Determine Webcam Model I Want To Try Webcam Imaging Of Planets. How Do I Figure The F Ratio W/ A Barlow Or Televue Powermate?

I want to try webcam imaging of planets. How do I figure the F ratio w/ a barlow or Televue powermate? - determine webcam model

I have a 10 2500 mm f10 LX200 and used toucam. I have a 2x Barlow, but I think one of the largest get Televue Powermate.

* How can I determine the relationship between the use of a Barlow lens and / or Powermate.
* How will it ever, if I could also be an extension tube?
* All proposals Powermate, 2x, or 5 times?

Thank you!