Monday, May 12, 2014

Saturn at opposition (almost), and Mars

Saturn reached opposition on May 10th, 18:15 UTC. Unfortunately the weather was cloudy at that time. This image was taken the following evening, around 27 hours after opposition. Around opposition the rings brighten quite suddenly and quite a lot; this is because the rings are illuminated from directly behind the observer. This effect is often called the Seeliger effect

From the same evening, my only Mars image so far this year. Pretty unimpressive...

Thursday, March 27, 2014

Returning with Jupiter...

It's been quite a while since my previous post - almost two years. During this time I have only occasionally done some observing. The reasons are many; work, other interests (I have been very interested in calisthenics the last couple of years), being tired of mosquitoes getting into my flat every time I open the door to take out or take in the telescope, being plain old lazy, and simply not finding the same joy as before in astronomy. Nevertheless, I do not intend to let this blog share the fate with so many blogs that die after a few posts. So, for starters, here is an image of Jupiter from some time ago. Captured from Ederi hilltop on 19th March 2014,  1741 UT.

Wednesday, April 18, 2012

Mini-review of Glatter Parallizer

As a planet imager I am obsessed with accurate collimation. One of the many sources of error lies in the lose fit between a 1.25" adapter and the 2" focuser, and lose fit between the 1.25" collimator and the adapter. In the past I would solve this by shimming the adapter (with tape) and the barrel of my laser collimator, making the fit so tight that I had to put the shimmed 1.25" adapter in the freezer to be able to insert it in the 2" focuser tube! That also meant I could not remove the adapter in the field.

My recently aquired Glatter Parallizer has solved my problems. While I have not done any extensive testing, I can tell that it gives me about the same accuracy as I could achieve with my best shimming efforts. What remains of wobble is probably inherent in the focuser and laser collimator. The design is remarkably simple, just an angled setscrew and outer surface that isn't quite round. The "manual" is equally short; just one sentence!

Tuesday, April 17, 2012

Wednesday, April 4, 2012

New camera problem

My new DBK618 camera has a problem with gridlines at 60 fps. I posted about this over in the Imaging Source forum a couple of weeks ago, and they are (still) looking into the problem. One of the big selling points of this camera is its (supposed) 60 fps capability without artefacts. The model it surpasses, the DBK21, was also supposed to support 60 fps, but eventually it turned out that it produced a "ring"-artefact at this frame rate. It is therefore disappointing that once again this new model does not function properly at 60 fps. It is also surprising that nobody else have reported this problem before, as the camera has been on the market for more than 6 months. After I reported my problem at the forum, a couple of other owners of the camera have reported the same problem. Nevertheless, the results so far (at 30 fps) seem to be significantly better than my old DBK21. 

Below is Mars from a 60 fps capture (sharpened and resized by 2X). It does not matter which DeBayer method I use, the gridlines are always there. Multipoint alignment will partially solve/mask the problem, probably because different parts of the planet are moved around a little relative to each other, and blended in a way that hides seams and averages out some of the gridlines. Still, it is not a good solution. 

Monday, February 20, 2012

First light with new camera

About a week ago I received my new camera; a DBK 21AU618.AS. It has the Sony ICX618 chip, which is a big improvement over the old ICX098 that was in my old camera (and my old Toucam web camera). The seeing did not cooperate, so these images are rather poor. Without further ado; first light: 

Thursday, December 8, 2011

An unexpectedly good Jupiter

I made these images from a couple of videos that seemed rather average; I even told people the conditions had not been good this night, and the whole trip was not worth the effort. That was before I started processing the videos. I was pleasantly surprised by the amount of detail that popped out during sharpening. The DIMM seeing at the time was also unimpressive, only 1.3 arcsec, but I guess there were enough good frames interspersed among the blurry ones to get a good result. Captured from Ederi, Dec 03 2011. 

A short video is avilable at