woensdag, juni 30, 2004
Proud new owners of digital SLR cameras are discovering a problem that they were not warned about and that didn't exist with film cameras: dust on the image recording sensor.
The sensor in a typical digital SLR is overlaid with a fragile filter screen. Dust enters the camera body cavity when the lens is being changed and gets past the mirror and onto the filter surface. The first the photographer knows about its presence is when he takes a photo with a lot of clear sky in it and sees grey blobs randomly scattered over the image. That's dust.
Dirt on the sensor of a digital SLR usually comes from particles that are caught in the back cap of the lens when it is placed in one's pocket. Rubbing in the pocket, it becomes charged with static. Then, when you remove the lens and replace the back cap from your pocket, the charged particles are attracted to the back of the lens when the cap is placed on it.
"The first time you use that lens, the air pump that rotates the zoom helicoid shunts all that muck from the back of the lens through the opening void as the shutter opens - presto: dirty sensor."
Nikon Australia suggests that an essential item in any photographer's kit is a sealable plastic bag. Lens and body caps should be put into the bags and sealed when not in use. And the camera should be held upside down and with your back to the wind while lenses are changed.
Bron: LiveWire.
The sensor in a typical digital SLR is overlaid with a fragile filter screen. Dust enters the camera body cavity when the lens is being changed and gets past the mirror and onto the filter surface. The first the photographer knows about its presence is when he takes a photo with a lot of clear sky in it and sees grey blobs randomly scattered over the image. That's dust.
Dirt on the sensor of a digital SLR usually comes from particles that are caught in the back cap of the lens when it is placed in one's pocket. Rubbing in the pocket, it becomes charged with static. Then, when you remove the lens and replace the back cap from your pocket, the charged particles are attracted to the back of the lens when the cap is placed on it.
"The first time you use that lens, the air pump that rotates the zoom helicoid shunts all that muck from the back of the lens through the opening void as the shutter opens - presto: dirty sensor."
Nikon Australia suggests that an essential item in any photographer's kit is a sealable plastic bag. Lens and body caps should be put into the bags and sealed when not in use. And the camera should be held upside down and with your back to the wind while lenses are changed.
Bron: LiveWire.
# posted by Jan-Edward : 17:32
|
|