Image of the day

Captured by
Ron Masters

Saturn Dione Tethys 28 August 2021

My Account

New to Astromart?

Register an account...

Need Help?

Focus Issue

Started by HowardP, 11/11/2003 10:59AM
Posted 11/11/2003 10:59AM Opening Post
I have a SCT 8 inch Celestar and have been looking at saturn with a 26mm plossal and a 2x barlow. I take out the scope an hour before observing to allow it to cool down. I think it is collumated, as when I de-focus on a bright test star the ring looks symetrical. Saturn comes into sharp focus and stays that way for just a few seconds and then it becomes fuzzy and stays fuzzy until I re-focus. This keeps happening.

Any ideas why and what I need to do to correct it?

much appreciated Howard
Posted 11/11/2003 11:01AM #1
Sounds like the scope is still cooling down. It can take a bit longer than one hour to completely cool down depending on the internal and external temperatures.

[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue grin
Amateur Imager