Dark Frame Subtraction & Light Pollution

This is not an article explaining what a dark frame is or how to take one or how to subtract it from an image. It is only to share with you a few test images I made lately (my first actually); I am not relating the two topics (i.e; dark frame subtraction with light pollution!):

No dark frame subtraction

With dark frame subtraction

Imaging Opportunity: Quadruple Conjunction

Hello again,

This time I am writing to raise your attention to a very amazing celestial conjunction, a quadruple conjunction.

The conjunction involves each of the "waning" crescent moon, Venus (brightest of all except for Crescent), Jupiter, and Aldebaran (alpha Tau).

You may also consider that around the conjunction there is the Pleiades & Capella!

Imaging Techniques -Part 1: Scenic Images

This post is one of a series of short posts on the three main astroimaging techniques; scenic, afocal, and prime focus. This series is also part of a larger series on the fundamentals of astroimaging which are based on a presentation was preparing a while ago. For today I will introduce you to the first, the scenic image which you naturally take quite often. As a start here's the definition of "scenic":

Scenic: Of or pertaining to scenery; of the nature of scenery; theatrical [1913 Webster]

As the definition implies, such an image is one of people or anything in the foreground along with some natural scene in the background. By natural scene I mean a scene of nature; a scene with trees or mountains or land or the horizon or anything Earthly or a combination of those.

This imaging technique is a relatively easy to use as people do it all the time, naturally; all that it requires is some perception. I chose this this particular technique for this post since a very nice imaging opportunity [1] is coming soon which you could use to both learn this imaging technique and to take a nice astroimage with relative ease. All you need is your cam and your tripod (or use your imagination & skills to position the cam on a surface with the right angle & direction; for example you could use a table mount, or an inclined book).

Conventions

This is to make a convention between us (me astrobob & you the reader) regarding some terms I use to ease any confusion that might arise due to those terms. Here's a list of the them and what I mean by them:

• Date & Time
• Date: 2012-06-06 (YYYY-MM-DD)
• Time (HHMM hrs)
• 0300 hrs = 03:00 AM
• 1700 hrs = 05:00 PM
• Examples
• 2012-06-06 1200 hrs = 2012-06-06 12:00 PM (i.e; mid-day)
• 2012-06-07 0000 hrs = 2012-06-06 12:00 AM (i.e; mid-night or start of new day!)
• Words
• image = photo (astroimaging = astrophotography)

Note: I'll update this list when required.

Thanks for reading :)

and clear skies!

Venus Transit (2012): Some collected images

Here are my images of the transit (first two). They are not great the setting was not appropriate for astroimaging as I was participating in a public observing event.

I was able to catch these images in between observers:

Through my cams' zoom only! You can see Venus in the upper centre!

Telescope eyepiece view @ 85x

And here's an image by my collaborator astroZ

Saida, Al Janoub; astroZ

Transit of Venus (2012)

Hello again :D

    WARNING    Before reading the article, please be warned that looking at  the Sun without appropriate precautions (using solar filters, viewers, etc...) may & will cause partial or complete damage to your sight. Please take appropriate measures in advance &/or participate in a local astronomy group that takes precautions on your behalf by letting you view the transit through its equipment. You have been warned!!!

    A rare event that comes in pairs every 120 years, more or less, occurred on June 8, 2004. This rare event is going to occur in a couple of days as the second of the 2004/2012 pair which will not repeat until the year 2117. In other words, this rare celestial happening is the last one to occur in our lives; no one might be able to witness it again, unless science offers a way to extend the human life span.

This special event is the Transit of Venus (i.e; transit of the planet Venus in front -from our viewpoint- of the Sun). The two events are separated by about 8 years. This is characteristic of such a phenomenon which occurs twice every 120 years, as I've mentioned above. That is, it occurs in pairs (e.g; 2004/2012). The next pair will start in the year 2117.

Transit of Venus 2004; astroZ (http://flic.kr/p/ac4z8C)

Welcome

Hello :)

This will be my first post &; outlined are some thoughts about what I might be posting in the future.
    Therefore I'd like to welcome you to the blog! This blog has been set in the couple of weeks after an idea of creating a Lebanese astrophotography blog to serve two main purposes:

• act as an archive &; reference for Lebanese astrophotographers, &;
• for everyone to benefit from the contributors' experiences

As such, the blog is licensed under a Creative Commons license (please see the Permission of Usage page). This means that you are free to share, distribute, &; modify the material on this blog under the "only" condition that you "attribute" the work to its original author &; blog &; linking back to it. Note that the images in this blog are the sole work of its creators &; all rights are reserved to them unless otherwise stated. Please write to the corresponding author(s) in regard of image permissions.

    First, I'd like to start by thanking astroZ, my kind friend &; astrophotographer, for his Welcome post. It is really exciting to be able to mutually share our experiences on this blog &; share it with you, our fellow readers. We hope that this blog brings something new for you to benefit from on your route towards imaging the night sky. I also like to add that he's been doing a great job hitherto; and I believe he will continue to do so hereafter!
Personally, I've been busy with several things most importantly my studies, Ubuntu testing and other related chores. For the same reasons I have not done any astrophotography, or photography in that matter, since last summer. I just wanted to write this introductory post in hope of following it with some useful posts later on.

    It is interesting to know that astroZ &; I share the same start, relatively speaking. I myself started in astrophotography with a Solar eclipse as well! The only difference is his early start. In my case it all began around March 29, 2006 during the partial solar eclipse (see below for some images from that day). My start was, like astroZ, with a "film" camera; a Canon EOS 750QD to be precise.

    Just a quick note: In regard of software, I mainly use open-source software which you may or may not have heard off or used before. In any case, I will do my best to keep things both readable &; applicable as much as possible. To clarify, I use open-source software since I am not required to pay a hefty price for or use illegal copies of commercial software.

Last but not least, I'd like to make a convention with you: When you read "astrophotography" or "astroimaging", it is the same meaning. Just wanted to make this clear.

Finally, my next post will be on the Fundamentals of (astro)Photography. I will list &; briefly define some terms used in photography &; some preliminary concepts on astrophotography.

Thanks for reading :)

and clear skies!