Thanks Karol! Yes, I'm just using two 5x7 Glass Prisms.
With the exception of a stray reflection on occasion, I'm happy with the results.
Now if I could just get these things AR coated! 🙂
Paul
With the exception of a stray reflection on occasion, I'm happy with the results.
Now if I could just get these things AR coated! 🙂
Paul
artbypaul said:
The only way for you get some idea of what I am talking about is to do what most consider pointless - display a blue screen (no signal) and walk up to the screen and look at the gaps between your projector's pixels.
With the prisms in place, you should be able see the horizontals quite clear, but the verticals will be burred. Prisms have no focal length, so there is nothing more you can do here. If you tweak the projector's focus, what you should notice is that you may bring the vertical into focus, at the expense if the horizontals where generally, it best to have the horizontals in focus first.
Now try and imagine a lens that allows razor sharp focus of the pixel gaps in BOTH the horizontal and vertical directions at the same time.
This is the benifit of a cylindrical lens with adjustible optics. Becuase the cylindrical elements have focal lengths, they can be precisely aligned...
Mark
@Paul:
Wow, it's really amazing what fantastic results one can get, if he's only using simple prisms 🙂
Your home theater looks very nice. It's a pity that i don't owe a house where i could realize a dedicated home theater room 🙂
@Mark:
Hi Mark, while visiting your homepage, i saw that you are using a samsung DVD-HD950 for vertical stretch (beside your projector), right?
Did you have ever any problems with certain mysterious pixel-lines in the black bars?
My DVD-HD870 doesn't work properly. For example, while using "Screen Fit" of the EZview function, the pixels at the bottom of the screen seems to copy a detail of the image above and show it, slightly shifted to the right, again.
Connection is HDMI and progressive scan @ 720p.
So i would like to ask you, if you know how to solve this problem and if your samsung player ever made similar problems?
Karol
Wow, it's really amazing what fantastic results one can get, if he's only using simple prisms 🙂
Your home theater looks very nice. It's a pity that i don't owe a house where i could realize a dedicated home theater room 🙂
@Mark:
Hi Mark, while visiting your homepage, i saw that you are using a samsung DVD-HD950 for vertical stretch (beside your projector), right?
Did you have ever any problems with certain mysterious pixel-lines in the black bars?
My DVD-HD870 doesn't work properly. For example, while using "Screen Fit" of the EZview function, the pixels at the bottom of the screen seems to copy a detail of the image above and show it, slightly shifted to the right, again.
Connection is HDMI and progressive scan @ 720p.
So i would like to ask you, if you know how to solve this problem and if your samsung player ever made similar problems?
Karol
Mark Techer said:
Hi Mark,
Is this some hint as to the new Aussiemorphic lens construction? Or have you sourced an "off-the-shelf" lens from somewhere? 😕
Neil.
Karol N. said:
Hi Karol,
I never saw anything like you descibe with my HD-950. I no longer need that player either now as my new BenqW5000 does all the CIH scaling over HDMI. Since moving into HD, none of the titles I own have subtitles in the black bars either, so it is all good - so far anyway...
Mark
Hi Mark,
yeah i see, i think it's the "best" solution to use a projector which does all the CIH scaling.
You've made a list with 720p projectors on your homepage, which are able to do the vertical stretch. You can add the Panasonic PT-AX200. It also does the CIH scaling for SD and for HD as well.
yeah i see, i think it's the "best" solution to use a projector which does all the CIH scaling.
You've made a list with 720p projectors on your homepage, which are able to do the vertical stretch. You can add the Panasonic PT-AX200. It also does the CIH scaling for SD and for HD as well.
Paul, i still have a question: What's your projection distance? In my case it would be about 11.5 feet and i'm a little bit afraid of the pincushion effect 🙁
Karol N. said:
I will do 🙂
Base your TR around 2.0:1 and the pincushion will not be too bad...
Mark
To find the TR of 2.0:1, measure the width of the native 16:9 image and times by 2. That distance is how far the lens of the projector should be away from the screen...
Mark
Mark
@Mark:
"TR" means throw ratio?
You mentioned that i should measure the native 16:9 image...that means the 16:9 image BEFORE placing the prisms set in front of the projector, right?
Ok, so the width of my actual 16:9 image (with the black bars below and above the image) is 2 meters (that means 6 feet).
To achieve a throw ratio of 2.0:1 my throw distance should be 4 meters (around 13 feet), this is a little bit more than my actual distance of 11.5 feet and shouldn't be so bad, i think....?
Did i understand you properly?
@digitalstore:
12-15 feet...hmmm...ok...my 11.5 feet are not so far away rom that 😉
"TR" means throw ratio?
You mentioned that i should measure the native 16:9 image...that means the 16:9 image BEFORE placing the prisms set in front of the projector, right?
Ok, so the width of my actual 16:9 image (with the black bars below and above the image) is 2 meters (that means 6 feet).
To achieve a throw ratio of 2.0:1 my throw distance should be 4 meters (around 13 feet), this is a little bit more than my actual distance of 11.5 feet and shouldn't be so bad, i think....?
Did i understand you properly?
@digitalstore:
12-15 feet...hmmm...ok...my 11.5 feet are not so far away rom that 😉
Yes "native 16:9" means before any anamorphic stretch.
2.0 will still have some pincusion, but the amount will small and with a decent black boarder on the screen, should go un-noticed...
Mark
2.0 will still have some pincusion, but the amount will small and with a decent black boarder on the screen, should go un-noticed...
Mark
Hi Mark,
ok, i'm glad to read this, thank you very much for your help 🙂
So, i can really hope to realize a CIH in my home.
I know a person, who would sell his anamorphic prism set from you, but he doesn't remember, if the prism have a AR coating or not. Is there any possibility to test this feature?
But beside that please tell me, how did you realize your curved scope screen? I have no idea how to "curve" it 🙂
ok, i'm glad to read this, thank you very much for your help 🙂
So, i can really hope to realize a CIH in my home.
I know a person, who would sell his anamorphic prism set from you, but he doesn't remember, if the prism have a AR coating or not. Is there any possibility to test this feature?
But beside that please tell me, how did you realize your curved scope screen? I have no idea how to "curve" it 🙂
Hi Karol,
If the prisms are coated, they will have a green tint whenviewed off axis. Either that, or take a photo of the lens using a flash. With mine, you don't get the bloom, but can see the flash elements...
The curved screen process is a bit of a long one and best to read about it on my blog, but it uses a thread rod to hold the tension...
Mark
If the prisms are coated, they will have a green tint whenviewed off axis. Either that, or take a photo of the lens using a flash. With mine, you don't get the bloom, but can see the flash elements...
The curved screen process is a bit of a long one and best to read about it on my blog, but it uses a thread rod to hold the tension...
Mark
Hello Mark,
ok, so i'll have to test them when they arrived here. The actual owner sells them because he thinks, that the image isn't sharp enough by using the prisms with his Pana AX200.
The AX200 uses the "smoothscreen technology" to cover the pixel structure by slightly defocusing the whole image.
Ok, so i'll have to take a look on your blog 😀
Thank you 🙂
Karol
ok, so i'll have to test them when they arrived here. The actual owner sells them because he thinks, that the image isn't sharp enough by using the prisms with his Pana AX200.
The AX200 uses the "smoothscreen technology" to cover the pixel structure by slightly defocusing the whole image.
Ok, so i'll have to take a look on your blog 😀
Thank you 🙂
Karol
Yeah, the biggest number of people not liking the effects of the anamorphic stretch due to a "softening"of the image all seem to own Panasonic projectors. "Smoothscreen" had its place in the 720 range, but there is no need for it in the 1080 range.
Of course the facts don't change - prisms will exhibit a softening due to Astigmatism and Chromatic Aberrations and you need correcting elements for this...
Mark
Of course the facts don't change - prisms will exhibit a softening due to Astigmatism and Chromatic Aberrations and you need correcting elements for this...
Mark
Hi Mark,
sorry for my late answer...i had some trouble with my work here.
In the last days, i contacted the epson and samsung hotline to ask them, if they know how to solve my problems with the Samsung DVD-HD870.
Unfortunately, no one of them heard about such or similar problems before, so i'm afraid, that the samsung player might be damaged or something like this...
Optical elements for correcting Astigmatism and Chromatic Aberrations are expensive, i think.
I hope, that the pincushion effect won't be too bad in my setup
sorry for my late answer...i had some trouble with my work here.
In the last days, i contacted the epson and samsung hotline to ask them, if they know how to solve my problems with the Samsung DVD-HD870.
Unfortunately, no one of them heard about such or similar problems before, so i'm afraid, that the samsung player might be damaged or something like this...
Optical elements for correcting Astigmatism and Chromatic Aberrations are expensive, i think.
I hope, that the pincushion effect won't be too bad in my setup
Karol N. said:
Optical elements for correcting Astigmatism and Chromatic Aberrations are expensive, i think.
I hope, that the pincushion effect won't be too bad in my setup
Yes they are and partly why the pro lenses cost what they do...
Mark