Well I got around to making an aperture mask for my 16" Meade Lightbridge. It really helps with viewing details on planets. Rick and I made the mask our Sunday telescope making project. We usually do some telescope making project about once a month. As you can see the masks has an opening for the secondary screws, this is really just because the screws are up above the secondary spider mount. The secondary blocks out any light that comes in the center hole. This mask vastly improves the details Mars by taking out the diffraction lines and central obstruction that normally isn't an issue with Deep sky objects. Also stopping the aperture down allows image to not be washed out. I spent about 2 hours looking at Mars and the moon tonight with and without the mask. I seem to like it!
I decided that I'd mount some Velcro on the top of my rocker box to hold the mask when it isn't in use