This object can help you in taking photos where there is too much light. The function of an umbrella is to block excess light, resulting in low contrast.
EOS 5D Mark IV/ EF100-400mm f/4.5-5.6L IS II USM/ FL: 124mm/ Aperture-priority AE (f/11, 1/125 sec, EV±0)/ ISO 100/ WB: Daylight, Photo by Toshiki Nakanishi
Source : https://snapshot.canon-asia.com
In the picture above you can see how to use an umbrella. You can adjust the composition and position of the image first, then place the umbrella in front of the camera and press the shutter button. To give the effect of light rays flowing downwards, move the sun as far away from the frame as possible so that only the rays are visible.
2. Black cloth
You can use this cloth in shooting fireworks. If you use long exposure when photographing fireworks, the shape of the fireworks is usually not captured on camera. You can try this technique, namely by covering the lens opening with a cloth and you only capture the desired lighting.
EOS 5D Mark II/ EF24-105mm f/4L IS USM / FL: 24mm/ Manual exposure (f/22, 12 sec)/ ISO 50/ WB: 3,000K,
Photo by Gensaku Izumiya
You can use black cloth as shown in the picture. With the shutter window still open, and you want to photograph the shape of the fireworks being launched, you can open the cloth. If so, you can close the cloth again. And so on. But remember to open the cloth very carefully so that the camera doesn't shake and the results are blurry.
Good luck!