AP155 EDF Field Flattener


Ken Browne
 

About three years ago I was fortunate enough to purchase an AP155EDF refractor from a wonderful person in the Bay Area.  I've been itching to to convert from visual to AP since I've recently retired.  

While I purchased the scope a few years ago, it did not come with the original field flattener.  Would there be a specific AP model of field flattener that would be appropriate for this telescope?  I have the 4" Feather touch "Made for AP" focuser installed.  

Happy holidays my friends!

Ken


Howard Ritter
 

Hi, Ken—

After I had retired, I too decided to take up astroimaaging (what people of our vintage still tend to call astrophotography) with my 155EDF. When I decided to upgrade its original 2.7” focuser earlier this year, I just missed getting the last available (forever, I think) 4” and associated TCC. But there was an upcoming production run of the 3.5” focuser, and I obtained one along with the QUAD-TCC telecompressor-field flattener.

Someone from AP will undoubtedly answer your question, but I think the answer will be that a FF for your focuser would have to come from the used market. And that’s only if the critical dimensions of the Feather Touch match those of the AP 4” unit. Or perhaps someone makes, or can make (Precise Parts?), an adapter. If none of the above, the alternative might have to be to do what I did. The two 3.5” components are priced at about $3000 total (when they’re available, which they don’t seem to be at the moment).

Good luck! 

—howard

On Dec 26, 2021, at 2:53 AM, Ken Browne <kenbrowne@...> wrote:

About three years ago I was fortunate enough to purchase an AP155EDF refractor from a wonderful person in the Bay Area.  I've been itching to to convert from visual to AP since I've recently retired.  

While I purchased the scope a few years ago, it did not come with the original field flattener.  Would there be a specific AP model of field flattener that would be appropriate for this telescope?  I have the 4" Feather touch "Made for AP" focuser installed.  

Happy holidays my friends!

Ken


dvjbaja
 

Give AP a call when they return from the holiday break.  I've read that they were making more field flattener optics, but for which scopes need to be checked.  The 155 can produce exceptional results with the 4" diameter f/7.1 field flattener, and the TCC which I recall put the scope at f/5.5. 

Good luck!