Once again Mars looked incredible in my 5" APO refractor on this night before its closest approach, 22 arc-seconds in angular size, or about half way between the size of Saturn's disc and Jupiter's.

 

I tired numerous filters so here are the results:

 

1. No filter, nice because Mars is so natural looking.

 

2. Vernonscope Wratten 25 red by far shows the best surface details but Mars in dark red is very unnatural.

 

3. Vernonscope Wratten 21 orange stacked with Mars A, wonderful details, almost as good as #25 but more natural and pleasing looking.

 

4. Mars A filter, natural, albeit a bit orange.

 

5. Vernonscope Wratten 85 salmon almost as good as the Mars A filter