Hi this is Rox, been reading the public forums since I decided to enter the menbership. I have been looking for information about the pro lens but didnīt find the desired information.
I would like to check the lens performances on a lens simulation program. This way I could see what's wrong with it. Have a look to this simulation of the spotsize of a 500mm triplet (spotsize resumes the performances of the lens on a graphic).
Full Version: lens design
Some very friendly users helped to me with the pro lens model. We got the measurements (they have some errors even with the micra precision of the meassurent 
)
I introduced the model on oslo and due to the meassuring error (mm precision) and the assumtions took by me on the materials, the pro triplet model isnīt actually 450mm-500mm varifocal on my OSLO, but it is close; 560-610mm.
It would be a good idea if brain could tell me the exact meassurements as well as the used materials. Anyway I think it is a closse enough model.
The simulation showed the well known thing; The lens works much better backwards.
I donīt know if the lens was designed so the focusing ring should be outside or not, but i have seen some ohp with varifocal triplet with the focus ring (meniscus lens side) facing the trasparency. But since the image quality is much better with the meniscus side facing the lcd, it was designed this way or not, why should we use it the other way?
I only know that the LL fixed lens triplet is made so the meniscus lens should face the projection.
upper lens is the meniscus lens, this should face the projection and the biconvex lens should face the lcd.
Now let's see the pro lens "close enough model" performances;
left side is with the lens on normal usage (the meniscuslens facing the projection)
Right is the backwards usage (check how the performances are better this way)
the two images on top are with the lens at 500mm position (well 610mm on my oslo odel) and the bottom are 450mm position (560 on my oslo model).
the graphis show the relation of the spot size VS field angle.
the spot size is a good sumary of the lens performances including all aberrations. Smaller the spot size, better lens we have.
The conclusion I can see from here, is that the model isnīt optimized as goog as it could be, check the first graphic I posted, there it is a 500mm triplet fully optimized, the spot size is half (and even smaller) the pro lens model spot size moreless.
Anyway, it agree that real specs would show a different (I guess beter) performances. Is it posible to check it with your aproval brainchild?
)I introduced the model on oslo and due to the meassuring error (mm precision) and the assumtions took by me on the materials, the pro triplet model isnīt actually 450mm-500mm varifocal on my OSLO, but it is close; 560-610mm.
It would be a good idea if brain could tell me the exact meassurements as well as the used materials. Anyway I think it is a closse enough model.
The simulation showed the well known thing; The lens works much better backwards.
I donīt know if the lens was designed so the focusing ring should be outside or not, but i have seen some ohp with varifocal triplet with the focus ring (meniscus lens side) facing the trasparency. But since the image quality is much better with the meniscus side facing the lcd, it was designed this way or not, why should we use it the other way?
I only know that the LL fixed lens triplet is made so the meniscus lens should face the projection.
upper lens is the meniscus lens, this should face the projection and the biconvex lens should face the lcd.
Now let's see the pro lens "close enough model" performances;
left side is with the lens on normal usage (the meniscuslens facing the projection)
Right is the backwards usage (check how the performances are better this way)
the two images on top are with the lens at 500mm position (well 610mm on my oslo odel) and the bottom are 450mm position (560 on my oslo model).
the graphis show the relation of the spot size VS field angle.
the spot size is a good sumary of the lens performances including all aberrations. Smaller the spot size, better lens we have.
The conclusion I can see from here, is that the model isnīt optimized as goog as it could be, check the first graphic I posted, there it is a 500mm triplet fully optimized, the spot size is half (and even smaller) the pro lens model spot size moreless.
Anyway, it agree that real specs would show a different (I guess beter) performances. Is it posible to check it with your aproval brainchild?
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