Scattered Thoughts . . .

Whenever I'm observing the night sky (as opposed to imaging the night sky), I use a diagonal placed into my focuser.  The diagonal reflects the light that is streaming through the telescope to a 90° angle making it easier to view through the telescope.  Some diagonals are at 45° but those are mostly used for terrestrial observing where the telescope is mostly horizontal or level.  The eyepiece is placed into the diagonal and, due to the diagonal reflecting the light  90°, the top of the eyepiece  is now pointing upward making it easier to look down into the eyepiece.  This is the purpose of the diagonal...  to direct the light to the eyepiece at a position that is easier for viewing. If you had no diagonal to change the direction of the light, you would need to crane your neck to view straight through the telescope.  Sometimes you would even need to be sitting or lying on the ground to view the sky through the telescope if not using a diagonal.  A diagonal makes it easier to view

Y esterday, while I was writing about my infrared converted camera, I realized that perhaps I should shoot some images for a comparison between visible light in color, visible light in monochrome and infrared in monochrome.     This morning I shot a photo of our backyard in color in visible light followed by a monochrome image in visible light with one camera body and then moved the lens over to my camera body that now only shoots in infrared and shot a monochrome infrared photo.  To keep things as controlled as possible, I used the same lens with the aperture set at f5.6 for both cameras.   The wavelengths of light that the infrared camera captures are in a relatively narrow band of light so I needed to slow the shutter speed down a bit for the infrared image so I could capture a bit more light.  Conversely, since visible light is a much broader band of light for our human eyes, I needed to use a faster shutter speed to cut back on the available light.  Although the infrared camera ne

Whenever I post some photos here of songbirds, ducks, loons, any wildlife as well as the moon, I know that few will understand the distances involved. I also know that few will understand many of the terms I use pertaining to these lenses.  After capturing some images of the moon last night, I thought it would be a good idea to get a couple of comparison images to show here. In this first image we see a fairly wide view... the red arrow is pointing to an insulator on a utility pole which is just peaking above the rooftops.... Just barely visible above this rooftop is an insulator on top of a distant utility pole... For the second image, I shot a photo using my longest lens... a 600mm lens...  of course, I understand that saying a focal length of such-and-such "mm" means nothing to most people which is why I am posting this comparison for everyone to see. These comparison photos help to picture the difference between focal length in millimeters. What may be mor