Telescopes and Equipment

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Telescopes and Equipment

In this page, we (Wolfgang "Howdii" Howurek and Walter Koprolin) describe the telescopes and equipment we own and use for observing and others which we got for testing. The short descriptions are in English, but most of the longer articles are written in German. If you are interested in them, but don't understand German, you can try the Google Translation Service. Sorry, no English versions are available yet.

The telescope testing and experience articles contain exclusively our private opinion. We do not work in commission of any manufacturer, we do this for the pleasure of observing and because of the constant need to find recommendable optics for amateurs. And perhaps we succeed in conveying a better feeling for optical quality to the astronomical amateur scene, which we miss a little bit nowadays ... but it's getting better.

The following articles are sorted in reverse chronological order of the last update.

4” Achromate im Vergleich

The TS Individual 102/1100 achromatic refractor is one of Howdii's favourite telescopes. He argued this model is as good as the legendary Zeiss AS 100/1000. On June 2, 2017, Howdii had the occasion to do a comparison of these two optics on an elusive target - Jupiter. Seeing was really good at this site. The views of Jupiter were great! And, the 102/1100 is really on par with the Zeiss AS 100/1000! The 102/1100 also did a respectable job compared to a Celestron 102/900 Fluorite lens. Read Howdii's Report (in German).

iOptron ieq45 Pro

iOptron ieq45 Pro - Howdii got this mount for a customer and tested its performance. He subsequently wrote a Test Report (in German, April 2017) about this model and referred also to the evolution steps of the ieq45. Howdii found fine guiding performance on this sample, which he carefully documented. This model of the ieq45 Pro provides refined gearing and stepper motors, whereas formerly servo motors were used. This new model has a real time clock, so it's no longer needed to wait for the GPS satellite fix. A new and quite unique feature allows the mount to recover from power failure during the session. So one simply is able to continue the session without loosing position of the scope or star alignment. A rigid hard-wood tripod is highly recommended for this mount.

Skywatcher NEQ6-R SynScan

Skywatcher NEQ6-R SynScan - Howdii got this mount for a customer and tested its performance. He subsequently wrote a Test Report (in German, Feb./March 2017) about this revised model. Howdii found fine guiding performance on this sample but also a surprising detail, which he carefully documented, and generally attributes the NEQ6-R good characteristics and handling. This revised model is better in many respects than its venerable predecessor, the NEQ6. Like the NEQ6 the NEQ6-R is best mounted on a rigid hard-wood tripod.

VMC 260L Fototest

After some visual observations with the Vixen VMC 260L Howdii was eager to do some astrophotography with it. But what mount for it, because of the long focal length of this scope. Fortunately, Howdii got also a Celestron CGE mount for testing, so there he went. Howdii and Andi used a quite dark sky at Mistelbach, however, seeing was only mediocre. Despite this, they managed to get the mount in guiding to image M57 and M27. Howdii has written a Test Report (in German, August 2016).

APM 140 f/7 SD-APO

Howdii got an APM 140/980 Doublet SD-APO for a customer and testet it visually as well as photographically (July/August 2016). This scope features a retractable dew shield, a handle on top of the tube rings, a Losmandy style dovetail rail, a 2.5" RPA focuser and a mounting base for finder scopes. The optics shows pinpoint stars across the field and a nearly textbook-like star image at high power. There is a trace of pinching, and a bit of spherical aberration. The color correction is good for a lens of this size and type. Visually, bright stars show up in their true color, however, traces of red to blue are shimmering in the diffraction rings. Photographycally, bright stars do show some false color. There isn't enough clearance between dovetail rail and dew shield, so these two parts accidentally can get in contact what causes scratches on the back ring of the dew shield. This is annoying. The vendor has promised to solve this problem. Howdii has written a Test Report (in German) about this telescope.

Celestron Ultima 8

Celestron Ultima 8. This 8" f/10 SC was produced from 1989 onward. It features a heavy-duty fork, and this sample was supplied with the heavy-duty wedge, however, PEC is not available on it. The Ultima 8 was well known for its stability and for its good optics, as well as for the accuracy of its RA drive. Howdii got this scope for inspection. Some parts were missing, and the RA drive did not work. He was lucky to supply the missing parts and could fix the drive electrics. The optics proved very good, and, as a surprise the collimation of the optics was spot on. The stability of the scope is ok, it shakes when bumped, but the vibration damping is good, about one second. Howdii wrote a Test Report (in German, July 2016) about it.

Celestron C9.25

Howdii has tested a Celestron C9.25 SC. The C9.25 is well know for good optics and lesser field curvature. This comes along with an increased tube length and a larger central obstruction, where the Fastar secondary locking ring adds some millimeters. However, this sample proved a smooth backlash-free and shifting-free focuser as well as excellent optics. Simply said, it's the best SC telescope Howdii has ever seen. Howdii has written a Test Report (in German, June 2016) about it.

Lacerta 72 ED

Howdii has tested a second-hand (in near mint condition) Lacerta 72/432 ED Refractor both visually and photographically (togehter with a 0.85x Reducer). This little Lacerta ED scope features a nice Octo 2" focuser. Visually, the performance is fine. There is only a bit false color and a trace of spherical undercorrection, nothing else. This lens is sharp. Photographically, it is capable of delivering nice wide field images. Howdii has written a Test Report (in German, June 2016) about this telescope.

Scopos ED APO

Howdii has tested a vintage second-hand Scopos 90/600 ED Triplet APO both visually and photographically together with a 0.85x Reducer (June 2016). Visually, the optics proved ok. The color correction is really good. There is some spherical undercorrection and a trace of pinching. However, nothing else. This lens will take some time to cool down. The Crayford-style focuser is a bit tricky, but can be tamed if carefully adjusted. Photographically, this triplet-lens is capable of delivering quite nice images. Howdii has written a Test Report (in German) about this telescope.

Intes-Micro Alter M603

Howdii got an Intes-Micro Alter M603 for repair. Solving the focusing issue was no problem. Howdii inspected the scope thoroughly and found some hairy looking dirt on the meniscus lens - probably fungus. So he had to clean the lens carefully and then to re-collimate the optics. Howdii also star-tested this scope. The visual performance is affected from cooldown problems, and the optics showed some spherical undercorrection. Good seeing and thermal equilibrium assumed, this scope can for sure deliver quite nice planetary images. However, this will not easily come together. Howdii has written a Report (in German, April 2016) about this telescope.

Skywatcher 100 ED

Howdii has tested a Skywatcher 100/900 FPL-53 ED Refractor both visually and photographically (March 2016). Visually, the optics proved quite nice. The color correction is ok for this ED Refractor, but compared with an FL-102 lens - the Fluorite can't be beat. There is a bit of spherical undercorrection and, maybe a bit of pinching. Photographically, this ED Refractor delivers fine star images. Howdii has written a Test Report (in German) about this telescope.

ES 80/480 ED APO

Howdii has tested a vintage Explore Scientific 80/480 ED Triplet APO both visually and photographically (October/November 2015). Visually, the optics proved quite nice. The color correction is sufficient. There is a bit of spherical undercorrection, nothing else. However, this lens will take some time to cool down, and typically, like every refractor, it will show some astigmatism during this period. Howdii wasn't very happy with the focuser. It tilts all accessories while clamping. So, photographically it's tricky to work with this scope. There is for sure a way to cope with it, however, at extra costs and careful work is needed. Otherwise, the optics is capable of delivering fine images. Howdii has written a Test Report (in German) about this telescope.

TS 70/420 ED Carbon Refraktor

Howdii got a TS 70/420 ED Refractor with Carbon tube for a customer and testet it both visually and photographically (October 2015). Howdii fought the foggy sky, so he was in hurry to get the scope tested. The optics showed a bit of spherical undercorrection, but not too much. The color correction is typical for an ED lens. It isn't really color-free, but there is only a tiny bit of false color on bright stars which will only show up at hight powers. A bit of drawback is the sliding dewcap which cannot be fixed. Otherwise this scope did what is should do. Due to the Carbon tube it is leightweight and a nice travel mate. For sure a small aperture scope shines more photographycally than visually. Howdii has written a Test Report (in German about this telescope.

115/800 APO

Howdii got a TS Photoline 115/800 Triplet APO for a customer and testet it visually (July 2015). He found the lenses out of center, so he had to return the scope to the vendor. When the scope got back, the optics did what was expected. It showed pinpoint stars across the field and a textbook-like star image at high power. Howdii has written a short Test Report (in German) about this telescope.

25 Zoll Dob

The 25" Dob - Howdii presents here the story about the 25" Dob project. He explains also his design goals and shows some images of this telescope. Even if this project looked "gaga" for some time, it finally came to an end. Read Howdii's Report about his work (in German, August 2015)

Skywatcher EQ8

Skywatcher EQ8 - Howdii got this mount for a customer and tested its performance. He subsequently wrote a Test Report (in German, May 2015) about this heavy-duty mount. Howdii found some Pros and Cons. Tracking and guiding performance ist fine. There were some issues with the Auto Home Feature, which could be solved by a FW update. On the downside there is the external polar finder attachment which could break the power cable. The partially exposed worm gears leave some doubt on the long-term reliability of the tracking performance. But overall it is a good mount, worth the money. For mobile usage a rigid hard-wood tripod is recommended.

Orion XTi 10

Howdii assembled and testet an Orion SkyQuest XT 10i IntelliScope. This is a 254mm f/4.7 Dobsonian with magnetic encoders and a telescope computer as addon. The scope showed Skywatcher typical good optics. However, to get the encoders work properly was not so an easy task. Despite it's a good scope overall, there were some minor and major quirks to solve. Read Howdii's Test Report about this scope, illustrating all the details (in German, April 2015).

Skywatcher AZ-EQ6 GT

Skywatcher AZ-EQ6 GT - Howdii got this mount for a customer and tested its performance. He subsequently wrote a Test Report (in German, October 2014) about this mount. It is a new version of the NEQ6, suited for AZ and EQ usage. Howdii found superb guiding performance on this sample, which he carefully documented, and generally attributes the AZ-EQ6 GT good characteristics and handling. He found it better than the even good NEQ6. As the NEQ6, the AZ-EQ6 GT is best mounted on a rigid hard-wood tripod.

Skywatcher MN 190

Howdii has tested a Skywatcher 190mm Maksutov-Newtonian both visually and photographically with good results. He has written a Test Report (in German) about this telescope in October 2014. Visually, Howdii found pinpoint stars across the eyepiece field. The startest revealed well corrected optics. Collimation of the MN secondary mirror is ususally tricky. However, the Skywatcher MN shines with a clever solution to make collimation easy. On the less positive side, the tube is top-heavy due to the large mass of glass of the meniscus lens, the focuser and finder scope. Test photos showed fine stars even on the corners of the image. No corrector ist needed! There is a bit of vignetting, but not much.

TS Photoline 130/910 Triplet APO, photo setup

Howdii has tested a TS Photoline 130/910 Triplet APO both visually and photographically with good results. He has written a Test Report (in German) about this telescope in May 2014. The air-spaced triplet lens is very fine and color-free. Mechanically, the new RPA rack & pinion focuser is a clear winner. On the less positive side, the tube is top-heavy due to the large mass of glass of the triplet lens, which means that the tube rings have to be moved towards the top end for balancing the refractor, thereby extending the dew cap. This has to be repeated during each setup because in this configuration, with extended dew cap, the refractor won't fit into the transport case. A fitting imbus tool is required each time. Also, the large mass of glass of the lens takes a long time to cool down to ambient temperature. However, when it has reached thermal equilibrium, the image quality excels. Howdii ventured a direct visual comparison of this optics to his excellent Ceravolo HD145, which the APO narrowly lost, but there is no shame in being beaten by a Ceravolo.

Vixen VMC 260L

Howdii got another telescope for "improvement", a Vixen VMC 260L 10" f/11.5 Field-Maksutov Cassegrain. Read his Test Report (in German) about this telescope. It came severely decollimated, which seems to be standard with this telescope. The mirror shifts - and thereby tilts the optical axis, making correct collimation tricky. After collimation was done, it actually showed visually fine stars all over the field-of-view, and Jupiter showed good detail. However, there are some thermal issues due to the long cool-down time of meniscus lens, which is mounted in front of the secondary mirror with this telescope type. Also, the thick spider vanes which have to support all the weight make for large spikes around bright stars with lots of diffraction effects. But in all, for a telescope of its size and type, it offers good optical performance.

10-inch f/8 GSO Ritchey-Chrétien

Howdii's test report about the GSO10" f/8 Ritchey-Chrétien which he collimated and tested in March 2014. Read his Test Report (in German) about this telescope. This telescope comes with a Monorail focuser which Howdii exchanged for a 2,5" Moonlite focuser. He had some trouble with the collimation of the RC. The visual and photographic performance was quite good after collimation. This telescope is quite heavy and not recommended for beginners.

PHD2 at work

Howdii and Andi tested PHD2, a new version of "Push Here Dummy", the well-known auto-guiding software for PC and Mac which claims to be simple to use and yet very powerful. Well, he found the software not quite so simple, rarely does a mount guide well with the default settings. But after tweaking the parameters, Howdii and Andi managed to guide an old Vixen SP mount very well within a +/-1" accuracy (at best) using an 8x50 finderscope and an ALccd5 CCD. The software comes with some useful supplements. Read and see Howdii's combined test and observation report in German, February 2014.

TS Photoline 102/700 Triplet APO, photo setup

Howdii has tested a TS Photoline 102/700 Triplet APO both visually and photographically. He found this to be the sharpest 3-lens apochromat he has seen up to date! The star test showed a near-perfect correction in green light, slight undercorrection in red light and slight overcorrection in blue light, just as expected. Test photos were made with a standard TS 2" field flattener and a larger 3" flattener. The images with the 2" flattener were just fine (with vignetting as expected) while the 3" flattener produced slightly elongated stars and ghost images of bright stars, probably because of a little tilt of the focuser due to the combined weight of flattener and camera. Read and see Howdii's Test Report in German, January 2014.

120/1000 Skywatcher Refractor on EQ5 Goto

Howdii has taken a liking in good-quality achromats and undertook a short test with a Skywatcher 120/1000 Achromatic Refractor in the autumn of 2013. This refractor comes with a 2" focuser with big handwheel, 9x50 finderscope and 2" zenith mirror. Howdii found fine stars, the optics are free from pinching, astigmatism and decollimation in the startest of two samples of this scope. The color correction is typical and the spherical aberration ok for an achromatic refractor of this price class. Read his Short Test Report in German, December 2013.

Bresser 152 vs AstroProfessional 152

Howdii wrote a Comparison Report about two 6" refractors which he had for testing and observations: Bresser AR 152L/1200 versus Astro Professional 152/900. Both are relatively inexpensive achromats, priced under 1000 Euros. Howdii used color filters for star-testing the optics as well as a Ronchi eyepiece. Her found both refractor to be surprisingly well corrected, except for the built-in chromatic aberration and slight coma on the optical axis (the latter probably caused by the cheap lens flanges) there were no further optical faults to complain on. The on-tube mechanics of the more expensive Astro Professional are better than those on the Bresser, this is especially true for the focuser. The Astro Professional should do well as astrophoto system, but only with color filters, the narrower the better. Read also Howdii's Observation Report with the Bresser 152 in August 2013. All reports are in German.

Skywatcher 180/2700 Maksutov

Howdii, who considers himself an expert in Maskutov and Maksutov-Newtonian telescopes, tested a Skywatcher 180/2700 Maksutov-Cassegrain visually in February 2013. Read his Test Report (in German) about this telescope. He found excellent optical performance when the tube reached thermal equilibrium, which was somewhat hard to achieve in nights with falling temperatures. It needs active cooling by fan to get there. When thermal equilibrium is reached, the scope delivers excellent lunar and planetary images. It f/15, it is a bit slow for deep-sky astrophotography. Mechanically, it would benefit by a finer-geared focuser.

150mm Refraktor auf EQ6 Stativ

Howdii adapted an EQ6 tripod to fit a Skywatcher mount, which is holding a customer's Skywatcher 150/750 Refractor. This greatly improved the rigidness of the whole setup. He wrote a short article about it: "Was ein stabiler Unterbau bringt", written in German, July 2012.

8-inch f/8 GSO Ritchey-Chrétien

Howdii's test report about the GSO 8" f/8 Ritchey-Chrétien which he collimated and tested in November and December 2011. Read his Test Report (in German) about this telescope. This telescope comes with a 2" Monorail focuser that proved inadequate, so Howdii exchanged it for a 2,5" Moonlite focuser. He had some trouble with fine-tuning the collimation of the RC and was delayed by bad weather, so he had no time for photographic tests. The visual performance was quite good after all improvements, especially so when considering the high linear obstruction of 46%.

Boren-Simon 8-inch f/2,8 ED Astrograph

Howdii's report about the Boren-Simon 8" f/2,8 ED Astrograph which he collimated and tested both visually and with a CCD in November 2011. Read his Test Report (in German) about this telescope which is marketed as "PowerNewt Astrograph". The Boren-Simon is essentially an 8" f/4 GSO Newtonian fitted with carbon tube, Monorail focuser and ASA 0,73x corrector. The variant which Howdii tested sports a Baader Steeltrack focuser instead of the Monorail, a larger 75mm secondary mirror, and wooden tube rings. Howdii found some complaints about the on-tube mechanics and photographic performance, the most serious being the rather limited photographic field due to off-axis radial distorsion and light falloff. Also, this is a rather difficult scope to collimate.

Equinox 120

Howdii bought a Skywatcher Equinox 120/900 ED APO and used it for a while for visual observations and a bit of CCD imaging. He tested it extensively and found a few optical and mechanical quirks. The lens is a doublet and is not, by strict definition, an apochromat (although advertised as such), "Semi-APO" would describe the chromatic performance better. Optically, its optics suffer from stray light, pinching and slight misalignment, although the overall performance is ok for a telescope of this price and class. Mechanically, it would need a better focuser to be usable for serious astrophotography. Read Howdii's Test Report for more information (in German, October 2011).

Vixen Super Polaris 102 M

The Vixen Super Polaris 102 M is a classical 4" f/10 CF achromatic refractor produced from 1986 onwards, which was usually sold together with the Super Polaris mount. Howdii got this well-used sample for testing, mounted it on his venerable SP-DX, and did a through visual star test using color filters and even a 33% obstruction. Read his Test Report (in German, June 2011). He found acceptable optics and solid mechanics on this scope, typical for a Vixen telescope of this period, with only minor complaints.

Skywatcher NEQ6 Pro SynScan

Skywatcher NEQ6 Pro SynScan - Howdii got this mount for a customer and tested its performance. He subsequently wrote a Test Report (in German, May 2011) about this mount which started some years ago as inexpensive mount for visual use only and became a serious platform for astrophotographers in the meantime. Howdii found superb guiding performance on this sample, which he carefully documented, and generally attributes the NEQ6 good characteristics and handling. He also found a few minor design glitches. The NEQ6 is best mounted on a rigid hard-wood tripod.

Celestron Celestar 8-inch f/10 Schmidt-Cassegrain

Celestar 8" f/10 Schmidt-Cassegrain. The Celestar was produced from 1996 onward, and is in essence a downgraded successor of the Celestron C8+ of the early 1990's. Howdii got this sample for collimation and visual testing in May 2011 and subsequently wrote a Test Report (in German) about it. The optics of the telescope are actually quite good, it is free of zonal errors, and spherical aberration is well within the λ/4 criterion, maybe even as good as λ/8. However, Howdii detected signs of a rough optical surface finish, which reduces the visual contrast. The mechanics, i.e. "wedgepod" (wedge and tripod), fork-mount, etc. were made with cost reduction in mind, and are not rigid enough for a telescope of this size, thus reducing it to visual use only. It would deserve a good German Equatorial Mount for better performance.

Meade 2080 8-inch f/10 Schmidt-Cassegrain

Meade 2080 8" f/10 Schmidt-Cassegrain - The "upper-class" telescope of the beginning 1980's. Howdii got this telescope for collimation and visual tests in March 2011 and subsequently wrote a Test Report (in German) about it. The optics and mechanics are quite ok for a telescope of its time and class, the spherical aberration and off-axis coma being well within tolerance limits. Howdii, who is usually not known as SCT fan, actually likes this sample, because it delivers sharp and contrasty images on-axis, although they suffer a bit because of ghost images and some color (aberration).

Baader Cool-Ceramic Safety 2

Baader Cool-Ceramic Safety 2" Herschelprism vs. Baader Astro Solar Foil - a Comparison Report by Howdii, February 2011 (in German, with photos). At low magnifications, the differences between both methods of solar observing are marginal, while at high magnifications, the Herschelprism has the advantage: The images of solar details delivered by the Herschelprism are more contasty then those delivered by the solar foil. However, this is partially caused by short-wavelength seeing oscillations which are visible with the foil but not with the Herschelprism. If a filter (for example a Baader yellow filter) cuts away the short wavelengths with the foil, the images become much more comparable.

DS Maksutov 152/1900

DS Maksutov 152/1900 (6" f/12.5 Maksutov-Cassegrain) - a catadioptrics made in China and sold by Teleskop-Service for Central Europe. It can be bought for a very cheap price. Howdii got this telescope for collimation and visual tests in May 2006 and subsequently wrote a Test Report (in German) about it. While the on-tube mechanics were solid, the optics of the tested sample proved to suffer from severe spherical overcorrection, which rendered the telescope quite useless for astronomical purposes. This may, however, have been a singular problem of the test sample and need not be typical for this telescope series. Some other minor problems (pinching, long cool-down time) were also identified.

Ceravolo HD145 5.7-inch f/6 Maksutov-Newton

Ceravolo HD145 (5.7" f/6 Maksutov-Newton) - an excellent telescope owned by Howdii. The optical performance of this instrument, which was made by Peter Ceravolo, never fails to astonish me, as this is an very good rich-field telescope, in fact the best I have seen yet, which as well delivers superb high-power views of planets. Howdii wrote an article about it, which has been updated in October 2003 (in German).

Meade AR-6 on LXD55 mount

Meade 6" f/8 Achromat (also known as Meade AR-6, LXD55 series) - a big achromatic refractor made by Meade. Howdii got this telescope for visual tests from Astro-Experts in April 2003 and subsequently wrote a Test Report (in German) about it. This refractor is usually sold on the LXD55 mount, which is a bit overpowered with this long and heavy tube. The telescope turned out to be an allrounder, with no distinctive strengths and weaknesses, although Howdii detected modest astigmatism and diffraction spikes originating at some screw which protrudes into the light path at the lens flange. The optics of this achromatic refractor are not diffraction-limited because of the chromatic error.

8-inch GSO Newton

Guan Sheng Optical 8" f/4 Newton - a fast Newtonian reflector made in Taiwan which Howdii got for servicing and testing in April 2003. Read Black and White - the double-test report of this telescope and the Leitz 8" f/4.4 Newton. This sample featured very good optics, but some major assembly problems like a pinched primary and an unnecessarily obstructing support clamp for the secondary mirror which had to be corrected to get optimum performance. In Austria this telescope was sold by Astrostudio Kamera in Vienna.

8-inch GSO Newton

Leitz 8" f/4.4 Newton - a fast Newtonian reflector made in China which Howdii got for servicing and testing in April 2003. Read Black and White - the double-test report of this telescope and the GSO 8" f/4 Newton. This sample had some constructions problems like incorrectly positioned screwholes for the secondary mirror's collimation screws and an annoying rivet in the focuser which made the use of 2" eyepieces impossible. Also, the optical performance was not satisfying, the sample suffered from spherical aberration which makes the optics just barly diffraction-limited. Slight astigmatism and a zonal error were also detected in the startest. In Austria this telescope was sold by Astrostudio Kamera in Vienna.

 

Meade SN-8 (8" f/4 Schmidt-Newton) - a fast catadioptric telescope made by Meade. I got this telescope for two photographic test shots on 35mm transparency film on loan from Astro-Experts in March 2003 and subsequently wrote a short Photographic Test Report about it. The images taken with this telescopes suffer from vignetting and distorted stars near the edges. If bright stars are present near or within the photographed field, multiple reflections and Schmidt ghosts also become a major hassle.

10-inch Skywatcher Dob

10" Skywatcher Dob (10" f/4.72 Newton) - These large and low-price reflectors made in China become increasingly popular in recent times. Howdii and I got a model for testing provided by Astro-Experts in Wolkersdorf/Lower Austria. Read Howdii's Test Report (in German, March 2003). It featured a well-designed mirror cell, tube and focuser, a well-considered tension ajustment in altitude; but arrived out of collimation and showed some astigmatism in the star-test due to a flaw with the secondary mirror. This telescope is recommended for beginners.

TMB 4.1-inch; f/6.2 APO

TMB 105 (4.1" f/6.2 APO) - My current wide-field imaging instrument. With the optional 3" flat-field corrector, this telescope is designed for medium-format photography, however I use it up to date only with small format. With the corrector, it delivers pinpoint stars out to the edges of 35mm format without any vignetting. It also proved to be a good CCD platform, there is an increasing number of CCD images in my Gallery of Astrophotography taken with the TMB APO. It is also an excellent instrument for visual observations, see the First-Light Report (April 2001, written in German). In the star test at high power the instrument shows stars free of any secondary color at focus, a slight trace of sperical undercorrection but no other aberrations. The internal baffling works well. About the only drawback is the heavy weight of the tube - approx. 8 kg (18 lb) for tube and optics without flatfield corrector. This telescope is designed by Thomas M. Back (TMB Optics USA), produced in Russia and sold in Europe by APM Telescopes, Germany.

TASCO 4.5-inch f/8.2 Newton

TASCO 4.5" f/8.2 Newton - This is a typical low-price reflector available at department stores. It comes with mount and tripod, 0.965" focuser, two Huygens eyepieces, a barlow lens and a tiny finderscope. Mount, tripod and finderscope are undersized and limit the usefulness of the scope.
This was Howdii's first "big" telescope. It had good optics, but suffered all the other problems mentioned above. To overcome these, Howdii built a solid tripod and bought better eyepieces before selling it. Read his retrospections about the TASCO Newton (in German, November 2000).

APM 4-inch f/6.5 APO

APM 4" f/6.5 APO - This telescope I did own from April 1999 until May 2001. I used it for taking wide-field astrophotos with success. Click here to read a photographic evaluation of this telescope (April 1999, updated in February 2000). Field curvature is noticeable at the edges of a 35mm negative, otherwise my pictures taken with it were quite good. It is also a fine instrument for visual observations, as you can read in the First Light report, written in German (also April 1999); it shows only a barely noticeable trace of purple around bright stars and slight undercorrection when viewed at high power. This telescope was sold by APM Telescopes Markus Ludes in Germany and features Russian optics contained in a Vixen tube. The picture at left shows it mounted on my trusty Vixen GP-DX.

Starsplitter II 18-inch f/4.5 Dob

Starsplitter II 18" f/4.5 Dob - Howdii's former big and excellent light-bucket (he has sold it by now). In this article (written in German, April 1999) he describes life and observation with this "monster". A good overview for those interested in what 18" telescopes are able to do and for those who intend to buy such a monster. The telescope was made by Starsplitter, the optics by Pegasus. Yes, that's Howdii standing beside the scope... :-)

APM 4-inch f/8 APO

APM 4" f/8 APO - a Russian-made apochromatic fluorite refractor in a Vixen tube, another telescope owned by Howdii. I have taken some astrophotos and CCD images with this instrument which are excellent. It is color-free and has very good optics. Click here to read the First Light report (in German, December 1998) written by Howdii. This telescope is sold by APM Telescopes Markus Ludes in Germany. The picture shows it in astrophotographic use at the Ebenwaldhöhe in Lower Austria. As guiding scope served my old Zeiss Telementor 63/840 and the mount is my Vixen GP-DX. Yes, the guy beside the scope, that's me... :-)

Konusscope 1765 (6.3-inch f/7.6 Newton)

Konus Model 1765 (6.3" f/7.6 Newton) - This telescope was tested by Howdii. The tested unit suffered from severe astigmatism and was only usable below an exit pupil of 1 mm, quality control on these scopes seems to be sloppy. The mount was shaky, barely sufficient for visual work and unacceptable for photography/CCD. This is a telescope often found in conventional photo stores and sold for cheap prices. Click here to read the test report (in German, September 1998).

Tal-2 (6-inch f/8 Newton)

TAL-2 (= Siberia 150, Sovietski 6") 6" f/8 Newton - This Russian-made telescope comes as a complete set and features ok optics and a firm, heavy mount. The drive has, however, some backlash. The telescope is a good bargain for the beginner, but is a bit heavy to haul around. When tested, it had a non-standard 32mm focuser and 32mm eyepieces; meanwhile 1.25" focuser & eyepieces should be standard. This telescope is sold under different names by many telescope vendors and are manufactured by Novosibirsk. Click here to read the double-test report about this scope and the GAT 10" (in German, 1995).

GAT 10-inch f/6.5 Dob

GAT 10" (=Discovery 10") 10" f/6.5 Dob - This telescope has good optics and on-tube mechanics, but a shaky mount which doesn't move well, allowing no higher magnifications than 200x. Click here to read the double-test report about this scope and the TAL-2 (in German, 1995). This telescope is sold by Grab Astro Tech.

Pentax 105 SDHF (4-inch f/7 Refractor)

PENTAX 105 SDHF (4" f/7 Refractor) - This telescope tested by Howdii is designed as astrocamera, is well corrected and has a very flat focal plane, but it shows visually a conspicuous purple halo around bright stars. It is quite expensive. In Austria this telescope was sold by Astrostudio Kamera in Vienna. Click here to read the report (in German, 1994).


If you want to contact Howdii or Walter, say you have a question concerning observing, telescopes, astrophotography or generals astronomy, feel free to do so and click on one of the names below:

Howdii specializes in telescopes, optics, and observation techniques;
Walter concentrates on astrophotography, science, and extragalactics.

© 2012 Wolfgang "Howdii" Howurek & Dipl.-Ing. Dr. Walter Koprolin

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