How To Use A Neutral Density Filter In Photography

antonyz long exposure iceland waterfall ND filter

Long exposure is an exciting and popular genre of photography – and for expert reason. The diverseness of images possible and the ability to reinterpret an everyday scene past capturing longer periods of fourth dimension can lead to some astonishing photographs. Using high quality neutral density (ND) filters, such as the Hoya PROND range, to extend shutter speeds, can result in some spectacular images that wouldn't normally be possible using traditional methods of photography.

As a long exposure photographer, I often receive questions on how best to use ND filters in the field. It is not quite equally simple to affix the filter and have the shot. There are various stages of planning and methodology required to reach swell results. I prepare out below my personal workflow and whilst this is naturally non the only mode to do things, through my experience I have plant that this works best for me.

antonyz long exposure architecture ND filter

Planning

All photography requires a little planning and forethought. What is the shot nosotros are really trying to achieve and what is it that nosotros are trying to convey to the viewer. Long exposure photography is no different. In fact it takes a little more thought as condensing periods of fourth dimension into a single image, you have to visualise in advance where any movement will occur and how this will affect the final prototype.

Take extra care to ensure that you consider the borders of your paradigm when taking a long exposure photograph. Behave in heed that the periods of movement tin bring things into (or remove from) your frame, such as tree branches that may detract from the overall image etc.

antonyz long exposure miami skyline ND filter

Gear up and Focus

When you lot have thought about your composition and the desired photo, it is necessary to set up the camera on a sturdy tripod and frame the paradigm. It is at this stage that I recommend taking a test shot to determine right exposure, depth of field and focus. Comport in listen that y'all should try to use the lowest ISO possible to keep dissonance to a minimum and select the advisable aperture for the required depth of field. To read more than about aperture and depth of field, you can read my before article here.

In one case yous are happy with the results of these test shots, plough off autofocus, every bit the camera volition struggle to refocus when the filters are attached. If your camera or lens has whatsoever image stabilization or vibration reduction modes, and then these should be disengaged also, as they may introduce a slight blur where the camera is on a tripod.

antonyz long exposure skyscraper ND filter

What ND filter should you cull?

The adjacent pace is to attach the ND filter. Hoya PROND filters come in a range of different strengths of light reduction. This is measured in 'stops' of light. A mutual question here is what strength filter should you utilize? Well this depends on a mixture of things but ultimately what you are trying achieve in the final photograph. If you are seeking to enable the utilize of a slightly longer shutter speed to capture the essence of motion in the image, then consider using the ii-end (ND4) filter. If you desire to capture much more motion, such as fast moving clouds and water and so a 6 finish (ND64) filter may be more than useful. To exist able to extend shutter speeds extensively and capture ethereal images then consider the 9 end (ND500), 10 stop (ND1000) or the sixteen stop (ND100000). These can dramatically extend shutter times.

antonyz long exposure ocean sunset ND filter

Calculating the correct exposure

How to determine the correct shutter speed to recoup for the called ND filter often confuses some photographers as it requires a calculation. Quite merely, consider the earlier test shot that you took and brand annotation of the shutter speed. The aperture should not change equally this will change the depth of field and the overall look of the image (besides as the exposure).

And then you lot need to consider that for each reduction of a stop of light, the shutter speed needs to be halved. So if you are using a 6 stop filter and then y'all need to halve the shutter speed half dozen times. This tin be seen more easily as a written example:

If the test shot is 1/250^thof a second and a half dozen finish filter is fastened, then the final shutter speed will be i/4 of a second. The original shutter speed is but halved 6 times: 1/250 – one/125 – 1/lx – ane/30 – 1/15 – 1/8 – one/4.

antonyz long exposure london skyscraper ND filter

Taking the shot

Ensuring that the autofocus is off (as above), put the camera to manual mode and dial in the settings – the original discontinuity and ISO from the exam shot and the newly calculated shutter speed for the appropriate ND filter.

Information technology is of import to cover the viewfinder to prevent whatsoever stray light entering into the photographic camera. Most cameras either have a switch or a safety eyepiece cover to do this. Then using a remote release, trigger the shutter.

Depending on the selected ND filter, there can be times where the shutter speed will extend beyond 30 seconds. Every bit a 30 second exposure is the maximum amount of time that is allowed in transmission way, and so information technology volition necessary to switch to bulb mode and use a remote trigger to extend the shutter time beyond 30 seconds.

antonyz long exposure building ND filter

Review the Image

The final stage hither is to review the image captured. Bank check the histogram to ensure original test shot, as they should both be similar. You tin read more about histograms in my earlier article hither.

If your image is under or overexposed, then yous tin simply reshoot the paradigm with a longer or shorter shutter time to compensate.

antonyz long exposure london skyline ND filter

Conclusion

Neutral density filters open up a whole new array of opportunities to shoot scenes in a unique and artistic way. A lilliputian forethought is required to conceptualize how the terminal prototype volition stop upwards. The longer shutter-times will capture extra movement which can pb to dynamic yet ethereal images. I hope that my accompanying images provide yous with some examples of what can be achieved. You lot tin meet more than of my images on my website at antonyz.com/portfolio

I promise that you observe this article useful. For more detailed data on ND filters and all other aspects of long exposure photography, please exercise check out my new book – Mastering Long Exposure Photography – A Definitive Guide, published by Ammonite Press and available at all good bookstores and online. https://www.ammonitepress.com/photography/photography-techniques/mastering-long-exposure/

I likewise have an before tutorial on ND filters that y'all can read here and a review of the Hoya range of PROND filters hither .

Naturally delight also feel gratis to contact me if y'all have any questions or comments relating to this topic or whatsoever other photography question. Delight practice pass this post onto whatever photographer friends that you think may find this useful.

You lot can see more of my electric current work on Instagram @antonyzphotoand you tin read more almost me clicking here.