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View Full Version : Narrow field dmk41



ASTROTRUCK
February 10, 2011, 01:19:46
I use a 100mm f9 refractor imaging the sun using a coronado 60 etelon with blocking filter 1500 1.25 inch. With a fl 900 many feel i should be getting full disk image thru the dmk41. I seem to get a bit more than a quadrant only as if the dmk magnifies resulting in a reduced field.
Any use this combination getting full disk ??

Eyes are bad but will use lower case next time - forgot - i always use caps when typing docs due to my eyes.

flyer
February 10, 2011, 06:53:15
For what it is worth, I use an F9 100mm refractor with a DFK31. I cannot get near a full moon and I doubt you can with the 41 series camera either. You might look into a focal reducer but I can't tell you if that will do the trick.

Try this. Project a sun image at prime focus (no eyepiece) onto some cardboard - perhaps with a filter of some sort. Notice the actual image size. Now have a look at the actual size of your CCD in the camera. I'm guessing the projected image size is about 4 times bigger than your CCD. That's why it looks like it is magnifying.

You can always stitch 4 images together.....I think this may be why a lot of solar imagers use shorter focal length scopes.