engineering on my part, due to the space constraints, or move the projector closer to the screen, or both.
There's no way to combine the Panamorph with the DIY lens, because the image is too large from the first lens to be useful in the second lens, and I get serious vignetting problems.
So ceiling mounting the projector where I had it still poses the problem for me, that the image is too large, even optically zooming out to the fullest extent possible, to fit my screen. So I either have to increase the size of my screen--which is doable, but will take a bit more engineering on my part, due to the space constraints, or move the projector closer to the screen, or both.
Two questions I haven't seen asked yet:
Is there any specific need to have the rotation point at the center of a prism?
Is there ever an adjustment where you want to tweak the tilt of just ONE prism, or do you always need them perfectly parallel to each-other vertically?
C
Is there any specific need to have the rotation point at the center of a prism?
Is there ever an adjustment where you want to tweak the tilt of just ONE prism, or do you always need them perfectly parallel to each-other vertically?
C
Hi guys, First off, I want to thank everyone for putting together a thread like this to teach new people to CH how to do this sort of thing and what it is all about.
Now I am one of those new people and have some questions about the DIY. I am new to this site, just found the other day and have read alot of this thread, I have also read Marks (thanks Mark) site and know what CH is all about. I do though have some questions about my setup. Right now I am running an HD-A1 through a Pioneer Elite82 to an Optoma HD72. I am using a scope screen the cheap, meaning for scope films I am running the A1 in 720p and for anything smaller I am running the A1 in 1080i basically getting the CH. So now to get to my questions, will using these new glass wedges make any difference in what I have now, and what size wedge would I need? Also my projector can move to wherever I need to put it to get the right distance, zoom, and height.
Thanks a lot guys
Josh
Now I am one of those new people and have some questions about the DIY. I am new to this site, just found the other day and have read alot of this thread, I have also read Marks (thanks Mark) site and know what CH is all about. I do though have some questions about my setup. Right now I am running an HD-A1 through a Pioneer Elite82 to an Optoma HD72. I am using a scope screen the cheap, meaning for scope films I am running the A1 in 720p and for anything smaller I am running the A1 in 1080i basically getting the CH. So now to get to my questions, will using these new glass wedges make any difference in what I have now, and what size wedge would I need? Also my projector can move to wherever I need to put it to get the right distance, zoom, and height.
Thanks a lot guys
Josh
Tried taking some photo's, but didn't come out too well.
got the projection setup as close as possible to what I want, but quite a bit of curve in the screen, probably due to projector only 3.8meters away from wall... might have to move it back to reduce the bending.
anyway some picks of the wall with first shot dvd paused, the rest are with the movie running, which didn't work to well, but you get the idea.
270cm wide, 115cm high
more afer the jump...
got the projection setup as close as possible to what I want, but quite a bit of curve in the screen, probably due to projector only 3.8meters away from wall... might have to move it back to reduce the bending.
anyway some picks of the wall with first shot dvd paused, the rest are with the movie running, which didn't work to well, but you get the idea.
270cm wide, 115cm high
more afer the jump...
stevodude said:Tried taking some photo's, but didn't come out too well.
got the projection setup as close as possible to what I want, but quite a bit of curve in the screen, probably due to projector only 3.8meters away from wall... might have to move it back to reduce the bending.
anyway some picks of the wall with first shot dvd paused, the rest are with the movie running, which didn't work to well, but you get the idea.
270cm wide, 115cm high
more afer the jump...
Two things when taking pictures of screenshots--the movie just has to be paused, or the images comes out terribly. 2--try to use a tripod--that helps even more.
Hi there!
Just wanted to thank you guys for this terrific thread, I've read the whole thing a couple weeks ago and finally got around to ordering my prisms from Massillon Plaque after being re-inspired by MikeP's blog. 🙂
I ordered the largest size as I have a Sony HS10 which has a recessed lens (same as Mark's HS3 I believe). I've been doing the "poor man's CIH" for a while using zoom and it works pretty well, but seeing how much can be done for a modest cost, I thought I'd give this a go.
Thanks again for all the effort, research and documentation!
Just wanted to thank you guys for this terrific thread, I've read the whole thing a couple weeks ago and finally got around to ordering my prisms from Massillon Plaque after being re-inspired by MikeP's blog. 🙂
I ordered the largest size as I have a Sony HS10 which has a recessed lens (same as Mark's HS3 I believe). I've been doing the "poor man's CIH" for a while using zoom and it works pretty well, but seeing how much can be done for a modest cost, I thought I'd give this a go.
Thanks again for all the effort, research and documentation!
Steve Scherrer said:
Am I reading this correctly, are you taking a 4:3 (1.33) and turning it into a 21:9 (2.35)? If so how are you doing this, I though streching by 33% or so, was the maximum possible? It sounds like maybe you are using two pair of prisms. Are you doing HE twice or HE and VC?
I'm very interested in if this is possible as my screen area is limited and I want to get maximum brightness. A few pictures or a diagram of your setup would help me understand.
That is correct, the stretch you get, obviously, is directly related to the angles between the prisms relative to the projector. More angle, more stretch. There does come a point where you can't stretch anymore because the image disappears from within the prism--in other words, you can get too much stretch, but I did not reach it when I experimented the other day on my screen. With more stretch, you end up with more geometry distortions--but I think with some adjustments and masking, most can be distortions can be minimized.
I am still trying to work out proper placement of the ceiling mounted projector to get the right size image--so it may be a while, but I can probably take the top off the housing and show about where the angles fall for the prisms.
Edit--It may be obvious, but to directly answer your question, I am only using one pair of prisms. I toyed with the idea of combining HE with VC, but my lenses are not large enough to support this.
I am still trying to work out proper placement of the ceiling mounted projector to get the right size image--so it may be a while, but I can probably take the top off the housing and show about where the angles fall for the prisms.
Edit--It may be obvious, but to directly answer your question, I am only using one pair of prisms. I toyed with the idea of combining HE with VC, but my lenses are not large enough to support this.
Enough lurking!
Hi Everybody,
After looking through this amazing thread for a couple of months, I thought it was about time for me to announce my presence. Sorry for the long post...
I'm an Aussie home theater enthusiast, back from the days of stereo simulators and two track linear VHS stereo! You can find a link to my (long neglected) web page in my profile.
CIH and home anamorphic projection has fascinated me for the last ten months, but commercial lenses were out of my reach.
I've been emailing Mark Techer for a while, enjoying his blog and forum posts, following his progress with the "Aussiemorphic Lens".
After contacting Mark, I took his MDF case, thought a little and designed a simple prism case from aluminum.. I applaud Mark's MDF Aussiemorphic Lens, it's just that I'm much more comfortable working with metal than MDF.
Here are a couple of build pics :-
After painting, the housing looked a lot more professional :-
The "rubber" material used to hold the prisms in place in the last image turned out to be a disaster, reacting with the carpet adhesive tape and turning into a nasty goo. I'm now using 1.5mm insertion rubber, it's much better.
Mounting my lens took a little thinking and planning, and in the end... it was back to MDF! I built a small shelf for the projector and lens to hang from. To allow me to move the lens, I used Igus Drylin N linear slide rails and carriages :-
The lens mounting bolts allow a lot of adjustment, I can slide the lens back and forth, left and right. Rotate the lens, plus adjust the pitch and roll of the lens.
After "hanging" the shelf in my HT, it wasn't long before I was projecting a beautiful 2.37:1 image on my existing home-made 16:9 screen.
I'm awaiting the arrival of a new 2.37:1 Majestic screen from OZ Theatre Screens www.ozts.com.au, hopefully it will be here very soon! After that, I will be finally replacing my aging Sony VPL-W400Q projector... most likely with a JVC DLA-HD1. I can't wait!
I love my old Sony, but she just doesn't cut it anymore. I'll try to get some screenshots of my current projected image soon, with no tripod it's a little hard. It's great being here!
Regards.
Michael.
Hi Everybody,
After looking through this amazing thread for a couple of months, I thought it was about time for me to announce my presence. Sorry for the long post...
I'm an Aussie home theater enthusiast, back from the days of stereo simulators and two track linear VHS stereo! You can find a link to my (long neglected) web page in my profile.
CIH and home anamorphic projection has fascinated me for the last ten months, but commercial lenses were out of my reach.
I've been emailing Mark Techer for a while, enjoying his blog and forum posts, following his progress with the "Aussiemorphic Lens".
After contacting Mark, I took his MDF case, thought a little and designed a simple prism case from aluminum.. I applaud Mark's MDF Aussiemorphic Lens, it's just that I'm much more comfortable working with metal than MDF.
Here are a couple of build pics :-
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
After painting, the housing looked a lot more professional :-
An externally hosted image should be here but it was not working when we last tested it.
The "rubber" material used to hold the prisms in place in the last image turned out to be a disaster, reacting with the carpet adhesive tape and turning into a nasty goo. I'm now using 1.5mm insertion rubber, it's much better.
Mounting my lens took a little thinking and planning, and in the end... it was back to MDF! I built a small shelf for the projector and lens to hang from. To allow me to move the lens, I used Igus Drylin N linear slide rails and carriages :-
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The lens mounting bolts allow a lot of adjustment, I can slide the lens back and forth, left and right. Rotate the lens, plus adjust the pitch and roll of the lens.
After "hanging" the shelf in my HT, it wasn't long before I was projecting a beautiful 2.37:1 image on my existing home-made 16:9 screen.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I'm awaiting the arrival of a new 2.37:1 Majestic screen from OZ Theatre Screens www.ozts.com.au, hopefully it will be here very soon! After that, I will be finally replacing my aging Sony VPL-W400Q projector... most likely with a JVC DLA-HD1. I can't wait!
An externally hosted image should be here but it was not working when we last tested it.
I love my old Sony, but she just doesn't cut it anymore. I'll try to get some screenshots of my current projected image soon, with no tripod it's a little hard. It's great being here!
Regards.
Michael.
cjd said:
The rotation doesn't have to be at the center of the prism. The prisms I am using are not mounted permanently, so I can rotate them about any axis. If I go from a pass-thru mode (with the outside prisms faces parallel) to stretch mode, I can just grab the edges of the prisms with my hand and turn them until the I get the right amount of stretch. I couldn't even tell you exactly where the rotation point is, but it's definitely not the center in my case.
This brings about another point that may have been mentioned before. When uncoated prisms are rotated back to a pass-thru mode, the reflections go up astronomically and I found that it wasn't very watchable, so the best economical solution seems to be to slide the whole lens out of the way when watching a non 2.35:1 movie (as most people seem to be doing).
Your second question is a good one. I think in general, the prism faces are parallel to eachother...but if you do this and later notice that one side of your picture is tilted up more than the other side, then this can often be corrected by tilting one prism and not the other. I've done this, but it was when I was tilting both prisms individually, so I couldn't tell you if the prisms were precisely parallel after I had finished aligning them. I think it's best if you allow yourself at least a tiny bit of adjustment here just in case you get everything setup and find out later that you need to "tweak" it a little bit.
Ed
cjd said:
Each prism controls one half of the screen. For example, rotating the first prism adjusts the right-edge of the screen, and rotating the second prism adjusts the left-edge of the screen.
When you tilt a *single* prism, you are adjusting the pin-cushioning of that single side of the image. Tilting the entire enclosure (both prisms) controls the pin-cushioning of all four corners.
You can't seem to eliminate pin cushioning entirely (except maybe with a curved screen). And if your projector is already properly adjusted without any keystoning, then you shouldn't ever need to tilt just one prism. But tilting the prisms can change the relative geometry between the top corner and bottom corner.
So, if for some reason you have unequal pin-cushioning at the top/bottom of a single side of the image, then you can tilt the corresponding prism to make that side more uniform.
The minimal need to tweak an individual prism is good, not bad, given what I have in mind. I'm going to try to put a mount together, and if it goes well it'll be something that hopefully will be a bit easier for folks to duplicate. It should also help keep prisms perfectly parallel vertically. And if it goes really well, I'm hoping to make micro-adjustments really easy. We'll see. 🙂
C
C
OK, got rid of the cardboard box, and made a temporary sort of permanent test box...
made out of 6mm mdf, and some left over L channel alluminium from the lense mounting.
10mm bolt hanging out of the 16mm mdf screwed to the ceiling beam.
upsite down U bracket has oval cuttout for left right positioning and rotating, that you can't see in the photo's.
I put the lenses closer together and that eliminated a reflection off the outside prism fat side back through the prism to the front right wall that I couldn't get rid of before, but now NO reflections on any other surface apart from front wall wooot.
More photo's of screen in action & of the prism mount after the jump.
Just waiting on my screen material to turn up to I can make a curved screen, and get a warm filter for the ae700...
man this maybe the cheaper solution to get a good setup, but it still costs hahahaha
😀 😀 😀
made out of 6mm mdf, and some left over L channel alluminium from the lense mounting.
10mm bolt hanging out of the 16mm mdf screwed to the ceiling beam.
upsite down U bracket has oval cuttout for left right positioning and rotating, that you can't see in the photo's.
I put the lenses closer together and that eliminated a reflection off the outside prism fat side back through the prism to the front right wall that I couldn't get rid of before, but now NO reflections on any other surface apart from front wall wooot.
More photo's of screen in action & of the prism mount after the jump.
Just waiting on my screen material to turn up to I can make a curved screen, and get a warm filter for the ae700...
man this maybe the cheaper solution to get a good setup, but it still costs hahahaha
😀 😀 😀I saw somewhere in this thread about stretch mode for video cards...
but I'll pose the Q here.
have 2.35 screen, 2.35 projection with cih 16:9 projector (ae700) and lense permanent set in wide mode.
now dvd's are fine as all I have are in 2.35 format, so the zoom1 on projector works for that.
actually I've just had a look at my menu options for 'pc' mode, and it has a 4:3 aspect ration, so I answered my own Question while typing this out.
This way I can leave the lense in 2.35 mode permanent, and in pc mode select 4:3 & ati theatre mode set to 'fill screen' to watch digital DVB-T (16:9) , obviously I loose a few horizontal pixels doing this, but when watching movies, get the full benifit of all pixels...
is this normaly what ppl do for cih 2.35 setups?
but I'll pose the Q here.
have 2.35 screen, 2.35 projection with cih 16:9 projector (ae700) and lense permanent set in wide mode.
now dvd's are fine as all I have are in 2.35 format, so the zoom1 on projector works for that.
actually I've just had a look at my menu options for 'pc' mode, and it has a 4:3 aspect ration, so I answered my own Question while typing this out.
This way I can leave the lense in 2.35 mode permanent, and in pc mode select 4:3 & ati theatre mode set to 'fill screen' to watch digital DVB-T (16:9) , obviously I loose a few horizontal pixels doing this, but when watching movies, get the full benifit of all pixels...
is this normaly what ppl do for cih 2.35 setups?
stevodude said:
Yes, I set my projector to 4:3 mode to "undo" the stretch of the prism lens sometimes. Since I use my PC a lot, I tend to just move my lens out of the way from the projector so that I don't loose those horizontal pixels. But if I'm just watching TV, or watching special features on the DVD, then I often use the 4:3 mode so that I don't have to get off the couch and move the lens.
Using 4:3 mode works pretty well, but I tend to be pretty picky about getting all of my pixels when doing computer work since text can be hard to read otherwise.
But I have to admit that I was really thrilled to find the 4:3 mode on my projector just like you. When watching a DVD in 2.35:1 mode and then viewing special features (which are never in 2.35:1 aspect ratio) it's very convenient to just change the projector to 4:3 without having to move the lens.
So I like the flexibility of both methods.
Hi, got my prisms today and started to play around....took my projector down from the ceiling mount and tried to get it set up to check the angles I needed. A couple of questions:
It's very difficult for me to get the PJ set up the same using my existing screen when it's not ceiling mounted, will the angles be the same as long as I use the same zoom setting? i.e. if I move it to another room with a much shorter throw but keep the zoom minimized, will I get the same angles?
I did manage to get a rough outline of what appeared to be the correct angles, but I'm not sure I had the PJ exactly squared to the screen, but it was centered and looked roughly correct. How important is it that these are precise as long as some adjustment is possible with the enclosure?
I am wondering if it would be worthwhile to just build a temporary enclosure and try to adjust the angles with the PJ in its normal mount.
It's very difficult for me to get the PJ set up the same using my existing screen when it's not ceiling mounted, will the angles be the same as long as I use the same zoom setting? i.e. if I move it to another room with a much shorter throw but keep the zoom minimized, will I get the same angles?
I did manage to get a rough outline of what appeared to be the correct angles, but I'm not sure I had the PJ exactly squared to the screen, but it was centered and looked roughly correct. How important is it that these are precise as long as some adjustment is possible with the enclosure?
I am wondering if it would be worthwhile to just build a temporary enclosure and try to adjust the angles with the PJ in its normal mount.
yep, best bet is to play around with it, if temp boxing for test.
I've gone from table test, to a length of wood with prisms mounted, to a cardboard box, to a wood test box, next step is a decent aluminium enclosure, and modify the lense holders.
I've gone from table test, to a length of wood with prisms mounted, to a cardboard box, to a wood test box, next step is a decent aluminium enclosure, and modify the lense holders.
I think as long as you keep the same zoom setting, then it should work fine in another room. In the other room you can just move the projector forward or back to fill the screen. The prisms should give you the same 133% stretch that you need as long as you are getting the same beam of light from the projector to the lens.
Certainly a test box is always helpful if you have the time and patience. However, if the prisms positions and angles are adjustable, then you shouldn't have much trouble.
Certainly a test box is always helpful if you have the time and patience. However, if the prisms positions and angles are adjustable, then you shouldn't have much trouble.
working on a curved screen for my setup... go the jump to check it out, let me know what you think.
An externally hosted image should be here but it was not working when we last tested it.
