Once a in a while a piece of software comes along that blows you away, well Topaz Denoise AI plugin for Photoshop or as a standalone just does that. Take a look at the screenshot below of takahe from North Island New Zealand, before on the left after Denoise on the right. This photo was taken on a really wet cloudy day in dark forest at ISO 1600 on a Nikon D7000 1/500 at F8 with a Sigma 50-500 mm lens and a North Island Kaka same settings. The processed image has no noise at all and I can still sharpen or resize it after - Amazing highly recomended!
Topaz Denoise AI - Here