Have just received the asi120mc and wonder what size of Barlow lens I need to get focus on my telescope?
Celestron C10-ngt. Tube length 114 cm, F/4.72
Best regards / Bo
you can choice with these models,
the X-cel serie is very good
http://www.celestron.com/astronomy/accessories/eyepieces/barlow-lenses.html
Something like 3x would do the trick.
Thanks guys! Will test my Barlow 3x if clearskies tonight! / Bo
I have tried to get focus with both 2x and 3x Barlow lenses with no result!
What to do?
Can tell you that with the wide angle lens I can get pictures on my laptop when I shoot on free hand so to speak. So the camera must be ok but there is a problem to find focus when connected (w/o the wide angle lens) to the telescope. So does anyone know how close you have to be with a Barlow lens to the secondary mirror to get focus ??
/ BosseH
In Newtonians with the Barlow it should be easy to focus. You should try focusing at day with the telescope on some far tree or building. By looking at the image you should be able to tell if you have to move the camera out or in the focuser. If you need it to lower it below the lowest focuser point then you will need to use lower eyepiece holder in the focuser or low profile focuser. If it would focus much further away from the focuser then you will need some spacers for the focuser :)
