Sunday, 28 June 2015

UTC control for the Samsung

UTC (Up The Coaxial) control is possible for the Samsung SDC-435 and SCB-2000 which can be controlled remotely using the hand controller. This is an advantage when using the camera with a telescope, particularly when using a less robust tripod, such as those supplied with low cost AZ GOTO systems.

The Samsung SDC-435 being controlled by the UTC hand controller

UTC hand controllers can be quite expensive. However, it is possible to buy really cheap controllers on Amazon. I paid about £8 for the controller shown which allows full control of the camera without having to touch the buttons on the back of the camera.

The next experiments will be with a low cost AZ GOTO system using the UTC controller.

Click on Older Posts to see more of this blog

Tuesday, 23 June 2015

35% waxing, crescent Moon with a monochrome CMOS USB camera

An Opticstar PL-130M monochrome, USB CMOS camera was placed at the prime focus of a 127 mm Maksutov and six, 500 frame AVIs were captured of overlapping areas of the 35% waxing, crescent Moon. The AVIs were stacked and wavelet processed in Registax 5 and they were combined into a single image in Photoshop.

Please use the scroll bars to see the whole image

Click on 'Older Posts' to see more of this blog

Thursday, 18 June 2015

Solar imaging with an Opticstar PL-130M monochrome CMOS camera in H-alpha light

The Opticstar PL-130M monochrome CMOS camera is a relatively low cost USB Imaging device that is marketed as a solar system camera and auto-guiding camera. It is very sensitive and I used a ND13 neutral density filter as well as an IR/UV cut filter and placed the camera at the prime focus of a Solarmax ll 60 BF15 H-alpha scope. (If a PST is to be used, then a Barlow lens should be screwed onto the nose-piece, as the scope doesn't have enough back focus). Two 1500 frame AVIs were captured at 8fps using SharpCap 2.5; one exposed for the disk and the other exposed for the prominences. The two AVIs were stacked in Registax 5 and the two resulting images were combined and colourised in Photoshop:

A monochrome camera is ideal for imaging in H-alpha light, which is monochromatic light at 656.28 nm. A monochrome camera has higher spatial resolution than a colour camera. The colour is added at the end of the process for cosmetic purposes to represent the wavelength of light used for the capturing. This camera has a 1/2" monochrome 1.3 mega-pixel CMOS sensor which is large enough for the whole of the solar disk to fall on the sensor. This makes the camera suitable for whole disk imaging.

Click on Older Posts to see more of this blog

Wednesday, 17 June 2015

Testing a £2 webcam as a possible starter camera for solar system imaging

I purchased this camera from Amazon for £2
As a webcam, it is quite good and would probably give a good result for video conferencing and video chat. The reason is that it has on-board compression that allows for a smooth video transmission. Artifacts are hardly noticeable due to the motion of the video. Unfortunately, the on-board video compression cannot be disabled and that leads to problems with solar system imaging. The camera has a standard 12 mm webcam/security cam lens thread. This means that a standard webcam telescope adapter can be fitted direct with no further remounting required. The camera required no drivers and worked well with Windows 8 and with Linux Lubuntu.

For First light the camera was placed at the prime focus of a Solarmax ll 60 BF15 H-alpha scope and the Sun was imaged.

These were encouraging first light images, obtained by capturing 500 frame AVIs and stacking them in Registax 5.

The camera was then set up in an afocal configuration as this one has a standard 1/4" photographic female thread on its Base.

The camera was attached to a 127mm Maksutov with a 20mm eyepiece and two overlapping AVIs of the Moon were captured. The AVIs were stacked in Registax 5 and the resulting images combined in Photoshop. This could also have been done with the Freeware, Microsoft ICE (Image Composite Editor). The result was an encouraging image of the Moon:

The camera functioned quite well as an electronic eyepiece using the Laptop as a viewer.

The camera was then placed at the prime focus of the 127 mm Maksutov:
Again, it served quite well as an electronic eyepiece, but at this magnification, compression artifacts started to show and they were obvious in the images produced by stacking the AVIs in Registax.

The camera was also used to capture an AVI of Jupiter.

Whilst this camera can in no way be considered to be suitable for serious imaging of the solar system, it is worth it for someone wishing to make a stab at imaging without having too high expectations before they spend significant amounts of money on a more expensive imager. It is adequate as a low end electronic eyepiece. The burden of the device is the built in video compression that makes it so suitable as a video conferencing device.
I would say that if a person lacks the confidence to invest in a better device, this one will enable them to get some introductory experience that will help them to decide whether solar system imaging is for them.

Click on Older Posts to see more of this blog

Thursday, 4 June 2015

The best of both adapter worlds with the £12-80, 1000 TV lines, colour TV camera

Today, I removed the sliding IR cut/ plain glass filters from the lens holder and re-attached the lens threads to the circuit board.

There is a small spring-loaded arm activated by the brightness of the light that slides the IR cut filter in front of the sensor in bright light, and slides the plain glass filter in front of the sensor in dim light.

With both of these removed, the lens threads were then re-attached to the circuit board beneath the C/CS thread aperture:

This allows for either a webcam adapter or a C/CS adapter (1.25" OR 2") to be used with the camera.

Back view

Side view

The box with the power/signal cable

Being a colour camera, it is most suited to lunar and planetary imaging. An IR cut filter is required if a scope other than a Newtonian is used because visible and IR light come to slightly different foci and produce a soft focus if an IR cut filter isn't used with a refractor. The original IR filter can be left in place if the filter slider is disabled.

I do however, intend to remount the circuit board in a smaller, black project box to produce a neater finished camera.

Click on Older Posts to see more of this blog

Results with a £12-80, 1000 TV lines board video camera and a capture card

The mounted board camera was placed at the prime focus of a cheap 80mm refractor. The camera was fitted with a 1.25" UV/IR cut filter (without this filter the image had a very soft focus because the IR and the visible came to focus at different points). The scope was mounted on a Merlin AZ tracking mount.

The camera was connected to a 12 volt power supply and a USB capture card, which was connected to the computer.

SharpCap was used to control the output from the camera and to capture two overlapping, 1000 frame  AVIs of the 98% waning, gibbous Moon at 640 x 480 resolution. The AVIs were stacked and wavelet processed in Registax 5. The two resulting images were merged into a single image and post processed in Photoshop.

Capturing the AVIs at 640 x 480 resolution results in the images being of the correct aspect ratio.

Click on Older Posts to see more of this blog.

Tuesday, 2 June 2015

Further experiments with a £12-80, 1000 line circuit board TV camera.

Nicola Mackin's Aspect Ratio Converter can scale the image up or down during correction:
Read more about Aspect Ration conversion HERE.
Original, uncorrected image of the wrong aspect ratio:

Image scaled up during correction:

Image scaled down during correction:

Remounting the board camera in a project box.

I decided to mount the camera without any of the lens housing, and with a C/CS mount on the outside of the project box. The advantage of this is that a 2" adapter can be used if required, and the chip is unfiltered. The disadvantage is that the chip is more exposed, and with a project box that is not black, light can enter through the walls of the box. This is not usually a problem as vastly more light comes from the subject than through the box walls.
The circuit board camera

The lens assembly showing the multi-element lens and the IR cut filter at the bottom of the lens thread.
If a webcam adapter was to be used, then the square filter could be removed from the bottom of the lens thread. In either case, an IR/UV cut filter ac be attached to the adapter, if a filter is required.

Mounted board showing the sensor

A plug keeps dust off the sensor

A C/CS telescope adapter attached, with a dust cover on the front
Note that the camera case is actually grey, but the flash has made it appear to be white.

Using a two inch adapter

This camera works fine with a USB capture card, which effectively turns it into a powered USB camera.

Under Windows 8.1, this USB capture card works fine. New cards cost as little as £6 on Amazon.

Click on Older posts to see more of this blog