Parracor effect?

Some day I may consider purchasing a Starmaster truss Dob. What effect will a Parracor have in terms of focal length on an f/4.3 Dob?

Jim D.

It will increase it by a factor of 15% making it an F4.95

I find the Paracorr to be an excellent addition to the SM 14.5". The small amount of FOV you lose is a small price to pay for a nicely corrected field.
The 31mm Nagler becomes a 26mm Nagler and that means a smaller FOV, but it makes the field look very nice.
I use it all the time.