Filters and step down rings
I have a technical(?) question concerning filters and step down rings. I tried the 'General Photo Techniques' forum but did not get any responses.
My Sigma 17-50 f2.8 lens is 77mm and the next lens I am considering is a Sigma 10-20 f3.5 with 82mm.
I shoot Landscapes and travel photography (along with the obligatory family pictures).
1) Do I buy the 82mm Hoya ND400 and a step down ring? Or two Hoya's. Any side effects with the step-down ring on the 17-50?
2) Do I really need to have a ND400 for the 10-20?
3) I have a 77mm CPL and I have heard that a) I do not need it on a 10-20 lens; is this true? Also, can both the CPL & ND x400 be stacked? Is the order relative?
Thanks in advance for everyone's help. I hope this is the right forum to post this query!
Pentax K-5 IIs, Sigma 17-50 f2.8 EX DC HSM, LX3, Pentax MX w/Pentax 40-80 & Soligor 80-200 f4.5 lenses, Lightroom 5.0, CS6