I see on the Celestron web, the Edge HD reducer is $599. It will only provide ONE f/stop faster... really, for 600 dollars? f/10 to f/9... that's not a lot to brag about for just a few more seconds if you are doing AP. Am I missing something?
CPC1100 housed in a slotted domed observatory (Exploradome) 4 and 5 inch refractors for use from the lawn, a 8" Sct (NS 8i) for star parties...
I Hate the winter so I use heated Motorcycle clothing to stay warm while observing in winter
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1. tinker with older Corvettes (6 in garage)
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The normal f/stop range is what I thought at first... but they only say "One Full f/stop", without telling you what the final f/stop would be . So I was thinking they were trying to fool people who didn't know a lot about photography.
Exposures with the reducer are shortened by a factor of 0.7x0.7=0.49, or about half. Is it worth $600? How much is your time worth? If you only have 8 hours a month available for AP, the reducer could give you the equivalent of 16.
One full stop = half the exposure time. F10 to F9 is NOT one stop! F10 to F6.3 is one stop.
Telescope:Equinox ED80 Pro (Schott/Ohara Fluorite) with Baader Steeltrack + Nexstar 6SE OTA
Mount: Skywatcher HEQ5 Pro+EQDIR + ADM bling Camera: JTW 1100D Ultimate V3, Astronomik Clip filters, Samsung SCB-4000, IS DBK21AU618.AS
Accessories: Baader 8-24 MkIII, Ortho 5mm, Aspheric 31mm, Meade 12mm reticule, Televue Powermate 2.5x, BAST Motorfocus+FCUSB, Skywatcher Field Flattener, Orion RACI, Orion Mag Mini/SSAG, Canon IS 15x50 Bins
Software: EQMOD/Stellarium/Registax/BackyardEOS/PixInsight,PHD,AlignMaster, AstroTortilla
Oh... Must be having one of those days. Don't know what I was thinking, f/11 would be f/8... So f/10 would surly be f/6.3. Thanks for setting me straight!
CHUCK WALTERS SCOPES: Celestron 1100 XLT; EdgeHD 800; Exp. Sci. ED80 APO; AR102; Orion 10" f/4 Astrograph; XT8 LE; Astro Tech AT72ED Coronado SolarMax II 60 BF15 MOUNTS: Celestron CGEM DX; CG-5GT CAMERAS: JTW Ice Cube 650D BCF; JTW Ultimate 1100D v3; Canon 1100D (unmodded); IS DBK21AU618; DMK21AU04 ZWO ASI120MC SOFTWARE: StarTools 1.3; PixInsight; DSS; RegiStax 6; PHD; BYEOS; APT 2.0; SharpCap 1.5; FireCapture 2.2
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f/10 to f/6.3 is "one stop". What is the definition of one stop? I know f/6.3 is faster than f/10 but I'm not clear on how one stop gets a telescope to that and what a "stop" is.
Modern lenses use a standard f-stop scale, which is an approximately geometric sequence of numbers that corresponds to the sequence of the powers of the square root of 2: f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64, f/90, f/128, etc. Each element in the sequence is one stop lower than the element to its left, and one stop higher than the element to its right. An 11 drops to an 8 and a 10 drops to a 6.3 in stop range.
I just got mine today. As someone mentioned, the HD version is .7x not .63x as the reducer/flatteners are for the non HD tubes. It weighs a ton, will definitely need weight added to the front of the tube. The reducer + T-adapter + camera is a lot of weight hanging off the back. Of couse now that I have it, I'm stuck with cloudy skies again. BTW, I believe it will also work well for visual use and provide a wider field of view or a given EP.