I have been invited to ComicCon and know little about the lighting I will encounter. I know the place is cavernous, with differing types of light. From what I have found in on-line advice, there is a difference of opinion. Either use a high ISO, with a fast shutter, or reduce shutter speed and ISO, increase the aperture and use a flash. I will have family with me, so I will be able to use my flash off-camera. Since I have not been in an atmosphere like this, before, I would like to know if there is a safe, go-to method. My lens is 24-55 and the largest aperture is 4, at 24mm and 5.6, when zoomed. I have posted a related question in Photographic Discussions about the etiquette involved in this.