Wednesday, October 27, 2010

Water in Motion

Water can be a challenging thing to photograph because it is rarely still. Today's photos are examples of a technique of photographing water that I find very attractive. This lovely silky effect of falling water is produced by long time exposures. The challenge comes from how to achieve long time exposures (4 seconds for these two photos) when there is lots of light. Under normal daylight conditions leaving the shutter open for 4 seconds would blur the waterfall beautifully but the photo would be badly overexposed. The solution is to cut down on the light using a filter over the lens. The filter designed for this purpose is called a neutral density filter. It blocks all visible wave lengths of light equally. Less light means the photographer can use a slower shutter speed or a time exposure. As is so often the case in life, however, a solution generates a different problem. Neutral density filters are hard to find and expensive. So how about today's photos - did I win the lottery? No, it turns out there is another solution. Many photographers will have a polarizing filter in their camera bag. These are readily available and relatively inexpensive filters generally used to cut glare and harsh reflections. The trick is to use two polarizing filters, one in front of the other. By rotating the front filter one can adjust how much light passes into the camera.(I didn't discover this myself but found it online in some forum or info page I've since lost. My thanks to the photographer who figured this out.) Hope you like these silky waterfalls since we will be seeing more of them from time to time. This particular waterfall was photographed yesterday in Goldstream Park, just outside Victoria.

10 comments:

  1. What a beautiful photo. The water looks so feathery! Do you have a remote shutter cable? My camera doesn't have anywhere to attach one, so even when I use a tripod, it still makes the camera move when I press down on the shutter.

    I used to use a polarizing filter but I thought it made my pics look 'dirty'.

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  2. Digital cameras let you manually override exposure by up to two stops. I'd be surprised if this effect couldn't be achieved these days without filters.

    As a second thought, how about a series of underexposed photos which are then 'sandwiched' and blended in post-processing? I wonder what kind of 'blurring' effect that might produce?

    I've never tried this but will add it to my to do list and report back at some future date.

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  3. For JoJo...

    A lot of modern digital cameras allow you to fire your camera with an IR remote. Possibly your camera does this? That might solve your problem.

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  4. Beautiful captures -- well done!

    JoJo: Try using the self-timer.

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  5. Thanks for the ideas Mike. I don't know about your camera but when I increase or decrease the exposure manually all my camera does is decrease or increase the shutter speed or aperture (i.e. it doesn't change the sensitivity of the sensor - it just alters the relationship between aperture and shutter speed so you can shoot outside the default range - but not very far outside - not far enough). The problem is then that you end up with a photo that is either over or underexposed. What you want is a correctly exposed photo using a long exposure time and the filter seems like the simplest way to achieve that. To get the effect I think you have to have that long exposure - a couple of seconds at least. HDR processing or exposure fusion will produce a similar effect but nowhere near as smooth.

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  6. Hi JoJo - yes I use a tripod and a cable shutter release for shots like these. But, if I don't have my cable shutter release with me I use SRQ's good suggestion - the self timer set for two seconds means you can push the shutter and then stand back while the camera stops shaking before taking the picture. It's worth checking out Mike's suggestion as well - see if there is a wireless remote shutter release available for your camera.

    Polarizing filters are quite sensitive to where you are pointing your camera and what kind of effect you want. I agree that sometimes they seem to make things look darker in an unpleasant way. But at other times they really do improve the contrast and colors. It's best to experiment with them a bit I think. They are supposed to be most effective when you are pointing your camera at right angles to the sun - when you have the sun on your left or right shoulder.

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  7. JoJo pointed out to me that you had posted a open shutter waterfall today, which I have also done. However, mine has the overexposure that you mention. I will try your filter suggestions next time! Thanks for the advice :)

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  8. Wow, nice capture and the color is so rich.

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  9. You certainly are able "to paint" with your camera.

    Please have a good Thursday.

    daily athens

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