ASTRO-PHYSICS
175 mm f/8 Starfire EDF (175EDF)

with 4" Focuser and CCD Field Flattener

175 mm f/8 StarFire EDF and 1600GTO German Equatorial Mount


Astro-Physics proudly introduces the new 175 StarFire EDF - our latest superb visual and imaging instrument! In keeping with the Astro-Physics tradition of offering the very finest of optics, Roland Christen has once again designed and produced this new air-spaced apochromatic triplet that is sure to be highly sought after in years to come.

After extensive testing on the bench using interferometers and autocollimation and nights of visual observing and CCD imaging, Roland sums up his impressions:

"I am happy to say that this scope performs up to my full expectations. The design is topnotch using the best glasses available polished to a high degree of perfection. The lenses will be coated with very low reflection multi-layers - less than 0.2% average reflection per surface. The design is broad spectrum correction, for both visual and CCD imaging. The glass is ultra-clear BK7 crown mated to Ohara FPL53 premium ED glass. The result is magic."

Roland chose the 1400 mm (f/8) focal length because he felt it was a sweet spot for lifetime enjoyment of visual and imaging pursuits. The planets and double stars are sharply defined, even in less-than-ideal seeing conditions. Regarding the astrographic capabilities, Roland shares his experience:

"The acid test was, of course, imaging and for that I added the the dedicated field flattener and my STL1100 CCD camera. The results were everything I had hoped for. All the colors came to the same exact focus - no focus tweek required for any of them. Stars showed similar size and full width half max resolution with all 8 filter positions (RGB, L, H-alpha, OII and SII). No color halos and, most important of all, no reflection halos from the lens itself or from the, as yet uncoated, field flattener optics. Stars are perfectly round across the 35 mm format (largest I had), lacking any spikes or flares even when stretched to the limits."

Roland Christen polishing the FPL53 of the 175 mm f/8 StarFire EDF lenses

Photographs Taken with the 175mm f/8 StarFire EDF

Click the links below to view Roland Christen's images taken with the 175mm f/8 StarFire EDF  
M37 M57 Crop Mars - May 22, 2012  
M37 at Half Size Saturn with Titan lower right - May 29, 2012 Mars - May 22, 2012  
     
M57 M57 Crop  
M57 - Ring Nebula at Half Size M57 - Closeup Crop of Ring Nebula  
Features Specifications
Color correction Less than +/ - 0.005% focus variation from 405 nm to 706 nm (r to h wavelengths)
Clear aperture 175 mm (6.9")
Focal length 1400 mm (55.1”)
Photographic speed f/8
Theoretical resolution 0.65 arc seconds
Coatings Multi-layer, broadband, overall transmission greater than 97% in peak visual wavelengths
Magnification range 25x to 700x
Tube assembly Cream white, 8.0" CNC machined aluminum tube, baffled, flat-black interior, push-pull lens cell, engraved retaining ring
Focuser type 4.0" I.D. Astro-Physics rack & pinion focuser, 4.15" travel; 2.7", 2" and 1.25" adapters; 4" extension; rotating collar; numerical scale
Telescope length 51.25" (1302mm) w/ dewcap fully retracted
Diameter of dewcap 8.875" (225.5mm) O.D. including paint thickness
Weight with dewcap 43 lbs. (19.5 kg)
Carrying-case type Wood case with grey vinyl covering and foam-lined interior



F/8.3 CCD Field Flattener Specifications, Included

This dedicated field flattener provides correction that is essentially diffraction-limited over a 76 mm (3") circle, encompassing 3.0 degrees of sky. Stars will be pinpoint into the extreme corners of the field. Please refer to the separate page for detailed information, field sizes and spacing requirements diagram.

Focal length 1452.5 mm @ f/8.3
Fully illuminated circle 3.0 degrees, 76 mm image circle
Back distance Maximum 114.9mm (4.5") from rear of housing (when extension piece is removed) to the focal plane; plenty of room for rotators, filter wheels, etc.


F/6.1 CCD Telecompressor Corrector (175TCC) Specifications, purchased separately

This optimized design uses 3 elements of high-index glass to widen and flatten the field while increasing the photographic speed of the 175 StarFire EDF triplet refractor from f8 to f6.1. Please refer to the separate page for more information, field sizes and spacing requirements diagram.

Focal length 1064 mm @ f/6.1
Fully illuminated circle 2.8 degrees, 53 mm image circle
Back distance 80.8 mm (3.18" from rear of Telecompressor Corrector housing)


Price and Delivery Information

Refer to Notification Update.
Price: $20,800

175EDF - What's Included? Items That You Will Need For Your Scope Mounting Recommendations

As shown in the photo, the new 1600GTO German Equatorial is an ideal match for the 175 StarFire EDF. However, you may also consider the 900GTO or 1200GTO (no longer available), which are all recommended for astro-imaging, depending on your requirements for portability and the amount of wind you are likely to encounter at your imaging site.

Additional Recommended Accessories and Options

There are many other accessories to consider. Please refer to these sections for additional recommendations:
Visual Accessories
Photographic and CCD Imaging Accessories
Baader Planetarium Filters
AstroSolar Solar Filter Material
Mounting Plates - your choices will be determined by the mount you own.

Specifications subject to change without notice.

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Copyright © 2012, Astro-Physics, Inc. - All Rights Reserved
This page was last modified: March 21, 2013

Astro-Physics, Inc.
11250 Forest Hills Road, Machesney Park, IL  61115, U.S.A.
Phone: 815-282-1513   Fax: 815-282-9847