I already owned a very good scope for widefield imaging but was looking
for something that would be a little more versatile. While I want this
to be a review of the Levenhuk 80mm triplet and not a comparison with
the Astro Tech AT65EDQ, I need to relate my thinking as to why I thought
I needed the new scope.
The Astro Tech scope is a 65mm quadruplet with a built-in field
flattener. It provided extremely flat fields all the way to each corner
of my images every time I used it. However, there were times I wished it
were a faster scope. There were times I wished I had a little wider
field of view. And there were times that I wished I could use my 2"
diagonal and 2" eyepieces to take in some widefield views. The AT65EDQ
would not reach focus with my 2" diagonal in the focuser, and the
built-in field flattener prohibited using a reducer/flattener, so I was
stuck with its f/6.5 optics that provided a focal length of 420mm.
However, it is marketed as an astrograph, and for the last year, it has
served me extremely well as just such an instrument.
Enter the Levenhuk 80mm triplet.....
|This is the scopes L-shaped mounting bracket bolted to my supplied Losmandy style dovetail.|
Upon receiving the scope, the first thing that caught my eye was the
paint job. In good lighting this thing is beautiful. It looks to be a
pearl white with some metal flakes. I tried to get a close up of the
paint but could not get a shot that I felt does it justice.
|Comes in a nice little case. The dew shield is extra long compared to other refractors I have used.|
The next thing I noticed that I really liked was the threaded metal dust
cap. This cap will never fall off and you can take darks in broad
daylight and never need to remove the camera from the scope.
The 2" crayford focuser seems to be relatively smooth, but since buying a
Moonlite for my newtonian, I can only say that it is adequate. There is
a lock for rotating the focuser which is nice for framing a target if
you have not already taken flat frames. However, it does not have a
screw to lock focus, only a tension screw.
Besides not having a lock screw on the focuser, there were only a couple
of things I did not like about the scope. First, it does not come with a
mounting bracket for a finder scope. It also does not come with
mounting rings. It comes with only the L-bracket that is bolted to the
Losmandy style D-plate in the photo. I have since purchased a set of
90mm ID William Optics rings and made a plate to go on top of the rings
to mount the finder scope bracket to hold my 50mm Orion mini guidescope.
The configuration seems to be very solid.
We all know that getting new astronomy equipment also brings with it
lots of clouds, sometimes for days on end. I did manage first light a
few days later for a bit of observing with the new telescope. I used my
Meade 2" diagonal with the Explore Scientific 24mm 82 degree apparent
fov eyepiece for some outstanding widefield views. This provided a field
of view of more than 4 degrees with a magnification factor of 20X. The
views were extremely crisp and I decided to up the magnification and
check collimation with a star test. For this, I installed my Astro Tech
2X barlow in the diagonal coupled with my Explore Scientific ES82 8.8mm
eyepiece and slewed to Vega. The diffraction rings showed a perfectly
concentric pattern, and when bringing the bright star into focus, I
could not see even a hint of chromatic aberration. The premium FPL-53
optics perform flawlessly.
The brief first night of viewing the stars between breaks in the clouds
satisfied me for a little while, but I was anxious to see what it would
do with my Canon DSLR installed in the focuser. It would be a few nights
before the Moon would allow me to do any imaging, so I called
Astronomics and ordered their Astro Tech 0.8X reducer/field flattener.
This reduced the focal ratio of the scope from f/6 down to f/4.8 and
dropped the focal length almost 100mm from 480mm down to 384mm. The Moon
allowed only a very short first night of imaging, but this is what I
was able to produce in one hour using five minute subs (12X300sec) at
|M33, Triangulum galaxy|
I want to add some more data to the M33 before posting a full resolution
image to Astrobin. Fortunately, I was able to get in some serious
imaging a few nights later. This image of Andromeda galaxy is a
combination of 53 subs of 300 seconds (4.4 hrs) at ISO 800.
|M31, Andromeda galaxy. I was quite pleased with how this one turned out.|
The Pleiades (M45) was done over 2 nights and is a total of 100 subs of 300sec (8.3 hrs) at ISO 800.
|This image of M45 is my personal record for integration time. I really wanted to pick up the faint dust in this area.|
Then I decided to try the Heart nebula, IC 1805. This target is best shot in h-alpha, but I thought I would
give it a try in RGB with my DSLR. It is 48 subs of 300 seconds (4 hrs)
at ISO 800. I probably should have gone with longer subs, but left it at
300 seconds, because I have a good library of dark frames at 300
seconds. Someday I hope to own a nice CCD camera and some narrowband
filters. I think it will help greatly on targets such as this one.
|IC 1805, the Heart nebula|
Full resolution images can be found here in my Astrobin gallery: http://www.astrobin.com/users/rflinn68/
The corner stars look very good on the M45 image, but not so good on
the Heart. The camera was never removed, so I suspect this is due to my
focusing technique. I probably will need to start focusing on a star
somewhere between the center and one of the corners. Everything
considered, I am very happy with the new scope.
|Here is the scope set up for imaging with the William Optics rings and dew heaters. I made a plate|
to go on top of the rings for mounting the finder bracket to hold the Orion 50mm mini guidescope.
I ended up selling my AT65EDQ and keeping the Levenhuk 80mm triplet. It
is simply a much more versatile telescope and better fits my needs. For
starters, it has 15mm more aperture, which is always good. It is a
faster scope at its native f/6 and much faster with the reducer at f/4.8
and will give me a couple of focal lengths (384mm and 480mm) to choose
from once I purchase a regular field flattener. It is also an excellent
grab and go telescope for observing that I can use with my 2"
accessories and eyepieces.
The key word I keep coming back to in regard to this scope is
"versatile." I am very pleased with the scope and expect to enjoy it for
years to come for both observing and imaging. Great job, Levenhuk, and
thank you for such a wonderful instrument!