Built a sun spotter5/5/2023 ![]() Table 1 lists a selection of good monochrome webcams used by solar imagers at the time of going to press. It is possible to image the Sun with a DSLR but it depends on the chip present in the camera and its software but it is still not as easy to achieve a good image as with a webcam. This automatically concludes choosing a webcam type camera and not a DSLR. In conclusion the best camera for solar imaging would be a camera with a high frame rate capable of taking many frames together in a short video sequence, a monochrome CCD chip and capable of recording in 16 bit. Also the dynamic range obtained from some CMOS chips can be generally lower than a CCD chip although the most recent CMOS chips on the market are very much improved particularly the Sony IMX174 CMOS chip which is fast becoming the solar imager’s chip of choice. Generally most solar imagers prefer CCD chips, this is because some CMOS chips can introduce a strange fixed pattern noise when the image is being sharpened after stacking. Using 16 bit increases the dynamic range of the resulting image.įinally the next choice is whether to use a CCD or a CMOS chip. When recording in monochrome (greyscale) it is desirable to record at 16 bit which is equal to 65,536 shades of grey if using 8 bit then the image will only be recorded with a scale of 256 shades of grey. The next question is whether to record at 8 bit or 16 bit. Therefore, using a monochrome camera will allow every pixel to be utilised increasing resolution and sensitivity. If imaging in Hydrogen alpha then only one pixel in 4 on the chip will be excited with light meaning the resolution will be reduced by a quarter. Colour CCD chips use a Bayer matrix where each square of 4 pixels has one blue, one red and two green. If a colour camera is used for narrowband imaging then ultimately resolution will be lost. This is true for Hydrogen alpha (red) and Calcium II K (violet) filters, however even when viewing in white light it is common to use a narrowband green Continuum filter. Most solar filters allow the viewer to see the Sun in a single very narrow wavelength of light. The next consideration is whether to choose colour or monochrome. ![]() Taking more captures will increase the probability of getting one frame during clear seeing and if a camera can take a higher number of frames per second then the chances of getting this lucky one frame is increased further. To overcome this, a camera is needed that can take very fast millisecond exposures and take a lot of them in a short burst. Unlike at night, the Sun is causing local heating of the ground and surrounding buildings, these air currents can change in fractions of a second. Instead of needing to take very accurately tracked long exposures, the Sun requires millisecond exposures and therefore accurate tracking is not entirely necessarily.Īnother consideration is seeing conditions during the daytime. Imaging the Sun requires a very different approach to deep sky astrophotography. ![]() Whether you become a serious imager for data submission or just want a personal record of daily solar activity it is important to have the right equipment to hand and to be able to get the most out of it.ĭeciding what camera to buy and use for solar imaging can be a baffling experience. Being prepared and able to accurately record a flare or a prominence lift off for instance can be a very rewarding challenge and can become very valuable data when submitted to the various astronomical associations and data collection sites. Many times an amateur astronomer has been the first to discover a new event but even if it isn’t a rare event it is important to you. Not only will this give you a lasting memory of the event but also it can become an important scientific record. ![]() You look through your telescope eyepiece and there in front of you is the most wonderful sight, you know immediately you must capture this moment forever. ![]()
0 Comments
Leave a Reply. |