Four holes in a Hartman Mask

[xelasnave]

I have been using a hartman mask to focus. After seeing other folk use triangles and more than two holes I made one with 4 holes. It is useful for focus even thru the small view finder of the 300d. But I started leaving it on and doing a capture to check focus by blowing up the image on the little screen on the camera. I now obtain the capture I will use to process thru the 4 hole mask. Its presence seems to sharpen the shot. The best I can figure is that doing this effectively lenghtens the focal lenght which sharpens your image. I guess it means you have four small long focal lenght telescopes acting as one. Do you think I am dreaming or is this working along the lines I outlined.
Alex

[[1ponders] (Paul)]

By the sound of it Alex, your using it as a aperture mask, basically reducing the aperture of your scope. From what I understand smaller aperture scopes are less affected by seeing conditions than an equivalent fl larger aperture scope.

[xelasnave]

That sounds good to me. The conditions were terrible, a sky bordered with storm heads and enough moisture to give up nee-moan-ya, and the wind was at about 25 knots at ground level.
Thank you for your interest and input.
alex