Starlight Xpress SXVR-H18 User Manual Download Page 11

Handbook for the SXVR-H18

Issue 1 March 2010

11

ignore flat fielding for current purposes and describe the process in detail at a later
stage.

Processing the deep-sky image:

Below you will see typical examples of a dark frame and an uncalibrated raw image
of M16.

A typical 5 minute dark frame exposure. Note the random scatter of ‘warm pixels’

A 5 minute exposure – many warm pixels are visible (see the magnified view below)

Summary of Contents for SXVR-H18

Page 1: ...CCD surface gives the greatest possible throughput of light to the pixels and the resulting QE is very good over the entire visible spectrum Our new R type USB2 interface hardware gives an exceptional...

Page 2: ...intend to view the finished images on its screen then you will also need a graphics card capable of displaying an image in a minimum of 1600 x 1200 pixels and 32 bit colour A medium specification 2 co...

Page 3: ...IOClass device and the camera software will be able to access it You can confirm that the installation is complete by checking the status of the USB devices in the Windows Device Manager see above Sta...

Page 4: ...the icon when you should see the main menu and image panel appear If this is the first time that it has been run you will receive a warning about the lack of an ini file just click on OK and then ope...

Page 5: ...you are imaging during the winter months Under indoor conditions the low airflow will limit the cooling capability and you should use a set point of no lower than 5C for stable cooling You can determi...

Page 6: ...aptor to achieve approximately the correct focal distance 2 Create a Pin hole lens by sticking a sheet of aluminium baking foil over the end of the lens adaptor and pricking its centre with a small pi...

Page 7: ...Also IR blocking filters are available from various suppliers True Technology Edmunds etc and are recommended for the best results when using a lens If you cannot record any kind of image please chec...

Page 8: ...brighten or dull the image highlights and shadows A Normal stretch is a simple linear operation where two pointers the black and white limits can be set at either side of the image histogram and used...

Page 9: ...nd select an exposure time of 1 second Press Take Picture and wait for the image to download There is a good chance that your selected star will appear somewhere within the image frame and with luck i...

Page 10: ...a few stars however there is a great deal of data hidden from view You can get to see a lot of this without affecting the image data if you go to the View menu and select Auto Contrast Stretch Image T...

Page 11: ...rocess in detail at a later stage Processing the deep sky image Below you will see typical examples of a dark frame and an uncalibrated raw image of M16 A typical 5 minute dark frame exposure Note the...

Page 12: ...curately match your darks to the light image If you average many dark frames together to create a master dark the readout noise will be much reduced by the square root of the number of averaged darks...

Page 13: ...are at the time of writing but Maxim DL can use this method The basic procedure is to capture a long exposure dark frame and then slice off all values below a threshold level which is selected so as t...

Page 14: ...to noise ratio Summing can be done in the Merge menu and involves loading the first finished image selecting a reference point a star then loading the second image and finding the same star with the...

Page 15: ...much better for this However lunar imaging is a different matter and the H18 can give impressive whole moon pictures Most deep sky objects are faint and relatively large so a long exposure is needed...

Page 16: ...conditions If you have exceptionally good conditions then a reduction to R 3 P 3 will probably give a more natural look to the image as too large a radius and power tends to outline edges with dark o...

Page 17: ...really do need to use a flat field for image correction then it must be taken with care It is most important that the optical system MUST NOT be disturbed between taking your original images and takin...

Page 18: ...des 4 active low opto isolator outputs and a common return line capable of sinking a minimum of 5mA per output This socket may be used for telescope control if the SXVR H18 is employed as an autoguide...

Page 19: ...declination axis of your mount This is not absolutely essential as the training routine will learn the angle of the head and compensate for it but it is easier to understand the motion of the guide st...

Page 20: ...on a 80mm refractor guide scope in the author s garden To use the autoguider please proceed as follows 1 Having started the SXVR H18 software open the autoguider control panel by clicking on the autog...

Page 21: ...scope and mount You have the option of manually selecting values or asking the software to attempt to determine what they should be This is done by pressing the Train button and waiting for the softwa...

Page 22: ...sation Removing Dust 1 Dust can be deposited on either the optical window not a big problem to cure or on the CCD faceplate difficult to eliminate entirely When small particles collect on the window t...

Page 23: ...disturbed renew it with fresh compound before reassembling 7 Replace all the camera parts in reverse order and the job is done Dealing with condensation The SXVR H18 is designed to avoid condensation...

Page 24: ...the CCD surface To make an adjustment slacken the appropriate set screw and then turn the adjacent cap head screw in the required direction Complete the adjustment by re tightening the set screw Avoi...

Page 25: ...ly be used for normal purposes described in the standard operating instructions and within the relevant safety standards of the country where the equipment is used 2 Repairs under guarantee will be fr...

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