Foghorn17 said:
This could be because the HD72 is a 1280 x 768 Native Res projector, whereas the stretch mode that you used takes it to 1280 x 720
CRIKEY! ...on the NOSEY!
Mark Techer said:If I am not mistaken, this projector is native 1.66:1, but does have a 1.78:1 function...
Mark
Have to check that out...it's all so new to me. Never had this much going on with my X1(trusty tho it is!)
Bud
Okay, I just spent an hour or so going back and re-reading a lot of this LONG thread.
My prisms will be here next week, hopefully by Wednesday.
A few questions:
1) I noticed some of the housings are left bare wood or even painted white. I was thinking the inside of the box needed to be flat black. Will it make a difference being light or dark inside the case/enclosure?
2) I know you need to tape/cover the short ends of the prisms. Should I cover the entire outer edges all the way around?
THANKS FOR ALL OF THE INFORMATION!
This thread is awesome!
Paul
My prisms will be here next week, hopefully by Wednesday.
A few questions:
1) I noticed some of the housings are left bare wood or even painted white. I was thinking the inside of the box needed to be flat black. Will it make a difference being light or dark inside the case/enclosure?
2) I know you need to tape/cover the short ends of the prisms. Should I cover the entire outer edges all the way around?
THANKS FOR ALL OF THE INFORMATION!
This thread is awesome!
Paul
Black inside housing in my opinion is the way to go, and yes, cover ALL the edges (Top,ends)of the prisms to avoid stray reflections.
Bud
Bud
artbypaul said:Okay, I just spent an hour or so going back and re-reading a lot of this LONG thread.
My prisms will be here next week, hopefully by Wednesday.
A few questions:
1) I noticed some of the housings are left bare wood or even painted white. I was thinking the inside of the box needed to be flat black. Will it make a difference being light or dark inside the case/enclosure?
The inside of the case should be flat black. I have been a bit slack and not painted the inside of my case, but I know that it will improve the image if I do. Right now the image so the most "square" I've ever had it and I don't want to remove the lens in case I don't put it back in the right spot...
artbypaul said:2) I know you need to tape/cover the short ends of the prisms. Should I cover the entire outer edges all the way around?
THANKS FOR ALL OF THE INFORMATION!
This thread is awesome!
Paul
Well it was suggested to tape the THICK end to stop unwanted light reflections. Taping the thin end as well couldn't hurt. As for the top and bottom, the case takes care of that...
Mark
I may be able to pick up a used Panamorph 752 to use temporarily. I figure I could use the 752 while I wait for the prisms to arrive and while I take the time to build my own prism setup which will ultimately be more adjustable than the 752. I could also use the Panamorph 752 to compare the optical quality of whatever I create myself. realize too, that I could also bring this folks places in and around the GTA to help out with their creations, if in fact it would be helpful at all to compare. How much should I be willing to pay for a used 752? $350 USD shipped to me too much or a good deal?
If the Panamorph 752 is a VC lens, I think it will still work with my 1.6 zoom projector (and the Mitsubishi HC5000 which also has a 1.6 zoom...of course, that will require a big drop in the price of the mitsubishi or a lottery win 😎 ).
Where it is sitting now, my projector can throw a 120" wide image and I only need one 114" wide. I guess I will be at or neat the extent of my zoom for 2.37:1 using the Panamorph. Hope that is ok. The menu screen I was using to check the width of the projection looked sharp to my eyes.
I think a HE lens would work better in my current setup, but if I can get the 752 I could at least experiment.
🙂
Where it is sitting now, my projector can throw a 120" wide image and I only need one 114" wide. I guess I will be at or neat the extent of my zoom for 2.37:1 using the Panamorph. Hope that is ok. The menu screen I was using to check the width of the projection looked sharp to my eyes.
I think a HE lens would work better in my current setup, but if I can get the 752 I could at least experiment.
🙂
I figure I could use the 752 while I wait for the prisms to arrive
Not sure if I read this right, but it sounded like you have prdered some prisms, but also want to buy a commercial lens - Panamorph 752...
Mark
Yes, I have "orded" prisms to be coming by way of roar's order. I have been searching for a Panamorph 752 and somebody has offered me one. I figure I may pick it up now and start my setup. When the prisms get here, I can hopefully make a cheaper but more tweakable DIY lens that will have optical quality as good or better than the Panamorph 752. The 752 can act as a measuring stick of sorts. May offer less for it though, so I won't lose too much if and when I sell it after I make my own lens. If the seller doesn't want to sell for my offer then I will keep waiting for the fun-for-the-whole-family prism adventure whenever we get those crazy things
If by "how far away.." you mean how long before I get them, ...I don't know. Roar has been hard at work trying to get an order moving from a Canadian distributor, but it may take a while longer. Maybe another month? What say you roar? How much longer you figure?

If by "how far away.." you mean how long before I get them, ...I don't know. Roar has been hard at work trying to get an order moving from a Canadian distributor, but it may take a while longer. Maybe another month? What say you roar? How much longer you figure?
Well that 2 weeks is being optomistic 🙂 I've got a call into the friendly people there, the lady I've been dealing with doesn't work Monday's and Friday's I believe, I'll update you when I've got more info 🙂
From HE to VC
Did some testing tonight...
My theory was based on the alignment of the prisms - that the lens can be used for multiple aspect ratios if turned and rotated.
As it turned out, my projector's very short throw prevented my experiment from working 100%, but gave me the proof that I needed to answer some questions that have been asked here and not answered...Yes those wanting a VC can do so if you build the HE first, then turn and flip the lens...
With the prisms aligned as shown in my blog, the lens is a Horzontal Expanding lens.
Turn the lens 180 degrees, and the opposite happens as the lens now becomes a Horizontal Compression lens.
In my current set up, I am too close to the screen to be able to enjoy films as much as I could in the larger room of the house I recently sold. The projector/lens set up works to fill the screen, but I am too close.
I turned the lens around as well as flipped it on to its side. What I found was that the HE now did become a VC with correct geometry, but the prisms which are 5.5" high are now 5.5" wide and are too small for my set up in this mode. The sides of the image were clipped hard.
If I was to build a lens with wider prisms, I might be able to achieve the results I was chasing, or change my projector for a unit with a longer throw, where the latter will not be happening for some time...
Something very interesting about the VC, the image brightness actually goes up, and the pixel structure is less visible...
I wish I could comment on the sides, but they were being clipped...
Mark
Did some testing tonight...
My theory was based on the alignment of the prisms - that the lens can be used for multiple aspect ratios if turned and rotated.
As it turned out, my projector's very short throw prevented my experiment from working 100%, but gave me the proof that I needed to answer some questions that have been asked here and not answered...Yes those wanting a VC can do so if you build the HE first, then turn and flip the lens...
With the prisms aligned as shown in my blog, the lens is a Horzontal Expanding lens.
Turn the lens 180 degrees, and the opposite happens as the lens now becomes a Horizontal Compression lens.
In my current set up, I am too close to the screen to be able to enjoy films as much as I could in the larger room of the house I recently sold. The projector/lens set up works to fill the screen, but I am too close.
I turned the lens around as well as flipped it on to its side. What I found was that the HE now did become a VC with correct geometry, but the prisms which are 5.5" high are now 5.5" wide and are too small for my set up in this mode. The sides of the image were clipped hard.
If I was to build a lens with wider prisms, I might be able to achieve the results I was chasing, or change my projector for a unit with a longer throw, where the latter will not be happening for some time...
Something very interesting about the VC, the image brightness actually goes up, and the pixel structure is less visible...
I wish I could comment on the sides, but they were being clipped...
Mark
Mark,
Based on your experiments, is it best to go for as big a prism as possible to give oneself HE vs VC flexibility? Is there a downside to using oversized prisms if one intends to stick with HE? Aside from the relative pricing, of course.
Based on your experiments, is it best to go for as big a prism as possible to give oneself HE vs VC flexibility? Is there a downside to using oversized prisms if one intends to stick with HE? Aside from the relative pricing, of course.
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