The AP155 EDT f/9 is one of (if not the) best visual telescopes in the world.
Light weight and sturdy, this substantial telescope is perfect for
observing the sun
or the stars. The optical and mechanical construction of the 6.1 inch
APO is
absolutely first class.
Performance
The Super ED design of
this f/9 StarFire is
free of coma, spherical aberration and other higher
order aberrations. It is highly corrected for false color (chromatic
aberration).
Nighttime views offer pinpoint stars to the edge of the field on a true
black sky background.
Planetary views offer tremendous resolution, detail and contrast.
Handling and
transportation is a breeze. The dew shield is removed and placed
on backwards to fit the scope into its case. Cool down takes at least an
hour.
Views of the sun are
stunning in this telescope! Prominences are big and bright
and handle magnification extremely well. Depending on the seeing,
you can often see detail inside them. There are no internal reflections
and
the red sun stands out against a dark black background. Surface detail is
astonishing.
Individual spicules can be viewed along the limb and around active
regions.
Magnified image of a large Active Region taken with the
AP155EDT (04/2006) Large
Summary
Observing
through this scope is about as good as it gets. For the sun, everything you want
to
see is there,
a highly magnified detailed view on a velvet black
sky.
For what this scope costs, you’d expect it to perform wonderfully. It
does.
Click to enlarge
Lens Cell Close-up
Focuser Close-up
Green Laser Test
Specifications
Objective Lens
Super EDT StarFire design, oil spaced triplet
(ZKN-7 crown with a FPL-52ED positive element), Push-Pull lens
cell
Color Correction
<0.01% focus variation from 706nm to 405nm
Clear Aperture
155mm (6.1")
Focal Length
1395mm (55"), f/9
Resolution
0.74 arc second
Coatings
Multi-layer, >97% @ peak wavelengths
Magnification Range
25x to 600x
Tube Assembly
6.5" aluminum, >12 baffles
Weight
22lbs (10.5 kg) without Ha equipment
Years of Manufacture
AP155EDT's were made from
1991 to 1994 in batches of 60 at a time. Last SN was around #250.
Click to enlarge
Data Sheet Front
Data Sheet Back
Original Ad
EDT Ad
Solar Data
150mm ERF, AP Barcon, 3"
extension, AP MaxBright diagonal and AP telecentric Lens,
Meade 56mm Plossl.
Focal Length
4082mm (f/29)
Magnification
73x
Exit Pupil
1.93mm
Arc Second
Resolution
1.2 arc seconds*
*Resolution = {(1.22 x Ha wavelength) / ERF diameter}
x 206265. Where resolution
is in Radians, Ha wavelength is .000656mm, ERF diameter is 110mm and
206265
is the number of arc seconds in one radian.
