Viewfinder focusing is much easier and more accurate if you add magnification. The best device for this purpose, whether your camera is a Canon, Nikon,
Olympus, or Pentax, is the Canon Angle Finder C (Figure 8.2). This is a magnifying right-angle viewer that comes with adapters to fit rectangular eyepiece frames of two sizes. It works like the time-honored Olympus Varimagni Finder and the popular Hoodman Universal Right Angle Finder, but the Canon Angle Finder C has a larger entrance pupil and gives a much brighter image. At the flip of a lever, it changes magnification from x 1.25 to x 2.5.
The Angle Finder C has its own focus adjustment. The way this interacts with the camera's eyepiece diopter can be somewhat confusing. I offer two pieces of advice.
Initial setup. To get everything at least approximately correct, first take the Angle Finder C off the camera, set it to x 2.5, and use it as a small telescope to look at objects around you. Focus it on objects about 1 meter away. Then put it on the camera and adjust the camera's eyepiece diopter so that you have a clear view of the focusing screen. You should then be able to switch back and forth between x 1.25 and x 2.5 with minimal refocusing of the Angle Finder.
In the field. To set up an astronomical photograph, aim the telescope and camera at a reasonably bright star in the same general area of the sky (not far away so that nothing will shift as you slew back to the object of interest). "High precision mode" on Meade computerized mounts is handy for this; it takes you to a bright star which you can focus and center before returning to the selected celestial object.
Focus the telescope and the Angle Finder to get as sharp an image as possible. The two interact. Only one of them affects the image that will actually be recorded, but both of them affect your view; my technique is to alternate adjusting one and then the other. When the star is a bright pinpoint, correct focus has been achieved, or at least a very good starting point for refinement by electronic means.
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Compared to film cameras, digital cameras are easy to use, fun and extremely versatile. Every day there’s more features being designed. Whether you have the cheapest model or a high end model, digital cameras can do an endless number of things. Let’s look at how to get the most out of your digital camera.