I get this spot in my images, on Sony A7III
shot data: 0,8" second, F/36, ISO3200. Focused at closest point.
Full Frame:
Frame crop:
As seen here, the spot is caused by dirt on the sensor:
I tried internal autocleaning, then using an air blower w/ camera pointing downwards, but it's been useless. What kind of dirt causes this particular spot? And what cleaning technique would be the appropiate for it?
With any mirrorless camera that does no close the shutter on lens changes, you will end up having dirt on your sensor occasionally. While I cannot say, what kind of dirt you have there, I would guess it to be a little piece of skin flake as it seems to be translucent.
Hold your cam and lens mount downward, when changing lenses, so that any dirt rather falls out of the cam
Check your sensor periodically for dust with an illuminated magnifier.
Always keep either a lens or lens cap on the camera body.
If you see something, it is almost always too late for the in-camera vibration method. Then remove lens, hold mount downwards and use an air blower.
If that does not help, try a lens brush, then blower.
If that does not work, use a speck grabber (a kind of stick with some sticky gel on one side). With that you just collect the speck and then transfer it to some sticky material which came with the stick. Note: Some people do not trust these, I succeeded in keeping my sensor clean until now using them.
If that does not work, you need to use a moist sensor swab on it. Note: The sensor itself is under a layer of glass, so you cannot damage anything unless you are really reckless or use way too much cleaning fluid.
