WO Megrez 90mm field flattener question/recommendations

[chrisp9au]

I have a WO Megrez 90mm (FL 621mm - F/6.9) in transit, should be here tomorrow.
Will be using an ASI294MC and am wondering which field flattener to look for?
Thank you :thumbsup:

[UniPol]

Bit of a minefield when it comes to Reducer/Flatteners for William Optics scopes I've found over the years. You may have already googled Megrez flatteners and possibly found a lot written about them on Cloudy Nights, Stargazers Lounge etc. and my overall impression is that is a hit and miss affair. I currently have a Megrez 110mm and bought the WO AFR-IV 0.8x R/F IV which doesn't come to focus (not enough inward travel) but I believe it is suitable for the Megrez 90. I've heard that the TeleVue TRF-2008 RF works so it may be worth researching some more. I also noticed in the Megrez 90 instruction manual that an RF is not shown, see https://williamoptics.com/download/support/megrez90.pdf

[chrisp9au]

Mmm, I have the WO Megrez 90 manual that just says a field flattener is highly recommended, but no recommendations.
Thank you for responding, I will continue researching!
I might also raise thread on Cloudy Nights.
Cheers :thumbsup:

[UniPol]

I forgot to mention also Chris is that it appears that the focal lengths of some WO scopes including the Megrez 90 are overstated, one example I read somewhere was 570mm instead of 621mm, maybe this is why some RF's don't work?

[chrisp9au]

I've read that also, but only on one CN thread.
I'll wait for the scope to arrive and check it out. :thumbsup: