Same here. When I use my 10" RC or my 9.25 EdgeHD I get HFR values that are larger than my lower F number scopes. HFR is directly related to Focal Ratio. The larger the Focal Ratio the bigger the HFR values.

But I do get inconsistent HFR values, I end us using the 2 or 3 frame average, this makes focusing 2 or 3 times longer, but at least I get somewhat good focus.

I do agree that the Focus routine works much better at 200-600mm Focal Lengths, once you start going deep, focus becomes more problematic.

Read More...