|
homemade focal reducer
Hi grant and phil,
I used an achromatic lens from an old spectroscope telescope, its about 2.5 cm in daimeter witha focal length of about 18cm. I force fitted it into a rubber eye cup from a binocular microscope and trimmed the rubber to make it cylindrical. it is a push in fit into the visual back of the lx90 before you attach the screw on adapter that takes the star diagonal. I got the idea from an amateur from a yahoo group who stated in one of his astrophotos that he used a homemade focal reducer. on contacting him he said he used the achromatic objectives from binoculars. So i experimented with a variety of lenses and found the one above to work. Im sure it could be refined but my "Heath Robinson " focal reducer works for me.Have attached some photos. one of the moon without and one with the focal reducer. Also a photo of m42 with lpi and focal reducer.
philip
|