APQ News

Statement on "Christen Superachromat"
Astro-Physics uses the terms "Christen Superachromat" and "diffraction-limited polychromat telescope", which in technical optics denote a higher class of chromatic correction insofar as these terms are used as technical performance descriptors. According to Herzberger/McClure, "The Design of Superachromatic Lenses", Applied Optics, 1963, a superachromat is corrected for four colors and thereby, in practice, for all colors; the reference wavelengths stated there range from 0.365 µm to 1.014 µm, i.e. from 365 nm to 1014 nm.
Haferkorn, in "Optik", 1981, describes the corresponding extension from dichromat and trichromat to polychromat as a system in which additional dichromatism conditions make the paraxial focal position coincide for a greater number of colors.
However, the data published by Astro-Physics for the 155CS and 190CS do not document such UV–VIS–IR correction. Astro-Physics describes both instruments as "Christen Superachromat" and as a "diffraction-limited polychromat telescope", while the published performance data refer to the visual or photo-visual spectrum; for the 155CS, the theoretical ray trace is expressly stated only for 435–656 nm. For both models, the 155CS and 190CS, Astro-Physics states that the color correction extends from the near IR to the violet edge of the visible spectrum, but not from 365 nm to 1014 nm.
The addition "Christen" does not in itself change the established technical meaning of the term superachromat. By contrast, APQ JENA uses the term Polychromat specifically and verifiably for diffraction-limited correction over 365–1014 nm and thus across the full UBVRI range of modern CCD and CMOS sensors. For the APQ 150/1200, APQ additionally specifies a polychromatic Strehl ratio of ≥ 0.95 over the range 365–1014 nm.
The Astro-Physics designation is therefore not technically substantiated by the published data and may suggest an equivalence with UV–VIS–IR- or UBVRI-corrected polychromats that is not documented by those data, as defined and documented by APQ JENA.
Astro-Physics 155mm f/6 StarFire CS (155CS)
Astro-Physics 190mm f/6 StarFire CS (190CS)
APQ Optical Design

APQ Eyepieces for Planetary and Wide-Angle Observation – Advance Announcement
APQ is developing a new generation of high-quality eyepieces for visual astronomical observation.
Development focuses on contrast transfer, natural color rendition, and imaging quality that remains as uniform as possible across wavelength and field of view.
Different versions are planned, ranging from orthoscopic eyepieces uncompromisingly optimized for image purity to modern wide-angle and ultra-wide-angle concepts.
Further technical details will be announced at a later date.

Comparison of Published Manufacturer Spot Diagrams with APQ
Theoretical spot diagrams from publications by the respective manufacturers are compared. The diagrams have only been placed on a common graphical scale of 100 µm.
Wavelengths, field positions, focus definitions, weightings and calculation methods are not fully identical. The presentation is not an independent laboratory test or a measurement of production instruments; by itself, it does not permit a definitive ranking of overall optical performance.
Comparison of Published Manufacturer Spot Diagrams with APQ

New Generation of Polychromatic Flatteners and Reducers – Advance Announcement
APQ is developing a new generation of polychromatic field correctors and focal reducer correctors for maximum imaging and focus stability under changing operating conditions.
Further technical details will be published after completion of the development and intellectual-property work.

Responsive Web Design for apq.de
Our website now features responsive web design. The pages automatically adapt to different screen sizes.
Whether viewed on a smartphone, tablet or large computer monitor, text, images and menus rearrange themselves so that the site remains easy to read and use without horizontal page scrolling.
APQ JENA

Astronomical exhibition 2027
We are planning to present the APQ 150/1200 Fluorite Quadruplet Polychromat at an astronomical exhibition next spring.
Further details will follow soon.
APQ 150/1200 Fluorite Quadruplet Polychromat

Current delivery situation of APQ JENA
APQ JENA has been working on the design and development of the world's only polychromatic refractors for several years now. During this time, we have made substantial personnel and financial investments.
We do not wish to attribute delivery delays to well-known causes such as material shortages or increased energy and labor costs resulting from global crises. Rather, the crucial point is that our products are innovative new developments that have presented unexpected technical challenges.
Please be assured that we have mobilized all available resources to complete production as quickly as possible so that we can deliver high-quality, flawless products to you. However, this will require additional time.
As things stand, we anticipate a further delay of approximately 12 months. Your deposit is, of course, fully protected.
We sincerely regret any inconvenience and ask for your understanding in these exceptional circumstances. We are always available to answer any questions or address any further concerns you may have. Thank you for your trust and patience.

Claims about APQ JENA
For some time now, in some astro-forums, inaccurate and unfounded claims about the delivery situation of APQ JENA have been circulating, which we of course reject with all decisiveness.

APQ 110/550 Fluorite Wide Field Polychromat
The first APQ Wide Field Polychromat starts with the following specification:
110mm aperture
550mm focal length
f/5 focal ratio
Ten-lens aspherical design
3 lenses from CaF₂
Integrated special focal reducer corrector
Retractable and lockable dew cap
Feather Touch Focuser FTF3545
The previously announced design variant with a 10° (Ø96.7mm) image field requires a focuser with a larger free diameter.
Ø67.4mm non-vignetted image field
UBVRI Fluorite Wide Field Polychromat
Polychromatic RMS spot radius vs. field ≤ 1.0µm in the spectral range from 365nm to 1014nm over the entire field diameter of Ø67.4mm (7°)
Polychromatic Strehl ratio ≥ 0.95 (365nm – 1014nm)
Compact travel-ready dimensions (427mm transport length)
Outstanding imaging performance for astronomy and nature observation – setting a new benchmark in its class
APQ 110/550 Fluorite Wide Field Polychromat

APQ 100/640 Fluorite Quadruplet Polychromat
Completion of the series of Fluorite Quadruplet Polychromats with the APQ 100/640:
100mm aperture
640mm focal length
f/6.4 focal ratio
Polychromatic Strehl ratio ≥ 0.95 (365nm – 1014nm)
APQ Field Corrector (system focal length 640mm): ≤ 4.2µm (365nm – 1014nm) / flattened image field diameter without vignetting Ø45.5mm (4°) polychromatic RMS spot radius vs. field
APQ 0.78x Focal Reducer Corrector (system focal length 500mm): ≤ 3.25µm (365nm – 1014nm) / flattened image field diameter without vignetting Ø44.8mm (5°) polychromatic RMS spot radius vs. field
Airplane cabin compatible (487mm transport length)
APQ 100/640 Fluorite Quadruplet Polychromat

APQ website further completed
Completion of the product section of the website with a detailed description of the features and specification of the technical data:
APQ Fluorite Quadruplet Polychromats (additionally with recommended accessories, applications and downloads)
APQ Polychromatic Focal Lens Systems
APQ Accessories
A separate flyer with the most important information is available as a PDF for each APQ Fluorite Quadruplet Polychromat.
APQ Products

APQ 110/550 Wide Field Polychromat – Advance notice
The APQ 110/550, the first Wide Field Polychromat, is ultimately suitable for astronomical and nature photography with modern CMOS cameras with small pixels due to its huge image field. Visual observers benefit from the high polychromatic Strehl ratio and its compact, travel-ready dimensions. The APQ 110/550 has the following (preliminary) features:
110mm aperture
550mm focal length
f/5 focal ratio
10° (Ø96.7mm) image field diameter
Polychromatic UBVRI correction from 365nm to 1014nm throughout the field of 10°
Polychromatic Strehl ratio ≥ 0.95 (365nm – 1014nm)
RMS spot radius ≤ 2µm for all wavelengths from 365nm to 1014nm in the entire field of 10°
Airplane cabin compatible
APQ 110/550 Fluorite Wide Field Polychromat

APQ Accessories
Completion of the mechanical design of our own mechanical telescope assessories:
Dovetail Plates
Mounting Rings
Carrying Handles
Steering Wheels
Dew Caps
Changer
Change Rings
Extension Tubes
Adapters
Dustcaps
APQ Accessories

APQ Polychromatic Focal Lens Systems
Specially designed polychromatic field correctors (flattener) and polychromatic focal reducer correctors (reducer) for each individual APQ Polychromat:
APQ 130/1000 Fluorite Quadruplet Polychromat
APQ 150/1200 Fluorite Quadruplet Polychromat (already known)
APQ 180/1440 Fluorite Quadruplet Polychromat
APQ 200/1600 Fluorite Quadruplet Polychromat
APQ Polychromatic Focal Lens Systems

APQ Fluorite Quadruplet Polychromats – The polychromatic APQ family with apertures from 100mm to 300mm is almost complete
Completion of the optical and mechanical design for these Polychromats:
APQ 130/1000 Fluorite Quadruplet Polychromat
APQ 150/1200 Fluorite Quadruplet Polychromat (already known)
APQ 180/1440 Fluorite Quadruplet Polychromat
APQ 200/1600 Fluorite Quadruplet Polychromat
APQ Fluorite Quadruplet Polychromats

APQ 150/1200 Fluorite Quadruplet Polychromat
A Polychromat 150/1200 was tested with an interferometer at 546.1nm with a Strehl of 0.976. According to the optical design, the maximum Strehl for this wavelength can theoretically be 0.986. Due to a design revision we were able to achieve a weight reduction of approx. 3kg. The OTA 150/1200 will therefore not weigh 15.8kg as originally stated, but less than 13kg!
APQ 150/1200 Fluorite Quadruplet Polychromat

APQ Astronomical optics from Jena
APQ JENA brings astronomical optics and instrument technology back to life after 25 years in Jena and announces a new line of Fluorite Quadruplet Polychromatic Refractors. A Fluorite Quadruplet Polychromat from APQ JENA is the first astronomical objective to be able to use the full UBVRI spectral range (365nm – 1014nm) of modern electronic sensors (CCD, CMOS).
APQ JENA