ND vs Polarizer

[fredlee70x7]

<p>I am looking to get a 2 stop ND filter so I can shoot wide open outdoor in bright sunlight. I wonder if I can use a polarizer (that I already have) instead to achieve the same/similar result. Is there output difference in image quality, assuming both filters are quality made?. Any comments?</p>

[howard_m]

<p>depending on the lens's max aperture, you'll probably find that 2 stop ND is no where near enough to be 'wide open' in 'bright sunlight'.</p>

<p>if you follow sunny16, you're only down to F/8 w/ a 2stop ND. Work the numbers and see what you need, probably more like 4 stop</p>

[howard_m]

<p>depending on the lens's max aperture, you'll probably find that 2 stop ND is no where near enough to be 'wide open' in 'bright sunlight'.</p>

<p>if you follow sunny16, you're only down to F/8 w/ a 2stop ND. Work the numbers and see what you need, probably more like 4 stop</p>

[david_henderson]

<p>I imagine that Frederico might be thinking of changing shutter speeds as well.</p>

<p>Otherwise, just remember that a polariser does some things that a neutral density filter doesn't do in addition to holding back light by maybe 1.5-2 stops depending on the polariser; such as darkening blue skies at certain angle with the sun, and reducing most types of reflections.</p>

[mendel_leisk]

<p>A Polarizer's only going to reduce light one stop at most.</p>

<p>I picked up a very heavy ND, good for around 6 stops or more. Have yet to really experiment with it, really should. You can take daytime time exposures, up to around 30 seconds, with all that entails. Things like motion blur (or complete disappearing) of pedestrians, daylight "streams" of traffic, glass-flat oceans, and so on.</p>

[Wouter Willemse]

<p>I've got a 6-stop ND with the idea of being able to shoot wide open (f/1.4 - f/2) in daylight. For where I am, 2 stops would not be enough (frequently ending up f/2.8, 1/8000th at lowest ISO). The downside, though, is that focussing with this filter on is undoable, so it does slow down and for me only works well with a tripod. In the end, I use the filter more for long exposures.<br>

And the wide open shots... I either wait for sundown, and shoot them then, without filters, or I accept that I cannot make that particular photo.</p>

[howard_m]

<p>If you have extra $$, you can get a variable ND filter which should really cover you. I use the new Tiffen which has a large front element (for you wide-angle fans (yes, I know about the 'X'))</p>

[norfolk_nsfw_maybee]

<p>Did nobody mention stacking 2 polarizing filters, then you have a variable ND filter?</p>

[joe_willmore]

<p>First, I second the comments about a 2-stop NDF. In bright light that won't make much of a difference. You really should look at 6-stop. I think I've even screwed 2 NDFs on top of each other at times.<br>

Second, I've heard of some shooters putting two polarizing filters on top of each other to get a NDF effect (make sure the degree of polarization is different with each filter so they block different light waves). I haven't tried it myself but 3 different shooters that I trust claim they've done this and had success with it.</p>