TED'S ASTROPIX:
Astronomical imaging in, around, under and through the Columbus nebula.

© 2008-2010 Ted Saker, Jr. All rights reserved.
Country of First Publication: The United States of America
These works are for the personal viewing and enjoyment of visitors to this site.
Any and all commercial use of these images is absolutely, strictly and totally prohibited without my consent.
Remember, I sue people professionally. Besides Astronomy, it's what I live for.

(Page Created: 23 June 2008. Last update: 25 July 2010)

New additions to this page appear in green type with the date of posting.

I have learned through much trial and error (mostly error) that imaging from sites in and around a major city is a difficult undertaking. Emulsion photography is pretty much limited to lunar and planetary subjects. In 1998, I decided to join the CCD revolution. CCD cameras held out the potential of conducting deep sky imaging from urban sites. The cost of CCD cameras in the late 1990s was beyond my budgetary reach. I built a Cookbook 245 camera, which saw first light in 1999. I imaged with it successfully through early 2002. At that point, I completed the construction of another homebuilt camera, the Genesis 16, which was equipped with a KAF-1600 ABG chip. This chip is the same one used in the first generation ST-8 that was at that time the flagship model of the Santa Barbara Instruments Group.

The Cookbook camera revolution eventually ran its course as newer, moderately priced, and more technologically advanced commercially manufactured cameras entered the market. Next, support for the Genesis line ended for the same reason. Both cameras eventually outlived their technological lifespans. The Genesis camera suffered a capacitor failure at the 2005 Texas Star Party. I was unable to get the Genesis camera functional quickly, so I had to press the Cookbook back into service for the 2006 Winter Star Party where it suffered some kind of tropical meltdown. It's currently sitting on a shelf awaiting a rebuild. Favorable market prices for previously owned equipment signaled that the time had arrived for the purchase of my first commercially manufactured camera. In mid-2006, I bought a serviceable SBIG ST-8 ABG camera equipped with the Kodak KAF-1600 ABG chip, the same class and vintage as the chip I built the Genesis camera around.

The most challenging aspect of urban CCD imaging is obtaining a sufficiently high signal to noise ratio in the face of severe to extreme light pollution. Anti-blooming chips are less sensitive than non-antiblooming chips, and the difference affects the ability to obtain a good SN ratio especially in tricolor imaging. One thing I suspect but haven't yet been able to prove is that the NABG chip is superior to the ABG chip. Comparing the Cookbook's NABG chip to the Genesis and ST-8's ABG chips, the Cookbook camera's TC 245 NABG chip yielded better images in my opinion. The Genesis and ST-8 cameras used the same chip (the KAF-1600 ABG) and I was generally unsatisfied with the results. The TC 245 chip's larger pixels and not the lack of a blooming gate may have been the reason for the better results.

However, having been without a camera with a NABG chip since 2006, there was no way for me to prove or disprove my theories. One immutable principle remains constant: S/N ratio in all images is and always will be the key to good results, and this is particularly true in tricolor imaging from an urban site. Thousands of low pressure sodium exterior light fixtures create a decidedly greenish background that makes image processing difficult. obtaining a good, black background and a proper representation of the object is still a significant challenge. The problem isn't limited to tricolor imaging, either. It's very similar to the problem with emulsion photography: light pollution would “fog” the film out before getting a decent image. CCD cameras yield better results than photo emulsion, but could be still better if people turned out a few lights.

In early July, 2008, a fantastic opportunity arose whereby I was able to acquire an SBIG ST-8E camera. It is equipped with the next generation of Kodak's KAF-1600 line of chips. The 8E is equipped with the KAF-1602E NABG imaging chip. I can now put my chief theory to the test: the NABG chip is superior to its ABG predecessors. In May, 2010, another opportunity I couldn't refuse presented itself. I now use an SBIG ST-8XME. It has a USB interface in place of the obsolete parallel port interface that all my previous cameras used. The extra bonus is the ability to utilize SBIG's proprietary I2C port which enables the user to control the CFW without separate interface and power cables. Coupled with the replacement of the heavier parallel cable with the lighter USB cable, the wiring harness is much lighter. Losing the extra weight of the cables reduces the load on the OTA, thereby making autoguiding easier. I believe this is reflected in the recent images I acquired with the new imaging rig.

Below is my gallery of images taken in various locations in and around the Columbus nebula.

• Images with red borders were taken with the SBIG ST-8 (ABG) camera with AO-7, SBIG CFW-10 with Astrodon LRGBHa filters (for tricolor images), Celestron C-11 Schmidt-Cassegrain optical system, and Losmandy Gemini G-11 GEM. Images processed with MaxIm DL™ v. 4.53 (2006-2008).

• Images with blue borders were taken with the SBIG ST-8E (NABG) camera with the same accessories (2008-2010). These images may be found in the Comparison Gallery : The Clash of the Has-Been Cameras.

• Images with magenta borders were taken with a Minolta X-370 SLR 35mm emulsion film camera, and/or other equipment as noted.

• Images with green borders were taken with the SBIG ST-8XME (NABG) camera, AO-8, and the same accessories. At last, I could use the I2C cable from the CFW-10, and lose the serial and separate power cables. I also replaced the heavy parallel cable with a much lighter USB cable.

CCD IMAGES

Clear (and Dark) Skies!

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