Luminous Landscape Forum
Equipment & Techniques => Beginner's Questions => Topic started by: pwbrian on November 16, 2012, 11:05:38 am
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Hey there.... Looking for a tip to get the long exposures for waterfalls n such. Sometimes the subject is bright enough that I can't reduce the shutter speed much. Looking for the key to this. Any tips would be appreciated.
Thanks!
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Neutral Density (ND) filter.
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Either the Lee Big Stopper (http://leefilters.com/index.php/camera/bigstopper) or the Singh-Ray Mor-Slo (http://www.singh-ray.com/morslo.html) or other brand filter should do the trick. Sometimes a simple polarizer is enough.
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Ah, thanks. I've got a pretty dark polarizer. I'll give that a try first and see if I can get what I'm looking for with it. I'll have to put a ND Filter on my must have list. Thanks for the advice.
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... I've got a pretty dark polarizer...
Though it might look dark, it typically reduces exposure by around two f/stops only, probably not enough for you purposes. A real ND filter would be generally in the 4 to 10 f/stops range.
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If you have them you can stack a circular polarizer and a linear polarizer; if you don't have them you're better off to buy a Vari-ND or equivalent.
Mike.
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If you have them you can stack a circular polarizer and a linear polarizer; if you don't have them you're better off to buy a Vari-ND or equivalent.
Mike.
The Vari-ND is interesting but not cheap, although dark quality ND filters aren't either.
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If you have them you can stack a circular polarizer and a linear polarizer; if you don't have them you're better off to buy a Vari-ND or equivalent.
Mike.
I agree. If you intend to take a reasonable number of water shots over time, the Singh-Ray variable ND filter is great. More than eight stops darkening is possible, and you can dial them in to bracket your shots. No matter how much experience you get shooting moving water it is always nice to twist a dial, shoot, twist a dial, shoot, and almost guarantee that one of the exposures will be just what you want. I don't use mine that often but when I do, it makes it much simpler to find the right shutter speed for the effect I want, which would vary with the speed of the water. Whether there are parts of the water moving at different rates, the angle of the camera to the water, etc, are all variables that affect what might falsely seem to be a simple decision concerning shutterspeed.
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I have the Fader variable filter. At wide angles - 20mm - the variance is only about 2 stops but when the lens is zoomed to about 70mm then the variance is about 6 or 7 stops. I don't know if the Singh-Ray is the same. Therefore if used close up it isn't practical.
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You can do all of that, or you can buy another el cheapo linear polariser (assuming yours is a linear) and stack both on the lens. This is the principle of recently "invented" variable ND (in fact two linear polarisers stacked on top of each other. This method has been used for other reasons in mineralogical microscopes since the 19th century). You can rotate them around thus changing the angle between the polarisation planes in the two (usually marked on the rim). What you will find is that when the two planes are crossed, basically no light goes through. The more you change the angle from this point, the more light enters the lens until the two planes are parallel and you get the maximum amount of light for the pair.
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I don't believe you can stack two linear polarizers on a camera with autofocus/TTL metering without affecting one or the other or both. Hence the linear/circular combination. Two linear polarizers and a lambda plate in between, manual focus and a light meter - that might be interesting!
Mike.
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Another way is to shoot a bunch of shorter exposures and blend the files together in Photoshop to get a silky look in the water.
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I don't believe you can stack two linear polarizers on a camera with autofocus/TTL metering without affecting one or the other or both. Hence the linear/circular combination. Two linear polarizers and a lambda plate in between, manual focus and a light meter - that might be interesting!
Mike.
I think that you are right but AF usually doesn't work very well with strong NDs or stacked polarizers. I've tried linear + circular don't have a second linear to test.
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I think that you are right but AF usually doesn't work very well with strong NDs
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I can AF with a 6 + 3 stop screwed together but can't with the 10 stop ND filters. Having said that it is better to manual focus filters.
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I can AF with a 6 + 3 stop screwed together but can't with the 10 stop ND filters. Having said that it is better to manual focus filters.
Yes, that's my experience too. I had much better success or accuracy with manual focus.
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AF would struggle with anything restricting the light (obviously), the more restrictive, the more it will. But I am not sure what long exposure shot would not be at hyperfocal distance and metering would be redundant anyway because of the really long exposure.
Plus, the expensive 10 stop (or whatever) vario-ND filters they sell are exactly that. Two linear polarisers stacked on top of each other.
I would be more concerned about vignetting if a wide(ish) angle lens is used. Hoya used to do some really neat 3mm linear polarisers. I guess you might still be able to land them cheaply off ebay.
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Tripod + cable release as well....
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Here's yet another version to get softer water (and even retain some details). It's easiest to do on a calm day with little to no wind as to not move the surrounding foliage around if there is any.
Take two or three consecutive shots of the same waterfall (preferably with a tripod, but can be effective without if your photoshop knowledge is adequate).
Blend the exposures together in photoshop.I believe lighten in layer blending can work, but you may have to check that as it's been a while since I've done this type of shot.
You can also layer mask and blend that way as well, which gives you much more control.
Good luck!