Photographer Neil van Niekerk recently invited his friend Marco Leibetseder into his NYC studio for a photo challenge: rather than using flash, Niekerk and Leibetseder set themselves the challenge to capture some creative portraits that showcased “depth” in-studio using only continuous lighting. We love it when talented photographers set themselves a challenge, whether it’s a cheap camera challenge, using only one lens, or capturing a new photo of the same subject for 365 days straight. This is where a photographer’s…