Altair Wave Series 125 EDF F7.8 APO Binoviewer ready 3.7" R&P Focuser
The Altair Wave Series 125mm EDF F7.8 APO is a highly specified doublet APO refractor which offers plenty of aperture, portability and high resolution for the visual observer.
Distinctive features of the Altair 125mm ED refractor:
- Better colour correction than any other ED Doublet in this size / focal range.
- Optical test report, with every lens carefully adjusted to meet Strehl 0.95 minimum in green light according to Atmosfringe software analysis over the full aperture of 125mm.
- CNC 3" Rack 'n Pinion geared focuser with self centering 2" aperture and 2" to 1.25" adapter.
- Binoviewer ready, removable extension ring between focuser and optical tube.
- Reducer gives tight spot size over 40mm image circle suitable for astrophotography.
- Optical tube weighs only 7.9kg!
Why a big doublet refractor? A 5" long focal length ED refractor hits the perfect balance for visual observers, whether you are into planetary, lunar, deepsky or solar observing. An ED doublet lens cools faster than a triplet lens, because there is no centre-element with an insulating air gap so thermal equilibrium is reached quickly. Frant-end weight is also minimised for a nice balance, and the longer focal ratio allows superb colour correction and memorable planetary views. Finally two lenses means two less air-to-glass surfaces than a triplet for better contrast and less scatter. The 125 EDF is a good choice for high resolution solar imaging. (Please see some solar images). Performance for white light solar observation with the Altair 2" Hershel Wedge gives the ultimate crisp views. The contrast and resolution are high enough to easily see granulation and delicate structures within sunspots. Views and images with the Daystar Quark Hydrogen Alpha, Sodium or Calcium eyepieces are also superb.
APO performance, modern design: Usually Altair's "APO" designation is reserved for triplet refractors only, however, the 125 EDF, whilst a doublet refractor, has no colour aberration visible in-focus. This is thanks to a long F7.8 focal ratio and a modern computer aided design. An optimisation process simulates lens performance, taking millions of permutations into account and consulting a vast catalogue of optical glass before deriving the radii and spacing of the ojective lens. The designer's only criteria was to use modern Synthetic Fluorite FPL53 ED (extra low despersion) glass and to keep the focal ratio at F8 or shorter to allow for an easy-to-manage tube length. Every lens surface has a different radius in this design, something quite uncommon amongst refractors, making the lenses harder to polish, however the results are well worth the effort. Glass melt data has also been used to calculate the lens element spacing.
- Aperture / Focal length: 125mm / 975mm.
- Focal Ratio: F7.8.
- Resolution: 0.93 arc seconds.
- Limiting Visual Magnitude +12.6.
- Highest Useful Magnification - 246x (atmospheric conditions permitting).
- Air spaced ED Doublet APO lens with optical test report and interferogram image.
- Fully multi coated on all optical surfaces for high transmission.
- New 2017 3.7" Dual speed Rack 'n Pinion focuser with 170mm backfocus and 100mm travel. Full 360 degree rotation with Teflon tipped screws.
- 2" rear Self-Centering Adapter on focuser with stainless steel "Capstans" for tightening.
- Aluminium tube with white matte powdercoat.
- Retractable, lockable dew shield.
- 1:10 ratio micro focuser knob.
Optional 60mm Deluxe right angled finder scope with illuminated reticule.
CNC machined tube rings compatible with Altair TMS M6x30mm hole spacing. Felt lined.
Vixen-format dovetail bar.
- 1.25-2" adapter with brass compression ring.
Scope Weight - 7.9kg without accessories.
Scope Length 838mm with dewshield retracted.
Availability: These optics are modified to achieve a higher quality images. Both the lens element spacing and the centration are set up to get the best balance between colour aberration and the best possible star-test. This process takes time and we regularly reject lenses or combine them in different combinations. It is impossible to predict how long it will take to modify a particular batch of lenses to our standard because each lens is different. Rather than manage a "wait-list", we have a simple "first come first served" policy. Please click on the "notify when in stock" button to receive an automatic email update when this product is ready for ordering. When the notification email has been sent, our system will automatically purge your email address. Please Note: The price and specification are subject to change without notice.
- Harrison Telescopes
- Telescope House
- Tring Astronomy Centre
- Rother Valley Optics
- F1 Telescopes
- Io Astronomy Please note: IO Astronomy voluntarily ceased trading with large unpaid debts affecting the entire UK astronomy industry. You may contact us for problems / issues with Altair or iOptron products ONLY - or try Darkframe Optics / Dave Woods. Unfortunately, we will not be able to support undeclared products bought from the ex-directors after the company ceased trading.
- Astro AS Denmark, Europe
- Robtics Netherlands
- Pierro Astro France
- SkyVision France
- Teleskop Service Ransburg Germany
North America & Canada orders:
- Land Sea & Sky (Takahashi America) USA
- Cloudbreak Optics USA
- Ontario Telescopes Canada/North America
Products can be ordered online from Altair with tracked insured shipping to anywhere in the world. For large items shipping price may need to be re-quoted.
Russia orders: Please contact.