Baader Classic Ortho/Plössl (Q-Turret) eyepieces
HT-MC-coated, plug-in diameter 1¼"
Parfocal eyepiece series with very high transmission, very high contrast and a completely distortion-free image due to the design. Extremely low internal reflections thanks to the multi-coating. The eyepieces offer a 50° field of view, sharp field diaphragms and excellent ergonomics for a comfortable viewing experience. In addition, no plastic is used and the lens groups are heat-resistant cemented to make all four Classic eyepieces suitable for solar projection.
Classic design of an orthoscopic eyepiece
The optical unit of each of the three ortho eyepieces consists of a plano-convex eye lens and a heat-resistant cemented lens triplet; or two heat-resistant cemented lens doublets in the case of the 32 mm Plössl. This means that all four Classic eyepieces each have only four glass air surfaces. All eyepiece materials are made of metal, with the exception of the eyecups and dust caps! For heat protection reasons, each eyepiece has two separate field diaphragms to dissipate the heat generated during solar projection in a staggered manner. All metal inner surfaces as well as the lens edges themselves are carefully black-matt anti-reflective and effectively suppress the occurrence of stray light, even when projecting the sun. In addition, the hard-anodized receptacle has an internal thread for holding eyepiece filters.
A look into the eyepieces reveals a non-reflective coating and blackened lens edges. The anti-reflection coating of our Ortho eyepieces is so good that you get the impression that there are no lenses in the eyepiece body at all. On the optical bench, we cannot detect any difference in transmission measurements compared to so-called pure planetary eyepieces that are up to 5 times more expensive.
The ortho eyepieces use the same type of glass and the same optical design as the former orthoscopic eyepieces from Carl Zeiss Jena.
The 32mm Plössl ey epiece is the perfect overview eyepiece for telescopes with a 1.25" focuser; the field stop diameter has the maximum diameter allowed by a 1 ¼" receptacle, so other eyepieces with a longer focal length would not provide a larger true field of view.
Baader Classic Ortho/Plössl eyepieces as planetary projection eyepieces
In order to achieve the high focal lengths required for planetary photography, simple Barlow lenses often offer too little magnification. The alternative is classic eyepiece projection, especially to increase the effective focal length by a factor of four or more. The Classic Orthos together with an OPFA (eyepiece projection focal adapter) provide the necessary high magnifications. Orthoscopic eyepieces are also known for their good sharpness on the axis and high transmission - ideal for planetary observation. This means that sharp planetary images are possible even at very high magnification.
With an OPFA, the magnification can be adjusted very flexibly via the distance between the eyepiece and the sensor. Information on calculating the resulting focal length can be found in the description of the OPFA system. However, for the very best results and highest resolution, we recommend the Fluorite Flatfield Converter (FFC / 3x-8x), which is specially calculated for projection photography, instead of eyepiece projection.
The Classic Plössl with its large eye lens is very well suited for afocal projection with the ADPS (Afocal Digital Projection System) and a compact camera with Lens - the large camera-side lens reduces vignetting so that a larger area of the camera sensor can be used. The low magnification and the resulting large field of view make this combination very attractive for photographing the surface of the moon or sun (the latter only with suitable solar filters).
Both the 32 mm Classic Plössl and the 18 mm Classic Ortho are also ideal for photography with a smartphone (digiscoping). The bodies are long enough to clamp smartphone adapters such as the Baader Lightweight Smartphone Adapter (LSA) # 2967000 or the Celestron NexYZ #825821. Simply position the camera lens centered over the eyepiece and use the camera zoom to adjust the image to the camera's field of view.
The slim bodies of the Classic eyepieces with a diameter of less than 35mm fit easily into standard projection adapters and can also be used visually on the binocular attachment without any space problems.
Solar projection
Solar projection has gone somewhat out of fashion in recent years, partly because the classic, open solar projection screens do not completely seal off the beam path, leaving a residual risk during observation, and partly because the classic eyepieces for solar projection without cemented lenses are no longer produced in good quality. The UV-hardening putty with which many eyepiece lenses are cemented in favor of quick lens mounting is not heat-resistant, so that the eyepieces become blind during solar projection because such a cement can easily burst.
The Classic Orthos and also the 32 mm Plössl eyepiece use a heat-resistant cement and have been tested successfully and repeatedly for up to six hours continuously on refractors with 150 mm objective diameters (150/2250 mm and 150/1200 mm) without any damage to the lenses or the metal parts of the eyepieces. Thanks to the double-staggered metal field diaphragms, even inaccurate tracking is not a problem, only the black anodization of the Body can fade a little on the inside if the bundled sunlight falls on the field diaphragm instead of centrally through the eyepiece for a long time.
This means that with the Classic Ortho/Plössl eyepieces, eyepieces are finally available again with which solar projection is also possible without destroying the lens putty or allowing plastic parts inside to evaporate and deposit as a milky layer on the optics of the telescope.
Technical data
Classic Ortho 10mm, 1¼" eyepiece (HT-MC)
Net weight (kg): 0.05
Eyepiece series: Classic (Q-Turret)
Eyepiecedesign
Anti-slip protection: Classic Undercut
Number of lens elements: 4
Number of lens groups: 2
Outer diameter (mm): 34.8 mm
Field diaphragm diameter: 8.7 mm
Field diaphragm Offset to reference surface: -2 mm
Height 1¼" receptacle: 24 mm
Eyepiece height above reference surface: 17.12 mm
Features
Eye relief (mm): 8 mm
Focal length: 10 mm
Field of view: 52°
Optical design: Orthoscopic
Parfocal: Yes
Specialty: No specialty (standard eyepiece)
Insertion dimension (inches): 1¼"
Coating (anti-reflection coating): High-Transmission Multicoated (HT-MC)
Accessories included
Eyecups: winged eyecup (1¼")
Optional accessories: Q-Turret Eyepiece Revolver
Dust caps: 1¼" dust cap (31.8mm)
Connections
Filter thread: No
