Those of you who follow my Flickr stream will have noticed the abundance of photos displaying creamy, silky water surfaces - the result of a heavily darkened ND filter.

ND filters (short for Neutral Density) are quite simple: pieces of grey glass, depriving the lens of light, thus forcing the camera to use longer shutter speeds. One would wonder, why anyone would want less light, when we pay large amounts of money for lenses with wide aperture and lots of light? There can be many instances when the use of an ND filter is justified. For example, in very bright sunlight, when I want to be able to shoot with a wide aperture for bokeh. Or, in my case, when photographing water and wanting that silky look that comes from water splashing about during a very, very long exposure.

A common ND filter is the ND8. This is a 3 stop filter, which means that you have to open your aperture 3 stops to get the same amount of light as without the filter. I own an NDx1000 filter (10 stops). This filter increases the shutter speed by times one thousand. So if my normal shutter speed would be 1/10, I end up with 100 seconds. 0,5 seconds turn into 500 seconds. And here’s what happens during that time.

Created with Admarket’s flickrSLiDR.

The NDx1000 requires a bit of special handling. When you look at it, you see - blackness. It is almost solid black, so when attached to the lens, you’ll see nothing in the viewfinder. Nothing at all. So composing the image and focusing must be done beforehand, and the filter is screwed into place just before taking the photo. This doesn’t allow forvery spontaneous photos, but it certainly holds an element of surprise - what you see on the LCD is often much more surreal than you’d ever expected. The way the motion of water and clouds blur in a single frame  is quite special and it’s always a thrill to see the result after those minutes in the dark.
If you need more exposure time than you camera allows (usually 30 seconds) and use the B mode, a remote control is necessary, as holding the shutter button down fith your finger will result in motion blur. It is essential to keep the camera steady, so in addition to the remote, you’ll also need a sturdy tripod for those dreamy shots.

Post processing involves getting rid of the hotpixels (red or white pixels scattered across the darker areas as a result of sensor warming due to the long shutter speed) and perhaps also some noise filtering. The NDx1000 tends to give a rather warm color tint to the photo. I usually don’t correct this in the RAW converter, as I feel it adds to the dreamy wuality, but this can of course be adjusted.

A dark ND filter like this is quite a pricey item, but I feel it was worth the investment as I really enjoy to see the clouds sail by and the water turn silky in my new landscape photos. If you don’t want to invest big bucks in and NDx1000, go for an ND8 to begin with. It will give you the same results, only you have to be onsite at a later hour for a darker window of time.

Another FAQ that comes up a lot is what software I use to process my images. I do use quite a few, so let’s see them one by one.
My absolute fave is Canon’s own RAW converter, Digital Photo Professional, or DPP for short. It’s simple and straightforward to use and has some great features. I especially like the super-easy white balance adjustment wheel. Often I need no more processing than the options provided by DPP - a tiny bit of exposure correction, some contrast and WB tweaking and I’m ready for upload. A gallery of only RAW images can be viewed here.

I run all my photos through Photoshop CS4 - some only for resizing and framing, others for extensive post-processing using layers, different blending modes and several brushes.

I use two kinds of HDR software - Dynamic Photo HDR when I want that raw, contrasty, dramatic HDR look, and Photomatix when I’m looking for a softer, more subtle finish. DynamicPhoto HDR has some really nifty features, for example you can manually align your photos if you want, with transparent image visualization and graphically ingenious knobs for dragging the images into perfect alignment.

I have had a go at Corel Paint Shop Pro IX and found it a useful program that - not unimportantly - requires way less hardware than Photoshop. And I’ve tested Lightroom a few times but neither of these have really grown on me. Maybe I’ll have another try at the new Lightroom and let you know about the results.

One type of HDR is the DRI. The acronym is very straightforward: Dynamic Range Increase. DRI images are made using one single RAW file. The technique comes in handy when there is no possibility to shoot bracketed photos of a theme (for example moving objects) or when you simply want to see what it does to your photos Here is an example to what DRI can do for your photos.

One of my most popular photos and one I get most questions about is that of the St. Stephen’s Basilica in Budapest.

It was made with real HDR technique, for which I used 5 bracketed photos. HDR is virtually unavoidable in circumstances where you want strong lights and deep shadows to be equally visible in the picture. This is especially true of building interior photos.
The point of HDR is to increase the bit depth (and thus the dynamic range) of photos with different exposure values into one single file, which is then tone mapped in order to achieve the final result. HDR merging and tone mapping is usually done with designated software, such as Photomatix or Dynamic Photo HDR (I use the latter), but can also be done in Photoshop.
For the Bazilika image I put the camera on a tripod, lens pointing upwards to the huge dome. I always use my camera with full manual settings. Here the exposure values were ISO100 and f/16. I then manually adjusted the shutter speed between 1 and 20 seconds to achive the 5 exposures ranging from -2 to +2 EV.  Taking 5 photos in stead of the usual 3 that the camera’s built-in auto bracketing function will allow will get you smoother, more detailed HDR photos. I sometimes take as many as 9 bracketed shots for a single HDR - a tripod is, of course, necessary.

I shoot in RAW, but I usually convert the photos before loading them into the HDR software.  There the tone mapping process will define the end result - whether it will have the ‘overdone’ look or a more natural appearance is totally up to you. If a natural look is desired, the most important setting is the ‘Light Smoothing’ (Photomatix) and the ‘Dramatic Light Range’ (Dynamic Photo HDR).  Here I went for the natural version. To eliminate the greyish tint often caused by the tone mapping process, I also ran the photo through Photoshop, tweaking the color balance a bit to restore the original colors seen inside the church.

A useful tip for your HDR photos is to run them through the Auto Level function in PS - this has a surprisingly good way of removing your usual tone mapping errors, such as loss of contrast and funny color balance.

Finally, here are three of the 5 original shots used for the final photo and the tone mapped, non-photoshopped result: