For serious astrophotographers, an optical tube that has quality optics and suitable specifications is key to producing successful images. Astrographs come in many different specifications and designs, so each model can be oriented or preferred for a different type of imaging (eg. solar, terrestrial, deep sky etc). Some common designs include the Ritchey-Chrétien, Riccardi Honders, and Catadioptric optical tubes. Choosing an astrograph depends on how the astro-imager wants to observe, what focal length and focal ratio it has, aperture, optical coatings, and how suitable it is for the camera they intend to use.
A key specification very important to consider when choosing an astrograph is focal ratio in relation to aperture. This is an important to remember because focal ratio determines what the magnification and field of view the observor will get. Therefore, if the observor intends to mainly view deep sky objects with lower surface brightnesses, a shorter focal length will reduce magnification and increase field of view since most deep sky objects tend to appear very large but not bright. Astrograph telescopes with slower focal ratios such as an f/12 will provide higher magnification and smaller field of views; better for planetary observing.
Imaging Harmer Wynne (iHW) astrographs are high resolution, fast focal ratio instruments with excellent on and off axis performance.... Learn MoreFREE SHIPPINGModel#: iHW12.5(48 States)
Imaging Dall Kirkham (iDK) astrographs are high resolution instruments with outstanding on and off axis performance across a 60mm field of view.... Learn MoreFREE SHIPPINGModel#: 145IDK(48 States)
A great benefit behind the Dall Kirkham design is excellent off-axis performance. The 12.5 astrograph from AG Optical is in a carbon fiber tub and has a medium focal ratio with a large aperture to support a variety optical and astrophotography combinations.... Learn MoreFREE SHIPPINGModel#: 125IDK(48 States)
Officina Stellare - Veloce Riccardi-Honders 250 f/5.6 Astrograph w/digital giant 95mm Finefocus and Rings Pair
Officina Stellare's Veloce RH 250 Riccard-Honders Astrograph features a large front full aperture corrector lens with near zero expansion glass in a Mangin mirror optical design, allowing a 250mm aperture, f/5.6 focal ratio, 1400mm focal length, double stage split internal light baffle, and a 3.6 micro spot size at the field's edge.... Learn MoreModel#: VELRH250
Learn MoreFREE SHIPPINGModel#: TSS1802(48 States)
Learn MoreFREE SHIPPINGModel#: TSS1800(48 States)
Designed to replace the Takahashi Baker-Ritchey Chretien BRC-250, the new Takahashi CCA-250P Tri-Focal Astrograph takes its place among the stars as the latest visual and astrophotogic instrument
"Check out imaging and collimation results and pictures below by New Mexico Skies Staff!"... Learn MoreFREE SHIPPINGModel#: CCA-250(48 States)