I can add a cautionary note to Jasmine's offer as we too have breeding spotties and in the past have had them ringed successfully but one year it was a bit late and Tony declined to ring them as there was a danger they might jump out in alarm. Apparently they are prone to premature fledging and even well meaning folk like ourselves can cause a disaster by seeming to approach too near at the wrong time.
Lenses are very disturbing as the UV coatings can be seen by the birds so best employed photographing the adults.