William Optics WhiteCat 51 APO f/4.9
William Optics WhiteCat 51 APO f/4.9William Optics WhiteCat 51 APO f/4.9William Optics WhiteCat 51 APO f/4.9
William Optics WhiteCat 51 APO f/4.9William Optics WhiteCat 51 APO f/4.9

William Optics WhiteCat 51 APO f/4.9

  (2 Reviews)
✓ 2 year warranty


In stock shipped 1-2 working days.
Request a Price Match

About this product

Model:  wo_whitecat_51
Part Number:  A-CAT51-W

WhiteCat 51 250mm f/4.9 Apo

The NEW William Optics WhiteCat 51 APO is a 51mm f/4.9 Petzval refractor that includes synthetic fluoride (FPL53 and FPL51) glass elements for a full frame, flat field image.

Provides high resolution images when used for astrophotography or wildlife photography.

It's fast f/4.9 focal ratio and compact size makes it ideal for convenient wide field astrophotography or piggybacking. 

Incorporates a smooth helical focuser, a field rotator graduated by degree, a slot for 48mm filters and a reversible dovetail for either Vixen style* or Arca-Swiss mounting. 

* Some customers have found William Optics' Vixen style dimension a little too narrow for their mount's saddle so you might need to fit a different dovetail. 

Telescope Field of View Simulator

What's in the box

  • RedCat 51 f/4.9 scope
  • Soft Carry Case
  • Patented Bahtinov Mask


Focal RatioF/4.9
Focal Length250 mm
Objective TypePetzval (4 elements in 3 groups) and Ohara FPL 53 ED element. 
Image CircleWhiteCat Φ 44mm (Full Frame)
Dimensions225mm x 80mm x 80mm
Tube Weight1.47kg

Customer reviews

Average Rating (2 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Design / Daylight Image Quality
Friday, 17 May 2019  | 

Delivery was fast and DHL package tracking was nice! The Redcat is a really beautiful looking scope! For now I can only review the peformance during the day since it has been completely overcast here. Having tested the image quality during the day, I can say the images very really sharp, no chromatic abberation as expected. Can‘t review it for astrophotography for now but I expect nothing less. Let the sky be clear

Update from Carsten: After a long time I finally got to test my redcat 51 under a dark clear sky which I have ordered from your store. I am impressed with the image quality and performance. I don‘t consider myself a professional astrophotographer yet, but if you want to have a look at the result. Here it is on astrobin:


Rating (max 5):  
Work of art
Tuesday, 2 April 2019  | 

This is a beautiful telescope. It oozes class. It also works wonderfully well. I am very happy with it. I took 50 unguided subs on the jellyfish nebula on my heq5 pro. The stars were pin sharp to the edge and the nebula colour was highly apparent. I cannot wait until I can take this little beauty out to a dark sky site.


Please fill in the form below to ask a question or request a price match.

Your Name:
Your Email Address:
Your Question / Request:
URL of the Cheaper Price:
If you are requesting a price match please let us know the URL where you have seen the product cheaper.