Shooting Waterfalls With Slowm Shutter During Day

[David Taylor]

Originally Posted by Andrew Briggs

Why's that Osmosis?

It really is dependent more on the lens quality. Inherent with small apertures is a phenomenon known as "diffraction". I used to use small apertures all the time (f/22 and higher) so I could have a lot of depth of field (DOF). But the problem is that the more you stop down your lens (use smaller apertures) the more diffraction you induce. So yes, you do greater DOF, but you also lose resolution. Very noticeably in some cases. Now I rarely go above f/16, if I need more DOF, I take 2 exposures and blend them in post if possible. That being said, if you have limited time to get the shot - DO WHATEVER IT TAKES, diffraction be damned! Hahaha.
As a test, set your camera on your tripod and take two exposures with a wide angle lens (or whatever lens you like). Use aperture priority mode and focus only once on the first shot then switch to manual focus but don't touch it, you want the same focus on both shots. Set your iso to around 400, and turn off your IS (image stabilizers can induce blur when used on a tripod). Then shoot two frames, one at f8, and one at your highest f-stop (like f/22 or higher). Then import the shots in your computer and zoom in on both. Look at the fine detail. Even though with higher apertures you will be getting a greater DOF, you also lose sharpness.

[David Taylor]

Originally Posted by twistedclocks

it's not working i simply can't get a decent exposed picture..
using a ND8 and i have a CPL with up to f22 i can't even get 1 sec out of it without it being too over exposed during the day.. tried adjusting the exposure comp. to -5.0 and flash compensation but nothing is working ive tried every conbination there is!

I really need to figure this out soon before i go away because i'll have the opportunity to photograph waterfalls so any help will be much appreciated..

We may have covered this, but I didn't see it in the thread. What are you setting your ISO at? If you arrant setting it at the lowest option, this may be the reason you are getting shorter shutter speeds than you need. Verify that you are using ISO 100 or 200. Hope this helps.

[RichardTaylor]

From the old "sunny 16" guide
In bright sunshine exposure = F16 @1/ISO

Ie: F16 @ 1/100
With a 3 stop ND8 filter you would be shooting @ around 1/10 & F16 or 1/5 @ F22
The polariser may help a little

You may need to use two ND 8 filters or shoot when the light isn't so bright.

[dcclark]

ND10s sure are fun!

They'll work on waterfalls if you want them to be totally milky and smooth.

But, they're better for shooting stationery subjects (for example, cityscapes) with lots of moving parts (people, cars). The people and cars will just disappear in the face of a 2 minute exposure, making the city stand alone!

[OsmosisStudios]

Originally Posted by dcclark

ND10s sure are fun!

They'll work on waterfalls if you want them to be totally milky and smooth.

But, they're better for shooting stationery subjects (for example, cityscapes) with lots of moving parts (people, cars). The people and cars will just disappear in the face of a 2 minute exposure, making the city stand alone!

What, like this?

f/11, 100iso, 30s. B+W 10-Stop ND.

[dcclark]

What do you mean by "can't get any"?

ND8s and ND10s are such extreme circumstances that every photo will be a separate thing to consider. The shutter speeds will certainly be long (that's the point!), the ISOs will probably be low, and the apertures should be... appropriate to the subject.

[inkista]

ND filter notation can be weird. An ND8 is actually only a 3-stop filter, not an eight-stop one. You're only multiplying your shutter speed by eight. (i.e., 1/100s -> 1/25s). Three stops may not be enough to get the shutter speed you need. 1/25s isn't long enough to blur water. Water blur generally requires seconds long exposures.

The Hoya 9-stop or the B+W 10-stop (aka 3.0 or 1000x) are extreme ND filters--they're so dark you can't see through them in the viewfinder.

I've also done really long exposures with a Hoya R72 infrared filter, which eats up about 12 stops. But that's only if you like white trees and black water.