ATM What's this camera?

[Aplanatic@aol.com]

Dear list,

I keep giving away my reference material -- several copies of R and vV, the 
ATM series, etc.  At the moment, I don't have a copy of R and vV or Wilson. 

I've been fooling around with Lurie-Houghton variants and came up with this 
ultra-wide field camera design:

http://members.aol.com/aplanatic//LHcam.len  (OSLO LT design file)

It uses a Houghton-style corrector where the surfaces can be ground against 
each other, an ellipsoidal primary with a conic constant of -0.425, and a 
curved film holder similar to a Schmidt camera.  This design is a 10" f/3 
with a four inch diameter film circle.  The design can be made faster than 
this and will cover a larger image circle.  The images are excellent all the 
way to the edge.

Knowing that there's nothing new optical under the sun, what is this optical 
system?  Probably an aspherical variant of the Lurie-Houghton camera that's 
been around for a while.  

Anyway, it has performance to drool over (if you like wide-field imaging with 
film), looks like it's practical to make and has several mechanical 
advantages including a shorter OTA than a Schmidt, less vignetting than a 
Schmidt for the equivalent sized primary and the corrector supports the film 
holder so there's no spider diffraction.  A quick analysis suggests that 
there's no "Schmidt Ghosts" from the corrector, but I need someone with a 
ghost analysis ray tracer to verify this.  Finally, if the surfaces are 
ground in pairs, the tolerances on the corrector lens radii are not tough at 
all.  The only tough part is figuring a fast primary to a mild conic, 
probably doable in less than the age of the universe.

Thanks,

Dave Rowe