About 10 months ago, I started getting into Astrophotography, which has been an amazing and positive experience for me so far. I started taking photos of Deep Sky Objects (DSO’s) with my Nikon D7000 DSLR and I was quickly enthralled with the beauty of what existed out in deep space. One of the first DSO I imaged with my DSLR was M13, the Great Globlar Cluster in Hercules. I remember being in awe that the pitch black patch of sky I pointed my telescopic contained so much beauty. After learning how to do some rudimentary unguided imaging with my DSLR, I wanted to see if I could get more detailed photos so I looked into purchasing a CCD camera, which is a specialized imaging system for Astrophotography. I received a ton of helpful advice from Michael Caligiuri who has been a tremendous source of inspiration and knowledge. I also did some research and subsequently purchased a monochrome SBIG ST-2000XM and a filter wheel from Astromart so I could now image DSO’s across the Luminance, Red, Green, and Blue channels. Flash forward to present day and here is a comparison of M13 taken 10 months and one I recently took back on June 4th:Read More >
A couple weeks ago I built a flat frame light box for my telescope so I can take these really important images so that imperfection (dust, etc.) in my telescope and CCD camera are subtracted from the frame. At the most basic level, flat frames are used to correct the vignetting and uneven field illumination created by dust and imperfections in the optical train. In the example above, the photo on the left is not flat frame calibrated and you can see dark circles in many places on the image. These imperfections are dust motes. The photo on the right has been calibrated with flat frames, serving two very important purposes:
1. Removing dust motes
2. Evening out the field around the corners of the image
Here is the final LRGB image of M13 that is both dark and flat frame calibrated:Read More >
Before I start, I wanted to say that almost 100 flat frames were sacrificed in the making of this light box. Last weekend, I built myself a Flat Frame Light Box using 5mm Foam Core and an A5 Electroluminescent (EL) Panel. I image with a Takahashi Sky 90II and an SBIG ST-2000XM and there are dust particles on the telescope as well as the CCD. I am not going to describe the need for flat frames or how to take them as it is covered in many other articles around the web. This blog aptly called DasFlatFrame does a good job at describing the need for flats. I am going to describe how I constructed the light box
- A5 Electroluminescent Panel
- 12 volt inverter (if you want a dimmer panel you can use a 9 volt inverter)
- 5mm White Foam Core
- White Printer Paper
- Vellum Paper
- White Duct Tape
- Scotch Tape
- Cardboard (used to hold the box on the telescope)
- Exacto Knife
Light Box Construction
Figure out your measurements based on the size of your telescope. This light box was made for a Takahashi Sky 90 so I figured a 10 in. x 10 in. x 10 in. box would suffice. For the outside of the light box, I cut 6, 10 in. x 10 in. x 10 in. Foam Core panels. I cut an additional 10 in. x 10 in. x 10 in. panel for the Diffuser Panel. The Diffuser Panel and the Rear Panel of the box have rectangular cut outs so that paper and the EL Panel can be affixed on to them...Read More >
Earthshine is a soft, faint glow on the shadowed part of the moon caused by the reflection of sunlight from the Earth. Tonight, the Moon and Jupiter were in close proximity of each other.Read More >
What happens when you spend 3 hours imaging an object only to find that you have only a handful of salvageable images from the session? That happened to me back on May 3rd when I imaged the Whirlpool Galaxy. During the night, at some point, I lost guiding and did not catch it so when I went to process the photos I was surprised to see that 2/3 of them were unusable. Having only 13 images to work with, I processed the images 4 times over to see if I could get a decent image to come out. Along the way, I learned a ton (as usual). Here are some of the things I tried and the outcome of each method:
1. RGB Misaligned – MaximDL RGB Color Combine (Average Method) + LRGB Combining in Photoshop CS6
The image above is a result of the RGB images being misaligned when processing. Sometimes I get a little impatient and don’t take my time getting everything perfect during the post processing aspect of Astrophotography and this can result in very sloppy images. When the RGB channels don’t line up, you get a mess of colors scattered throughout the image. The RGB and the L images were first combined (using the Average method) in MaximDL and then combined in Photoshop CS6. As you can see, even Photoshop can’t save this image.
2. LRGB Combination in Photoshop CS6
The photo above represents an image that was combine using Photoshop CS6...Read More >
The Bode’s Galaxy (M81) and the Cigar Galaxy (M82) are located in the Ursa Major constellation, which is right outside my backyard. Taking advantage of clear night on 2/14, I decided to see if I could capture these two galaxies. I got everything set up, ready, and started imaging. Two and a half hours later, I started to process the images and boy was I disappointed. M81 and M82 were severely out of focus. I told myself no big deal and I could just wait for another clear night and image them again. Here is the output from the night of 2/14:
Three days later , on 2/17, I tried it again. Thinking I had a much better focus, I imaged the two galaxies for another 2.5 hours. As I was processing the images from that session, the same thing happened! I was out of focus again. How could this happen two times in a row? Taking a step back and do some research on focusing. Turns out, there was still a great deal to learn. The clouds rolled in after that night so this gave me some time to do some research into how to achieve a better focus.
Turning to youtube, I came across this fantastic tutorial by John Blackwell on understanding a Star’s Full Width Half Maximum (FWHM). Huh? What is FWHM? Turns out this four letter F word (not the one you are thinking about) is very important for determining whether your image in focus or out of focus...Read More >
The Universe, space, and time, is a difficult concept to comprehend due to its vast and infinite size. That is why the Lightyear was created, which is the distance that light travels in 1 year or just under 6 trillion miles (5,878,625 million miles). The “year” contains measurements of both time and distance, where time is calculated on the Julian scale, where 1 year is equal to 365.25 days. Because light takes time to travel from one place to another, we can therefore look farther back through time through telescopes. We see objects not as they are now but as they were at the time when they released the light that has traveled across the universe to Earth. That is what fascinates me about Astronomy and why I started the hobby of Astrophotography.
Take the image above, for example. We are looking at the NGC 3395 and 3396 galaxies as they were 85 million years ago because the distance that these objects are in space are 85 Million Lightyears from Earth. So what was happening on Earth 85 million years ago? Earth was in the Cretaceous Period, defined by following characteristics:
Read More >
“Flowering plants proliferate, along with new types of insects. More modern teleost fish begin to appear. Ammonoidea, belemnites, rudistbivalves, echinoids and sponges all common. Many new types of dinosaurs (e.g...
A meteor exploded over Russia’s central Ural Mountains earlier today, February 15, 2013. A large fireball can be seen blazing across the sky with a brilliant flash of light and a sonic boom.
According to Reuter’s
“People heading to work in Chelyabinsk heard what sounded like an explosion, saw a bright light and then felt a shockwave according to a Reuters correspondent in the industrial city 1,500 km (950 miles) east of Moscow.”
“A fireball blazed across the horizon, leaving a long white trail in its wake which could be seen as far as 200 km (125 miles) away in Yekaterinburg. Car alarms went off, windows shattered and mobile phone networks were interrupted.”
You can see a large streak and fireball sailing over the sky in the video posted by BBC Europe
Update: Here are some photos this historic eventRead More >
It was another crystal clear night on February 10th so I decided to do some deep sky imaging. I really did not know what to shoot that night so I turned to the hand controller on my Celestron CG-5 GOTO mount and I started slewing to various objects in hopes I could find an unobstructed patch of sky. After spending 30 minutes trying to find something to image, I slewed my telescope to NGC 3395 and 3396, a pair of interacting galaxies in the constellation Leo minor. After focusing the image, I programmed the number of exposures in in the Luminance, Red, Green, and Blue (LRGB) filters and I 2 hours and 26 minutes later, I began processing 34 sub exposures. In my mind, I was thinking that the pair of galaxies I was shooting would fill quite a bit of the frame I was shooting. To my surprise, after successfully processing the image, I noticed that the pair of galaxies was quite small. After getting over the initial shock, I started to look closer at the image. Not only did I capture NGC 3395 and 3396 but also NGC 3340, 3424, and 3413 showed up in the image as well.
After discovering how small the galaxies were given my apparent field of view (FOV), I decided to calculate my FOV for the telescope and the CCD camera. After plugging in my telescope focal length and and my CCD sensor size, I calculated my full field of view of my images are 74.8 x 99.7 arcmin (an arcmin is a unit of measurement in astronomy)...Read More >