It is the first time I tried it in PS, which I thought was rather complicated. Does anyone have a link to an easier one? The problem is that my PS is 2018/19 and some of the functions are a bit different than in the older tutorials.
I find just using the quick selection tool on the section you want to leave in colour and then click on select, inverse and then go to image adjustments black and white. This is using Photoshop CC and if you are using Elements the process might be slightly different but you get the idea.
oooh interesting replies - I've always converted to bw then used the history brush to bring back the coloured areas I want. so many ways to achieve it!
I use Ipiccy , convert to black-and-white and then use the paintbrush as part of the effect mask to “erase” the black and white. It is more of a manual process but it works for me. What you have done here is beautiful and I especially like the red frame you have put around it
