Dumb question of the day - Eclipse/D80/C-11

I beg forgiveness in advance for my ignorance, this is my first post, but can anyone tell me if the full moon (Feb 21 eclipse!) will fit in one frame on my Nikon D80 mounted on a CPC 1100 with T-adapter and f6.3 focal reducer? Love shooting eclipses and will be buying a scope in the next several weeks. Sold my C-11 and have given up on waiting for Celestron to come out with a 14" version of the CPC. I know the image would fit in one frame when I was shooting film, but I realize the sensor on the D80 is smaller. Thanks in advance!

Rich

Not a dumb question at all. At f/6.3 the focal length of the 11" is about 69 inches. A pretty good rule of thumb for the size of an image of the full moon is that the image diameter is about 1/100th of your focal length. So on your 11" f/6.3 the image will be around 0.7" or 18mm. If you know the size of your camera's sensor, you can determine if the lunar image will fit.

Or, you can hook the camera up at, say, first quarter, and if the lunar image fits across the frame, well, there you go!

Steve

Here's a screenprint of Ron Wodaski's ccd calculator using an 11 inch F6.3, with a D70. You might enjoy going to Ron's website for a free download and then playing with your different combinations of scopes, cameras, and images for your own edification.

Alex

Attached Image: