Cat's Paw with T69

[theskyhound]

I got a little carried away in testing the new iTelescope, T69, at Siding Spring. It's a simple color system, and I almost have it dialed in for SkyTools.

   

[PMSchu]

Both T69 and T68 in New Mexico look like great scopes. Both are Celestron RASA 11" OTAs.

Looking forward to having T69, T70 & T19 added to the list. I see there's also a T71 being installed in Chile.

Phil S.

[theskyhound]

T70 just keeps failing, so I wouldn't get your hopes up for Chile anytime soon. Its been failing with some sort of configuration error for days now. I don't know why they don't just take it offline.

[PMSchu]

Hi Greg,

At least I managed to log onto T70 recently. It uses a 135 mm Samyang camera lens as the OTA. 68 mm objective diameter. I don't know what they've planned for T71.

Your image of the Cat's Paw is very impressive. What was the exposure time? T69 is f/2.2 just like T68. Photographically fast.

Phil S.

[theskyhound]

Hi Greg,

At least I managed to log onto T70 recently. It uses a 135 mm Samyang camera lens as the OTA. 68 mm objective diameter. I don't know what they've planned for T71.

Your image of the Cat's Paw is very impressive. What was the exposure time? T69 is f/2.2 just like T68. Photographically fast.

Phil S.

It was 10 x 240s exposures, stacked in Pixinsight, and processed in Lightroom. I asked them why the maximum exposure is 240 seconds and they said that was what they expected the maximum useful exposure to be. Right now, I'm having some trouble getting the model to accurately predict T68, but once I do I can investigate longer exposure times to ensure they are correct (that 240s is the maximum useful exposure). I'm a big fan of long exposures at dark sky sites. I see people stacking large numbers of 60 second exposures and it drives me nuts.

Its basically a function of how deep you want to go, but I always seem to want to go as far as the system will allow.

[PMSchu]

The long exposures are best if the sky fog is low. With all the Starlink satellites, though, there's a higher chance one will appear in the longer exposures & cost the whole shot. Can't win.

Phil S.

[theskyhound]

Hi Phil,

True, and there are other cosmetic things that can happen when you use long exposures. Of course, satellites in low earth orbit can be avoided by not exposing near twilight. If the satellites are in the earth shadow, they don't show up.