I am using LR 5. Is there a way to apply settings to images upon import? For example, I want to set noise reduction to X if an imported image has a ISO setting between 1000 to 1250, from camera A with lens B. Right now I am applying the changes manually by using the metadata filter, but it will be great if the same settings can be applied upon import (to save time)
You can create presets that reduce the noise and other settings thing you want, and then you can choose to apply that preset on import. However, that will apply the preset to every image that is imported in that session. Your other alternative would be to create camera defaults and make them ISO-specific. To do that, you would go to your Lightroom Preferences, presets tab, and make the appropriate choices. Then, make your adjustments and save as many camera defaults as you want and different ISO settings.
To set detail settings based on ISO, it's best to use a plugin (in my opinion), otherwise you have to mastermind which ISO's your camera is capable of having, and save a default for each, then if you want to change you have to go through the process again.
Some cameras can have dozens of different auto-ISO values, and it's best if you don't skip any of them.. granted it's not so bad if you never shoot auto-ISO .
* ISO Detailer (author: me), or
* Bulk Develop (author: Jeffrey Friedl)
instead - both plugins are essentially free.