I recently bought an Explore Scientific 3″ Field Flattener .7x Reducer from Highpoint Scientific and was able to test it out having a clear sky last night. My scope is the Explore Scientific 127MM ED Essential Series with a ZWO MiniEFW and a ZWO ASI-1600MM-Cooled camera.
I was so impressed on the flatness of the field and stars are pin sharp up on the edges. Unfortunately it was full moon last night and I’m also living in a place where light pollution is a real problem, and the image below is all the best I can get.
Before I continue, I’d like to give the Highpoint Scientific Team a shout out. Their service is top notch and willing to entertain and answer any question.
Above is the image, a total of 10 subs x 5 mins exposure using Hydrogen Alpha (Ha) filter. My capture software and pre-processing software is Nebulosity 4.1.2 and for post processing, I used Photoshop CC 2017.
I have been using the Explore Scientific 0.7x Reducer/Flatter for a couple of my sessions and below are the images.
Giving more information specially to some of the comments below. I have captured and photo of the distance between the camera and the ES 3″ .7x Reducer Flattener.
Here are some of the images that was taken using the ES 127ED with the ES 3″ FR/FF