Best filter for Mars..

Our Star party will coincide with Mars' visit this Aug. 5K' elev. in Central Dark Oregon.. I will have my new C8 up and running with an array of EP's. My question to some of you seasoned Veterans is; what is the odds on choice when selecting a filter? Would like to accentuate the regions and bring out some dimension.. any suggestions will be appreciated.. I will probably bring several, and see what works best.. thank you, John M

For Mars, I like a #21 red, especially with 6" and smaller scopes because of higher light transmission. A darker #23 red is useful when more aperture is available. See Fred Price's Planetary Handbook and this excellent filter site:

http://sciastro.net/portia/advice/filters.htm

Hi, John.
I usually observe without filters, but here are three that I have used in the past. These would be my own first choices for Martian surface features:
(in no particular order)
#15 yellow
#21 orange-red
Baader Planetarium Sky Glow

Of course, your question just triggered my curiosity, so I'll likely give these three stooges another run. :-) I'll report back with my impressions...

Best wishes.
-Dan