winter star party

4 weeks and counting...

As most of you in the U.S. know, this winter has already been brutal.  So today begins my 4 week countdown to the Winter Star Party near Marathon, FL.  I plan on blogging daily from WSP and hope to incorporate video for those of you just finishing your snow shoveling:-)  The star party is really a wonderful break from the winter climate of the mid-Atlantic area.  I spent some time today working on compositions for the week and hope to bring back some wonderful data.  I also have plans for documentary work that I hope to share on the site sometime down the road.  So I post an image today taken from the 2009 WSP as I longingly look forward to the 2010 event.  Stay tuned for much more to come...

Horsehead: A refinement in processing

With some time to process, I have dug into the Horsehead and astronomical workflow to find the best approach. My main efforts are built around noise reduction and determining at what point to apply noise reduction software. The choices are to apply in RAW conversion in LR or to wait and use a PS plugin or 3rd party independent software. I have previously used Noise Ninja after the image is nearly complete, but was recently introduced to Noiseware. I am using the Pro version of Noiseware as a PS plugin. The main advantage to Noiseware is that I can use it in my normal workflow within PS and can use color profiles effectively. Noise Ninja did not work well with color profiles as an independent app. Noiseware has numerous controls, too numerous to mention here, for controlling how and where the noise reduction is to be applied. My thoughts are that it might be best to add some noise reduction in the RAW file in LR and then utilize Noiseware late in the processing stage. This particular image had no noise reduction applied in LR. I am going to rework the Horsehead image with that approach and will report back with results. One thing I love about astronomical photographs is that they are so difficult to work with that it makes landscape optimization so much easier. Take care and check out Noiseware if you get a chance on some really noisy images.

One other change in workflow with this image involved applying a flat field from the RAW camera files to the image in PS. This worked very well and is now a part of my workflow. I found no advantage to applying dark frames to the image. I believe dark frames are largely a waste with the Canon 450D and that simply increasing the amount of signal is the best way to maximize the signal to noise ratio.

Link to larger image.

Comet Lulin

Comet Lulin graced North American skies in the winter of 2009. Fortunately, the closest approach was during the Winter Star Party in February. Comet Lulin proved to be much more interesting than I had previously been inclined to believe. The comet brightened dramatically over the week of February 24 and sported a beautiful ion blue tail. I slewed to the comet with the scope and began my initial exposures and was surprised by the views on the LCD screen. The blue ion tail was crumpled and extending away from the comet nucleus in a beautiful fashion. So this object became the main target object during the 2-4 a.m. imaging window on most nights. More information on the comet can be found by clicking on the title of the blog at NASA's website. You may also click on the image for a larger presentation.

This particular image was taken during the 2 a.m. hour of February 21, 2009. It is a composite of 9 exposures of 3.5 minutes each at ISO 1600 on the Canon 450D through the TMB 92SS refractor. Comet imaging poses additional challenges when the comet is fast moving such as Comet Lulin. The imager must combine several short exposures for the background sky as well as for the comet. So two iterations of stacking are needed since the comet is moving relative to the fixed star field. This is quite challenging in processing, but we do have techniques that allow us to accomplish this with nice results.

All of the processing was accomplished with Adobe Light Room 2.0 and PS3 with some Noise Ninja for noise reduction. Images were aligned and stacked with Images Plus. A Sigma median combine was used on the comet nucleus to achieve a reduction in star trails and isolate the comet nucleus and tail in the combination. The total exposure time is approximately 30 minutes. I am also going to present a movie which depicts the comet moving relative to the star field. I hope you enjoy the image and please check out the NASA link for more information on the comet.

An Orion experiment

Now this is simply crazy. I had some Orion Nebula data from WSP that I basically captured on a whim. So in reviewing the data in Light Room I wanted to see just what the new techniques could bring out of this data. Let me state up front that this is simply not enough data to get what I eventually want out of this image. But, it is a great exercise in seeing exactly what the technique can do with very limited amounts of data. I selected 11 of the best frames captured on the Canon 450D and TMB 92SS combination. I optimized each image in LR 2.2 and exported to tiff. I used Images Plus and Sigma clip for the alignment and combination and then processed as normal in PS3. Now one other major error on my part, not that the clouds at WSP had anything to do with it, was that I failed to capture shorter exposures to compensate for the over-exposed core of M42. So I did plug in some old data from other instruments for the core of M42 in this image. There is a fair amount of noise reduction via Noise Ninja applied to the shadow areas. So for only 40 minutes of data with a lowly DSLR, I am very happy with the potential to really capture the Orion Nebula area as I hope next year. My expectations are that two hours of data at ISO 800 will be wonderful data to work with and accomplish my imaging goals. Please drop me a line if you have any questions or comments and I hope you enjoy the image.