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(Since I now own a MX7C USB and a laptop, focusing is a lot quicker, but the technique described below is still the same). Good focus is probably the single most difficult part of using a CCD camera. If you look at some of my earlier images, none of them were in focus. This causes loss of takes around 60 seconds to download, so each focus tweak takes a minute, so a focus run can go on for hours. I will explain my setup. I have a meade electronic focuser and a long RS232 cable coming from the roof of my house, down two floors into my office. I control the telescope and the focuser from the pc. Once I am happy with my polar alignment, I aim the telescope at a bright object, the moon preferably, but if not then a hotel a couple of miles distant that is brightly lit up. I put the focal reducer and the extender into the eyepiece holder (everything that would normally go on without the camera). I then put an opaque piece of plastic (we have some table mats that are perfect!) over the end of the open tube. The opaque plastic should be the in the same position as the chip will be. I then manually focus the image onto the opaque plastic. The telescope should now be somewhere close to focus. After putting the camera and the electric focuser on, I then put a mask over the front of the telescope. I use a 2 hole mask with about half inch triangles cut out (made from a cereal packet), and point the telescope to a bright star overhead.  This is the shape of the mask that I use  I then go downstairs and sit in front of the computer and take a series of about 25 images in full resolution at 1 second exposures, with a delay of 30 seconds between them so I can change focus.  I move the focus any direction in fast mode for a couple of seconds to see if the focus is getting better or worse. As you can see from this image, I am going the right direction.   Once I get fairly close then I switch to slow focus and move it as little as possible between each exposure. I will also enlarge the image as much as possible to check.        This is about as good as it gets. I am now ready to start taking images. | ||