Leaf problems during flowering phase

[Gav2020]

Hi all. I’m a fairly inexperienced grower and recently noticed some spotting on some of my leaves. Plant is around 3 weeks into flowering.
Any ideas what this could be and how I can put it right. Many thanks

 

[Beachwalker]

Need whole plant pic

 

[Gav2020]

Need whole plant pic

Difficult fir me to get one at the moment, but will later. Lower leaves seem to be worst.