In this article you can read how to use PREVIEW tab in PLAY software to set your camera and start image acquisition. Please note: PLAY is designed to support cameras provided with ASCOM drivers designed for ASCOM Platform at least 6.5. If you have a camera released prior to ASCOM 6.5 or if your camera comes with an older ASCOM driver, it may not connect to PLAY or it may not show the picture after connection. Please check you’re using the latest ASCOM driver available for your camera. In the PREVIEW tab you can find all your camera settings, see the picture recorded from the connected camera, move your mount, move your focuser and start a sequence acquisition. On the left column you can see all your camera settings.
- Expo (s): this is the exposition time of your image, in seconds. We suggest you to increase the exposition time in order to improve visibility of your target but here you will have to test different exposition times since you will have to set the longest time as allowed by your telescope and mount (the trick here is to set a long time but also that still allow you to see point shaped stars).
- Gain: this is the gain setting as accepter by the ASCOM driver of your camera. You can check your camera manufacturer user manual in order to check the suggested values.
- Shots: this is the number of pictures you want to record. Usually recording a set of images allow you to stack them by using dedicated astrophotography processing softwares and improve target visibility. Usually a good sequence is composed at least by 30-40 pictures of the same object.
- Delay (s): this is the delay time between consecutive pictures.
- Temp (°C): this is the cooling temperature your camera sensor will be set during sequence acquisition. Usually the lower this value, the lower electronic noise you will have in your pictures but this is limited by the cooling capability of your camera. For example, if your camera cooling system provides you a cooling capability of -30°C in respect to the ambient temperature, and you’re making astrophotography at an ambient temperature at around 10°C, you can’t expect to be able to set a “Temp (°C)” value lower than -20°C (10°C minus -30°C = -20°C) since your camera cooling system is not able to reduce sensor temperature even more. Please also note that by reducing cooling temperature value you increase also power consumption.
- Binning: this is the binning settings. Usually Binning 4×4 is used to have a preview on object position in the image, to you can better frame it and (if you have) rotate ARCO in order to obtain a perfect framing for your telescope. Binning 4×4 will also improve the speed of pictures showed on the screen since images have 16-times lower resolution. Binning 1×1 can be used instead for focusing and to record the final picture.
- Live view: this option set PLAY to repeat preview image until you stop it. This is useful when you are framing the target object (at binning 4×4) or when you’re focusing (at binning 1×1).
If you press the “PREVIEW” button, camera will collect image (or images) based on the settings you previously selected and the picture will be shown on the screen.
Thanks to the on-screen controls, you can make a final control on your framed object and on the focus:
- move your mount by using the NSWE buttons and select one of the moving speeds by using the controls in the lower-left part of the image.
- zoom-in or zoom-out the preview picture by using the controls in the lower-centre part of the image. You can also reset the preview view by using the central button.
- move your focuser by inserting a step number you want to use and press the < or > buttons to move the focuser by the number you entered. Press the << or >> buttons to move the focuser by 10 times the number you entered.
In the lower part of the screen you can also set the histogram stretching, here you will see a slider with 2 points. W refers to the white level and B refers to the black level. You can move the W slider to the left in order to increase lightness and you can move the B slider to the right in order to darken the sky background: both are useful in order to improve object visibility on your screen. Please note that the histogram modification doesn’t affect recorded images and it’s useful to help you and better identify your target.
When you’re happy with the acquisition settings and the object framing, you can press the large PLAY button in the lower-right part of PLAY window and you will see a new popup window that asks for confirmation of your acquisition settings. Press OK to start the sequence acquisition.
During acquisition, if you want to stop the sequence you can press the large STOP button in the in the lower-right part of PLAY window and you will see a new popup window that asks for confirmation. If you press the OK button to stop sequence acquisition, based on the time of your sequence acquisition, you will need to wait until the end of the actual picture before the sequence will be stopped.
Pictures are saved in FITS format in the directory you selected in the camera configurator. Default directory is:
FITS is the format commonly used in astrophotography in order to have the maximum image quality and allow the best flexibility in astrophotography processing. Then you will have to use a dedicated astrophotography software i order to process your images sequence and get your final picture.