Shooting in Front of a Glass Window

<p>I am looking for advice on a lighting set-up for a portrait sitting that involves the subjects in front of a large glass window overlooking a city landscape. I am concerned with two major elements: 1) reflection in the glass and, 2) beauty light on the subjects.<br>

I would like to shoot a portrait with both sunset and evening shots with the city lights in the backdrop. I am shooting digital and would like input on how to place lights and what kind of lighting would be advisable and/or any other relevant tips that would be helpful. </p>

<p>First and foremost, the all-important rule when it comes to glass or any other reflective surface:<br /><br /><em>The angle of incidence equals the angle of reflection</em>. <br /><br />Simply, place your light source(s) at an angle that makes them invisible (as refelctions) to the camera. The more shallow the angle, the less likely they are to be in the camera's field of view. <br /><br />Likewise, the longer your focal length, the narrower your field of view. Meaning, if you shoot with a short telephoto lens, you'll have less of the window in the frame, and thus more latitude in placing the light(s). <br /><br />As for exposure: remember that if you want to get city lights to show up, you'll need a long exposure (a slow shutter speed). Meter in order to get the backdrop looking the way you want, and then add just enough flash power to light up your foreground subject the way you'd like. <br /><br />Bring a roll of paper towels and a bottle of glass cleaner. The cleaner that window is, the less you'll see it. <br /><br />Will you have an assistant? You may need to position or hold some flags (large pieces of something dark, like black foam core or painted cardboard) to help control spill from your light(s).</p>

<p>It is perhaps worth adding that if the outside ambient, the city-scape in the background, is reasonably bright (without being over-exposed) any stray reflections in the glass will be less noticeable. Dark glass is like a mirror. Matt's advice is all good and the point about a longer focal length is especially useful for containing what may be intrusive reflections.</p>

<p>Very difficult proposition to do successfully in a single image. Even if you can find an angle for the strobe that takes the light reflection out of the window it may not successfully light your subject at the angle you want it to. And if you go with a short telephoto it's going to be harder to show the full breadth of the city or sunset behind the couple, and will also be harder to carry the depth of field to keep the background in focus.</p>

<p>I did a very similar shoot with my daughter in the bathtub a couple weeks ago. Wanted to include the interesting skies outside the window behind her but couldn't find a strobe position that would work and avoid the reflection. I got around this by just turning off the strobe and having her sit down for one shot so I could capture the sky without the reflection, then masked the two images together in Photoshop. The camera was set to expose the background sky correctly, so I didn't need to change any settings between the shots. In retrospect I should have shot from a tripod... would have made the masking a lot easier.</p>

<p>If you find the complete lack of reflections to look a little surreal, keep in mind that you can use the opacity slider to bring back a hint of reflection after you've layered them together. Decided I preferred the surreal look rather than reality for this image.<br>

<img src="http://img.photobucket.com/albums/v483/sheldonnalos/AnEveningBath.jpg" alt="" width="1000" height="703" /></p>

<p>Also, if the flash lights up part of the interior behind you, that will reflect in the glass.</p>

<p>If you want to do this in-camera without compositing in photoshop, you may want to turn off the modeling lights and all the interior lights, and put the camera on a tripod. This will let you use a long exposure for the background city lights, while the short burst of strobe will light the people in the foreground without causing any motion blur. By adjusting the shutter speed and strobe power, you'll have complete control to balance the relative exposure of the interior and exterior.</p>

<p>Set Camera on tripod and turn off all lights in room. Set the framing and composition exactly how you want the finished portrait to frame. Bring subjects into frame and focus on them. Lock the focus *i.e. take the camera out of auto focus -- and shoot them and the background at the aperture you want d.<br>

Now take the subkects sout ofthe picture, turn off all lights in the room including your photographic lights and without changign aperture, focus, framing and composition, shoot the now empty composition.<br>

In Photoshop combine the best exposures using layers and masks to only show on that layer, what you want to be in the final photo. You'll do this by creating a mask for each layer you add on top of your base image and painting with a brush set to either pure black or pure white. The rule here is "black reveals and white conceals". Start with black. </p>