Wednesday, June 24, 2009
First light...sorta
Last night was my first night to setup the Mach1 and Tak FSQ 85 for an imaging run. The clear sky clock looked wonderful and the skies were pristine during the evening. I setup in the backyard since I was hoping to have two straight nights of imaging and wanted to work out the kinks in the new gear. Setup went very smoothly and the equipment worked flawlessly. Unfortunately, a persistent puffy partly cloudy sky never relinquished. So no images were taken, but the gear checked out nicely. I was able to do a lot; monitored the drives performance via the autoguider, perform calibration for autoguiding, refined technique for using the laptop for focus with and without an h-alpha filter in place in the camera, and tested all of the new USB cords and hubs in use. So it was a successful night and I am ready to tonight! Clear skies!
Saturday, June 20, 2009
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.
Thursday, June 18, 2009
Apple's other update
While all iPhone uses were upgrading to 3.0, and it is a nice upgrade, Apple also made some very nice enhancements to their Safari web browser. I hadn't really seen anything about this upgrade and was pleasantly surprised to see some new features. Two new features that I love are tied to the "new tab" request. Upon forming a new tab the surfer is presented with a screen of previously visited top websites by you in a portfolio presentation of images. I love this and it makes browsing my favorite sites even easier than pulling down a bookmark. In addition, the user can browse or search for previously searched webpages. This webpage looks just like the iTunes page of album art search for movies or music. These two features have not only made Safari my preferred browser on the MAC, but I have now upgraded to the Safari 4.0 on my Windows machines and I love it. Check it out if you haven't already, especially if you are a tab browser.
A bit of an update: There is a "Top Sites" icon at the top left of the browser that pops up the top 12 sites you visit. This actually may replace tabbed browsing. Finally, Apple has applied their creativity and genius in user interface to the web browser!!!
Monday, June 15, 2009
Cinderella's Ice Castle
In the fall of 2008 our family visited Disney World for my son's senior high school trip. For a camera, we had my wife's convenient Canon 400D. The stock 18-55mm lens was on the camera which limited compositions as well as perspective control options. Long telephoto lenses can help minimize distortions when photographing from a distance. The ice decorations on the castle were quite stunning and so I worked on a couple of different compositions, mainly for practice, as I knew there would be some different techniques involved. On this particular image, I combined 4 frames vertically in Photoshop to give extra image area so that I could then perform a perspective correction. This composition poses several challenges including a huge dynamic range, hand-held image capture at ISO 1600 and 1/8 of a second, large crowds of people, and a tired tourist at the shutter. So this is the final presentation after RAW conversion in LR, vertical stitching and perspective control in PS3. I hope you enjoy the image and I encourage you to visit Disney World during the holiday season for some special treats like Cinderalla's Ice Castle.
Saturday, June 13, 2009
Comet Lulin video
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.
This video is a time-lapse sequence of 9 3.5 minute exposures taken on February 21, 2009 from the Winter Star Party in the Florida Keys. Each image was optimized in Adobe Light Room and the video was compiled with Windows Movie Maker. The video loops several times so that the viewer can pick up the subtle changes in the blue ion tail. Geostationary satellites are common in this area of sky and pass through the field as through they were moving airplanes, but in fact it is the telescope and camera moving to compensate for the Earth's rotation.
You can download a wmv file from my Vimeo site which is a much larger and higher quality presentation.
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.
Monday, June 1, 2009
What size should web image be?
With the introduction of the "netbooks" and smart phones, I was curious to revisit the most common screen resolutions currently being recorded by web browsers and those data mining groups that do such things. One report I found lists 36% of surfers are using 1024x768 in January 2009, down a bit from 2008. Where is the move? To higher resolutions. The report only lists resolutions higher than 1024x768 and that percentage is 57%. But are we possibly seeing a move back to smaller screens? Do the data mining groups account for web browsing on smart phones? I know that I look at images on an iPhone, Macbook Pro, and a 24" Apple Cinema display. I have looked at the netbooks and can't say that they catch my fancy at the present time. A quick look at one of the HP netbooks (N270) shows it sporting a 1024x576 screen resolution. Will netbooks find a strong foothold in the marketplace? Another consideration for how large of an image to post to the web is how much of an image do you want your audience to view. I personally always want the entire image showing with no zoom effect. Why? I take great care on the entire composition of the image and want the image always viewed in its entirety. To me, posting a larger than 1024 image on the web would be like Ansel Adams only allowing you to view one of his prints from a distance of 6" away. There is a proper viewing distance for all images and one should consider that even for web presentations. Now I do understand that some browsers can re-size the image to fit the window, but I really don't want to rely on that effect 100% of the time. So at the present time I have chosen to post images with a long side of 1000 pixels with some modifications for portrait orientation. To me that hits the sweet spot of fitting nearly every screen resolution out there (93%)and presenting the image in its entirety to the viewer. So that is my take on proper image size in June 2009. I hope to revisit the issue as time passes to see where screen resolutions may go into the future.
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