Beginner Noise reduction

[Roy1212]

Hi,I've started taking long exposure photos around 10 minutes and one recently 35 minutes,should I have noise reduction off as I have to wait the same length of time for it to process,will Lightroom get rid of the noise if it was off.

 

[Phil V]

Yes

 

[Roy1212]

Thank you Phil.

 

[sk66]

IMO, it depends...
The long exposure NR function is "dark frame subtraction" (which is why it takes so long). The advantage of this is that it maps/removes sensor specific issues like hot pixels, which basic color/luminance NR in LR will not do so well.

I would say that you should do some testing to determine if/when there is a benefit to you.

BTW, those are rather long exposures... there might be another way of going about it that will minimize heat buildup/noise.