Tuesday, July 15, 2014

20140715 Saturn

First time doing planet with my Nexstar SE mount.  Seeing poor at 2/10, transparency also low at 4/10, I believe.  This is done with my white C5 at f/20.

At 1/15s, gain was pushed to 80% which indicates poor transparency.

Visual observation with a 20mm eyepiece renders a solid image, but pushing to 125x by adding a 2x barlows, image becomes a bit too dim.

Tracking is very nice, however, the initial alignment is a bit difficult inside home given a narrow view angle from a small window.  Given the alignment is done, GOTO is rather accurate as I can quickly go to the Mars even at 62x!

I will do it again soon whether the sky gets better.  Saturn is quite nicely positioned this year.

Saturday, July 12, 2014

20140711 Moon, mount testing

This is yet another test of my Nexstar mount.

A table top mount is good in the sense that it can aim higher since it's lower!  And without the tripod, it could get closer to the corner to gain wider view.

This is a testing shot at 2400mm prime focus to see whether the tracking is good enough or not.  So far I'm satisfied, even with solar system alignment with the moon alone.

Thursday, July 10, 2014

Celestron Nexstar 4/5SE mount

I got one used without the tripod.

The first impression is good.  The mount is mostly metal, it's stable and the capacity is good.  I bought it down stair to try it out on the road side.  I just placed it on the road side.

GOTO is accurate even with solar system alignment, i.e. I pointed it to the moon and let it go!  Going to the Mars is fine enough, Saturn was blocked by a lamp post.  But the general direction is correct.

In order to see whether it was stable or not, I plugged in a 4mm eyepiece to check with the moon.  Focusing was easy, image was stable within one or two seconds.  Tracking was smooth and no shaking...  Later I realized that it was 312x!

People said this mount is better with the 4" Maksutov than with a 5" SCT, but I found that it's enough!  This mount will be used for solar imaging with my Ranger, so I consider it a nice purchase.


On the next night, I tried to use for my solar setup.  Yes, I did it at night.

The Solarmax filter makes it seriously front heavy, I've to slide the balance plate all the way to the other side to reach proper balance, but then the rear side will hit the mount base when the scope was pointing up. 

I guess I will need to add some weight at the rear side for balancing.