Category: Equipment

Saturday, September 28, 2013
Sketchlight, getting ready to sketch M31 ....
I am planning to sketch M31 this autumn. Until now I was struggling with my red lights while sketching at the eyepiece, but think this flexible arm will be the solution smile


Posted by Math on 09/28 at 11:13 AM | (0) Comments | filed in: Equipment | Print
Sunday, September 01, 2013
Mirror cleaning time!
Getting the mirror of my dobson ready for the autumn.... and it needed some cleaning as you can see smile





Posted by Math on 09/01 at 03:21 AM | (0) Comments | filed in: Equipment | Print
Sunday, August 15, 2010
First light for my 12-inch on an Equatorial Platform
Almost three years I have been observing with my 12-inch Dobson from Orion Optics UK. I love to work with the Dobson. The setup goes very quickly (five minutes) and I'm ready to observe. I also like the fact that you can push the tube to any direction when starhopping, without having to use electronics. However, about one and a half year ago I took up sketching again, and very soon I noticed a big difference with my old telescope I used for sketching, an 8-inch Cassegrain mounted on an EQ-6. When using this set-up for sketching, the object stood perfectly still in the field of view, at any magnification.
Posted by Math on 08/15 at 11:13 AM | (0) Comments | filed in: Equipment | Print
Sunday, June 06, 2010
Observing deepsky objects with a binoviewer......
I finally had a chance to test my new binoviewer on some deepsky objects, and I must admit, it did not disappoint me. Of course the binoviewer is not very useful on the larger open clusters or on double stars, but on objects with some kind of "surface" like planetary nebulae and globular clusters, it is definitely an improvement over the view with just a single eye. I had a look at three globulars, M13 and M92 in Hercules and M56 in Lyra. All objects were viewed at a magnification of 217x.

M13 was simply stunning, watching it drift across the field like a giant spider with several legs of stars stretching out from the crowded centre, a very large and attractive globular cluster. M92 was a very different story. Compared to M13, M92 is very compact, with not so many outlying stars, but with a very bright core. M56 surprised me. Until now, from my suburban backyard, it looked very dim, a faint smudge of light with little or no detail. But now, even during the period we call the grey nights (it doesn't get really dark), I saw M56 partially resolved in individual stars, thanks to the observation with both eyes.

Below you see a comparison of the three globular clusters from the POSS-1. The National Geographic Society - Palomar Observatory Sky Atlas (POSS-I) was made by the California Institute of Technology with grants from the National Geographic Society. All three images cover an area of 1 degree by 1 degree.


After the globular clusters I had a go at a few planetary nebulae, The Blinking planetary (NGC 6826) and Hidden Treasure 78 (NGC6210). The sight of the blinking planetary amazed me. For the first time ever I saw this small nebula in full color, right at first site. A small blue-green patch of light. During earlier observations of this nebula, I always had trouble to see the color. NGC 6210 in Hercules was jumping at me with a bright blue color. Is it easier to see color with two eyes?

After tonight I definitely know that the binoviewer will be used for observing smaller deepsky objects like globulars, planetary nebulae and galaxies. But I am also very curious what this binoviewer will do on extended nebulae, like M42 or M17.

Posted by Math on 06/06 at 06:21 AM | (0) Comments | filed in: Equipment | Deepsky observing | Print
Saturday, June 05, 2010
First light for the binoviewer
Today I tested my new binoviewer on the Sun. I directly connected the Baader Maxbright to the Herschel Prism on my 4-inch refractor. I had to use a 1.7 corrector to get into focus. With the 25mm Televue plossls, I achieved a magnification of 70x. My first impression was stunning, what a detail! A glowing green Sun set against a pitch-black background. But what really amazed me was the intricate detail I could see both in the sunspots of active region 1076, as in the area surrounding it. Very clear were the faculae around the whole region.

Below you see an image of the binoviewer. I also shot two pictures of the active region with the Coolpix 4500. However, the live view through the binoviewer/herschel shows much more detail than I can record with my camera.




Posted by Math on 06/05 at 11:31 AM | (0) Comments | filed in: Equipment | Solar scraps | Print
Sunday, July 13, 2008
Eye-relief for my 12-inch telescope


About one and a half years ago I bought a 12-inch telescope for deepsky observing, an f/5.3 Newtonian telescope from Orion optics UK. The tube is mounted on a dobsonian rocker-box and equipped with the Argo Navis Digital Telescope Computer. During the past 18 months I have put together my set of eyepieces for this telescope. I had four major criteria for selecting the eyepieces:

1. High quality
2. Large true fields of view
3. Weight between 400 and 800 grams
4. Lots of eye-relief

All selection criteria were important, but the most important was number four, eye-relief. In this article I will tell you why these criteria were more or less important to me, which eyepieces I finally chose and why I chose them.

Posted by Math on 07/13 at 12:54 PM | (0) Comments | filed in: Equipment | Print
Tuesday, December 19, 2006
My new 300mm dobson from Orion Optics UK
I have been observing the deepsky visually for a few years with my 8-inch TAL 200K mounted on a Synta EQ6. What I didn’t like about this setup were two things: it was a lot of work to take it apart for transport when I wanted to go to a dark sky site and the aperture was just a little too small for deepsky observing from my light polluted backyard. A lot of objects just stayed out of reach.

So I wanted a telescope that could be setup and taken apart quickly and I wanted a telescope with a little more aperture. Set-up should only take a minute or two. I also wanted to be able to put it into my small family car without any help and carry it around on my own. My lower back problems limited the weight of each component to 20 Kilograms maximum. Because of these back problems, I also wanted a telescope that allowed sit-down observing. I decided to buy a closed tube Dobson with the largest aperture I could manage on my own.
Posted by Math on 12/19 at 01:02 AM | (2) Comments | filed in: Equipment | Print
Friday, November 10, 2006
Crayford focusser Orion Optics UK
I have received a few questions about the height of the Crayford focuser on my 300mm Orion Optics UK Dobson. Here are three images that show the Crayford in its different positions. On the first image you can see the height of the focuser when it's inside the tube, 6 centimeters. The second image shows the focuser when completely outside, 9 centimeters. So you only have 3 centimeters of travel. On the third image you see the focuser with an extension and completely outside. The total height is 14 centimeters. I have to use the extension on all my 1.25 eyepieces as well as on the Zeiss zoom-eyepiece. For my 32mm Televue plossl, the extension is just a few millimeters to short. I have to pull the eyepiece a little out to get it into focus.

Image 1

Image 2

Image 3

Posted by Math on 11/10 at 07:06 AM | (1) Comments | filed in: Equipment | Print
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