Cat's Paw with T69

[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.