Product Details

• Description
• Specifications
• Included Items
• Reviews

• 

  The Limited Edition RedCat 51 Upgrade f/4.9 APO 250 mm Telescope!

  Designed to be the best, affordable, small, lightweight and fast Apochromatic refactor for astrophotography. The unique optical design includes the highest quality glass for the best possible color correction and flat large image circle. The result is a 51 mm objective lens, in a sleek Petzval design, for a full-frame image.

  Optical Design

  51 mm lens, in a sleek Petzval design, using Synthetic Fluoride (FPL53 and FPL51) glass for a full-frame flat field image. The optical quality provides exceptional performance at a fast focal ratio of f/4.9. The Limited Edition RedCat 51 Upgrade will out resolve most high-resolution DSLR lenses of similar focal lengths.

  

  

  

  Field Rotator

  Inspired by luxury watches, the telescope's field rotator is laser etched with a  degree indicator. To ensure that you will have the most precise framing possible in a small portable system, the camera can be rotated to fit within a degree of accuracy.

  Filter Adapter

   It is now easier to connect your filter to the Filter Adapter.  

  Filter Index

  The filter index marks let you know the estimated focusing site when you twist the focuser.

  Camera Sensor Tilt Adjuster

  The Tilt Adjuster can adjust the tilt of the image plane.

  

  

  Modular Mounting Ring

  The single-tube Cat ring is sturdy enough to hold the optical tube and a large-sized DSLR without noticeable flexure. It is modular in the sense that you can add a finder scope or guide camera.

  All New Mounting Plate

  William Optics has reinvented the V-style dovetail. Not only will it fit into a Vixen style saddle plate, but if it's flipped over it can be attached to any Arca-Swiss style photography tripod head. This allows you to use the telescope for both day and night photography. The length of the new mounting plate is 210 mm.

  Reversible Dew Shield

  To maximize portability, the dew shield on this telescope is reversible. When stored backwards it can shorten the telescope length by approximately 83 mm.

  

  

  Bahtinov Cap

  The cap with this telescope not only protects the glass from the elements, but it also has one of the most useful tools when it comes to focusing.

  The Bahtinov Cap creates three lines that pass through a bright star. There is a main large line and a smaller cross-section of two lines making an “X”. The goal is to get the large line centered between the X and centered on the star. Once that is done, you have a perfect focus in as little as 2 to 3 seconds.

• specifications

  Aperture	51 mm (2")
  Camera/Eyepiece Connection	Male M48x0.75
  Dawes Limit	0.46 arcseconds
  Focal Length	250 mm
  Focal Ratio	f/4.9
  Free Shipping	Yes
  Glass Type	FPL53 and FPL51
  Highest Magnification	102x
  Light Gathering Power	53x
  Limiting Magnitude	12.3
  Optical Design	Petzval
  Tube Color	Red
  Tube Diameter	51mm
  Tube Weight	3.2 lbs

• included items