[Phat Phreddy]

As it seems the Panamorph is going to have a problem with my projector, and the reason is due to the fact that it is not edge aligned, I am thinking of workarounds and solutions...


Some projectors come with an optical image shift lens to be able to adjust the final image position and not induce keystone... It seems to me that if I could do this and still have room to get the (especially wide) image from my projector through the lens and Panamorph, then I could create an edge aligned situation and it would all work as advertised..


I have a feeling that edge aligned projectors are a minority so it would be of advantage to many of the potential Panamorph owners if this solution would work...


So has anyone ever heard of or seen such a device ??


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[mflaster]

Quote:

Originally posted by Phat Phreddy: As it seems the Panamorph is going to have a problem with my projector, and the reason is due to the fact that it is not edge aligned

As I said in the other thread, my personal theory is that it's *not* because of edge alignment, but rather it's strictly related to throw ratio, and only throw ratio.


Like *I* really know... http://www.avsforum.com/ubb/smile.gif


Mike




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[Phat Phreddy]

But think of this... If it is because of throw ratio why is it you are not seeing distortion at the side edges of the convergence grid ???


I would argue that it seems clear that the advanced angle that the Davis units (and other non edge aligned projectors) are intersecting the Panamorph makes the distortion...


This does not make your argument invalid rather it is correct... The edges of the image (sides) are possibly suffering this distortion too due to the light beams not being parallel (very slight however) but it is the really sharp angle of interaction of the bottom of the image (combination of off axis projection + the light paths not being parallel + the fact that a Davis unit has a very large light beam compounding all of this) that is creating this effect...


If we could (without inducing keystone) raise the image light beam we would at least improve upon what I think is the big issue (the angle of intersection at the bottom of the image)...


After waiting so long and even spending extra money to buy another 'shipping now' spot I just don't want to give up hope yet !!!


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[mflaster]

Quote:

Originally posted by Phat Phreddy: But think of this... If it is because of throw ratio why is it you are not seeing distortion at the side edges of the convergence grid ???

But the panny doesn't care about light left to right - it's only up and down that matters. In other words, a beam that's left 10 degrees, 20 degrees, 30 degrees, the Panny doesn't care, it just passes it. But if it's *up* 20 degrees, it bends it a little straighter, which causes "compression".


So side to side there should never be distortion, as far as I can tell. But there have been reports of bowing at the bottom edge - don't know what causes that.


Mike




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[KFung]

Mike,


I think Phreddy is right, it is probably related to offset angle. After all, the light doesn't change after is exits the lens so with identical positioning of everything and just changing the throw distance (and focus) you will get the same image. Similarly, I don't think different zoom setting would make a difference unless you're hitting the edges of the Panamorph.


Regards,


Kam Fung

 

[mflaster]

Yes, Shawn posted in the other thread, it does seem to be offset angle, not throw ratio.


That'll teach me to speculate about optics!!! http://www.avsforum.com/ubb/smile.gif


Mike



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[Phat Phreddy]

Well the bizarre thing is when I read your post about of course there is no side distortion due to it only being horizontal compression I thought... DOH !! and believed I had missed the obvious...


In truth I think the Davis is a "3 strikes your outta here" situation... Short throw + Image offset + large beam spot size will all compound this problem..


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