Bottletopburly Posted September 30, 2018 Share Posted September 30, 2018 Is the focal length of a 25mm cctv lens 25mm , being a tad lazy after doing PA in sharpcap and not swapping over to my qhy mini guide scope fl 130mm only just realised phd is set up for the qhy mini guide scope so thinking ? this not helping my getting to grips with guiding , mind the 25mm does pick up stars nicely. Link to comment Share on other sites More sharing options...
Tweedledee Posted September 30, 2018 Share Posted September 30, 2018 Yes, that refers to the focal length. The aperture would normally be 25mm divided by the focal ratio though the lens could look bigger if it had some internal baffles. Bottletopburly 1 Link to comment Share on other sites More sharing options...
Bottletopburly Posted September 30, 2018 Author Share Posted September 30, 2018 25 minutes ago, Tweedledee said: Yes, that refers to the focal length. The aperture would normally be 25mm divided by the focal ratio though the lens could look bigger if it had some internal baffles. Cheers Pete I’ve will swap over next time anyway me just being lazy , not sure what effect this has with phd2 not having the correct focal length obviously won’t be helpful . Link to comment Share on other sites More sharing options...
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