In July, I've ordered, at OPT, my first APO refractor in my astronomer life to complete my setup with my new Meade 12" UHTC SCT OTA.
I've compared a lot of APO refractors. My choice was for a Triplet APO refractor with a diameter between 4" & 4.8" with a short focal.
After several days of reflexion, I've decided to purchase the famous William Optics FLT-110 (4.3") Triplet APO refractor.
A diameter of 4.3", good to me, f/6.5 for the focal ratio, perfect, Triplet SD oil spaced optics made by TEC, Colorado.
I use this refractor for my wide field CCD pictures with my SBIG ST-10XME CCD camera.
With my first CCD images I can say the optics are outstanding. The tube is very solid. The 4" focuser is really big and the focusing is very soft. A Great feature of this focuser, the rotation, very soft, on 360°, very nice to find a guide star on the TC-237 guide chip. The FLT-110 has a large backfocus, more that the Takahashi FSQ-106.
The FLT-110 is delivered with 2 rings I've adapted on my Losmandy TITAN mount with the Losmandy Universal Dovetail plate. The dew cap is enough long to protect the optics but I add a Kendrick dew heater.
I've received my WO FLT-110 in a beatiful aluminum case. This APO is solid as a rock. It is a real pleasure to use it to take Great nebulas.
I think now, on the market, the FLT-110 is the best APO for this diameter, this quality at that price $2995.
If you want a very good triplet for a nice price I think the FLT-110 is the best choice.
I just ordered the WO FLT-110 Field Flattener to use it with my ST-10XME. With the large CCD chip of my CCD camera I am out of the flat field. That will be the same thing for the 35mm & 6x7 format.
This is my page about my FLT-110 :
http://www.astrosurf...o/WOFLT110.html
You can see too my first pictures taken with this APO (NGC-6992 and NGC-6888) :
http://www.astrosurf...ao/immonth.html
You can see my FLT-110 on my TITAN mount at the end of this page :
http://www.astrosurf...zao/titan3.html
Regards,
Florent
