Whenever I try
it's too bright. So I need an nd filter right?
'no' you need less
exposure.. the problem you identify here is in your technique, not your gadget bag; to get less exposure you 'may' want an ND... but if the picture's too bright, it's your settings that's wrong NOT your gear, and if you don't sort the technique, an ND wont do it for you, and you will carry on over exposing, and probably more so, not less.
Start here
Exposure - Exposed!
I want to take landscape pictures with a wide aperture and a long exposure in the hope of getting a nice soft water shot.
Please ask yourself whether the world hasn't already got enough of them, first.... they are a rather over done cliche.. but still.
Question of settings, and many people think 'long exposure' and so set FAR too slow a shutter.
AND, thing with milking waterfalls is, you are capturing highlights.. that are moving, streaking accross the frame, filling it with more highlights than actually exist in 'real time'.
Imagine metering the scene not to 'milk' the water, but 'freeze' it, with a very short shutter speed, maybe 1/1oooth. Camera averages the scene, highlights and low-lights, and offers an aperture to give an exposure in the middle.
Now you drop the shutter to 1/60th.. the camera's meter is still metering the same 'scene', so it will suggest you stop down the aperture 3 stops to maintain the same exposure.... BUT... with the shutter open four times as long, you will get the highlights dragged across the frame covering perhaps four times as much area.. hence you get 4x the amount of highlights blotting out the low-lights, and what you get appears over exposed.
You know what you want the picture to look like, but the camera only knows what its looking at... so you need to better understand 'exposure', and that this is one of the situations where you probably need to use a little 'compensation', and choose settings to under expose the scene from what you meter to compensate for multiplying the highlights during the longer exposure period... the camera doesn't 'know' they are going to move and drag accross the frame, you do.
OK... slap on an ND filter.... this will NOT solve your 'problem'.
Camera will still meter through the lens, AND the filter. It will still meter the scene as it sees it and suggest settings between high-light and low, and will STILL not know that the highlights will drag accross the frame, and so suggest settings that will give more exposure than you actually desire.
Doesn't matter how heavy an ND you try using, the problem will persist and you will likely still suffer over exposure; And an ND dimming the scene as metered, suggesting longer and longer shutters though, will likely make it WORSE, as the longer shutter will increase the amount of highlight dragging during the exposure, making the effective exposure brighter than metered.
Make sense?
Nail the 'exposure', how much compensation you need to bring the picture back from what you metered, to get what you want, and you may not 'need' to use an ND at all.
The ND only dims light going into the camera; it will only really 'help' if you are against the buffers, and at the shutter speed you want, you cant stop the aperture down enough to get the exposure you want.
On which notion, the 'trap' if milking water falls IS to presume to need far to long an exposure, and turn the water to a milky textureless streak, and NOt get the 'delicate' smokey effect you are probably hoping to achieve.
So, a more concervative shutter speed, is likely to be more help; you can still get a lot of streaking, depending on how fast the water is moving, and your framing, but freeze it 'enough' that you dont have all the highlights streaking over one another, and can retain detail and texture and 'subtelty' you hope for... AND you are less likely to run into teh buffers and run out of low enough ISO's or small enough appertures, and NOT need to resort to filters to get you back in range.
Its ALL win, and a situation, in which, to solve the 'problem' you suggest, its in your technique not your gadget bag, and without the technique, a filter is likely to actually make it harder for you to acheive what you hope, rather than easier.
To wit; my suggestion is forget the filter for now, work on the technique. Start with faster shutter speeds and see just how much milking they still give; without needing so much exposure correction or running out of available aperture/ISO settings... then go up the shutters, NOT down... see how fast you have to go before you actually freeze motion and loose all milking.. BEFORE you come back down, and need to start adding compensation for highlight streaking..
Do that.. a lot! In different lights; different times of days, different angles, different framing on different waterfalls, to learn how much you need to compensate to get the exposure you want, rather than the camera measures. and forget about the filter, until you are hitting the buffers on the aperture&ISO.. and even THEN.. consider whether it would be 'better' to come back later in the day, or earlier in the morning when its naturally darker, or to choose a different framing or view point, rather than reach straight for the 'gadget'.
Like I said, problem is in your technique, not your gadget bag; ND filter isn't the 'solution' to the problem; and there are many ways to skin a cat; and alternatives to get the effect you desire without using a filter.
The 'cliche' has been created as this is a traditional academic exercise to teach THIS lesson on technique, and that you need that technique, YOU need to have the know how, and do the work, the gear wont do it for you.
Five Arches
