Saturday 19 May 2012

Taking photos of star clusters

Just sharing my attempts at taking the photos of star clusters, an object I find most pleasingly pictured via a Canon 550D Camera docked to the Astroview 100mm.

First you have to focus on the subject. I focus by swinging the rack and pinion focuser back and forth until I get the sharpest image in my opinion.

Then, the photography settings - I usually use an exposure of 1-2 seconds max to reduce star trailing. ISO is cranked up to the region of 1800-6400.

Below are some of the images I've taken through prime focus. You may have seen them on facebook but here it's much clearer :)





Saturday 5 May 2012

Astrophotography Workshop with William Chin

The sky is clear on the night of May 3rd, a sign of great luck to the budding astrophotographers who is eager to record the celestial portraits the sky has in store for us.


Photo Credits to John Lim.

With the leadership of Malaysia's ace astrophotographer William Chin, stargazers Chrono, Simpson, Kenza Chen and John Lim starts snapping away in <30 secs exposures to freeze the stars in motion.
William Chin Pro Tip : Focusing is all-important in photographing the stars. If you don't focus properly, your picture is shit. How to focus on the stars?
  1. Turn off the AutoFocus, the Image Stabilizer.
  2. Point your camera to a streetlight far away, or if any bright stars is visible, to the bright star. 
  3. Turn on LiveView (or any other programmes that makes the scene visible on the LCD) and focus manually until you get a sharpest dot for the streetlight.
  4. For better results, zoom in - and focus again until you get a sharpest dot. 
  5. When you are happy with the focus, point to the stars - and DO NOT touch the focus anymore. If you touch it the focus will go off and you will have to redo it. 

This is an example of a star shoot. The blue background which makes it looks like daylight is caused by a combination of factors - the fact that it was almost Full Moon at that time, some light pollution and the Custom White Balance setting in the camera. It can be corrected in Photoshop. More details about that soon.
William Chin Pro Tip : Exposures without guidance (just tripod and DSLR) are best in 20-25 seconds for stars near the North or South (e.g. Big Dipper or Southern Cross), and 10-15 seconds for stars near the equator (for Malaysia, it's the stars directly above our heads), for example the Zodiacs - Scorpio, Sagittarius, and others such as Orion and Canis Major. 
This picture features the Big Dipper! Can you spot it? :-) This was taken with Canon 40D, f/3.5, exposure 15s at ISO 400. Same for all the other pictures below.


Centaurus and the Southern Cross! 


This super large one features the most easily spottable constellations Scorpio and Sagittarius - as well as the most heavy traffic observed in our skies - the Milky Way! While the stars may be little in others parts of the sky, along the Milky Way Expressway the stars just keep on going, and the number of clusters and nebulae inside are too damn high!

Do you see a faint cloud-like thing at the centre of the picture? That's the Milky Way!!

Well that's about it for the brief astrophotography session with William Chin at (undisclosed location), Kajang! We look forward to more sessions with him!


Amateur Telescope Making starts in Kajang!

Amateur Telescope Making(ATM) has started in Kajang with Chrono Fong and Tan Simpson!

First, What is ATM?

ATM is an activity of making your own telescope from scratch. You can also buy the parts separately and assemble them. Most ATMmers usually grind their own mirrors though. The most popular design for ATMming is the Dobsonian Reflector, also known as the 'Poor Man's Telescope' due to its most simple design.

We recommend ATM because when you make your own telescope, you will understand the very delicate workings of a telescope. It is also a chance for you to experience yourself the applications of the optical laws, the trigonometry mathematics, even the mechanics involved with the telescope! However, it is entirely optional and pretty much anyone can build a decent 6-inch Dobsonian given that they have lots and lots of passion. Yes, you need LOTS AND LOTS of passion.

Our fellow stargazer Simpson was recently back from his 'pilgrimage' to Universiti Sains Malaysia and his apprenticeship to the Malaysian ATM mentor Dr Pierre Chong (Find him on Facebook). Immediately he started the gears in creating ATM fever in Kajang, Selangor!







 This is the makeshift workshop for Kajang ATM. The left table is Simpson's, whose mirror is still in progress. The right table is Chrono's, who have just started the ATM in Kajang.
 These are the 'ingredients' in mirror making and polishing - carborundum (silicon carbide, SiC) of varying grades from 120-220, polishing powder, lots of water, and the glass.

We are just starting out and in our progress of trial and errors, we hope that our successes and blunders will be a guidance for future ATMmers in KL interested to pursue this craft. Next up we will post about the stages in mirror grinding for a Dobsonian!

Stay tuned! Everyday we ATM-min'!





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