Experiments with a low cost board video camera

I am looking into suitable, entry level astronomical imaging devices and am considering the merits of video TV board cameras. I located and obtained this device from Amazon:

The lens was removed and a standard webcam adapter was screwed in place of the lens. The camera, as yet unmounted was placed at the prime focus of a 127mm Maksutov scope:

The camera was powered by a 12 volt adapter and the composite video output was connected to a domestic DVD recorder, set to High Quality. A 7 inch TV monitor was connected to the output of the DVD recorder. Below is the live view from the monitor when the scope was aimed at, and tracked the Moon:

The video stream produced by the camera was recorded to a recordable DVD disk, and later, the BMP images were extracted from the VOB (video object files) on the disk using Ian Davies's VOB extractor software.

1500 video frames were stacked in Registax 5 to produce the following image, which was de-interlaced and post-processed in Photoshop:

The Aspect Ratios were corrected using Nicola Mackin's AR-Corrector software

Rupes altai, Mare Nectaris, craters Piccolomini, Catharina, Cyrillus and Theophilus

Aspect Ratio Corrected

Similarly, another two images were extracted from the DVD: 

Lunar Apennines

Aspect Ratio Corrected

Craters Herschel, Ptolomaeus, Alphonsus, Alpetragius, Arzachel, Albertegnius with Rupes Recta at the bottom of the image.

Aspect Ratio Corrected

More details will be put in this blog entry very soon. The camera will be mounted in a protective project box and more details will be posted on the resulting images.

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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

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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.

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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.

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

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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:

M57

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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:

M13

M3:

M51

M64:

M57:

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

June 21/22, 2010

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Comet McNaught C2009/R1 with a Mintron and an 11" SCT at f/10

I used an Omega modified 1/2" chip colour Mintron fitted with a light pollution filter to image Comet McNaught. The comet was in the lightest part of the June 21-22 sky, just above and to the west of Capella. I captured 15 min of high quality DVD of the comet and of dark frames. The BMP images were extracted from the DVD with VOB Frame Extractor and the dark-frames were scaled with Dark Frame Scaler. The dark-frame corrected frames were stacked in Registax.

Comet McNaught

Considerable structure is visible in the tail and the movement of the comet against the background stars can be seen by the faint, streaked stars.

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Comet McNaught C2009/R1 with a Mintron

An 80mm f/5 refractor was mounted on a Merlin Altazimuth Autotracking mount with a 1/2" inch chip Mintron fitted with a light pollution filter and an IR/UV cut filter. Comet McNaught was recorded on DVD at high quality for 15min and dark frame data were also recorded.

Comet McNaught C2009/R1

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M57 with Mono and Colour Mintrons and an 11" SCT

I used a half inch chip Monochrome MTV-22S85HC-EX Mintron and a half inch chip OMEGA MTV-72S85H-EX-SW colour Mintron camera at the prime focus of an 11" f/10 SCT. The monochrome image was used as luminance and the colour image was used for chrominance and the two images were combined:

Monochrome Image:

Colour Image:

Combined Image:

The monochrome image captured fine whispy detail at the edges of the nebulae which is visible in the final combined colour image.

Image data and darkframe data were recorded at high quality to DVD. The BMP frames were then recovered from the DVD with no loss of quality using our VOB Frame Extractor software. The darkframes were scaled using our Dark Frame Scaler software. The aspect ratio of the final images was corrected to 4:3

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Solar Image with a 1/2" Chip Monochrome Mintron

A MTV-22S85HC-EX monochrome 1/2" chip Mintron camera was used with a x2 Barlow lens assembly and a H-alpha PST solar scope. Video was captured at shutter speeds to reveal the disk and also to reveal the prominences.
There were numbers of dark filaments as well as some prominences:

The two levels of exposure were combined and the image was colourised to indicate the colour of H-alpha light

Saturn with an Omega 1/2 inch chip colour Mintron video camera

An unexpected clear spell between the clouds allowed an attempt at imaging Saturn.
An OMEGA 1/2" chip colour Mintron was used with a Skymax 127 with the lens assembly of a Skywatcher x2 Barlow (approx 1.5x) and a Revelation 2.5 Barlow produced this image from 2000 captured frames:


Steve Wainwright

RGB images with a monochrome Mintron and a 6" f/5 achromatic refractor

A 6" F/5 Achromatic refractor was mounted on an EQ3-2 polar aligned mount. DVD was captured with red, green and blue filters at each of 256, 64 and 32 frame accumulations. The Mintron 22S85HC-EX 1/2" chip, frame-accumulating video camera also had stacked light pollution and UV/IR cut filters. Opticstar RGB filters and a manual filter wheel were used.

The different images for each colour channel and each level of frame accumulation were stacked in Registax. Then the colour channels were combined using Andrew Sprott's CAP (Colour Alignment Processor) to produce a colour image for each level of frame accumulation which was then processed for levels in the Gimp. Finally the three images for each level of frame accumulation were registered and combined in Andrew Sprott's FIC (Flexible Image Combine) to reveal all parts of the nebula. The Aspect ratio of the image was corrected in the Gimp and the final image was resized down a little.
M42/M43 RGB image

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RGB Colour Imaging with a Monochrome Mintron

I had some help with our first experiments on RGB imaging with an MTV-22S85HC-EX monochrome 1/2" chip Mintron. Wayne Jones of the Swansea Astronomical Society used his 130mm F:900mm Newtonian on a driven equatorial mount. He used Red Green and Blue simple colour filters that are not designated for RGB imaging but which have good characteristics of filtering out the other colours.

The technique he used was to place the Mintron back in the focuser in exactly the same orientation after each filter change. This was essential because there was not enough in focus on the scope to use a filter wheel. He has devised an ingenious way of doing this.

AVIs were captured at different levels of frame accumulation for each filter. The unique frames were extracted from the AVIs using VOB Frame extractor which will work on AVI containers as well as DVD VOB files. The frames were stacked in Registax and the different 'exposures' registered and combined in Flexible Image Combine, which computes a weighted average of the frames used. The resulting monochrome images taken through Red Green and Blue filters were registered and combined into an RGB image in CAP (Colour Alignment Processor). The final image was adjusted for levels, colour balance and saturation in The Gimp image processor.

This is the result obtained by Wayne on March 4th; an RGB image of M42:

I used a Skymax 127 on an equatorial mount with a Kson manual filter wheel.

The Red and Green filters were Opticstar Imaging filters and the blue filter was a Kson filter, somewhat darker than the Opticstar one. With hindsite, maybe this was a mistake. 15 minutes of DVD were recorded with each filter and 10 minutes without a filter. However, for all of the video, a Skywatcher light pollution filter was on the nosepiece of the MTV-22S85HC-EX 1/2" chip monochrome Mintron.
The unique frames were extracted from the DVD VOB files and were stacked in Registax.
The resulting monochrome images were registered and combined as RGB colour layers in the CAP software. The final image was adjusted for levels, colour balance and saturation in The Gimp image processing software.

RGB image of the trapezium area of M42

This was the Luminance image

The RGB image produced above was registered and combined with the Luminance image in FIC (Flexible Image combine) weighted averaging software to produce the LRGB image below. The RGB image was given a weight of 6 with the Luminance image having a weight of 1.

LRGB image of the trapezium area of M42

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New 1/2" colour Deep-Sky Mintron for 2010

The new 1/2" chip colour Deep-Sky Mintron, the 72S85HP-EX-SW OMEGA has wider fileds of view, better colour fidelity and lower amp glow than the previous incredible 1/3" Helix version. This camera was launched at Astrofest.

M82 with the new 1/2" chip colour 72S85HP-EX-SW OMEGA Mintron with a 10" f/4.8 Newtonian

The Cat's eye Nebula with a 10" f/4.8 Newtonian and a x2 Barlow

The previous post in December 2009 gave the proving results for this camera.

Extracting unique Frames from DVD recordings

The Vob file extractor software as described in my December 2009 article in Astronomy Now can be freely downloaded here.

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Advances in colour Mintron deep-sky imaging

The Shape of things to come.

I am working on a new colour Mintron camera with Mintron Enterprise Co., Ltd. and have some preliminary results to show. This is the 72S85H-EX-SW-OMEGA colour 1/2" chip, deep-sky Super Wide field, low amp-glow Mintron frame-accumulating video camera..
I have tested this experimental camera with a variety of telescopes and present some results here:

M42/3 with an f/5 130mm Celestron Nextstar SLT Newtonian.



M42/3 with an f/5 Kson 80mm apochromatic refractor

In both cases the image was made by combining three images: one exposed for the outer, fainter nebulosity (256 frame accumulation), a second exposed to an intermediate level (64 frame accumulation) for the nebulosity immediately surrounding the central, trapezium area, and a third exposed for the central, bright, trapezium part of the nebula (8 frames accumulation).

M43 with an f/4.8 10" newtonian



The Flame nebula in Orion with an f/4.8 10" Newtonian



The Running Man nebula in Orion with an f/4.8 10" Newtonian


The blue reflection nebula has shown up quite well in the final image.


M1 The Crab nebula with a 10" f/4.8 Newtonian and a 0.5 focal reducer

M13 with a 10" f/4.8 Newtonian and a 0.5 focal reducer

M57 with a 10" f/4.8 Newtonian and a 0.5 focal reducer

M27 with a 10" f/4.8 Newtonian and a o.5 focal reducer

Telescope Planet Mintrons

Remember that a monochrome camera is always going to be much more sensitive than a colour camera.
To obtain satisfactory colour images you must have a fast scope, and the bigger the aperture the better.



Dont forget to click on 'Older Posts' or 'Newer posts' below or browse the 'blog archive' on the left, or click on 2009 to see all of the posts for this year on one page.