I generally avoid posting negative feedback about any small businesses especially an American small business so involved in outreach programs to advance the sciences. However, I think after the countless hours I’ve spent trying to get to the bottom of this issue it’s well merited.
I initially had an ES 102mm triplet FCD1 and bought an ES field flattener with it, using an ASI183MM-P and was never able to get a full flat field. However I had an FF/FR Stellarvue and that had a perfect field. I chucked it as beginners problem and after countless hours I gave up on it. Fast forward I replaced my 102mm with an 80mm fcd100 with ASI071MC-p this time I couldn’t use the FF/FR and had to rely solely on ES FF. Again, countless... and I mean countless hours spent troubleshooting why I can’t get a flat field why on one side if I try to get them in focus the stars start having a T shape diffraction no matter what I do. After talking to ES about it I sent the scope and the FF back to have them checked. They returned them saying everything is fine, really pretty much NO feedback.
As luck would have it a friend of mine got the same scope with the same FF and he was experiencing the exact same issue. I met with Scott at NEAF and explained to him the situation, he said he’ll send me a different FF to test. Sure enough he sent me another one, and sure enough the same problem persisted. Again countless hours spent trying to identify the cause of these T diffraction from verifying sagging, potential tilting of sensor, tilting of focused... etc.
Eventually a friend of mine felt pity for me and came over to help, after a while we swapped the ES flattener with another of a different brand and BOOM! the field is 90% better with no T diffraction anywhere. I shared these findings with my friend who was experiencing same issue and we both went for different field flattener and we both were able to notice immediate improvement.
I shared in-depth analysis of the situation with Scott and ES support, explaining to them my findings with data, they said to send them my FF and they’ll have their imager test it out. Almost a month later they told me that their imager found out that 55mm was perfect and there are no issues, after all the data I sent them, all the time I wasted building the data for them, all I got back was (yeah no it’s not it, it’s you, your friend and everyone else’s fault)... at this point I gave up on them told them they can keep the FF I’m done doing business with them. My friend who also returned his FF was told the same, he asked for an image to show the flat field, they asked him for an address to send him the refund.
Personally for me the $149 or whatever it was that I paid for this FF and getting it back is a drop in the bucket of the value of the time I wasted of my life troubleshooting an issue for a vendor with a piece of equipment whom they have sold for YEARS and have had several occasions where it was pointed out to them issues with it.
The moral of the story here is avoid ES FF like the bubonic plague, and take this story as a cautionary tale if you are deciding to buy ES equipment.
Edited by TimmyTim, 18 September 2019 - 05:43 PM.