Do I need one of these?

[azrabella]

As I am contemplating purchasing a Skywatcher f/6 Dob, I am being advised that I should arm myself with a coma corrector by some, whilst others say that it won't be needed as f/6 is not that fast. Does anyone have first hand experience with this "potential" issue, please? If a coma corrector is recommended, then can anyone advise on price?

[Stu]

I don't know of anyone that uses a coma corrector in a 200P. I'm sure some do, but at f6 you really won't need one. There is plenty more to spend your money on that will give more benefit.

[michael.h.f.wilkinson]

For visual work, I would not use a coma corrector. I used a much faster Dob (not mine alas), and did not find coma much of an issue, even in ultra-wide-field EPs

[DHEB]

I use a coma corrector for visual observation in a 200PDS f/5. It makes a difference in a 1.5 deg field, not so much in narrower fields. You might want to look for tables specifying the width of the coma free field in different focal ratios to decide for yourself. As far as I understand it will not be necessary in an f/6.