The Guardian's chief photographer Ken Mears picks his favourite pictures of the week.

Picture one: A qualified mental health cut off his hair to raise awareness of an incurable degenerative disease.

Frank Brennan, a former dementia nurse at Whipps Cross Hospital has been sporting the same hairstyle for 30 years but all this changed when he cut off his 30in locks to raise money for the Alzheimer's Society.

It is a lively shot of the subject proudly showing off his locks before they are cut off. Read the full story here.

Picture two: A boy who has spent half his life battling cancer is to donate dozens of gifts and thousands of pounds to two children's wards.

Seven-year-old Robert Blackbourn, of Meadow Close in Chingford, is finally on the road to recovery after undergoing 40 months of chemotherapy.

This is a nicely composed picture of brave Robert capturing his vitality. Read the full story here.

Picture three: Firefighters tackling a blaze at a house in Brunel Road Woodford Green which threatened other properties

Up to 30 firefigthers were called to Brunel Road, Woodford Green, on the border of Chigwell, on Tuesday afternoon following reports of an entire home engulfed in flames.

Mark Soanes took a number of strong images from the scene but this one particularly captures the breaking news story with the firefighter battling the blaze, the debris on the street, billowing smoke engulfing the houses and the almost surreal partial sight of wooden garden fence and street lamp. Read the full story and see a video here

Picture four: Families have taken part in a nature hunt in search of all types of bugs and insects.

The Big Bug Hunt, at Lloyd Park in Forest Road, Walthamstow, saw dozens of children scour the bushes, trees and grassland areas of the park as they captured slugs, bees, snails and millipedes.

This is a creative and imaginitive composition showing a boy's fascination with a snail. looking through a magnifying glass at some bugs. Read the full story here

Picture five: Children showed off their horse riding skills at an equestrian centre this Bank Holiday.

Young jockeys at the Lee Valley Riding Centre took part in jumping and showing in front of audiences who gathered to watch them in Leyton, on Monday. Entrants as young as five impressed the crowds before rosettes were handed to the winning riders.

This is a lovely shot of a proud lad with his show jumping trophy. He has the air and demeanour of an adult, which is emphasised by his outfit. Read the full story here.