Re: DIY prisms
Will do as soon as I collect my coated prisms from the in-laws place in July. I'm HOPING the 4 prism set will blow me away. I do prefer the 4 set, i find the picture noticably sharper, more intense color wise. Just my opinion of course. Of cours, the problem with the uncoated lenses is the reflections. Mind you, a 2 prism set has them as well, just not as many or as pronounced. I'll have to give ROAR a shout to get him to take the pics for me(he's really good & has a great camera).
Stay tuned...
Bud
PrabhatB said:
Will do as soon as I collect my coated prisms from the in-laws place in July. I'm HOPING the 4 prism set will blow me away. I do prefer the 4 set, i find the picture noticably sharper, more intense color wise. Just my opinion of course. Of cours, the problem with the uncoated lenses is the reflections. Mind you, a 2 prism set has them as well, just not as many or as pronounced. I'll have to give ROAR a shout to get him to take the pics for me(he's really good & has a great camera).
Stay tuned...
Bud
I've got some A/B (2 and4 prism) comparisons but the light reflections are crap on the 4 prism version, so why I did not go that path.
CA is reduced on the 4 prisms version...
Mark
CA is reduced on the 4 prisms version...
Mark
Mark Techer said:
Reflection trouble STILL on the coated prisms?
I'll have to wait till July to give mine a test, hate to think I spent MUCHO $ for nothing. Hopefully it won't be the case. Wouldn't mind seeing your A/B pics.
Bud
Yes and I am not sure why - possibly the air/glass interface between the prisms. I am having them bonded so we'll see how that pans out...
Mark
Mark
Hey Mark, here's one and your post from AVS...
Quote:
Originally Posted by Steve Scherrer
Has it been established that the coating does a good job on the "stray light problems?"
Quote:
Originally Posted by klemsaba
Based on my experience with both coated and non-coated prisms I would say YES.
And I second that
Mark
__________________
CAVX - Cinematic Audio Visual eXperience
So is it yes or no?
Bud
Quote:
Originally Posted by Steve Scherrer
Has it been established that the coating does a good job on the "stray light problems?"
Quote:
Originally Posted by klemsaba
Based on my experience with both coated and non-coated prisms I would say YES.
And I second that
Mark
__________________
CAVX - Cinematic Audio Visual eXperience
So is it yes or no?
Bud
Another posting from an AVS member with the coated prisms...
"I have to say again that these prisms are great! There is some light loss using the prisms... probably about the same as when i zoomed the image before. But the prisms are way cooler and easier to use than zooming and positioning the image on the screen plus the image doesn't get softer as it does when zooming. The AR coating is amazing. I have yet to see any stray reflections on the screen. Yea, I have some geometry issues at the edges of the screen and a little CA, but you really don't notice those issues when watching a movie."
So I guess i'll have to wait till I set mine up to give my opinion but the few postings i've read from people who have the coated prisms seem to like the results.
Bud
"I have to say again that these prisms are great! There is some light loss using the prisms... probably about the same as when i zoomed the image before. But the prisms are way cooler and easier to use than zooming and positioning the image on the screen plus the image doesn't get softer as it does when zooming. The AR coating is amazing. I have yet to see any stray reflections on the screen. Yea, I have some geometry issues at the edges of the screen and a little CA, but you really don't notice those issues when watching a movie."
So I guess i'll have to wait till I set mine up to give my opinion but the few postings i've read from people who have the coated prisms seem to like the results.
Bud
And I have no problems stating that again for a AR coated 2 prisms lens. It is the 4 prisms version that I am having problems with...
Mark
Mark
Mark, i'm not trying to be confrontational, i'm just trying to understand what the problem still is. I have been reading positive results from the US coated prisms so could it be you have a slightly different coating? As I recall, you didn't have the same ghosting I displayed in my pictures so is yours the same as before or worse? I realise your Aussiemorphic lens is based on 2 prisms.
If you have pictures, could you please post them so I can see what's up, and if anyone who got the L&L coatings, could you post some pics of a 4 prism lens.
Bud
If you have pictures, could you please post them so I can see what's up, and if anyone who got the L&L coatings, could you post some pics of a 4 prism lens.
Bud
Hi Bud, the light reflections I got were more like those seen from Steve back (link here ) when he was first trying to stretch 4 x 3 to Scope. You can see the "rainbow" on the side of his image - too much stretch? - and I got similar results but in the centre, so worse than his.
I cannot explain why the reflections are there except to say that maybe the light between the faces of the pairs is the problem as the coating does not totally remove the stray light, but reduces it.
The results of a 4 Vs a 2 prisms lens is not trivial so far as a reduction in CA is concerned, but there was too much stray light for me to work with, much less market.
When I have the prisms bonded, I will conduct further testing...
Mark
I cannot explain why the reflections are there except to say that maybe the light between the faces of the pairs is the problem as the coating does not totally remove the stray light, but reduces it.
The results of a 4 Vs a 2 prisms lens is not trivial so far as a reduction in CA is concerned, but there was too much stray light for me to work with, much less market.
When I have the prisms bonded, I will conduct further testing...
Mark
Tested the new bonded prisms today. For the effort that is required Vs the end result, I don't think it was quite worth it. Sure there was some benefits (CA was slightly less for sure) but I could not see this being economically viable long term...
Mark
Mark
CANADIAN DISTRIBUTOR OF LENSES
Hey Roar,
I am just finishing my basement with a HT room. I have abandoned my old house/HT set up to start anew. Only gear i am bringing across is my speakers. I want to make a hd projector purchase soon, before November, and will ensure it has V stretch (looking at Optoma HD81-LV as Optoma offers their own Anamorphic lens I am making an assumption it does). Think I will need a set of the prisms. Where in Ontario can I find them. I live in Brampton.
Any help appreciated.
Biting at the bit to get started. Will be going Blu-ray for sure... hope that is not a hinderance to working out CIH...
Rotten Rod. (sorry would have e-mailed but i am new to DIY)
ps. this thread is like a train wreck, have been unable to look away.
Hey Roar,
I am just finishing my basement with a HT room. I have abandoned my old house/HT set up to start anew. Only gear i am bringing across is my speakers. I want to make a hd projector purchase soon, before November, and will ensure it has V stretch (looking at Optoma HD81-LV as Optoma offers their own Anamorphic lens I am making an assumption it does). Think I will need a set of the prisms. Where in Ontario can I find them. I live in Brampton.
Any help appreciated.
Biting at the bit to get started. Will be going Blu-ray for sure... hope that is not a hinderance to working out CIH...
Rotten Rod. (sorry would have e-mailed but i am new to DIY)
ps. this thread is like a train wreck, have been unable to look away.
Refractive Index
It has been documented from the beginning of this extremely long thread that we should be using prisms with a different Refractive Index.
Whilst researching the topic, I found a link that showed a lens element made from two different materials bonded together - flint and corning.
Given that most of use are using optic glass for both prisms, does anyone think that some improvement could be made by bonding another type glass to the prisms face?
Mark
It has been documented from the beginning of this extremely long thread that we should be using prisms with a different Refractive Index.
Whilst researching the topic, I found a link that showed a lens element made from two different materials bonded together - flint and corning.
Given that most of use are using optic glass for both prisms, does anyone think that some improvement could be made by bonding another type glass to the prisms face?
Mark
Re: CANADIAN DISTRIBUTOR OF LENSES
I'll have to see if I can dig up that list that I had with the local vendors... that was a long time ago 🙂 I'll send it your way if I can find it...
In the mean time I may have 2 prisms for sale, I bought 4 originally and I am only going to use 2 I think, not sure yet, have to do some more 4 prism testing first, so that may be an option for you as well...
When considering your projector make sure you look into whether it does the stretch over HDMI, if you are going Blu Ray, I'm guessing you are going to want to run HDMI. I was originally looking at the Optoma HD70 because it does the stretch but my research lead me to believe it does not do the stretch over HDMI, only Component, I ended up puchasing the Panny AX100u insteadto go with my Toshiba A20, I will be using that player to upconvert my SD DVD's over HDMI.
ROTTEN ROD said:
I'll have to see if I can dig up that list that I had with the local vendors... that was a long time ago 🙂 I'll send it your way if I can find it...
In the mean time I may have 2 prisms for sale, I bought 4 originally and I am only going to use 2 I think, not sure yet, have to do some more 4 prism testing first, so that may be an option for you as well...
When considering your projector make sure you look into whether it does the stretch over HDMI, if you are going Blu Ray, I'm guessing you are going to want to run HDMI. I was originally looking at the Optoma HD70 because it does the stretch but my research lead me to believe it does not do the stretch over HDMI, only Component, I ended up puchasing the Panny AX100u insteadto go with my Toshiba A20, I will be using that player to upconvert my SD DVD's over HDMI.
Roar, if your going to get any improvement from 4 prisms, you need to bond them. Not the easiest thing if you want perfect bubble lamination, but other wise you just get more stray light reflections - even with coated prisms...
Mark
Mark