Lightweight Dobson Telescopes And High Quality Parabolic Mirrors - Made in Germany!
News and updates in the "Spacewalk Telescopes" Blog
10.12.2022 - 20" Infinity NL no longer available
In order to slim down my product line a bit, I have decided to stop offering the 20" Infinity NL as of next year. Previous or ongoing orders
are of course excluded from this.
The 16" Infinity NL is not affected. So you can continue to order this wonderfully lightweight telescope.
03.11.2022 - Update Drawings
After a long time there is an update of my drawings. Instead of a slew of new objects, I have revised many of my old drawings, because
I now use a different method to set stars and adjust their brightness.
Especially the open star clusters have changed a lot.
Have fun looking at them. :))
20.10.2022 - Three times 20 inches
As I was scrolling through my blog, I noticed that there hasn't been anything on the subject of mirrors for even a long time. Since every now and then a mirror gets finished, I would like to present a collection of three 500mm mirrors. All mirrors have a measured Strehl ratio of 0.91...0.93 and therefor surely provide beautiful and contrasty images in the sky.
04.10.2022 - Diligence...
Every now and then, a few packages of aluminum profiles find their way into my workshop.
These first have to be marked and cut to length. Then the profiles are sanded and the holes are drilled. And that's a hell of a lot of drilling,
which can feel like it takes forever. But you shouldn't let up on your concentration, because a single wrong hole can ruin at least part of
the work. Finally, everything is sorted neatly so that nothing is missing.
12.09.2022 - Reworking my DeepSky drawings
In the last days I spent some time to completely rework my subpage with the DeepSky drawings, to restructure it, to separate it from
my homepage and to move it to a separate section.
All drawings can now be found in the "Spacewalk Telescopes Universe". In this sense have fun looking and browsing. :)
01.09.2022 - Update of my drawings
After a long time there is an update of my drawings. 14 new objects have been added - all from an observation night in
September 2018, so I'm hopelessly behind.... 4 years to be exact ;)
Among the new objects are for example the Egg Nebula, the galaxy Messier 74, the Skull Nebula NGC 246 and also three star
clusters from my "Teutsch" project.
Have fun looking at them.
26.08.2022 - Summer drought in Central Europe
The summer here in the southwest of Germany in 2022 was even a little extreme - and gives a foretaste of what could become
the new normality due to climate change.
There were 106 days with a temperature of more than 25°C (77°F) and 50 days with more than 30°C (86°F), so-called heat days.
The average maximum temperature during the three summer months was 29.8°C (86°F), which is 4K more than normal. Unfortunately,
only 43% of the normal rainfall fell over the period, less than half. The high temperatures and little rain resulted in many corn
fields being completely withered.
31.08.2022 - Secondary mirrors
This is what it looks like when a parcel arrives from the USA with many secondary mirrors. All well packed and neatly
sorted by size. A really nice sight, isn't it?
All imported secondary mirrors have a surface quality of better than lambda/10, but are also available with an accuracy
of incredible lambda/30 for an extra charge (depending on the secondary size).
So if you want an extremely good secondary with a surface quality of better lambda/10, please let us know when you order
your telescope.
09.08.2022 - The moon and some of Europe's highest peaks
From Switzerland comes this beautiful photo showing the waxing moon at dusk next to the 4,190 metre (13,800 feet) high
"Strahlhorn". It was taken at the Britannia Hut at just over 3,000 metres above sea level.
Below the Strahlhorn, the mighty streams of the Allalin and Hohlaub glaciers spread out. Due to the very warm summer
and the low precipitation in winter, the glaciers are very overexcavated up to great heights. Unfortunately, we have to
assume that 2022 will be a very bad year for all glaciers in the Alps and they will lose a lot of ice, which will probably
never be rebuilt.
04.08.2022 - Summer heat
On August 4th it was particularly hot here in southern Germany. That's why I took my calibrated thermometer to the city
centre to measure the prevailing temperatures. The maximum was a hot 39.4°C (103°F) at 5:10 pm.
Afterwards I drove into the surrounding countryside, where the temperature dropped to just under 38° (100°F). So it is a little
hotter in the city centre than in the surrounding small towns. But that's not surprising, because the city is like a concrete desert.
This effect is particularly glaring when I come home from observing well after midnight in summer. While the car thermometer
shows 20°C (68°F) in the surrounding area, it rises to 25°C (77°F) in the city. So there's usually not much chance of cooling down
the bedroom.
01.08.2022 - Price adjustment
In recent weeks and months, the prices for some telescope assemblies have gone up significantly. This concerns in particular
raw materials such as aluminium, but the costs for stainless steel screws have also risen sharply. The coating of the mirrors has
also become more expensive.
Unfortunately, I also have no choice but to increase the prices on 01.08.
Because glass production is a very energy-intensive process, we will have to wait and see how the increased prices for gas or
bottlenecks in the energy supply will affect the prices for mirror blanks. So it is quite possible that I will have to raise prices
a little again this year, but perhaps we will be lucky and the situation will calm down again somewhat.
16.07.2022 - A summer evening on the hills of the Black Forest
It takes about 40 minutes to get from Karlsruhe to the beautiful corners of the northern Black Forest. A particularly beautiful
area can be found east of the Murgtal valley, where the hills reach an altitude of just under 1,000mNN. There are many small
paths and trails that wind through this area. Some of them lead the hiker to great rock formations from which one has a
wonderful view.
It is especially beautiful in the evening hours of a long summer day, when the sun is low in the sky at 9 pm and bathes everything
in a golden light.
If you like, you can enlarge the picture by right-clicking and selecting "Open graphic in new tab".
04.07.2022 - Surface grinding of a 25 inch mirror
When my mirror blanks arrive from the company "Schott", they first have to be prepared a little before the mirror
is ground. The first step is to apply the bevels to the front and back, then fine sand the edge of the blank.
After that, the back has to be ground flat - one of my least favourite jobs. To be honest: I'm always glad when it's over ;)
A heavy granite tool with a suitable diameter is used for this. I start with grit size K60, because the back is sometimes
very wavy. At the beginning, the surface grinding makes a lot of noise, because the Karbo likes to collect in the grooves
and depressions and then grinds granite directly onto glass... That sounds very unpleasant to the ears. From time to time
I check the progress. At the beginning everything goes pretty fast, but towards the end it drags on quite a bit because
the entire surface has to be ground to the lowest point - even if the missing area is quite small. And that can really take
some time. As I said, I'm always glad when it's over.
Once that's done, the final thing is to smooth the back with finer Karbo, but fortunately that's quite relaxed.
11.06.2022 - Profiles for mounting the trusses with grooves
The aluminium profiles of the model series "Infinity NL" are now available again with the well-known grooves.
When setting up the telescope, the four pairs of rods are simply pushed into these grooves one after the other and
clamped with large star knob nuts.
It is a very simple, effective and extremely fast way to mount the telescope's trusses.
10.06.2022 - New segments for the "Trackie" tracking platform
In the last few days I have been working again on the construction drawing for the EQ platform and designed some
new segments, which now cover a much larger range.
The new segments are available in 4° steps from 40°N up to 60°N. The maximum range in which "Trackie" can be
used thus goes from 38°N up to 62°, since deviations of +-2° can be neglected in visual use. This means that stargazers
in the Mediterranean countries and in Scandinavia now also have the possibility of equipping their Dobsonian telescope
with a tracking system.
By the way: The segments are not permanently mounted, but can be exchanged as required, e.g. if you want to take
your telescope on holiday to southern latitudes.
02.06.2022 - Northern Black Forest Observatory
Early summer has finally arrived up at 900 metres above sea level. So what could be nicer than taking a nice tour into
the Black Forest on a mountain bike. My destination was the observatory of our Karlsruhe club, which has been running
it for several years. The sky up here is wonderfully dark because the site is cut off from the bright lights of the Rhine
valley by a chain of hills in front of it.
By the way, only a few kilometres away from here is my observing site, which is a little higher and a little darker.
25.05.2022 - Overhaul of my polishing machine
After my polishing machine with the name "Polly" has been doing its job for several years now, it was time for an
overhaul. So I removed the turntable and the drive discs as well as some of the wooden plates.
Then everything was freshly painted, new bearings and a thicker shaft were mounted or knocked in with a sledgehammer
and the machine was completely reassembled. A short test run and bang, the general overhaul was finished. But "bang"
is perhaps the wrong expression, as it took a whole day.
09.05.2022 - Mysterious circles...
In the northern Black Forest, a mysterious stone lies somewhat hidden at an altitude of just under 700 metres. It lies
on a small path a little off the beaten track. The stone is probably 3-4 metres tall, flat and made of red sandstone.
The mysterious thing, however, are the many circles in an irregular pattern on the top. Speculations say that these
circles served the worship of the stars, but according to geologists the circles are of natural origin. The latter sounds
rather unexciting, which is why I like the story with the astral cult much better. ;)
02.05.2022 - Back to the year 2006...
I constructed my first telescopes with pencil and ruler on squared paper. That worked quite well, but of course it was
very time-consuming as soon as you had to change something. The eraser was my best friend. At some point I switched
to expensive millimetre paper, which at least made dimensioning much easier.
In the meantime, of course, nothing works without CAD and 3D views. Too many drill holes and individual parts that
have to fit together. In addition, STEP files are needed for the milled carbon plates, for example.
All in all, it's always nice to take a look at the past and realise in a quiet minute what has changed.
21.04.2022 - How to pack a mirror...
Many years ago I still had time to retouch a mirror now and then. To do this, of course, they had to be sent to me first.
With some mirrors I was really extremely surprised that they survived the transport in one piece and did not break into
pieces.
Since I cannot afford to damage a mirror during shipping (after all, a lot of working time goes into it), I have found my
own way of shipping mirrors. I don't know how many mirrors I have made in the meantime, but so far not a single one
has been damaged in transit. So I am now really relaxed about shipping expensive telescope mirrors.
20.04.2022 - 300/1255mm mirror
This is what a 300mm mirror with 25mm rim thickness looks like after completion: round, thin and beautifully
shiny. If you look carefully, you can see four numbers on the edge: 0°, 90°, etc. These are the angles at which
the mirror is measured. This is because the interferometric measurements are taken in different positions towards
the end in order to be able to average out astigmatism due to the storage in the test stand.
Can you see the strehl ratio of 93 points? Well, not really. But the finished "mirror" looks nice anyway. Now
all that's missing is the coating.
07.04.2022 - Side by side comparison of the secondary cages for a 16" and a 25" telescope
After the parts of the 25" Horizon were back from welding, I quickly mounted the spider. Since I still
had some rings lying around for the upcoming batch of 16" telescopes, it made sense to do a little size
comparison.
And yes, the aluminium rings for the 25" f/3 do look a lot bigger, although you might not think so from the
numbers. Let's face it, 16" is really quite a large aperture with which you can discover and explore our
wonderful universe. But you can always go a little bigger. Aperture fever: a terrible, incurable disease once
you've been afflicted with it ;)
05.04.2022 - Welded frames
It took much longer than expected until I could finally pick up my frames from welding. Corona
has caused a backlog of orders at many companies.
Nevertheless, it is always a beautiful sight when the super-light frame parts are finally in the boot
and immediately travel on to powder coating. Before that, however, a quick check is made to make
sure that all the individual parts are in the right place so that there are no nasty surprises later on
uring assembly.
02.04.2022 - Four 16 inch mirrors
Besides some custom-made parabolic mirrors I still make mirrors for my own telescopes.
In these days four 16 inch mirrors for the model series "Infinity NL" have been finished.
All mirrors have Strehl values of 0.92...0.93 and will surely show beautiful and sharp images
of our moon, the planets and lots of deepsky objects.
I wish the future owners a lot of fun with it and of course many clear nights under a dark sky.
01.04.2022 - Deepsky Drawings
If you are outdoors on almost every clear night, as I am, you accumulate a lot of observations and
rough drawings over time. Since I increasingly lose track of what I have already drawn and what
I haven't, I took all my folders and made a list of all the objects.
To be honest, I was a bit shocked that I made almost 850 drawings with my 20" f/3, of which certainly
700 still need to be edited on the computer. Plus all the texts and background information. What a
lot of time that will take. Phew...
And with every clear night, more objects are added. A never ending story...
30.03.2022 - New springs
I wanted to replace the springs of the mirror cell against better ones for a long time. After a long search I
have finally found the right size and strength. It is hard to believe how many different springs there
are... Fortunately, there are search masks with which the number of hits can be greatly narrowed down.
The springs in the photo are now much harder and should hold the mirror cell in position even better
than before. I will also equip my own 20" f/3.2 called "Nessaja" with them.
28.03.2022 - Night over a small village in the Black Forest
March has gone down in history with a record amount of sunshine hours. Never since weather records
began has there been so much sun in March. Therefore there were naturally also many clear nights, in
which one could go stargazing. As an astro friend once said: "It threatens to become clear again" ;))
On the way up you have a nice view of one or the other small village in the Black Forest. In the
background the gentle hills can be seen, which are up to 900 meters high.
The image can be enlarged by right-clicking and selecting "Open graphic in new tab".
15.03.2022 - Yellow sky over southern Germany
When I looked outside in the middle of the month, I immediately noticed the yellow sky. I
knew already a few days before from the weather maps that dust from the Sahara is on the
way to us, but that it will be so blatant, I would not have thought. The mood with the very
yellow sky was quite surreal, but also kind of cool.
Less cool was that it rained a short time later. :( As nice as the dust is in the atmosphere,
it's not quite as nice on my car....
10.03.2022 - James Webb in a smaller version
After I have already built some telescopes for visual observation, now it was the turn of
one for space: The James Webb Telescope!
It's not meant for space and it's a bit smaller than the original JWST, but it looks pretty
much the same. I bought the balsa model in the USA and it was assembled in about 2-3
hours. The individual parts are laser cut and fit together perfectly. A really nice story. :)
Has been fun!
01.03.2022 - Spring clean
As in every spring it was also in these days so far and I have filled a container
with things that accumulate over the year in my workshop. That is not
not even little - which surprises me again and again. ;)
Now the workshop is free of junk again and there is enough space for new mirrors
and telescopes in 2022!
21.02.2022 - Lunar images with 20" f/3.2 under good seeing conditions
I am currently processing some lunar images from one of the recent sessions. The seeing
was really good in parts this evening. So many good images were taken.
No one should claim anymore that high-resolution photos are not possible with f/3 mirror optics. Because
they are. Of course, you have to make a little effort, especially with the adjustment. The secondary mirror
was adjusted with the "Concenter Ray" from Spheretec. Super easy and fast to do! So the adjustment took me
only a few minutes in my shop. In the evening the optics is first roughly adjusted at Polaris. The exact
adjustment is done with a connected camera at a brighter star close to the moon.
The image can be enlarged by right-clicking and selecting "Open graphic in new tab".
20.02.2022 - 500mm f/3 parabolic mirror for the "Horizon" model series
Once again I was able to finish a very short 20 inch f/3 mirror with my polishing machine.
With a measured Strehl Ratio of about 0.93, this mirror will also show great images of globular
clusters, nebulae, galaxies and of course planets in combination with a high precision 125mm
secondary mirror from Antares Optics. :)
05.02.2022 - Manual for the "Infinity NL" and "Horizon" model series
Since the beginning of the year there is a revised version of the manuals for the model series "Infinity NL" and "Horizon".
Again, some suggestions from customers have been taken into account, so that no question remains unanswered when
setting up the telescope. In addition, the drawings are even better labeled and the screws for the individual assembly steps
are packed in separate sealing bags with labeling, so that you always have exactly the parts in your hand that you need
for this step. A comprehensive chapter on the adjustment of the individual optical components as well as helpful tips for
own observations are also included.
And the best part is: The manual is included with each telescope in printed and bound form!
15.12.2021 - Super fast + thin 400mm f/2.95 mirror
Shortly before Christmas the time had come and a 25mm thin 16 inch mirror with a focal ratio of only f/2.95 could be finished.
With a focal length of a little more than 1,170 millimeters, 8.5mm of glass is missing in the center, so that there is only a little
more than 16mm left with a total thickness of 25mm. Accordingly, the weight is also low, which is only 5.9 kilograms - perfect
for the use in an ultra-short Dobsonian telescope as planned by the happy customer.
25.11.2021 - Fast 410mm f/3.18 mirror for a photographic Newtonian
With a diameter of 410mm, this very fast mirror with a focal ratio of f/3.18 will be installed in a photo Newton. The thickness of
the Supremax blank is only 31mm, which allows it to cool down very quickly.
With a Strehl Ratio of S=0.92, it has turned out very well and will hopefully deliver many great images from the depths of our universe.
06.11.2021 - Hike in the Northern Black Forest
During a hike in the northern Black Forest a very beautiful mood arose after sunset during the beginning dusk. In the west a little
higher in the sky the brightly shining Venus could be seen, while the narrow crescent of the moon could be found just above the gentle
hills on the right side of the photo. Down in the valley at this time the first high fog fields spread again and should later flood
the whole valley.
The picture can be displayed enlarged with right click and "open graphic in new tab".
28.10.2021 - Image of Uranus with my 20" f/3.2
At the end of October there was a clear sky and I wanted to try my hand at Uranus, or more precisely, I wanted to capture the cloud
structures of this ice giant on the chip with a red filter.
I think I succeeded quite well - you can see the division of the planetary sphere very nicely in the image. A total of around 25,000
individual frames were stacked. So it took a while until they were in the box.
The image can be enlarged by right-clicking and selecting "Open image in new tab".
10.10.2021 - Update of images and information material
Since there were some small technical changes to the Infinity NL series (such as the new focuser), the images of the telescopes
have been updated. Also the downloadable info material has been updated.
The information material for the new EQ platform called "Trackie" has also been updated.
28.09.2021 - Welding and powder coating please!
It is always a nice feeling when you have spent many hours in the workshop and finally the many individual parts for the next
batch of telescopes are ready.
Some of them go first to welding (model series "Horizon"), the others directly to powder coating. The companies are located in
the near vicinity, so I can bring the parts there myself and pick them up again. And besides, it's always nice to have a short chat
with the people there.
25.09.2021 - Lunar images with 20" f/3 under good seeing conditions
After a long time I finally got the chance to start a session with my own 20" f/3.2 telescope at the moon with the ASI178MM.
The seeing was partly very good, so I managed some nice shots. :))
The lunar crater shown here is "Piccolomini", which has a diameter of 88 kilometers and a depth of 4,500 meters, similar dimensions
to "Copernicus". The inner walls of the crater are terraced and the central mountain rises to a height of 2,000 meters.
The image can be enlarged by "right-clicking" and "open image in a new tab".
15.09.2021 - New focuser for the "Infinity NL" series
Since the previously used 2" focuser from Moonlite has been discontinued for some time and is therefore no longer available, the
telescope series "Infinity NL" has been given a new focuser.
It is the short focuser from Teleskop Express, which is very solidly made and comes with a 1:11 reduction. In addition, it has a lock
function with which the position of the focuser tube can be fixed. Furthermore, the fine movement can be adjusted via a small Allen
screw.
06.08.2021 - New 2021 version of the EQ platform
Now the EQ platform has finally received its long-awaited update. Goodbye wood plate and welcome powder-coated aluminum
profiles in a cool design. :)
But not only the design is new, but also on the drive side a lot has changed. The two drive shafts are now turned from stainless
steel and run in two sealed housing bearings. In addition to easy pole height adjustment, the platform now also comes with carrying
handles and three rubber-armored articulated feet that adapt beautifully to sloped surfaces.
What is also great: The platform weighs only 6.6kg, so it's just 4kg lighter now.
More info can be found here:
01.06.2021 - Main prize in the "Sterne und Weltraum" magazine
Like last year, I will also donate a 16" telescope of the model series "Infinity NL" in this year's column "To think about".
Of course you have to do a little bit for it - namely send in as many correct solutions as possible to the corresponding tasks.
In this sense: buy the "Sterne und Weltraum" magazine, solve the tasks and with a little luck win a great 16" telescope!
I keep my fingers crossed!
11.12.2020 - A large and fast 635mm f/3.2 mirror
Today I finished a large 25" f/3.2 mirror which will take its place in a very light telescope of the model series "Horizon".
With a focal length of f=2,020 millimeters, I hit the target focal length of f=2,000 millimeters pretty closely. This means that there
is about 12.6mm of glass missing in the center, so the blank will be 4.5 kilograms lighter and end up weighing pretty much 20.0
kilograms. Parabolization takes a lot of time with a mirror like this. You wouldn't believe how slowly the parabola develops. Fortunately,
my polishing machine does most of this physically demanding work for me. The fine-tuning at the end is then done with very small
subtools, which are used to iron out the last irregularities.
With a measured Strehl value of over 0.90, the mirror will deliver great and contrasty images even at very high magnifications and will
certainly give the lucky owner many great hours under the starry sky. :)
06.10.2020 - The star atlas for those on short notice (named "BafK")
Probably many know it: without preparation you stand with your telescope on the meadow and think feverishly what you could look at
this night. It should not be the Orion Nebula again, also the Pleiades have been seen often enough. So what to do?
And exactly here the "BafK" comes into play: Over a thousand more or less known DeepSky objects including images and descriptions.
A real treasure trove for all visual observers. Because I like the concept and the layout very much, I created a small subpage about the
"BafK" to make this project even more popular!
02.10.2020 - A carbon plate for the "Horizon" model series
It is always a great moment to open the package with the carbon parts and find beautifully processed carbon tubes and milled carbon plates
for the "Horizon" model series inside. :)
Unlike previous versions, the new carbon plates have two larger cutouts to save weight. This can be done, because the plate is extremely stable
and absolutely torsion-resistant despite the recesses.
The photo can be enlarged with a "right click" and "show graphic".
28.09.2020 - Two new episodes of "Spacewalk Destinations" are online
Two new episodes of "Spacewalk Destinations" in one go! :)
The first episode is about the beautiful open star cluster NGC 7789, which is a stunning sight in a larger telescope. But not only the cluster
itself is totally interesting, but also a very special star population in it: the somewhat mysterious "Blue Stragglers".
In the second episode we will turn again to the globular clusters in Messier 31. But this time we will go far away from the galaxy in search
of globular clusters in the galactic halo and visit three extreme objects there, one of which holds a very special record.
Have fun reading and rewatching:
26.09.2020 - Update with 4 new drawings
After many months I finally found some time to work on some drawings. Since I created two episodes of "Spacewalk Destinations" at
the same time, I concentrated on the objects I needed for the episodes. These were on the one hand the beautiful open star cluster NGC
7789 and on the other hand some globular clusters in the Andromeda galaxy, for which I also had to create a separate section.
Have fun watching and observing!
22.09.2020 - Another episode of "Spacewalk Destinations" is online
If you look up on a clear autumn night, you will notice a pale, elongated spot of light in the constellation Andromeda. It is the
well-known Andromeda galaxy - also called Messier 31.
But this episode is not about the galaxy itself, but about "Mayall II", the brightest globular cluster in Messier 31. Even with a
relatively small telescope, this exciting, extragalactic object can be observed.
20.09.2020: The 12" Infinity+ in the Black Edition (already sold!)
Since I still had an unprocessed 12" blank left, I decided to turn it into a final mirror for the Infinity+ series. To bring the telescope up
to date, the rods, the rod mounts and the struts were powder coated matte black, so that it corresponds to the current Black Edition
from the overall impression.
The 300mm main mirror with a focal length of f=1.290mm turned out very well with an interferometrically measured Strehl Ratio
of S=0.97. A test report is of course included as always.
As focuser a high quality 2" Moonlite in black finish with a 1:8 reduction is used, which can be operated very sensitively. The telescope
is also completely equipped with a secondary heater and a main mirror fan. As a small bonus, there is a carrying bag for the rods and struts
with it.
09.09.2020 - Moon shots with my 20" f/3.2
I like the half moon, especially the last quarter. In autumn, our Trabant is particularly high in the sky at this phase.
So I struggled outside into the darkness at three in the morning and soon found myself on a lonely dirt road south of Karlsruhe. My own
20" f/3.2 named "Nessaja" was cooled down to ambient temperature some time later thanks to the big fans, the laptop was ready for use
and the camera was connected. The EQ platform was also whirring quietly. I only had to press the "Capture" button in "FireCapture"
and thousands of individual images were already collected on the hard disk. At home I edited the data the same day with various programs.
And so I would like to show here the lunar craters "Arzachel", "Alphonsus" and "Ptolemy", which always remind me a little bit of a
crooked snowman. Further up in the picture we find the "Long Wall" or also called "Rupes Recta" and directly beside it the crater "Birt"
with its small groove. Also the famous "Catena Davy" has sneaked into the picture. Well, who will find it? By the way, the photo can
be enlarged with a "right click" and "open graphic in new tab".
With an effective focal length of f=1,800mm, the results are really nice shots. The whole effort was worth it in any case. Sometimes
you just have to get over yourself, even if it's hard.
16.05.2020 - A main mirror for a fast photo Newton
In spring I could finish a very short 14" f/3.47 mirror for a fast photo Newton.
Despite the edge thickness of only 25mm, the mirror is free of astigmatism and has a nice, smooth surface. This results in a high Strehl
Ratio of S=0.95.
I am curious what great images will be possible with this telescope in the further course.
06.04.2020 - Venus observation with "Nessaja
Since a few weeks Venus is wonderfully high in the evening sky.
And that's why I have set up my own 20" f/3.2 Dobsonian of the "Horizon" series named "Nessaja" on pretty much every clear evening
since then to look at the ever narrower and larger Venus crescent. But not only the shape itself is beautiful to look at, I find the observation
of the Venus clouds through a Wratten #47 violet filter especially exciting. Admittedly, the sight takes a little getting used to.
But the many drawings I have made so far have yet to be finalized and can then be viewed here on my homepage.
27.03.2020 - The next episode of "Spacewalk Destinations" is online
If you look up into the sky on a clear spring night, you will notice a faint spot of light in the constellation of Cancer.
This is the star cluster Messier 44, which is a great sight in small telescopes. But with larger telescopes you can observe not only the
cluster itself, but even galaxies far behind it with a distance of up to 750 million light years.
Have fun reading and observing:
17.03.2020 - The secondary mirror mounts of the "Horizon" model series
At the beginning of the year, I designed new secondary mirror mounts for the "Horizon" model series.
The reason was that the secondary mirrors from the USA are quite massive and I wanted to achieve that the heating not only heats the
outer areas, but also the inner ones. That's why I had to split the center bar into two parts, so that there is room for two more resistors
in the gaps.
In the process, I also extended the larger plate a little to the rear to be able to continue to support the entire length of the secondary
mirror, which is glued with an offset.
10.03.2020 - A primary mirror for a 16" telescope of the "Infinity NL" series
Also in the year 2020 there is once again an exemplary evaluation of a 400/1700mm mirror, which is currently installed in a 16 inch
"Infinity NL".
Despite the edge thickness of only 25mm, the mirror is free of astigmatism and has a slightly raised area at the edge at about 12 o'clock
as the most noticeable feature. The rest of the surface is nice and smooth, so the mirror has a very high Strehl Ratio of around S=0.94...0.95.
All in all, the mirror in combination with the installed secondary mirror with its outstanding surface quality of lambda/12 will provide
sharp and high-contrast images.
06.03.2020 - A new episode of "Spacewalk Destinations" is online
In the spring sky, the constellation Leo rises high above our horizon. There, in a distance of less than 8 light years, we find a very special
star with the name "Wolf 359".
This star is well known to every Startrek fan, because a huge space battle between the Borg and Starfleet took place here. So what could
be more obvious than to take a look at this red dwarf star with your own telescope?
Have fun reading and observing:
10.02.2020 - Two new episodes of "Spacewalk Destinations" are online :)
It's that time again - two new episodes of "Spacewalk Destinations" are online. They are about the dance of two supermassive black
holes in the constellation Cancer and about a red dwarf star in the constellation Aries, which can almost be counted among the brown
dwarfs because of its extremely low mass.
Have fun reading and observing:
04.02.2020 - Product modifications
1) The model series "Infinity NL" is now only available with black powder-coated rods and rod holders, i.e. in the "Black Edition".
A small price adjustment was necessary for this. Since I can now have all parts powder coated directly and both the price for this and
my labor are lower, I was able to keep the price increase small.
2) The upgrade to carbon rods for the "Infinity NL" model series will no longer be available in 2020. The carbon material will thus
be reserved for the "Horizon" model series.
3) Likewise, I no longer offer the measurement of Newtonian mirrors and mirror retouching for the time being due to time constraints.
02.02.2020 - Update with 5 new drawings
In January there were some beautiful clear nights when I was out stargazing with my 20" f/3 Dobsonian named "Nessaja". Normally
it takes quite a while until actual observations find their way to my homepage, but here I just couldn't resist. Because the three big
Auriga star clusters Messier 36/37/38 have always been close to my heart, they can already be found in the DeepSky section.
Enjoy reading and observing!
10.01.2020 - Update with 16 new drawings
On my subpage "DeepSky" there are again many new drawings to see. Most of them are great planetary nebulae in the constellations
Dolphin, Vixen and Swan. But also some star clusters of my project "Teutsch Cluster" have made it to my homepage. Finally,
there are also two new sections with "Dark Clouds" and "Galaxy Groups".
Enjoy reading and observing!
27.12.2019 - New category: Spacewalk Destinations
There is now a new section on my homepage called "Spacewalk Destinations". Here I would like to describe exciting observation
objects in irregular intervals. I will start with two destinations in our solar system: Venus and asteroids.
Enjoy reading and observing!
26.11.2019 - English version online
After many hours of work an english version of my homepage is now available. For the time being, only the product pages for my
telescopes and the mirror optics are online. The other sections will then be translated into English step by step over time.