First Light for Orion Skyscanner
Posted 21 October 2013 - 08:18 AM
first light! But conditions around 9pm local time are very bad:
huge bands of clouds drifting about, and even the open spaces
quite foggy, around mag 3.5 naked eye, and the full moon hitting
from the east! Nevertheless, new equipment must of course
be used as soon as possible.
I bought the Skyscanner for a two month trip to Western Australia,
where I know from previous visits that outback skies well away from
Perth are simply spectacular. On the other hand, my baggage limit
looms very close, so I wanted something lighter than my trusty
Starblast, and much lighter than my 10 inch Skywatcher Flex.
I will put the Skyscanner in perspective with these other scopes,
fully aware that a direct comparison is of course unfair,
especially with the 10 inch.
The Skyscanner is quite similar to the Starblast, except
- aperture of 100 mm instead of 114 mm
- somewhat smaller and much lighter, only about half the weight
- eyepiece faces upward, not Dobson-style sideways at an angle
There are other differences, but none of them a show stopper.
Only the last point turned out to be a real problem. The
Skyscanner is marketed as a tabletop, and it actually only works
well when your table and your chair are the right height, as you
have to lean over the scope from behind to look into the eyepiece,
rather than look into it from the side, in the usual Dobson style.
Unfortunately, my table and chair were the wrong height; for viewing
close to the zenith I put the little scope on another chair and
an overturned bucket, but for viewing close to the horizon I had
to try all kinds of improvisations, none of which were completely
successful. I realize that you should not view close to the horizon
anyway, but there it is.
I did not even mount the 1x red dot finder. With the 20x mag
and 2 1/2 degree of the 20mm eyepiece the finder is not really
necessary. Just aiming the scope in the approximate direction and
scanning worked nicely for the few well-known objects I aimed for.
But still, it would work much better with the eyepiece facing
sideways at an angle. There are good reasons why Dobson chose this
arrangement. I suppose you could easily drill additional holes in
the OTA and mount the tube at an angle, which I may well do, but out
of the box things are not optimal.
Other than that the scope works well, especially given the low price tag
of about 100 bucks. I had already been resigned to deliver the stock 20mm
and 10mm straight to the land of unloved eyepieces, but surprisingly
they were actually not that bad. Given the total price of the scope
they must come very cheap, but both the 20mm and the 10mm have
decent eye relief, and focus extends up to about 70% of the FOV.
Coma becomes very pronounced beyond that. They also sport rubber
eyeguards, in contrast to the Starblast stock eyepieces, which have none.
There is no easy way to collimate the primary on this scope,
but star testing showed perfect collimation out of the box, and given the
rugged construction of the optical tube my guess is that you would have
to treat it real rough to mess up the collimation. This is an F4 scope,
and given the very low price level the overall performance is really
With 100mm aperture and 400mm focal length the 20mm eyepiece delivers
20x magnification and 5mm exit pupil. This fills my own 5mm pupil nicely.
In other words, the image at 20x could not be brighter. The focuser at
this price level is of course a simple rack and pinion, which works OK
with the 20mm, but gets quite fiddly with the 10mm. The mount is sturdy,
and movements in both altitude and azimuth have just the right stiction.
A 100mm scope is not exactly a light bucket, and first light conditions
were very bad, but even so I was able to observe a number of objects:
M45 about fit with the 20mm, but looked much better in 8x40 binoc
M31 was easily found, but very uninspiring with these conditions
M52 same here
M27 easy to find with the 20mm, and the 10mm showed an extended
disk, but no structure
M39 as always not spectacular, but not as badly hit by low transparency
NGC 869 and 884 the double cluster unusually disappointing, maybe
15-20 * each, but nicely framed at 20x
M57 shows disk shape with the 10mm, rather than ring
To finish off I tried the 10mm on the Moon. The scope comes with
a second lid inside the cover to reduce the aperture, and this was really
necessary with the power of the full moon. With better seeing probably
Just out of curiosity I also hauled out the 10 inch Skywatcher Flex
for comparison. It was able to cope much better with the fog, showing
much more than the Skyscanner, and of course going to much higher
magnifications easily. On the other hand, with close to 60 pounds it's
no fun to drag about the backyard, even for a short distance.
At this point there was just too much fog, and I gave up.
At 06:00 I woke to find Orion framed in my window. Out again
with the Skyscanner, and it really does not take longer than a minute.
I would certainly not have gone out with the 10 inch at that point.
The clouds were still there, even worse than in the evening.
M42 was easily found with the 20mm, and showed shape, if not structure,
with the 10mm.
Sirius was sparkling crazily naked eye, and in the Skyscanner the
effect was even more pronounced, quite a spectacle in itself.
To sum it up I am satisfied with the Skyscanner. It is very small and
light, absolutely grab and go. It fits into a normal sized bag or backpack,
and getting it out and putting it away is almost as fast as with my binoc.
If the eyepiece were not at such an unfortunate angle it would be the perfect
quick-and-easy scope. As it is it's still a good purchase, and certainly
very easy to handle. Compared to the Skyscanner, even the Starblast is
Johann from Austria, observing in small town area 20 miles from capital
Posted 21 October 2013 - 05:46 PM
Posted 23 October 2013 - 05:24 AM
A very nice write up.. that should be a wonderful trip, Austria to Australia.. they are close together in the dictionary, it should be just a short trip.
It will be interesting to see how the Skyscanner fares under dark skies, should be a real treat. What eyepieces are you taking with you? I have to think a 24mm WF would be spectacular.
Posted 31 October 2013 - 08:42 AM
Regards from Austria,
Posted 02 December 2013 - 10:58 AM
I looked at M38, M36, M37, M45, M42, and the double cluster; after a lot of eyepiece and scope switching the Starblast turned out to be significantly better in every respect. Not only was the image slightly brighter with all eyepieces, but the level of detail was always better with the Starblast, and with both the 17mm and the 32mm stars were needle pin points to about 80% towards the edge. With the Skyscanner everything looked a little bit more mushy across the whole field of view, I guess the mirror just isn't up to the Starblast's quality level. The Skyscanner is certainly not a bad scope in its own right, as it is very cheap, and also very small and light, but unless for some reason you absolutely cannot exceed your budget or weight limit you should spend the additional 80 bucks or so to get the Starblast. This is old news and has been reported here and on other forums in a similar fashion, but now I can confirm it from my own experience.
On a different note, the Hyperion turned out not to be the best choice for either scope. Maybe the design just doesn't work very well with F4 scopes; the Hyperion showed about 50% of the field of view very well, but beyond that the image deteriorated very fast, and was almost useless near the edge, rendering the wide angle effect pretty much useless. The Baader Classic 32mm which is a Ploessl design gave about the same angle of view, of course with lower magnification, but tack sharp to about 80%, with only maybe the last 10% or so markedly out of focus. Overall the impression was much better with the 32mm than with the Hyperion. Considering that the 32mm is less then half the price the disappointment was even greater.
On the other hand I was surprised how well the 17mm from the Starblast kit performed in comparison. This seems to be a Ploessl design; the only gripe I have is that there is no rubber shield, but that is really a minor thing. Having used this one side by side with the Baader 32, judging very roughly and subjectively, I would say they are about the same level of quality.
Johann from Austria
Posted 06 December 2013 - 05:30 PM