I have a question for some of the more experienced photographers on this site. Have you used neutral density filters (a.k.a. ND filters), especially with regards to urban photography? I am starting to play around with them and would love to hear any advice that anyone has.

 

Quick summary for those who don't know -- ND filters are essentially dark glass you put at the end of your camera lens to block some of the light coming in to the camera. This allows you to take longer exposures during daylight hours. The resulting photo looks like a normal daytime shot (for the parts of the photo that stay still) but the faster-moving elements turn into a blur. These are often used to get cool effects with water, like this:

 

Zuccarello [ Explore ] by Opiesse, on Flickr

 

Or with clouds:

 

Moving Clouds by ToZaFoto, on Flickr

 

While this technique seems to be most popular with nature photography, I have seen a few examples of this being used in urban areas:

 

Brooklyn Bridge Drama by digital-dreams, on Flickr

 

Anyone who has experience with this, please share your advice!

If you are looking for an overall smooth and silky effect, I would recommend using a square ND filter like from Cokin (http://www.cokin.co.uk/pages/cokinX.htm). Their X-Pro series is best if you have wide angle lenses. I switched over to the Lee 100mm system last year (http://www.leefilters.com/index.php/camera/index) and have been very pleased with the results. The main difference on this, other than price, is the quality of the plastic, but both are suitable for any situation.

 

Both companies make hard and soft ND filters. Hard ND filters are best for landscapes or horizon shots; soft ND filters are best for anything else (http://www.leefilters.com/index.php/camera/ndgrads). They also have just ND filters and what they call the "big stoppers" which can make daytime photos with clouds look absolutely amazing (haven't tried the latter yet but seen it in action).

 

I don't use my filters that often in urban settings since it's just not my thing, but I use it all the time in landscapes and during sunrises/sunsets/blue hours. Here is one I took with a Hard ND .7 filter a few nights ago:

 

 

It has a good horizon and I used the filter to block out the sky, allowing for a longer exposure on the bridge deck. To be safe, I did 5 exposures expecting to have to do some blending, but I didn't need to with the ND filter. Without it, the scene could still be possible but it would be a lot more work. For the examples you posted above, a ND filter would need to be required.

Thanks! I picked up three levels of solid ND filters but am not quite ready to invest in graduated ND filters yet. I might try getting multiple exposures and blending them. I will post some of my results here.

Some of my experimentation with a 10-stop ND filter at Washington Park:

 

 

Look at YOU getting all technical!

I have a question for some of the more experienced photographers on this site. Have you used neutral density filters (a.k.a. ND filters), especially with regards to urban photography? I am starting to play around with them and would love to hear any advice that anyone has.

 

In cinema production, ND filters have always been used to minimize depth of field in a brightly-lit scene (say exterior shots on a sunny day). In photography, it's for the same reason or for special effect. I personally use Tiffen filters for everything. They're big in California and used in Hollywood productions.

 

I personally use graduated ND's (top half of the filter is darker than bottom half) for sunset and sunrise shots with cityscape or general landscape. I prefer a soft transition as opposed to hard one. The secret is to keep it subtle so the foreground subject gets more light than the sky with the transition zone being soft along the horizon in your shot. A 2-stop or 4-stop graduated ND is generally about as far as I go. I also sometimes stack an ND with a Polarizer. Keep in mind polarizers result in a 2-stop loss of light themselves so the effect can be similar (thus a 2-stop ND + a Polarizer = a 4-stop loss of light). A goal of using ND filters is to make things look more natural as opposed to the more processed look of HDR. Keep in mind too that things like moving cars, boats, trains, etc. look bizarre in long exposures with HDR. This is where ND filters really shine. You can capture smooth streaking motion in long exposure that looks more natural and more pleasing to the eye.

 

If the primary goal is just to cut light to capture a longer exposure, why not just stop down the lens to f/16 or f/22 (or beyond)? The reason you generally don't want to do this is because most lenses peak in overall corner-to-corner sharpness around f/8 to f/11. Beyond that, you risk introducing diffraction, which results in a softer image across the frame. The level of diffraction varies from lens to lens, but as a general rule, you'll start to notice it if you stop down too much. Or maybe stopping down just isn't enough sometimes, and you are OK shooting at a small aperture on top of using an ND to get your desired effect.

 

*Also keep in mind modern digital camera sensors have far more dynamic range today than they did just 10 years ago. If you shoot in RAW (which you should be doing for any landscape work or work you plan to edit or print), you have a lot of detail to play with in highlights and shadows. This isn't the same as using a graduated ND, but the options in post today are pretty incredible. Personally, I shoot only RAW for my personal landscape and cityscape work (some which will be printed or go online for marketing), and I shoot RAW+JPEG for event coverage where I need to deliver some files quickly. I save the RAW files for editing later. Though honestly, if I'm shooting JPG, I might just deliver those and forget about the RAW files until much later for a different project or portfolio. :wink:

 

**Also, if you shoot with Canon DSLR's, use Highlight Tone Priority whenever possible since this gives you about an extra stop of highlight detail. I leave it on at all times.

I'm no expert yet, but here's a few other random shots I've taken with ND filters:

 

 

They only work well in a few areas, waterfalls and waterways being one of them.

 

 

The coast works really well, but having people (or moving objects) in the shot complicates things. With the shutter open long enough, the figures can become non-existent. Not long enough, and they can still show. The opener for the Walking Dead is really a great example of this being done well.

 

This one shot irritated me to no end. It was a very crowded day, and no matter how many times I tried, there would be some person showing through a 30"+ shot.

 

 

Eventually, patience won out. I did the exposure and had only 3 people walk through. None stopped long enough for it to be captured.

 

The red rocks with the skies would work really well if it was at sunset or had strong side lighting. I can see the rocks illuminate well with the evening sun and passing orange clouds!

 

Have you tried them at night yet?

I like the way that the coast photo above turned out with a scattering of people. But yeah, it's frustrating when you are trying to eliminate people from the photo and only a few get stuck in the shot.

 

I have ever tried it at night, will give that a try soon. More recently I have been playing around with using filters in the daytime to reduce depth of field rather than to get a longer exposure.