How do I add an f/6.3 reducer/corrector to a telescope?

[derangedhermit]

I want to add a Celestron f/6.3 reducer/corrector to an SCT in Skytools 4 Visual.

I am currently using the "Select Eyepieces to Use with Telescope" panel, and putting 0.63 in the coma corrector magnification box, but am not sure if that is how to do it.

There is also the "Built-in focal changer" checkbox in the "Add/modify telescopes" panel, but checking that does nothing that I can see.

[theskyhound]

Hello,

It sounds like you have it set up correctly with regard to the coma corrector.

The built-in focal changer setting adds a piece of glass to the calculations used in the telescope model. Its meant for the special case where you have entered the modified focal length of the telescope to reflect the presence of a permanent focal changer. In practice its not going to make a big difference in the calculations. So one thing you could have done was to enter the corrected focal length of the telescope with the coma corrector in place, ticked this box, and then you would be done. But the other way to do it, especially if if you are ever going to remove the focal reducer, is to set up the way you have already done. This gives you the ability to uncheck the box on the eyepiece selection menu if you remove the reducer.

To sum up, there are two ways to do it:

1. Enter your focal reducer and leave the built-in box unchecked
2. Skip the focal reducer by entering the modified focal length, and check the built-in box.

[derangedhermit]

Thanks Greg! I will keep the definition of the scope at f/10 and enter the 0.63 "coma corrector" magnification factor, since sometimes I do remove the R/C for high powers.