I have a 700 mm focal and 76 mm aperture telescope. I bought it a few days ago. I tried to spot Mars for 3 days but I only see red light. I use an 20 mm eyepiece for finding it and 4 mm eyepiece for seeing but only red light is visible. Please help me.

  • 1
    $\begingroup$ Is the red light just a dot or a ring of red light? EDIT : If you could also link to your telescope model, it would be great. $\endgroup$
    – RyugaGod
    Nov 12, 2020 at 11:09
  • 5
    $\begingroup$ If you go to astronomy.tools' FoV calculator, select Mars from the "Solar system" dropdown, then enter in your telescope and eyepiece details, and click "Add to view"; does the resulting image look like what you can see? $\endgroup$
    – Aaron F
    Nov 12, 2020 at 22:10
  • $\begingroup$ As RyugaGod asked, is it a dot/disk or a ring? 'Cause my first thought is you're out of focus, and a ring would be very indicative of that. Also, I assume you DON'T have a filter on there that's red? (I've left filters on my camera that I forgot about.) $\endgroup$ Jan 13, 2021 at 6:20

1 Answer 1


Mmm... it's a pretty small scope using a fairly high power. The disc of Mars is not going to be very large (just a few seconds of arc across) so I don't think you should expect to see something that looks like a HST image! Mars is pretty red as a rule, so 'red light' is what you should be seeing because the disc is too small to show much detail.


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