I was just planning a bit when and how observations of this year's great Mars opposition could be optimized given my personal "boundary conditions".
1) I shall be able to watch Mars at comparably high altitude of 1850 meters. Unfortunately, there is a high prize despite the crisp atmospheric conditions: at high altitudes, the horizon is usually not flat;-) and Mars' opposition will be exceptionally low at our typical latitudes over here.
2) we shall be talking in August for example, about typical maximal altitudes of only around 20 degrees, which is still significantly afflicted by atmospheric dispersion!
3) So even the excellent contrast e.g. of a Takahashi FS-102 4"-refractor does not help here. My 8 inch Schmidt-Cassegrain [C8] telescope, the inferior definition of which (due to the 2" central obstruction) being balanced by its total absence of color aberrations and its doubled diameter, will not have better chances in that respect...
There are tools against atmospheric dispersion available like an adjustable glass wedge or a so-called Dall transfer lens by means of which the prism effect of the air at low observation altitudes in the sky may be (partially) compensated...Well I have never tried one of those myself.
Anybody else did?
Bye Fridger