Megastar Amitabh Bachchan is in the capital to shoot a cameo for R. Balki39s "Padman", starring Akshay Kumar and Sonam Kapoor.Akshay, Sonam and Balki have been shooting here for the film on a real life man who made sanitary pads accessible to women of his village, but Big B joined them on Saturday.In a late night blog post on Friday, the veteran actor wrote: "I work tomorrow... A shoot for R. Balki for the film he does with Akshay Kumar. A special appearance for a few minutes."Amitabh and Balki have worked together in films like "Cheeni Kum", "Paa", "Shamitabh" and he also featured in cameos for the director39s other projects "English Vinglish" and "Ki Ka".Talking about the director, Amitabh wrote: "Balki does carry his sincerity at every step of his creativity, and must have my presence in some form or another, and so here I am."The 74-year-old actor has been busy with projects -- including advertisements -- of late.He sported a heavily bearded look for an ad, and many on social media conjectured it may be his get up for "Thugs of Hindostan". But he had later denied it."It be for an advertisement that I worked on yesterday with the affable Imtiaz Ali, director of repute, for one of the products that I endorse," he posted, even sharing some photographs of two completely different looks that he has sported.Turning a bit philosophical, Big B said: "And so goes the day and our life... Disguising our shapes and sizes... Hiding the real from the unreal... Never allowing the insides to reveal the outside... No matter what the confessions, the honest blurt outs, the compelling circumstances... there shall always be that inner that no one shall ever discover. And long may that last."