I am going to purchase either a CDK14 or a CDK17 in the near future. I am also purchasing a FLI Kepler KL4040 camera. The chip diagonal for this camera is 52.1 mm. Since the CDK's have an image circle of 70mm what would be the best size of filters to use with this setup? I am looking at Astrodon's 49.7 x 49.7mm unmounted filters or Astrodon's 65 x 65 mm filters. Any thoughts on the pro's and con's of this other than the price difference?