## 4 Results and Discussion  
The dark current noise of the sensor that came out was very high in the long exposure frame that was taken without the on-sensor dark current technology [15; 16]. Dark current is a steady accumulation of charge with time due to heat that moves electrons in the pixel. Figure 21: Teeth gear to slow down the RPM. Figure 20: Working model of a Barn Door Tracker, a self-made tracker setup. Higher temperatures move more electrons, and dark current goes up. It is typically around one electron or less per second, so we do not see problems from dark current with short exposures. Subsequently, when the on-sensor dark current technology was used, a much cleaner image without the sensor heat noise was obtained, and the results are shown in Figure 22.  
Samples taken with the process discussed are attached in Figure 23a-e. These photos were captured in the middle of the populated city of Ranchi, Jharkhand, with a light pollution of Bortle 5.5. The experiment was carried out during a rare, dark, starry night sky with no clouds in such high light pollution. These are a stack of 600 light frames, each of 5-s exposure, 30 dark frames, 30 bias frames, and 50 flat frames. The images of the Orion Nebula and Scorpius constellation were taken in the open air, in the light pollution of Bortle class 5, brightness = 1.27 \(\mathrm{mcd}/\mathrm{m}^{2}\), artif. brightness = 1100 \(\mathrm{ucd}/\mathrm{m}^{2}\), in an uncontrolled environment (in terms of wind speed and temperature). The artificial sky brightness levels are those used in the legend and indicate the following: up to 1% above the natural light (black); from 1 to 8% above the natural light (blue); from 8 to 50% above natural nighttime brightness (green); from 50% above natural to the level of light under which the Milky Way is no longer visible (yellow); from Milky Way loss to estimated cone stimulation (red); and very high nighttime light intensities, with no dark adaption for human eyes (white). To avoid taking any exposures that would cause any significant change in the temperature of the camera body to avoid photon noise/shot noise, we limited our exposure time of individual frames to 6 s, as compared to the 30 min of single exposure performed in the previous study. The low amount of noise that still made it into the image was easily removed through the process of stacking. Hence, the influence of temperature was negligible. The temperature of the sensor, however, was maintained at 16 degrees Celsius at the time of recording via external cooling fans to minimize the thermal noise even further. A total of 500 lights, 50 darks, 30 bias, and 30 flat frames were recorded, all at the same temperature, at an ISO gain of 160. Even the dim Orion Nebula and Flame Nebula are visible through this process. Figure 22: Technology samples (a6100) (**a**) without sensor and (**b**) with on-sensor. Figure 23: (a) Orion molecular complex 16-bit flat RGB image; (b) Orion molecular complex 8-bit enhanced color-graded image; (c) Orion Nebula flat 16-bit RGB image (d); Flame Nebula flat 16-bit RGB image; (e) Scorpius constellation down-sampled 8-bit RGB image. We attempted a study to quantitatively compare the brightness of astronomical objects in question to the glow of the human body. This way, we would get a better idea of how much longer the total exposure of the latter needs to be as compared to the astronomical objects. We attempted this by studying four different metrics for each application, namely: lumens, lux, candela, and luminance. However, this study had several practical constraints that pushed us to pursue a different route. It was difficult to find the lumens value of the exact portion of the night sky in question. Even if we did manage to find the values for all the objects we were recording, it would be of close to no use for the following reason: the observable night sky is constantly changing.