Exposure Help

[smoke665]

Need some help understanding how to handle significant differences in light and dark. I've tried several things but still end up with a lot of editing. Suppose I'm inside looking out a large window that has strong natural lighting and "sunbeams", spilling in. When I look at this my eyes apparently adjust so that I can easily see the details of things outside the window, the "sunbeams", and the details inside the house without a lot of difference. When I try to shoot, if I meter for the window, the inside comes out underexposed, if I meter for the inside the window blows out, and if I try to use a flash to counteract the outside light, I lose the sunbeams. What would be the recommended procedure to shoot this to get as close to actual "in camera", without relying so much on post processing, or is it possible?

 

[Overread]

HDR.

Basically your eye resamples a scene a lot; plus only ever looks at a small part of it for any one moment so it can work with a wide range of different light values. The camera has to try and do it all at once and in situations where the brights and the darks are very distinct this can be a problem.

The best is to take at least two if not more shots so that you can cover the exposure range from the brights and the darks and then combine them in editing to suit your desires.

You can do this from one photo in some cases; but you generally want to shoot RAW and process the shot at least twice - you're basically doing the same as taking more shots; but instead have to generate the various different effects by editing and then merging hte same shot; so its easier to take a selection of shots at the time,



You might be able to achieve what you want with flash; but you'd likely need off camera flash setups and diffusers/excluders to make the light go where you want it to and to land soft.

 

[smoke665]

Pretty much what I assumed. The use of any flash obliterates the sunbeams. Think I'll try to get window and inside details right then add back the sunbeams as a layer. Thanks for the response.

 

[yaopey]

Hi,

Unfortunately, that is the limitation of cameras...at least with the current technology. The dynamic range in real life is much wider than that of the digital camera. So in situations when there is extreme contrast (like what you've just described), your camera simply cannot capture all the brightness and darkness all together in a single image.

The ways to overcome this is either adding artificial light to illuminate the inside, therefore compressing the dynamic range to fit into the dynamic range of the digital camera.

Or, take multiple exposures and blend them with HDR software or manual blending. You can take one photo to expose for the indoor, one for the outdoor and one for the sunbeams.

Hope that helps

 

[Watchful]

I would also use a tripod and take 5 to 7 images at variable exposures from under to over exposed and meld them into one final image that keeps the detail in both the shadow and the highlight areas.
You can use exposure bracketing to set it up in the camera.

 

[smoke665]

Unfortunately my K30 only supports 3 shots in bracketing. I've manually taken multiple images at different exposure levels, but the risk is always there for a slight shift that shows up in processing. Thanks for the suggestions

 

[wfooshee]

Tripod, set the camera a couple of stops under the meter reading, bracket three shots a stop apart, change the camera to a stop over the metered exposure, bracket three more there. Now you have -3, -2, -1, 0, +1, and +2. If you want the +3 shot, do that one by itself.

I've also been known to shoot just two shots, on for the view out the window and one for the detail inside, and make a simple composite. Sometimes that works, sometimes it looks like a window view pasted on.

As you view a scene by eye, your eye adjusts for the part you're looking at directly and pretty much ignores the rest of the scene. As you look into the dark corners, the outside view is lost, but when you look through the window, you can see that scene, but you lose sight of the interior. You simply look at what you want to see at that moment, and your eyes adjust dynamically.

A photograph is not dynamic. It can't adjust for you to accommodate the section you're looking at. It can't simultaneously present very dim and very bright areas of the scene.

HDR, high dynamic range, helps that by raising the levels of very dark areas to an acceptable minimum, and restricting the very bright areas to an acceptable maximum. It's nothing more than compression of the dynamic range, something radio music people have been doing for nearly a century: bringing soft sound levels up so they don't disappear into background noise and limiting high volume levels so they don't blow out some piece of equipment, or distort.