If you’re a seasoned astronomy buff, you might remember reading about the negative-stacking techniques photographers used back in the film days to produce rich, detailed prints of the deep sky. The process of preparing a usable ‘film sandwich’ was one filled with pitfalls though, and most everyone has turned to digital as a much more user-friendly method of combining exposures.
HDR, or high dynamic range photography is not unlike the process of stacking negatives. Essentially, the goal is one of the same: combine a number of bracketed exposures in an effort to create one final image that embodies perfect tonal range. HDR is not limited to astrophotography by any means; with new hardware and software readily available to the general public, it’s common to see images in every genre that attempt to utilize HDR processing. Thus, it comes as no surprise that real estate photographers have taken hold of HDR – using it to create both stunning masterpieces and disastrous flops.
The perfect shooting conditions are rare, especially when it comes to real estate. Fluffy clouds, blue skies, perfect light… these conditions come together sometimes, but not always. So, it’s nice to have a few tricks up your sleeve that still allow you to create great photos even when your timing is off. I stepped out the other day for instance, to shoot a photo of the Point2 building (above) only to find washed-out skies and all around ‘bad’ light. The perfect exposure was not a possibility, and my polarizing filter did nothing to correct the hot sky. I had a tripod with me though, and shot a number of photos at varying exposures, later merging them with HDR techniques.
Here’s a few tips for shooting raw images for later HDR processing:
- Use a sturdy tripod, and a cable release or remote control so your framing remains consistent.
- Bracket your exposures by adjusting your shutter speed rather than your aperture so your depth of field does not change.
- Shoot at least three photos – one underexposed, one overexposed, and one metered correctly. Spreading out each exposure by a couple of stops is best.
- Shooting at dusk or dawn works great, and you may want to turn on all of the house lights to create a warm, ‘homey’ feel to the final shot. Keep an eye on varying light sources though, as interior light will appear yellow. Alternatively, exterior light may appear blue when shooting interiors.
- Avoid shooting areas that have moving objects if possible. It complicates the merging process.
Once you have three or more bracketed exposures, it’s just a matter of merging them into the ‘perfect’ shot using specialized computer software. Here’s where things can get tricky, but once you find a system that works for you it becomes much quicker and easier. When it comes to HDR, practice truly does makes perfect – so don’t expect to master it on your first try.
Keep in mind that the best HDR images tend to be those that appear vibrant, colorful, and clear, while retaining realistic and natural tones. Unnatural HDR images are everywhere, and there are a number of people who love them as an type of photographic art. For real estate purposes especially, it’s very important that your images retain their realistic and natural appeal. After all, you’re using them to sell houses not to win art competitions. Here’s an example of an unnatural-looking HDR image:
Just because you’re using software designed to create HDR images, doesn’t mean that it’s always correct. Color and tone can become skewed in the processing stages – sometimes to a point where they can’t be saved. Just learn to trust your eye.
There’s a growing mass of software solutions that allow you to merge photos for the purposes of HDR. The most popular is Adobe Photoshop which allows for both automated and manual processes. Other common solutions include Photomatix, EasyHDR and PTgui Pro. PTgui Pro also provides photo-stitching solutions for panoramas, and 360-degree virtual tours. Free solutions include: Enfuse Gui (PC), xFuse (mac), and Hugin (both).
Countless tutorials are on the web for those looking to get started. Here’s a few decent one’s I’ve come across:
Personally, I like to merge photos manually with Photoshop. It takes more time, but it always looks more natural in the end. I have tested both Photomatix and PTgui Pro though, and I find Photomatix best for automated HDR processing and manual tone mapping. Almost all of the paid solutions offer free trials, so I suggest testing as many of them as possible before making your final decision. In the mean time, have a peek at some real estate HDR samples on PFRE’s Flickr page. Enjoy!