Thanks Tanveer,Hot pixels will depend on ambient temperature. Some cameras have "Long exposure NR". This option takes a "dark frame" after finishing your exposure.
So camera will take a 300 second exposure after your 300 second bulb exposure and subtract the 300 second dark exposure. This will give cleaner image, but can double your actual exposure time
2. Point your focus point to the object, half press shutter when in AF mode. After camera locks focus, simple release shutter button without taking picture, and then flick switch to MF
I understand that it does takes the dark frame and then subtracts the noise'd/hot pixel area. Is there any other way to do it, rather than using the Long Exposure NR. I mean to get it right without adding on the extra exposure time and relying on the camera NR?
I guess, I sort of confused you with my second question. What I wanted to ask was the immediate glare, an object's reflection that is visible through the glass when seeing through the viewfinder. It is analogous to viewing a glowing bulb through your spectacles (especially with cylinders and a power of positive diopter) when actually two objects are visible sometimes, rather than one. The other one is just the reflection/refraction of the actual subject.
Will the CPL help? But it would be useless during night.