What’s a Telrad? – A Short Introduction

A question I’ve been asked quite a few times when at public astro society events concerns the black box that is perennially attached to the side of my 200P Newtonian.  I’ve also been surprised how many people, who seem otherwise fairly adept with astro kit on various astronomy forums and the like, don’t seem to know what Telrads are or how they work. A quick search has turned up very little in the way of video on the subject.

To me, the Telrad is one of the most singly wonderful and useful things that I’ve ever added to my collection of Kit.It makes alignment so much easier than it ever was with a mangifying finderscope, to the extent that I now have a guide camera attached to my finderscope permanently, and don’t use it as an actual finder at all.

I’ve made a quick video, explaining what a Telrad is, and why you want one (or something similar!).

By the way, I forget to mention in the video that the three circles are 1/2, 2 and 4 degrees when superimposed on the sky, and you can get charts that utilise Telrad circles to help you find things visually. It’s also possible to vary the brightness of the reticle via the variable on/off switch.

You may also like...

7 Responses

  1. Lee Phillips says:

    Nice video Adam


  2. Andrew Ervine says:

    Great video – I have been using a telrad for a couple of years, which Lee Phillips helped install. I am led to believe that some of the component parts come from the Japanese province which was hit by the tsunami and for a while they were difficult to obtain. Don’t know if this has affected the price?

    • Adam says:

      I’m not sure – I got mine about a year ago now, so am not sure if they increased in price from previously. I know they became a little scarce for a while, so maybe that was the reason. To be honest, they’re really plasticy, but fairly sturdy. They do seem a little overpriced, but I like them so much I saw past that! You can often pick them up second hand on places like astrobuysell.com, but I find they’re not much cheaper than they are new…

  3. Thanks for sharing it I have been using Telrad for over 30 years. I generally look from above, using the reflection of the star on the sloping glass; instead of looking through it.

    • Adam says:

      Interesting I’ll have to give that a go… though I’d think fir star hopping that would be harder as you’d have to deal with the reversal of the image? Any particular reason you do that rather than the standard way? Physical constraints?

      • Yes, 90º of reasons. Looking at the transverse reflection, the view is aligned with my eyepiece. But if I have to see fuzzy objects, I only look from the conventional position, which- in some cases- is uncomfortable. Thanks for your answer. Regards.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.