Friday, 18 January 2013

The Swan Nebula, M29 and M13 with a Samsung SDC-435 and a 6", f/5 Newtonian

The Swan or Omega Nebula, M17 with a 6," f/5 Newtonian
The SDC-435 was fitted with a light pollution filter

M29, Open cluster in Cygnus with a 6", f/5 Newtonian

M13, Globular cluster in Hercules with a 6", f/5 Newtonian

Click on Older Posts to see more of this blog

Thursday, 17 January 2013

SSNR3 Samsung noise reduction in the SDC-435

The SDC-435 has a built in noise reduction function that is intended to be used in low light environments. It is important to use this function, particularly if the camera is being used as an observation camera and the image on the TV monitor is to be observed.
Below are two individual captured frames to show the quality of the viewed image. One has SSNR3 turned off and the other has the function turned on. The two images were captured within minutes of each other. The camera was fitted with a light pollution filter and the telescope was an f/10, 11" SCT:

Noise Reduction OFF

Noise Reduction ON

The noise has been drastically reduced but the stars in the image remain unaffected.
For the production of images, dark-frame subtraction using dark-frame scaling removes the amp glow in the top left of the image.

M57 & M82 with the modified Samsung SDC-435 and an 11" SCT

The modified Samsung SDC-435 was used with slightly changed white balance values and noise reduction. The camera was fitted with a light-pollution filter and was placed at the prime focus of the 11" f/10 SCT. Dark-frame and image data were recorded to DVD in high quality. The BMP frames were recovered from the DVD with VOB Frame Extractor and the frames were stacked in Registax. The aspect ratios were corrected and levels were adjusted in the Gimp.

M57 the Ring Nebula

M82 the Cigar Galaxy

The white balance has been improved with the current settings.

Click on Older Posts to see more of this blog

Modifying the Samsung SDC-435 video camera for deep sky astronomy

It should be noted that the Samsung SCB-2000 is the same camera as the SDC-435, re-named by Samsung following company reorganisation.

Warning. Modifiying your camera will probably invalidate the warranty

Screws at the top and bottom of the camera housing are removed. This allows the top and bottom parts to be removed exposing the internal circuit boards.
The front board which houses the CCD and the blue filter it attached by small screws to the front metal housing of the camera. It is attached to the main circuit board that runs from the front to the back of the camera by two ribbon cables. These are gently detached and the screws holding the filter assembly are removed. The assembly is shown below. The camera is then re-assembled.

The filter assembly in place

Filter assembly

The exposed chip

The two screw holes can be seen through which the screws attaching the filter assembly passed.

These are the settings on the OSD to set the camera up for deep-sky observing

Changes to the White Balance produce the correct colour balance in the image. The settings were obtained by fitting a lens to the camera and adjusting the Red and Blue gain in daylight to produce an image with correct colours.
These settings work but the user should experiment.

I fitted a light-pollution filter on the camera and mounted it at the prime focus of the 11"SCT.
15min of DVD (1 Vob file) were captured at high quality and a similar amount of dark-frame data were recorded. There was a bright Moon in the sky.
The VOB Frame Extractor software coded by Ian Davies was used to extract BMP images from the DVD with no loss of quality.
Andrew Sprott’s Dark Frame Scaler program was used to correctly scale the raw darkframe produced by Registax.
The BMPs were dark-frame corrected and stacked in Registax. The resulting image was aspect-ratio corrected and cropped.
This is the resulting image with absolutely no colour manipulation:


Click on Older Posts to see more of this blog

Using the Samsung SDC-435 (SCB-2000) video camera for astronomy

It has been a while since I wrote in this blog but I am back from my other projects. Previously I was exploring the Mintron series of cameras and some modifications that Mintron made to the cameras for me that gave them more capabilities as astronomical imagers.
I am now reporting on some experiments on using the Samsung SDC-435 (SCB-2000) frame-accumulating, colour video camera for deep sky imaging:

The camera:

I attached the camera to a 10" f/4.8 Newtonian reflector telescope and used Astrovideo to capture 100 frame AVIs with a 5s delay between the capture of individual frames. The sens was set to auto and max accumulation of 512. AGC was set to high and the camera was set to colour. A 100 frame dark-frame AVI was captured with fixed align with the cap on the front of the scope.

The camera adjusted automatically so that the dark-frame was far too light as discussed for Mintron Dark Frames in our article in ‘Popular Astronomy’ April-June 2010. Astrovideo also simultaneously tracked and summed the captured frames and produced an image that was saved as a .BMP file. This image was then used along with the dark-frame in Dark-Frame-Scaler to produce a corrected dark-frame for use with the AVI in Registax.

The first results are presented here rescaled from 640 x 480 to 500 x 375:






I needed to investigate camera settings to see whether the colour balance can be improved. The blueish tinted filter that filters out IR in front of the 1/3" chip will also cut down H-alpha to levels that could be below 20% of their actual values. I then modified the camera by removing this filter.
My intitial reaction was that this camera can be used for Deep Sky observing and imaging although the live views have a fair bit of colour noise.

Comet McNaught C2009/R1 with an Unmodified Samsung SDC-435 frame-accumulating video camera and an 11" F/10 SCT

June 21/22, 2010

Click on Older Posts to see more of this blog