Why do architectural photographers use hot lights versus strobes? Primarily, hot lights are easier to control than strobes, provide a much more natural look, and mix better with incandescent and quartz bulbs.
Strobe lighting is one big blast of light that is very hard to control in the limited area of a predefined architectural space. Strobes often overpower the available ambient light and can give a false look to the fixtures and lamps. Since my philosophy of lighting is to augment the architectural lighting already present in the space, this effect can be a conflict for me. When using hot lights versus strobes, the photographer can "see" where the light is directed. Strobe lighting, on the other hand, is an educated guess at best, and even after years of experience using them, you still require "digiroids" to evaluate before committing to the final shot, especially with multiple strobe setups.
A critical time is prior to the actual location shoot, when a photographer has the opportunity to scout the space and make the decision as to the approach they will take on the actual day of the shoot. The greatest challenge of photographing an interior space is balancing the extended contrast range of the scene with the dynamic range of the camera. The contrast range of the scene will solely dictate how many lights are used to bring these two ranges into balance.
The only obstacle to using hot lights would be the available electrical power at the site, since they use a lot of amperage. We often run electrical extension cords to different rooms, floors, or even other buildings in order to access power and not overload the electrical system on-site.
Another major consideration at the location is the amount of daylight illuminating a space and how much daylight can be controlled using color-correction gels on windows and glass. However, gels are costly and time consuming to put up, and most photographs done with hot lights are taken at dusk or night, eliminating the need to control the daylight. When using gels to control daylight as an option, it produces a beautiful effect: a balance of daylight and natural indoor ambient light.
The number of lights required on a shoot depends on the size of the space, how much ambient lighting is present, whether there is an abundance of dark furniture that needs to be spotlighted, and the overall mood of the space that we are attempting to capture. With dark furniture, we need to add reflective lighting. What I mean by reflective lighting is that we sometimes need to use reflections in dark furniture, side tables, bookcases, chairs, etc. to keep them from appearing to be in a dark abyss. It is a way to visually add some dimension to an area that would otherwise have no detail and be lifeless. A lot of furniture these days is actually black with no grain or detail, so giving it something to reflect helps to add a sense of dimension to an otherwise black area of the shot. We may use up to 16 lights for any given space, with five to seven lights being the norm.
The color temperature of quartz (hot) lights is very close to that of incandescent lighting. A quartz bulb is generally 3200K, while incandescent bulbs are 2800K. We use gold reflectors to bring down the color temperature, as opposed to filters that are cumbersome and can burn. I like to use a diffused glass in front of the light head with barn doors that can be closed down to direct the light. The spot-focus attachment on the head then becomes more like a rheostat and allows us to adjust the light intensity up or down as needed (most importantly, without changing the color temperature). We also bounce lights into ceilings and walls for a diffused fill light. We do occasionally use umbrellas, although on a limited basis.
I personally do not compromise on the lighting techniques and the amount of lighting used based upon the client's end use. There is no difference to me if the photography is for a billboard or a 3x5 image on a website. It always amazes me when a client says, "But it's just for the web." The smaller and lower-res the image, the more that bad or inadequate lighting stands out. Shadows get dumped into oblivion, grain in furniture disappears, and highlights lose their fine detail.
So why does everyone think that you can compromise on lighting? We light every photograph as though it was for publication in Architectural Digest. If the client doesn't have the budget to do it properly, I'll walk away. I'm glad to be able to say that at this point in my career!
Rob Faulkner (www.faulknerstudios.com) is a self-taught photographer specializing in architectural photography, with clients ranging from architects, interior designers, premier residential builders, major construction firms, and developers. Faulkner realized digital was the future of photography in 1993, when he purchased a drum scanner and digital printer. This move to scanning images and printing digitally paved the path to digital capture, now the exclusive way he photographs. Faulkner is also an advocate and dedicated user of color management. His work has appeared in more than 100 publications.