|
Hi guys...
I wish to jump in here also as I
too, am building am astrograph. Its a post WWII lens, 225mm clear dia. @ F4.0.
It used to take 9x9; roll film but is being revamped to take 4x5" vacuum film
holder and a sliding slot to take 6x6" a Kodak Wratten 25 and/or 2A
filter. I hope to have pics of this baby out on my FTP server soon.
Focusing is via knife edge,
magnifier, micro adjusted and the plate holder can be rotated and locked
into any posse to suit the image. Each lens, and there is 5 of them, were pulled
apart, polished, and AR coated on each surface. The total weight rolls in
at 145Lbs!! (yeah, tell about it!) and for a shutter, I will use the
'hat trick' method.
This camera is the second only one
of its type in OZ, and was used for many years, by Dr. Arthur Page (a pro
astronomer) for his flare star program. I also use a Speed Graphic 4x5
with its Kodak Graflex Optar 135mm F4.7 lens with a yellow filter and
believe you me, this lens is sharp at wide open!
My other astrograph is a 6" F6
which also uses 4x5" I have two slip on filters a red and yellow. Both this, the
bigger lens and an 8" F4.8 RFT will be mounted onto a new, 500kg payload max.Eq.
mount I am designing. A 4" refr. F15 acts as an ST4 autoguide scope and a
Byers 12" RA drive.
A 4x4 meter rolloff roof obsvy.
will house the gear.
clear
skies..
Jim
|