Megastar Amitabh Bachchan, who has endorsed various products, has now shot for a Maggie noodles ad and says making an effective commercial is tougher than creating a three-hour movie.

"Did a shoot for ad campaign.. Maggie Noodles. Fun, " the 69-year-old tweeted.

However, he feels it is an uphill task to make ads that can leave an impact.

"One would imagine for a 1 minute film it would be a cake walk for those that make films that last 3 hours. No.. baby! Its a tougher job! In one minute one has to convey and convince the viewer what most of us need 3 hours to do!, " the actor wrote on his blog bigb.bigadda.com.

"There is meticulous work and drawing boards done after great deliberation and approval from the clients, management of the production crew, technical departments in place, shot divisions done in advance and then the artist briefing and the takes begin, " he added.

Creativity is very important to make an ad effective and Big B says a lot of effort and research by specialised are needed to make every advertisement.

"Campaigns for products are a specialized venture. Huge number of professionals get behind research and development, design and execution, writing the catch lines that would attract and eventually finding the appropriate talent to deliver the goods, " the actor wrote on his blog.

The actor has endorsed brands like BPL, ICICI, Parker Pens, Maruti Versa, Pepsi, Reid & Taylor, Nerolac Paints, and Dabur.