[avandonk]

I have found with bitter long experience that for very dim and faint objects that are just above noise levels NOTHING beats ICNR!

There are a few reasons for this.

1. The camera sensor will heat up during a long exposure by a few degrees from its idle temperature. Even the idle temperature is higher than the 'off ' temperature and the 'off' temperature most closely approximates ambient.
If you take a series of exposures using ICNR the first image will have darker 'holes' due to the sensor heating up during the light exposure. The situation gets worse if the ambient temperature is dropping.

2. Neither amp glow nor noise is completely removed by dark subtraction as it is impossible to know what temperature your sensor was actually at. The only dark that comes close is the dark taken immediately after the light and even then it is the second exposure where all temperatures have settled to a quasi equilibrium. If the ambient temperature is dropping the rate of temperature change will control the residual noise even with ICNR.

The only thing that really works is ICNR.

The only way to beat this is to have a constant ambient temperature. The fridge I am working on will be thermostatically controlled and then I will start using darks as I can "set" the ambient temperature.

Bert