Posted 13 July 2018 - 17:40
Posted 13 July 2018 - 20:49
In my experience, visible marks are usually caused by dust on the sensor of the camera. Check that your lens has no fungus or dust by opening the lens aperture and looking through it against a blank white background such as a fridge door. If it looks clear then use the sensor detection option on your camera, in the menu.
You will have to take a test shot against a plain white background using the lens aperture fully closed. If dust spots show up then get your rocket blower out or send the camera to a specialist to get the sensor cleaned. You can do it yourself if you know what you are doing. Good luck.
Posted 14 July 2018 - 08:17
Posted 16 July 2018 - 00:52
Sensor dust is close to the sensing elements, but not on the sensing elements (separated by glass thickness). Distant light coming from a wide area (wide aperture) spreads the dust shadow (imagine shadows forming from different angle, making blurry shaded area underneath each dust spot). For narrow light source, the dust shadow becomes more well defined with sharper shadow edges.
Why does the visibility of sensor dust depend on the aperture?
Another analogy is blurry shadow inside room from window light (wide light source) whereas outside in the Sun, shadows have more well defined edges.
Edited by jmahto, 16 July 2018 - 00:56.
- Exodies said thank you to this
"There are always two people in every picture: the photographer and the viewer." - Ansel Adams
Posted 16 July 2018 - 06:40