Nice job, Steve! Looks like you've got a great setup. I'm following your progress closely 🙂
I just ordered my prisms a couple days ago. Anxiously waiting their arrival!
Andy
I just ordered my prisms a couple days ago. Anxiously waiting their arrival!
Andy
No, I got mine is Australia. The have a steeper angle and are thicker at the base, but I would say thay are made of the same stuff, so should perform the same.
The interesting points I raised previously seem to have proven correct.
1. A prism (any two non parallel surfaces regardless of the angle) will work to bend light. Steve's prisms are just 5 degrees, where mine are closer to 15degrees.
2. It is the angles of the front and rear faces that affect the amount of stretch. The results are the same for both mine and Steve's lens, and looking at the photo he posted, the angles of both the front and rear prisms faces are the same...
Mark
Just looking at the pictures I posted again, and they seem a bit hazy--this is not what I saw at all, and is an artifact from the camera I am using. I have the camera set up on a tripod. Does anyone have a good camera setting to take good screen shots?
Also, some other observations. Last night, any distortions were pretty much confined to the right side of my screen, including pincushioning issues and CA. In fact, you can see some CA on the pictures I just posted running down the right side of the screen. I am absolutely convinced that playing with the angles of the prj, the housing and the prisms will get rid of these annoyances (and as you can see, I pretty much eliminated the geometry distortions).
I noticed that when I was adjusting the footings of the pj with the housing in front of the pj, the image, when moving up and down, was "wavy" as it passed through different parts of the lenses. This is an indication that the prisms are not absolutely clear and free of internal striations. But once the pj is settled and the image remains in once place relative to the prisms, there is absolutely no noticeable distortion due to this. It's just a product of slight imperfections in the crystal, and I think you would be hard pressed to get better than this. I would be interested in playing with the solid Pr*sonic wedges to see if these do the same thing--I would imagine they do.
Since I am pretty resigned to the fact that achieving true 21:9 form a 4:3 pj is probably not going to work, my job gets much easier, in that I only have to have two settings on each prism to dial into--passthrough and stretch, like the Pr*sonic. Whether it is in front of a 4:3 or a 16:9 projector, it should work the same, and the settings should stay the same to achieve ~33% stretch.
Also, some other observations. Last night, any distortions were pretty much confined to the right side of my screen, including pincushioning issues and CA. In fact, you can see some CA on the pictures I just posted running down the right side of the screen. I am absolutely convinced that playing with the angles of the prj, the housing and the prisms will get rid of these annoyances (and as you can see, I pretty much eliminated the geometry distortions).
I noticed that when I was adjusting the footings of the pj with the housing in front of the pj, the image, when moving up and down, was "wavy" as it passed through different parts of the lenses. This is an indication that the prisms are not absolutely clear and free of internal striations. But once the pj is settled and the image remains in once place relative to the prisms, there is absolutely no noticeable distortion due to this. It's just a product of slight imperfections in the crystal, and I think you would be hard pressed to get better than this. I would be interested in playing with the solid Pr*sonic wedges to see if these do the same thing--I would imagine they do.
Since I am pretty resigned to the fact that achieving true 21:9 form a 4:3 pj is probably not going to work, my job gets much easier, in that I only have to have two settings on each prism to dial into--passthrough and stretch, like the Pr*sonic. Whether it is in front of a 4:3 or a 16:9 projector, it should work the same, and the settings should stay the same to achieve ~33% stretch.
I looked at the 5" x 7" prisms locally available from a trophie shop and they looked awesome. They just wanted more for them ($59)plus tax too.
I called Massilon Plaque this morning and ordered two of the J24, 4" x 6" Prisms for $29.00 ea. I spoke to Suzan. She said to tell everyone to call her and order them. The price was better than the internet price.
800-854-8404 ext. 226
Now I just have to wait!
I guess I will start shopping for my screen. I decided the other night that 130" wide 16:9 was just a tad too big for my seating distance. (Too much eye movement for a 2 Hr. Movie) I still want to see if I would like 130" wide for a 2.35:1 aspect. If not I may go to a 116" wide screen.
Mike
I called Massilon Plaque this morning and ordered two of the J24, 4" x 6" Prisms for $29.00 ea. I spoke to Suzan. She said to tell everyone to call her and order them. The price was better than the internet price.
800-854-8404 ext. 226
Now I just have to wait!
I guess I will start shopping for my screen. I decided the other night that 130" wide 16:9 was just a tad too big for my seating distance. (Too much eye movement for a 2 Hr. Movie) I still want to see if I would like 130" wide for a 2.35:1 aspect. If not I may go to a 116" wide screen.
Mike
Thanks for the updates Steve, pictures look great. I'm hoping to check Buds work out when he is ready too! He has the exact projector I want to buy so it will be a great demo for me...
Bud has invested in 4 lenses... any thoughts on expectation of picture quality with the 2 vs the 4? Mark, I believe you had said you ordered 2 more to test that very thing, any luck?
Bud has invested in 4 lenses... any thoughts on expectation of picture quality with the 2 vs the 4? Mark, I believe you had said you ordered 2 more to test that very thing, any luck?
Steve,
The last set of photos I took, I just used "natural".
mfeidler,
If your going to have a 16:9 screen then times the height by 3.68 to get your seating distance. If you go a scope 235 screen than you can times the width by 1.54.
roar,
I am in the process of making a 4 prism lens, but have not ordered the second set yet. It is said that there is a 70% improvment over a 2 prism lens...
Mark
The last set of photos I took, I just used "natural".
mfeidler,
If your going to have a 16:9 screen then times the height by 3.68 to get your seating distance. If you go a scope 235 screen than you can times the width by 1.54.
roar,
I am in the process of making a 4 prism lens, but have not ordered the second set yet. It is said that there is a 70% improvment over a 2 prism lens...
Mark
70% improvement includes way less CA, barrel/pincushion etc...
That is why I am looking forward to getting another set of prisms soon...
Mark
That is why I am looking forward to getting another set of prisms soon...
Mark
Mark Techer said:
70%? You ever watch The Mask when JimCarey's character see's Cameron Diaz's character for the first time and his jaw hits the floor? That's what mine just did 🙂 Impossible I say! Prove it 🙂
(Just kidding of course, hopefully I'll be able to see it action personally!)
roar said:
I did build a 4 prism (water prisms) lens a while ago and worked really well, until I got inventive, hinged the main prism bodies and could not get proper stretch anymore. This is why I went back to a 2 prism lens.
The 70% quote actually comes from Prismasonic who claim that they have tests to confirm the improvment. I must say that I did see a huge improvment with my 4 prism lens when it was up and running. If you go back (many pages now), you can see some images I posted from it including that Jango Fett shot...
Lately my focus has been simply on getting a lens with solid clear prims - and we have done that - so now comes time for tweaking 🙂
Mark
If any Canucks have advice on where I can go to buy the parts, I am game. Do I go online or are there local places in the Toronto area or elsewhere that have parts?
There is a supplier on the 'net listed back on page 64(?), but last page (73) has a phone number and a contact name for the prisms in the US...
Mark
Mark
Ok, thanx Mark, I will check it out after reading up on the most recent developments. How far back should I read to get the newest background info on the latest regarding these prisms folks are ordering?
morkys said:
No problem. Progress is going slower than expected...painting the screen and working on the lens and setting up for calibration all the same time. Hope to have some shots this week.
Prism supplier info...
http://www.massillonplaque.com
Contact The Massillon Plaque Company
Thanks for visiting The Massillon Plaque Company online. Please feel free to use any of the following methods for answers to your questions, requesting product information, or reaching our Customer Service department.
Mailing Address
The Massillon Plaque Company
5757 Mayfair Road
P.O. Box 2539
North Canton, OH 44720
Phone: 330-494-4199 or 1-800-854-8404
Fax: 330-494-5037
Customer Service:
Suzanne Stoneman
And the price is a LOT less than posted since you're not getting engraving! But there is the duty!
Bud
Just a quickie...
I got my prisms yesterday (Friday). Talk about lightning shipment! I ordered them on Tuesday! I did notice that they ship from New Hampshire. That would explain it.
I'm going to play with them tonight.
Cheers!
Andy
I got my prisms yesterday (Friday). Talk about lightning shipment! I ordered them on Tuesday! I did notice that they ship from New Hampshire. That would explain it.
I'm going to play with them tonight.
Cheers!
Andy
morkys said:
HERE is where it all changes for the better 🙂
And a quick word on clarity. Whilst I have dived back into the gamma table to correct the green blobs of my LCD, I didn't really check the other controls until last night. A friend comes over and wants to see the new lens, I load a SW film, go into the THX optimizer and wow, I can clearly see the drop shadow behind the THX logo.
This means that the setting I had brightness at for the water prims is now too high for the crystal prisms. This means that I can pull it down to give even better blacks 🙂
I guess I need to re-cal the entire unit...
Mark
Hey guys, just came back upstairs to post. Tried the US prisms in front of my Optoma HD72. Did the 2 prism & the 4 prism...I find that the angles between the 4 set is smaller than the 2. The 2 set is almost 90 degrees offset, well at least in my case. Also the 4 prism set had a LOT of ghost images. I guess I have to play more with which sides to put together. Haven't taken any pics yet (still have to set up another account to post them on). Also, I just set them in front of the beam on the ceiling mounted pj which caused some image warping instead of being perpendicular to the beam, but i still have to construct the housing. Ya, if you don't seal the ends....BOY, you get projections all over!
Just my 2 cents....and the project continues....
Bud
Just my 2 cents....and the project continues....
Bud
Bud Bray said:
I would suggest that this happens becasue the light is partialy stretched by the first prism in each pair, then the "stretched" light is further stretched by the second prism of each pair.
I am taking that you have made 10 degree wedges out of the two 5 degree wedges.
Some thing I am curious to try is to add some space between the two prisms - say if they are 5 degree, then add 5 degree of space between them. Basicaly they would still be joined at the apex...
Bud Bray said:
What did you seal the ends with? I have just used 2" duct tape, and it worked really well. I have also contructed a "shelf" that extends down from the projector mount, so initially I just placed the two prisms on the shelf, but I since built the case which holds everything in place, and I can simply remove the entire lens if need be...
I am also thinking about adding a small panel on the back to prevent the small side reflection I am still having...
Looking forward to seeing some shots...
Mark
Oh, another thing Mark. You suggested curving my screen, ya that would be a good idea but i've already secured it to the wall most of the length so a curve is out, at least on this screen, i'll curve the next one. I have noticed the slight stretch at the sides but you REEEEALY have to look for it.
Also, the LBX mode on the HD72 cuts some of the bottom off when watching 16:9 in anamorph mode. I know, you're NOT supposed to watch them like that but thought i'd check it out.
Also, the LBX mode on the HD72 cuts some of the bottom off when watching 16:9 in anamorph mode. I know, you're NOT supposed to watch them like that but thought i'd check it out.