Controlling exposure of cascades/waterfalls

With all the talented photographers on PNWNP who photograph in the Gorge and rain forests of the PNW, I thought this would be the perfect place to pose the following question:

How in the heck do you prevent rushing cascades from blowing out when photographing under dark forest canopy?

I've been exploring the La Sal mountains and have found some really interesting and beautiful canyons that are heavily forested. I'm discovering that the required exposures are so long that the cascades/waterfalls frequently blow out, or come very close to doing so. Is there a secret, or do I just need to learn how to blend exposures?

I appreciate any advice ya'll can offer!

Well, blending can help in some situations but it's far from necessary. Like anything you're shooting, control the highlights first. If that means exposing to the right is still 80% on the left side of your histogram, then so be it. You have to reign in those highlights or they're gone.
Obviously, RAW processors these days are tremendously effective tools for restoring shadow details. Again, check the histogram and make sure you have enough shadow detail there to bring out in the first place. It's likely you will, if your highlights are pushed as far as they can go without blowing. If you find that, given your exposure for highlights, the shadow detail is still less than acceptable, then it's time to blend. For the record though, I have yet to ever blend for any water highlight in a scene that wasn't directly lit. You should be able to do it in one exposure with the right amount of shadow recovery if you exposed right to begin with. And use a polarizer to control that pesky glare.
Learning to blend from the RAW or multiple exposures is useful, however. Blending allows you to achieve greater image quality when done flawlessly because your pixels are closer to being maximized by exposing everything further to the right in the first place (no digging out barely-recorded shadow details). It can, of course, be a hassle to get looking natural though, so use caution. Water scenes are at least easier than most sunrise/sunsets in that regard though.

Tremendous info, Marc. In those situations, do you ever monkey with a straight ND filter, or is it just CPL and getting the exposure right?

Regular ND filter won't make any difference other than allow you to take a longer exposure. Dunno about Marc, but in shooting waterfalls for over 15 years now, I've very very rarely needed a ND and a Polarizer at the same time (the only times was when I wanted to slow the water down in bright, direct sunlight). I've found you can generally overexpose a waterfall by 1/3 to 1/2 stop without blowing the highlights, but much more than that and you'll start to lose the highlights. The great thing with digital is you can change your settings as much as you need until you see that you got the shot right before you leave, so just go out and see what works, that's the best way to learn.

Thanks Bryan... that makes sense.

Thanks for the info, Marc. I always expose to the right. Even so, there were a bunch of photos that were so dark that too much noise was obvious when I opened up the shadow detail in LR2. I'll keep working on the technique, though. Much appreciated!

For me, shooting streams, waterfalls or cascades is all about indirect lighting. Direct sunlight on the water is the curse for blown highlights. I purposefully choose to shoot these subjects in overcast, broken cloud, early morning or late evening conditions. Having the sky as a giant softbox is what manages dynamic range by opening the shadows and lowering digital noise. Similar to Brian, I've never needed an ND filter.

As we all know, using RAW and exposing to the right like Marc pointed out is most important even in these "softbox" conditions. I also use the blinking hightlights feature to check for blowouts that I might not notice in the histogram.

I always use my polarizer both for slowing down the exposure and reducing color killing reflections on the foliage. Another trick for great foliage color is to shoot in between light drizzle or shower conditions. This coupled with your polarizer can really make the colors pop.

Finally, Marc and others who have really mastered these techniques watch for those special conditions where warm filtered light bathes the background foliage opening up what otherwise might be a dark background. This really enhances the compostion adding a unique quality to the shot. Below are a couple of examples:

Pic1
Pic2
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Pic4

Sorry Marc for picking mostly your shots, but you've really got this technique down.

Marc covered most of the points already...great advice all that I follow.

I will add that working in soft diffused light really helps.

When I need it this tutorial I created really helps with the blends...once you get used to it, it only takes a few min to complete.

http://www.nwpphotoforum.com/ubbthreads/information/php/2007_Articles/rjohnston/roman2.php

just copy and paste it into your browser address window.

Roman

Thanks for the link, Roman. I'm planning a few photo outings this weekend and will be sure to find a way to experiment w/ this technique.

I have to admit....for waterfalls, creeks, streams and other water shots...blends are not needed....

1. shoot in the morning or evening...or on overcast days.....
2. know your camera, know the light and how it is read...
3. meter on the "hot spot" and shoot....then overexpose and shoot...like it was said before...given certain conditions you can really overexpose your shot and still not blow anything out....I have also found that if you shoot at say 1/8th of a second, water might be blown...but if you kick down your f stop and shoot at say 4 seconds.....then the water is not blown because its a blurred area...and therefore less likely to blow out