Astronomics finally had AT60FF in stock a few months ago and the difference in the sharpness of my imaging from my AT60ED is mind blowing. I've got a Celestron C102-HD that I use for planetary imaging and occasional deep-sky imaging. I know being an f/10 the need for a field flattener is not as important, but I am curious if it would improve my images to get a flattener or flattener/reducer for it. Whether that is getting slightly sharper details on some planets, or getting a sharper star-field around a globular star cluster.
If it would help, where would I get one that would work for an f/10 1000mm FL achromatic? I see ones for SCT's, would those work? I don't see a lot about flatteners or reducers for slow refractors.
I image with a Canon T5i - an APS-C crop sensor. I do deep-sky imaging with the full sensor, but planetary is with BYEOS using the 5x zoom live view feed so just a small rectangle in the center of the sensor.