Trying to make a decision on selling my WO FLT91 for a WilliamOptics FLT120

Hi Joe

I have the FLT91 and 120 scopes and use them both. The light gathering increase and resolution are quite noticeable with the 120. I haven’t tried the 120 on my AM5N yet and use it on an EQ6-R-Pro which is more stable for such a beefy scope. I use the WO 68III flattener on both scopes at the native focal length. The 91 works well for wider field shots and is easier to set up and less sensitive to the wind. I have the 6AIII reducer for it and it works reasonably well. The 120 needs a calm night or you will lose frames unless you have an observatory. The focusers are similar, a little wobbly when extended out more than 30mm but don’t cause any problems. I have paired the 120 with a 533 camera and mainly image the smaller targets with it.

John

Astro Jeep · Nov 30, 2025, 02:55 AM

I have been looking at the FLT120 and FLT132 for this coming galaxy season, but my concern is that I will purchase one, and the next month they will come out with a WIFD design for it like they did with the Zenithstar and Grand Turismo 81! Maybe an Ultra-Cat version to compete with the Askar PHQ107. I have an Ultra-Cat 108 that I swap a Poseidon-M Pro and a Uranus-M Pro on (depending on target) which I am very happy with, but a little more reach would be nice for galaxies.

There will always be that concern. Been “burned” a few times. Or was I?

I had a ZWO EAF that was bad, it wouldn’t auto focus (Its sole intent). While ping-ponging with ZWO Service, I replaced it with a Pegasus Astro Focus Cube2. Been wonderful to me.

1 week after I got my cube2 it was discontinued and the cube3 replaced it. I felt burned. Then I realized the Cube3 gets its power via the USB. The Cube2 has a separate 12 VDC input and a data (control) port.

So, the Cube2 does more of what I wanted using my 12 VDC daisy chain for driving. And not loading down the USB Data system sucking power through it. So, I consider the Cube2 more of a lucky break for me.

I jumped from my beginning 80mm triplet refractor to my AT130mm EDT. One big jump in aperture. Much happier with the 130mm. Bigger portions on my display of why I’m there for in the first place. 😊

I was disappointed when I got the 0.8 FF/FR and discovered it dropped me back to 728FL from 910FL. I did not expect that but have round dots (stars) out to the corners.

I’ve known a lot of disappointments since getting into Astrophotography, but I persist at it. (13+ years now.)

Maybe I’m a glutton for punishment? 🤣

Peter Robertson · Dec 2, 2025, 07:28 AM

I am the happy owner new owner of a FLT 120. before this I was only using camera lenses on a star tracker. It is fairly heavy but as others says works well on my EQ6-R, but not on a windy night. I found it incredibly easy to focus. FOV is 624 mm with the FLAT7A, which frames the Pleiades or andromeda nicely on a full frame sensor, and 780mm with the Flat68III , which would frame Orion nebula nicely, and of course much tighter on a smaller sensor. I found it to be very sharp, very sold and a nice quality feel for everything. I doubt I’d ever want anything bigger - its easy to handle but anything bigger would not be. The huge objective lens is beautiful.

Hi Peter,

You might try adding weight to your EQ6-R. What I did with my AVX when I was struggling with it was to rig a block and tackle (very small set) under it from the spreader. I used a 5-gallon bucket and filled it with water as a weight to stabilize that mount.

My present equipment weighs in at ~150 pounds and does not need additional weight.