Higher Noise in Sunrise shooting

Question

I am beginner in photography and tried first hand on shooting sunrise, though i am not satisfied with my results of first shoot. and left with some questions, it would be nice if you can answer that will help me improvise my skills. see the images here, i shoot with Nikon D3300 & 35mm F/1.8 prime lens.

Questions:

1. There is visibly higher noise, even at ISO-100. i expect lower noise at iso 100, can someone explain what i did wrong here? is it camera or lens or i did not expose properly, or something else?

2. What while balance i should use to get reddish sun?

3. What metering i should use? is spot metering & spot on sun should help?

Thanks in advance.

Answer 1

Noise is only peripherally about ISO. What really determines noise is the Signal-to-Noise Ratio. The reason we assume high ISO is noisier is because we normally use high ISO when the signal (the amount of light falling on the sensor) is weak. But shooting at high ISO when there is plenty of light in a scene will produce less noise than shooting at low ISO when there is less light in the scene unless we increase the amount of light collected by the sensor by exposing longer or increasing the size of the aperture.

In the case of your sunrise photo the culprit is the difference in brightness between the bright sun and the darker parts of the scene. There's just too wide a difference to allow you to properly expose the shadows and the sun with the same settings. One thing that will help is to expose the sun for almost saturated rather than trying to expose it for medium gray. This will allow the shadows to be exposed brighter as well and will increase the overall signal (light) in the photo without a corresponding increase in the read noise produced by the sensor.