Friday, 7 March 2014

Architecture Photography Tips - Combining Multiple Exposures for Interior Shots

Article by Jijo John

Quite often we come across interiors which have a combination of very bright and very dark areas. The contrast level is simply too high for our digital cameras to capture in a single image. High end DSLR cameras like the Canon 5D MK III and Nikon D 800 are way better than their predecessors, but even they could not handle the dynamic range present in certain situations in a satisfactory manner.

When faced with such a situation we photographers have basically two options. One is to use lights (strobes or continuous light sources) to fill in the shadow areas thus making the whole scene come within the dynamic range of the camera. Our Second option is to use HDR, or put simply take multiple shots exposing different areas of the scene properly and then putting it together in image editing software like Adobe Photoshop.

Both methods have their advantages and disadvantages, but the major disadvantage of using supplemental lighting are:

  1. It is simply impossible to recreate the exact effect created by the interior lighting when using strobes or continuous lights and
  2. The time and effort needed to light a large interior is simply exhaustive, not to mention the amount of gear needed and what it’ll cost. Moreover in certain cases you simply can’t light certain areas the way you wish due to practical limitations in the scene.

In comparison taking multiple exposures and combining them into a single exposures is quite simple if you adhere to certain guidelines.

Tips for Shooting Base exposures required for blending

  1. My preferred method is to set the camera spot metering mode and take readings from the brightest area and also from the darkest area. This will tell me the amount of contrast present in the scene.
  2. Now I set my camera up firmly on a solid tripod, take an exposure that nicely balances both the highlights and shadows and then get the additional exposures necessary. Since I know the amount of dynamic range in the scene I could easily determine the number of exposures I need both ways (underexposed and overexposed). I prefer to shoot in manual mode so all I need to do is adjust the shutter speed up and down.
  3. It is recommended that you get your white balance settings as accurate as possible using the Kelvin settings even though you can later adjust them in post production (if you shoot RAW -which you should). Using Auto White Balance feature is not recommended as chances are white balance settings may change from shot to shot making it impossible to synchronize many files taken at the same settings in a single action. 
  4. Make sure the exposure difference between shots is not too much; if that happens you will find hard transition in certain areas difficult to tackle while post processing.
  5. Make sure you have all the highlight details you need in your darkest exposure and all the shadow details you need in your brightest exposure.

Here’s a couple of examples.

The pictures given below are single exposures as per exposure suggestions given by the camera. the bright windows caused the camera to underexpose the scenes. But if i try to increase exposure by raising the shutter speed i will end up clipping my highlights, totally losing detail on the window and also the interior lights.

Click on the images to enlarge.

exposure blending in architecture photography
Exposure suggested by the camera.

Ty imagining the amount of work involved in properly lighting such big spaces, the amount of time and effort required and also the cost of lights, support systems, modifiers, cost of assistants etc. even with all that it is a very difficult task to exactly match the feel given by the existing interior lighting. So what we did was take a series of exposures.

First thing we did was to take an exposure which was 2/3rd of a stop under than the ones given above (which was suggested by the camera and we treat it as our base exposure)  to capture detail in the brightest highlights (windows).

hdr interior photography
Purposefully underexposed image for the window details

Now we did an exposure which is 2/3rd of a stop over the base exposure. This is for details in the interior lights. You could see that the windows are now slightly blown out.

combining exposures in interiror photography
Exposure for interior lights

And now a final exposure for the shadow areas. This is 1 1/3 stops over exposed than the base shot. Windows and interior lights are now completely blow out but the floor and ceiling has now come alive.

hdr architecture photography
Exposure for floor and ceiling

So now we have four different exposures of the same scenes all taken with the camera secured on a tripod. We have not used even a single light for these shots, now let us see the final images.

architecture photography tips
4 exposures combined in photoshop

And here's the second shot.

professional interior photography tips
combined shot - 4 exposures

The possibilities of this technique is endless, provided you keep it realistic. It is very easy to go overboard while editing and create a very unrealistic or surreal looking image. That is not what architects, design firms or property owners demand from professional photographers. In the next article we will discuss how best to combine the different exposures using Adobe Photoshop.

Have Fun

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  2. What Lens for Architectural Photography
  3. Architecture Photography Tips - Combining Multiple Exposures for Interior Shots
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