Optical Equipment


Fields of view and magnification

The edge of the field of view (white circle) in each drawing covers an area of sky that is dependent on the telescope and magnification.

For the 10.1" reflector the fields of view (FOV) and magnifications are roughly as follows:

For the 2.4" refractor, FOV and mags are:

For the 10x30 binoculars, FOV is approximately 4.5 degrees.

For the Mallincam DS432CTEC camera, FOV is approximately 42' x 29' and about 83x on the 10.1" Dob. With the 0.5 Mallincam Universe focal reducer it's about 65' x 45' and 54x; with the 5x barlow it's about 9' x 6' and 415x.
FOV with the 80mm refractor is 124' x 85', and with the 0.5 focal reducer 190' x 130'.

All the sketches indicate the magnification, so the information above tells you how much area of the sky your looking at (eg. a sketch saying 115x would suggest the 10mm eyepiece on the 10.1" was used, and it has a 25' FOV). 


Observing Conditions

Unless otherwise noted, all deep-sky sketches were done with the Moon somewhere between last quarter and first quarter and below the horizon. Sky conditions were generally good to excellent both for seeing and sky contrast. The limiting visual magnitude for most sketches was usually between 5.8 to 6.2 (NOTE: I moved to a suburban location years ago so some of the more recent sketches were done with poorer sky conditions - my current location has a limiting visual magnitude of about 5.0 under Bortle 7 skies). Observing site lattitude and longitude is 45 degrees N, 75 degrees W.