Founder Optics 1.25" Dielectric Diagonal Mirror - DIA1.25-M Adjustable Dew Shields but can be used for

but can be used for all types of viewing

The optical design is air-spaced and produces a 44mm image circle so you can use larger full frame sensors without vignetting

25" Schmidt-Cassegrain and 9

may not have enough focus travel to allow the photographic image to come to focus when used in prime focus mode

Founder Optics 1.25" Dielectric Diagonal Mirror - DIA1.25-M Adjustable Dew Shields but can be used forIf you're looking for a nice 1. 25" diagonal for your refractor, this model from Founder Optics will do the trick. The compression ring twists to lock in 1. 25" barreled accessories without marring and fiddling with small screws in the dark. The telescope side slides into 1. 25" focusers. This Founder Optics 90 degree mirror diagonal has a dielectric coating with over 99. 99% reflectivity for bright images.