When shooting a group portrait (25ppl +/-), how wide a lens would you anticipate I would need (for 35mm/equivalent)? I'm thinking of doing this in a small format because they (the customer) will want color, and doing color in large format is significantly more costly. On the flip side, if I were to go large format (4x5), would a 90mm be wide enough (that's the widest lens I currently have, that has a flash sync)? I'm trying to keep the kit I take on location as small as possible.