Handbook for SXV-M5C Issue 1 August 2004 Starlight Xpress Ltd SXV-M5C CCD camera user manual Thank you for purchasing a Starlight Xpress CCD camera. We hope that you will be very satisfied with the results. The SXV-M5C is a medium-resolution cooled CCD camera, especially designed for colour astronomical imaging. The SXV-M5C uses a Sony SuperHAD CCD, with 500 x 582 pixels in a 4.9mm x 3.65mm active area.
Handbook for SXV-M5C Issue 1 August 2004 ‘Quick Starting’ your SXV-M5C system In the shipping container you will find the following items: 1) 2) 3) 4) 5) 6) The SXV-M5C camera head. A power supply module. A 3 metre USB camera cable. An adaptor for 1.25” drawtubes. A CD with the ‘SXV_M5’ software. This manual. You will also need a PC computer with Windows 98SE, Windows 2000 or Windows XP. This machine must have at least one USB port (ideally USB2.0) and at least 64 Megs of memory.
Handbook for SXV-M5C Issue 1 August 2004 Connect the miniature 4 way power plug to the socket on the rear of the camera and screw the retaining ring into place. The LED on the rear of the camera will light a dim yellow. The other connections should not be attached until after the software has been installed. Installing the software: Switch on the computer and allow it to ‘boot up’. Once you have the system ready to run, insert the program disk into your CD drive and select ‘Setup.
Handbook for SXV-M5C Issue 1 August 2004 You now need to set up the camera control defaults (shown above), as follows: Start SXV-M5C by clicking on the icon and select the ‘File’ menu. Now select ‘Set program defaults’ and a window, which contains the various software settings, will appear.
Handbook for SXV-M5C Issue 1 August 2004 2) Create a ‘Pin hole’ lens by sticking a sheet of aluminium baking foil over the end of the 1.25” adaptor and pricking its centre with a small pin. If you use a normal lens, then stop it down to the smallest aperture number possible (usually F22) as this will minimise focus problems and keep the light level reasonable for daytime testing. The pin hole needs no such adjustments and will work immediately, although somewhat fuzzily.
Handbook for SXV-M5C Issue 1 August 2004 Point the camera + lens or pinhole towards a well-lit and clearly defined object some distance away. Now click on the camera icon in the toolbar of the SXV-M5C software and the camera control panel will appear (see above). Select an exposure time of 0.1 seconds and press ‘Take photo’. After the exposure and download have completed (between 1 and 3 seconds) an image of some kind will appear on the computer monitor.
Handbook for SXV-M5C Issue 1 August 2004 seconds. Restart the camera software and see if it can link now. If not, check in Windows device manager (via ‘System’ in ‘Control Panel’) and see if the BlockIO device is installed properly. 3) If you cannot find any way of making the camera work, please try using it with another computer. This will confirm that the camera is OK, or otherwise, and you can then decide how to proceed.
Handbook for SXV-M5C Issue 1 August 2004 In some cases, there may be a difference in colour bias between the faintest and brightest objects. When this happens, first reduce the error of the faint detail, using the ‘START’ sliders, and then correct the bright objects by using the ‘MAX’ sliders. The ‘MAX’ slider allows you to vary the ‘slope’ of the transfer curve and so change the way that the balance alters from faint to bright detail.
Handbook for SXV-M5C Issue 1 August 2004 Your first image may now be reasonably good, but it is unlikely to be as clear and sharp as it could be. Improved focusing and exposure selection may correct these shortcomings, and you may like to try them before applying any image enhancement with the software. However, there will come a point when you say, “That’s the best that I can get” and you will want to experiment with various filters and contrast operations.
Handbook for SXV-M5C Issue 1 August 2004 When the par-focal eyepiece is fitted into the telescope drawtube, you can adjust the focus until the view is sharply defined and the object of interest is close to the field centre. On removing the eyepiece and fitting the CCD camera, the CCD will be very close to the focal plane of the telescope and should record the stars etc.
Handbook for SXV-M5C Issue 1 August 2004 Opinions vary as to the utility of flip mirrors. They are a convenient way to find and focus, but they add quite a bit of extra length between the camera and telescope. This can be very inconvenient with Newtonians, and not a lot better with SCTs, especially if the assembly is somewhat flexible.
Handbook for SXV-M5C Issue 1 August 2004 For a 200mm SCT, this is an F ratio of 844 / 200 = F4.22, which is easily achieved with the Meade converter and appropriate extension tube (as supplied with the converter). Moderate deviations from this focal length will not have a drastic effect and so any F ratio from about F3.3 to F6 will give good results. The same equation can be used to calculate the amplification required for good planetary images.
Handbook for SXV-M5C Issue 1 August 2004 value’ (the value of the brightest pixel) will also be shown in the adjacent text box and this can be used as an indication of the focus accuracy. Although the peak value is sensitive to vibration and seeing, it tends towards a maximum as the focus is optimised. Carefully adjust the focus control on your telescope until the image is as sharp as possible and the peak value reaches a maximum.
Handbook for SXV-M5C Issue 1 August 2004 take another 60 second exposure. This image will be a picture of the dark signal generated during your exposure and it should be saved with your image for use in processing the picture. The SXV-M5C generates very little dark signal and so dark frames are not essential for short exposures of less than a few minutes, but it is a good idea to record at least one for each exposure time used during an imaging session.
Handbook for SXV-M5C Issue 1 August 2004 2) The resulting image will probably look faint and dull, with a bright background due to light pollution. It is now time to process the ‘luminance’ (brightness and contrast) of the image to get the best visual appearance. First, use the ‘Normal’ contrast stretch to darken the background by setting the ‘Black’ slider just below the main peak of the histogram. Alternatively, you can use the ‘Remove Background’ option to let the software decide on the best setting.
Handbook for SXV-M5C Issue 1 August 2004 image. Strong ‘High Pass’ filters are usually not a good idea with deep sky images, as the noise will be strongly increased and dark rings will appear around the stars, but a ‘Median’ filter can remove odd speckles and a mild ‘Unsharp Mask’ (Radius 3, Power 1) will sharpen without too much increase in noise. Other things to try, include adjustment of the colour saturation and summing several images for a better signal to noise ratio.
Handbook for SXV-M5C Issue 1 August 2004 ‘Autosave’ directory. Dozens of images will be saved, but only one or two will be satisfactory for further processing. To start the Autosave process, call up the SXV Camera Interface and select the ‘Continuous Mode’ check box at the top (make sure the rest are unchecked). Now check the ‘Autosave Image’ checkbox near the bottom of the window. If you now click on ‘Take Picture’ the automatic sequence will begin and will not stop until you press a computer key.
Handbook for SXV-M5C Issue 1 August 2004 more natural look to the image, as too large a radius and power tends to outline edges with dark or bright borders. As a finishing touch, the application of a Median filter or a Weighted Mean Low Pass filter can be useful to smooth out the high frequency noise after a strong Unsharp Mask. As with deep-sky images, it is advantageous to sum planetary images together to improve the signal to noise ratio.
Handbook for SXV-M5C Issue 1 August 2004 read-out noise will become dominant. About 30 seconds is a reasonable minimum. Now go to the ‘Multiple Exposure Options’ and select a number of exposures to take. You can also select to average the images, rather than adding them, and there is a ‘Alternative Slew Mode’ available, which uses the correlation of image areas, rather than a single star. This mode can be better in dense star fields. Another option is ‘Auto remove dark frame’.
Handbook for SXV-M5C Issue 1 August 2004 across the aperture of your telescope and point the instrument high in the sky, to avoid any gradient in the light near the horizon. Now take several images with exposure times adjusted to give a bright, but not overloaded, picture. Averaging flat field together is a good way to reduce their noise contribution and so recording 4, or more, images is a good idea. To use your flat fields, they must first have a dark frame subtracted.
Handbook for SXV-M5C Issue 1 August 2004 box and cables are available as an accessory and may be chained in series with the autoguider cable, when the guider is in use, or may be used on its own. The two serial connections are in the form of standard RS232 PC style plugs and provide TX, RX and Ground connections at RS232 levels. Access is via commands sent through the USB connection and, at the time of writing, is limited to any serial controls that are provided by the SXV software.
Handbook for SXV-M5C Issue 1 August 2004 The advantages of S.T.A.R. are very great, but there are two negative aspects, which you should be aware of. The main loss is in the sensitivity of the CCD, as only half of the pixel area is integrating an image at any one time.
Handbook for SXV-M5C Issue 1 August 2004 mounts will use the guider output from the camera. Once the above connections have been made, you are ready to start up the system. Starting to guide: Power up the camera and computer, and start the telescope drive. Click on ‘Set Program Defaults’ and examine the current settings. In the ‘Telescope Guiding’ box, set the interface selection to ‘LX200’, or ‘Via Control box’ (ST4 output of camera), as appropriate.
Handbook for SXV-M5C Issue 1 August 2004 displayed image, but, if not, try increasing the exposure time a little. Remember that the ideal guide star is one that is bright enough to be easily detected in a 1 second exposure, or less. Once you have the test image and can see an appropriate guide star, go to the ‘File’ menu and click on ‘Select guide star’. Now click the mouse on the image, with the pointer on your selected star.
Handbook for SXV-M5C Issue 1 August 2004 cycle has completed, the optimum correction speeds, backlash correction and hysteresis values will have been calculated and inserted into the default boxes. Note that the pixels per second rate for the R.A. correction will vary with the cosine of the declination angle, so you may need to alter this value, or re-train the system when changing between objects at widely different declinations. Exposure times and image calibration S.T.A.R.
Handbook for SXV-M5C Issue 1 August 2004 camera, or with a separate guide telescope, rigidly mounted alongside your imaging telescope. I personally use it with an 80mm aperture F5, inexpensive refractor as a guide ‘scope, but a shorter focal length lens will make more guide stars available in any given region of sky (See the picture below). To use the autoguider, first orient it so that the connector plug is roughly parallel to the declination axis of your mount.
Handbook for SXV-M5C Issue 1 August 2004 The autoguider installed on a 80mm refractor guide ‘scope in the author’s garden To use the autoguider, please proceed as follows: 1) Having started the SXV-M5C software, open the autoguider control panel by clicking on the autoguider menu button.
Handbook for SXV-M5C Issue 1 August 2004 The autoguider control panel with a guide star selected 2) Press the ‘Start’ button and a series of 1 second exposure guider images will begin to appear in the picture frame. If the images look too dim, use the ‘Stretch Image’ slider to increase its contrast and brightness until the noise begins to be visible.
Handbook for SXV-M5C Issue 1 August 2004 5 minutes) and press the ‘Autoguide next image’ button. The autoguider window will reappear and, after a few seconds, you should see error values appearing in the text windows at the top. The guide star will be fairly close to the green cross, although not necessarily accurately centred, and you should see the power/ guide LED on the rear of the camera brighten and change colour with each correction.
Handbook for SXV-M5C Issue 1 August 2004 will be very much out of focus. However, if a powerful contrast boost of the image is carried out, they may well begin to show as the shadow ‘Do-nuts’ mentioned earlier. Images taken with a large F ratio optical system are more likely to be affected by such dirt, owing to the smaller and sharper shadows that they cast.
Handbook for SXV-M5C Issue 1 August 2004 N.B. DO NOT leave the camera switched on for long periods between uses. The cold CCD will collect ice by slow diffusion through any small leaks and this will become corrosive water on the cooler and CCD pins when the power is removed. If substantial amounts of moisture are seen on the CCD, dismantle the camera and dry it thoroughly.
Handbook for SXV-M5C Issue 1 August 2004 Dear User, Thank you for purchasing a Starlight Xpress CCD Imaging System. We are confident that you will gain much satisfaction from this equipment, but please read carefully the accompanying instruction manual to ensure that you achieve the best performance that is capable of providing. As with most sophisticated equipment a certain amount of routine maintenance is necessary to keep the equipment operating at its optimum performance.
