Long Exposure Noise Reduction causes a dark exposure with the shutter closed under some circumstances. The resulting dark frame is substracted from the photo. At high ISO, a larger number of averaged darkframes (master frame) substracted from a photo gives better results than a single dark frame.
1) The thermal noise is dependent on shutter speed, ISO and sensor temperature. Three variables make up a lot of combinations and a series of 50 to 100 dark frames for each combo make a lot of dark frames ;D
How temperature / shutter speed sensitive are the dark frames? Would it be noticable if the substracted dark frame temperature would be 2 - 4 degrees Celcius off from the actual photo temperature? What about the shutter speed?
2) with LENR = ON, the camera takes a dark frame with the shutter closed. It would be quite convenient if you can do this manually and write the resulting CR2 to the SD card. It also saves on shutter actuations. Is there a way (e.g. hack) to do this? Maybe via usb and some remote control or a special piece of firmware that can be installed?
1) The thermal noise is dependent on shutter speed, ISO and sensor temperature. Three variables make up a lot of combinations and a series of 50 to 100 dark frames for each combo make a lot of dark frames ;D
How temperature / shutter speed sensitive are the dark frames? Would it be noticable if the substracted dark frame temperature would be 2 - 4 degrees Celcius off from the actual photo temperature? What about the shutter speed?
2) with LENR = ON, the camera takes a dark frame with the shutter closed. It would be quite convenient if you can do this manually and write the resulting CR2 to the SD card. It also saves on shutter actuations. Is there a way (e.g. hack) to do this? Maybe via usb and some remote control or a special piece of firmware that can be installed?
