This for the casual photographer or real estate person who wants decent results with primarily a digital camera.
Interiors are tricky because the light is usually awful. If you're a professional shooting for Architectural Digest you bring a ton of lighting and spend a few hours setting it up. Then the photography is easy.
In the daytime the light from the windows usually fools every camera meter, so you're going to have to fiddle with exposure.
Since you have mixed sources from both natural and artificial light you're going to need to fiddle with white balance.
You also tend to need very wide angles which can require special lenses or techniques.
Often a camera sees a daytime window and makes everything too dark.
If the images are too dark simply use your exposure compensation to make the image lighter. You may easily need a stop or two or three.
This is one of the few occasions in which I'll use manual exposure. This is because the interior exposure tends to remain the same even as you change your composition to include or exclude windows.
With a digital SLR with a really wide lens I usually shoot at f/11 and whatever time is needed on a tripod.
Turn on all the lights and be sure your exposures are light enough.
Forget being able to show both the inside and window view as it looks to your eye. Unless you are very good with fill flash, lighting, filtration or Photoshop tricks you'll have to settle for washed out views of the window.
Ways around this are complex. Among them:
1.) Use your fill flash.
2.) Add more interior supplemental lighting.
3.) Try Photoshop CS and newer's lighten shadows command. I have more here on that. See the caution below.
4.) Make a couple of images at different exposures and composite them. I have not tried Photoshop CS2's high dynamic range compositing trick; this might be worth a look.
5.) Wait for exactly the right time of dusk when the outside matches the interior lighting.
6.) Put neutral density gels like Rosco Cinegels over the windows. That's what we do in Hollywood and it's a pain. We use things like dark orange (85N9) gels which both convert daylight to tungsten (the 85 part) and dim the light to match (the N9, or ND 3 stops, part).
Two cautions if you try these tricks:
1.) Go easy on it. It looks bad to use a perfect exposure for the outside since it's not natural. Be sure to make the outside look as light as it should.
2.) Go easy on Photoshop's lighten and darken commands. Now that Photoshop CS and newer has a brilliant lighten shadows adjustment here I see it used too strongly on real estate flyers. It becomes obvious when you can see the bright halos around darker areas. Go easy here and fix the lighting first.
One way to help with lighting is to use the free wireless feature of your flashes. Nikon makes this easy on the D70 camera. I have a page about this here. I prefer to use a Novatron strobe system when I use more than one light, but you may prefer to bring a few SB-600s and SB-800s to light a place. See my page on Studio Strobes. Studio strobes work better, are easier to use and cost less than buying several Nikon or other battery-powered flashes.
I start off in AUTO and go from there. There's no need for RAW; I just look at my LCD to see how it's looking.
Play with your white balance. You may want to try the Shade setting if it's mostly lit by window light, or the Tungsten setting if inside at night. Just use whatever looks good on your LCD. Try all the settings until it looks right. I have a page about white balance here.
If I have a lot of tungsten light I often want a setting between Tungsten (often too blue) and Daylight (often too orange). There isn't any unless you go into a manual Kelvin setting (Canon) or a manual white card setting. On my Nikons I often try to use the +/-3 trims on either Daylight or Tungsten and hope for the best.
It's quite likely that you won't ever get a perfect setting if you have more than one source of light.
Professionally on film we'll sometimes make multiple exposures with different light balancing filters over the lens. We'll have an assistant switch various kinds of lights on and off while the appropriate filters are put over the lens to expose for each kind of light.
In Hollywood movies we actually put filters over all the lights and all the windows to balance them all to the same color! This is what I mean by lighting being a pain!
Timing: Magic Hour
The prettiest exterior shots are made just after the sun has set and the sky gets a deep blue to match the lighting of the exterior.
Magic hour isn't even an hour: it's only a few minutes somewhere about 10 - 20 minutes after sundown. You determine the exact time by eye; it varies with location, season and the lighting of your exterior. Try a series of shots and you'll see just how wildly the light varies as day turns into night. Do this as an assignment if you haven't already.
Shooting during the magic minute is how you get brilliant, contrasting colors in the sky, building, and everything!
This allows the image to show the building in whatever artificial light is used as well as detail in the sky and shadows. Daytime shots can't see the building's own lighting, and night shots show too much contrast with a black sky.
Really advanced photographers will make a double exposure (film) or composite (digital). They'll make a shot when the sky is perfect, and a second shot at night exposed for the lights coming through the windows of an office building.
These magic hour shots for residential shots are literally as powerful as sex drive. Primitive man sought shelter for the evening as the sun went down and the light of the fires came up. Photographing a home at magic hour draws on a million years of primal need and psychology. Show a home at magic hour and people want to live there. Show it in the day and you lose that power. The colors are also prettiest at that time of day, presuming the home is lit from the outside.
Use a tripod and set the ISO to its lowest setting. The tripod lets you make long exposures so you can use small apertures for sharp focus and use slow ISOs for clean images. It's optional, especially during the day.
Lenses for Digital Cameras
Personally I always want a super wide lens. On my Nikon D70 DSLR I use nothing but my Nikon 12 - 24 mm lens. With Canon I'd get the Canon 10 - 22 mm lens. See also my page on discount ultra-wide lenses.
An ultrawide lens is needed to show an entire room instead of just a part of one wall. Showing just one wall with a normal camera means you wind up showing just one piece of furniture instead of the room!
This is important; normal lenses that come with cameras usually only go wide enough to show one part of a wall at a time. When searching through real estate listings you usually wind up seeing the owner's taste in furniture instead of the rooms themselves!
A normal lens would just show a bed instead of a bedroom.
I suggest against add-on external conversion lenses. These don't go very wide and they often add a lot of distortion.
Of course the very best camera for professional use is a 4 x 5" film view camera. It allows you to make perspective corrections and get all the lines perfectly straight. These are used for professional magazine shots.
Of course with a film camera it's almost impossible to get the colors and lighting right unless you also spend hours with your own lights, so for most things I just use my D70. I can correct distortion and angles easily in Photoshop. When I sold my condo in July, 2005 I used my 12 - 24 mm lens and D70 and created these shots at La Jolla Mesa Estates in half an hour. We put those on the MLS listing and it was sold in just a few days.
Compact digital cameras are what most real estate people use. This is too bad because their lenses don't go wide enough to show the full room instead of just the furniture. Some pocket cameras, like the upcoming Canon S80, offer slightly wider lenses, but not by much.
If you do much of this I do strongly suggest a DSLR with a super wide lens.
(From my Canon A70 and Canon's stitch program, far easier than printing from film. The original composite file was 10,500 x 1786 pixels, big enough for a three foot wide print at 300DPI!)
Canon digital cameras in particular make it easy to shoot and stitch many images together to show a huge horizontal view. Canon cameras often include the special software, and their pocket cameras often include a special shooting mode to facilitate getting a perfect series of shots for stitching.
This is better than anything digitally for showing things like a view or a yard. This view above looks across 300 degrees, skipping only the home itself behind you!