My smallest refractor is 4" used on a Giro mount (AP Traveler 105mm f/5.8). I occasionally wish that the setup was even smaller and lighter, especially when traveling. The length and weight of the tripod and mount needed is a bit of a drag. Oftentimes I will use my f/6 5.1" APO (AP 130EDF) on the Giro mount which is almost as easy as the 4" but does require the use of the counterweight and the size of the 5" is a bit more than the 4".
On the other hand, going below a 4" APO, especially from my light polluted locale would stink. One must use more magnification than one wants to dim the field to fight the light pollution and the 4" runs out of light fast. An 80mm APO would be almost useless I fear. On planets the 4" is OK, but when bumping the magnification the exit pupil shrinks to such an extent that floaters become an issue. A smaller APO would be that much worse.
On the third hand (Moties!) my 5.1" APO is just too big to be the smallest grab & go. What I want is the portability of an 80mm with the views of the 130mm. Argh.
Perhaps that is just what the 4" APO is for - a compromise. Thoughts?
Philip
On the other hand, going below a 4" APO, especially from my light polluted locale would stink. One must use more magnification than one wants to dim the field to fight the light pollution and the 4" runs out of light fast. An 80mm APO would be almost useless I fear. On planets the 4" is OK, but when bumping the magnification the exit pupil shrinks to such an extent that floaters become an issue. A smaller APO would be that much worse.
On the third hand (Moties!) my 5.1" APO is just too big to be the smallest grab & go. What I want is the portability of an 80mm with the views of the 130mm. Argh.
Perhaps that is just what the 4" APO is for - a compromise. Thoughts?
Philip
