The Fluorite Quadruplet Polychromat 180/1440 does not show any decrease of the Strehl ratio near or below the diffraction limit in the peripheral regions of the visual spectrum, as is the case with most apochromats.
Due to its polychromatic correction, the 180/1440 CaF₂ Quadruplet is the first astronomical optics that exploit the full UBVRI spectral range (365nm – 1014nm) of modern electronic sensors (CCD, CMOS).
We source the high-quality fluorite blanks with special parameters in selected quality from a certified manufacturer, which also supplies the global players of precision optical equipment with CaF₂ raw material for the production of stepper lenses for VUV photolithography.
The surfaces of the objective lenses made of three different special optical glasses of SCHOTT® or OHARA® and CaF₂ are precision machined, a lens surface is an asphere.
Because every fabrication can only be done with finite precision, even the latest technologies and state-of-the-art CNC precision machining processes are subject to errors. All manufacturing parameters must therefore be tolerated conscientiously.
The required high image quality is achieved by a final system correction, which is performed by a precision optics master with decades of experience in his field.
Thanks to a novel compensation cell, the lenses of the completely oil spaced objective (without air gaps) are held in stable position with fluctuations in temperature.
The thermal equilibrium sets in quickly and rattling of lenses in the cell with all negative consequences is prevented.
The objective can be adjusted precisely to the optical axis of the OTA.
The CNC precision machining of lens cell, dew cap and telescope tube ensures the required high centering accuracy.
Inside the OTA, a defined surface structure and a diaphragm system in combination with an antireflective coating of all internal surfaces effectively prevent the occurrence of scattered light and tube reflections.
The over 190mm sliding dew cap, which can be clamped in any position, takes into account the maximum image field diameter of the field corrector and focal reducer corrector of 3.5° each. On the dew cap the label Polychromat 180/1440, the brand logo APQ as well as the indication of origin Made in Germany are applied.
At the end of the refractor, the Feather Touch focuser FTF3545 from Starlight Instruments is mounted with an APQ Quick Changer with the S108 dovetail ring system for coupling adapters and components.
The Feather Touch focuser is rotatable by 360°, so that it can always be turned into the desired position. The dual-speed mechanism with coarse and fine drive has a reduction ratio of 10:1.
The eye-catching color of the OTA stands out significantly from the general standard white and gives the APQ Polychromat a unique and distinctive design with a high value of brand recognition.
The APQ 180/1440 Fluorite Quadruplet Polychromat is a premium refractor that is predestined for all types of observations – visual and photographic.
Polychromat 180/1440 Objective
Lens type
Fluorite Quadruplet Polychromatic refractor
Optical design
four lens aspherical design
Coupling technique
completely oil spaced without air gaps
Mounting type
compensation cell
Cell material
high quality aluminum and stainless steel alloys
Polychromatic Strehl ratio
≥ 0,95 (365nm – 1014nm)
(theoretical)
Maximum focal shift range
±0,004% (365nm – 1014nm)
(theoretical)
Anti-reflection coating
Ultra broad band AR coating RAVG < 0.7% (365nm – 1014nm)
(theoretical)
Clear aperture
180mm
Focal length
1440mm
Focal ratio
f/8
Image scale
2.387'/mm or 0.419mm/'
Resolution
0.63"
(theoretical)
Magnification range
33x – 540x
(exit pupil 6mm – 0.33mm)
Test protocol
optical inspection certificate
Tube assembly 180/1440
Tube and dew cap material
high quality aluminum and stainless steel alloys
Tube and dew cap colors
silver metallic / black metallic
(individual colors such as cream white or black velvet are possible by arrangement)
Tube diameter
Ø197mm
Telescope length
1105mm / 1409mm
(dew cap and focuser retracted / extended)
Dew cap diameter
Ø231mm
Dew cap length
325mm
Backfocus
280mm
Feather Touch Focuser FTF3545
Focuser
Feather Touch FTF3545
Clear diameter
Ø90.17mm (3.55")
Focusing range
114.3mm (4.5")
Lifting capacity
8.1 – 9.1kg (18 – 20lb)
Reduction ratio
10:1
360° rotatable and lockable
yes
Motorized drive as option
yes
Weight
2.7kg (6lb)
Polychromat 180/1440 OTA
Adapter
S108 Quick Changer
Dust-covers
covers to protect the lens and tube
Tube rings
optional
Dovetail Plate
optional
Accessories
optional
Weight (including Focuser)
< 17.5kg (38.58lb)
* The eyepieces, mirror diagonals, binoculars and cameras shown here are only intended to illustrate the observation options of the APQ 180/1440. Any resemblance to existing products would be purely coincidental.
APQ 180/1440 Polychromat with eyepiece for visual observations*
APQ 180/1440 Polychromat with mirror diagonal and eyepiece for visual observations*
APQ 180/1440 Polychromat with mirror diagonal, binocular and eyepieces for visual observations*
APQ 180/1440 Polychromat with APQ Flattener and IMX411 (image diagonal 66.7mm) CMOS camera for astrophotography*
APQ 180/1440 Polychromat with APQ 0.7x Reducer and IMX461 (image diagonal 55mm) CMOS camera for astrophotography*
APQ 180/1440 Polychromat – Observation options at a glance*