Tag Archives: Graduated Neutral-Density

NiSi Filters: Initial Impressions

Today I picked up my new NiSi filters.

My filter kit now consists of:

  1. NiSi 150mm x 170mm Nano IR 1.2 (GND16/four-stop) soft graduated neutral-density filter;
  2. NiSi 150mm x 170mm Nano IR 0.9 (GND8/three-stop) reverse graduated neutral-density filter;
  3. NiSi 150mm x 150mm Nano IR 3.0 (ND1000/ten-stop) neutral-density filter; and
  4. NiSi filter holder for Canon EF 14mm f/2.8L II USM.

I just had a look at my new filters, and my initial observations are as follows:

  1. They are extremely high-quality glass filters.
  2. The filter holder for my Canon EF 14mm f/2.8L II USM is surprisingly large and heavy for its size.
  3. A 150mm filter is literally a handful; two hands are needed to safely mount and dismount filters this size.
  4. Extra care will be necessary when using them, as a drop could be disastrous.
  5. They take up considerable more room in the camera bag — particularly the filter holder.
  6. NiSi products are very nicely packaged.

The NiSi 150mm system is quite a change from my former Lee 100mm resin filters.

I am looking forward to using these.

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New NiSi Filters Ordered

Having recently replaced my Canon EF 16-35mm f/2.8L II USM with a Canon EF 14mm f/2.8L II USM, my Lee 100mm filter system was rendered obsolete.

Unfortunately, 100mm filters are not wide enough to work with the 14mm lens.  What I now need is 150mm filters, and I decided to invest in the NiSi 150mm filter system, which seems to be popular with landscape photographers.

Yesterday I ordered a filter holder specifically for my lens, a 150mm x 170mm 1.2 (four-stop) soft graduated neutral-density filter, a 150mm x 170mm 0.9 (three-stop) reverse graduated neutral-density filter, and a 150mm x 150mm 3.0 (ten-stop) neutral-density filter.

This lineup should nicely cover my needs.

Fortunately I was able to sell all of my other filters in one go (including some screw-on filters which were also surplus to my needs).

I am looking forward to picking up my new filters next week and putting them to use for some landscape photography and long-exposure cityscape photography.

Which Filters for Landscape Photographers?

A discussion about creative filters on an Internet forum got me thinking, and prompted me to post a quick article here on a question new landscape/seascape/cityscape photographers often ask: Which filters should I buy?

I personally recommend Lee filters (although I have a HiTech filter in my rig), and use the Lee filter holder and adapter ring.

I shoot cityscapes, landscapes and seascapes, and generally don’t use graduated ND filters for cityscapes, as I tend to only shoot at twilight, or otherwise when the light is soft and low in contrast.

For landscape and seascape images, particularly when shooting towards the brighest part of the sky, I recommend the following kit:

  1. 1.2 (four-stop) soft GND;
  2. 0.9 (three-stop) soft GND;
  3. 0.6 (two-stop) soft GND;
  4. two 0.9 (three-stop) ND; and
  5. ten-stop ND.

Apart from the 1.2 GND, this is the combination I use.  (At the time I bought my filters, the 1.2 GND may not have been available.)

I sometimes stack both of my grads, which provides for a five-stop transition.

My view is that 0.3 (one-stop) grads are useless in harsh Australian light.  For the money a good grad filter costs, I’d recommend something far more effective.

Some people recommend using hard grads for scenes with flat horizons (eg, ocean views), but in my experience of having shot a lot of seascape images, I’ve never found soft grads to be lacking.  Soft grads offer more flexibility and a less-pronounced transition between filtered and unfiltered subject matter.

Now, Lee filters are not particularly cheap, and buying all of the above equipment will be a rather expensive undertaking; so if I had to recommend a single filter to someone whose budget is only so accommodating, I would recommend the 0.9 soft grad.

Similarly, if someone could only have one neutral-density filter, I’d recommend 0.9.

A three-stop filter of either kind provides a good middle-of-the-road approach if one’s limitation is a single filter.

Natutrally, a photographer will quickly find a single filter limiting, but as a starting point it will provide sufficient flexibility.

Graduated Neutral-Density Filters in the Digital Age

Introduction to Graduated Neutral-Density Filters

Graduated neutral-density (GND) filters were used in the days of film to lower the contrast (sometimes expressed as ‘dynamic range’) in a scene.

When shooting a landscape or seascape image (especially when shooting towards a rising or setting sun), the difference in brightness between land (or sea) and sky can be significantly different, in the order of up to seven or eight stops.

The solution to this problem is GND filters, which are positioned in front of the lens, and optically even out the brightness levels between sky and foreground by darkening the much brighter sky via a semi-opaque darkened portion of the filter and transitioning to a non-filtered (ie, 100% transparent) portion of the filter.

Neutral refers to the grey, non-colour-altering property of the filter.

By positioning the filter such that the darker portion covers the sky and transitions to unfiltered where sky and land meet, the dynamic range in the scene can be reduced, which makes exposure easier.

GND filters come in various grades of darkness, measured in stops.

  • GND2 or 0.3 = one stop.
  • GND4 or 0.6 = two stops.
  • GND8 or 0.9 = three stops.

One major brand even offers intermediate GND filters, such as 0.75 (2.5 stops).

Transitions are ‘soft’ or ‘hard’, with soft GND filters transitioning subtly from dark to light, and hard filters transitioning more abruptly.

Soft filters are best used for uneven landscapes (eg, mountains) and hard filters for horizons (eg, oceans or flat landscapes).

So, what does ‘GND8’ mean?

There is a simple formula for translating the filter nomenclature into the number of stops of filtration offered by the filter.  The formula is as follows:

GNDx = 2 ^ y stops of darkness

Examples:

  • GND2 = 2 ^ 1 (ie, one stop)
  • GND4 = 2 ^ 2 (ie, two stops)
  • GND8 = 2 ^ 3 (ie, three stops)

Are GND Filters Necessary?

In the digital age, some people might propose, as an alternative to optical filters, exposure bracketing and blending of multiple exposures either manually, or using Photoshop’s own gradient filters.

My own philosophy is that while you can do this type of work in post-production, attempting to decrease the dynamic range in a scene during the capture phase makes capture and post-processing easier in the long term.

Depending on the nature and intensity of the light and cloud cover, the use of a GND filter at the capture phase may eliminate the need to employ exposure bracketing and blending in post-processing at a later stage.  In other cases, even stacking multiple GND filters may not produce a balanced single-frame exposure.  I have certainly experienced cases where the sky is still blown out despite me having stacked my two-stop and three-stop GND filters.

My approach is to use both GND filters at the capture phase, and blending during the post-processing phase.  I want to give myself the most flexibility and ensure I have a good range of exposures to cater for the dynamic range in the scene I have captured.

Recommended GND Filters

I personally use and recommend the Lee creative filter system.  It is a modular system, consisting of a filter holder, an adapter ring (for mounting the filter holder onto the lens) and the filters themselves.  Lee GND filters are 4 x 6″ (100 x 150mm) in size, and made of resin.

A filter system such as this is quite handy, as the filters are large enough to cover ultra-wide lenses without introducing vignetting, and if you have lenses with different filter thread sizes, all you need to do is buy an adapter ring of the appropriate size.  Adapter rings are quite inexpensive.

Unfortunately, the filters themselves are very expensive.  I chose the more expensive Lee filters because I had heard good things about Lee filters, and I had also heard about, and seen, the magenta colour cast introduced by Cokin filters.  Unfortunately the magenta colour cast issue is far from a simple case of brand, as I have personally experienced a magenta colour cast with my Lee filters when stacking GND and ND filters (both Lee-branded).  It may be a combination of the colour of the light, the white balance, the filters and even the camera.  The jury seems to be hung, but in my experience with Lee filters, colour casts have not been problematic for me with the exception of one dawn shoot.

Many people use the much less costly Cokin filters, which are more readily available, and have also shown themselves to work quite well.  Someone using the Cokin system may never experience magenta colour casts.  In my case, I decided not to risk it, so I opted for the Lee brand, which generally had much better feedback.

In Conclusion

My recommendation is always to give yourself the most options when it comes to capturing images.  You cannot easily add what wasn’t captured, and in my experience, using filters can eliminate the need for exposure blending.  However, I still bracket so that I have the most options, and I will mostly continue to blend exposures that were captured with filters.

Where filters can also help is in cases where there is movement in a scene.  Wind has a nasty habit of blowing branches and leaves, and if these are in the sky portion of a scene, blending multiple exposures will be somewhat tricky, whereas the use of a filter can eliminate that problem.