If static and dynamic elements come together in a scene, one can create eyecatching effects in an image by slowing down the shutter speed. Moving clouds appear as washed out stripes in the sky and waves turn into softened mist. In landscape photography ND 1.8 (6 stops) and ND 3.0 (10 stops) filters are very popular because in twilight situations or when the sun is low on the horizon they deliver appropriate exposure times in the lower range of minutes. My preferred filter supplier HAIDA has recently started to sell an ND filter with incredible 15 stops of light reduction (ND 4.5 or 32000x). This filter is intended for use in bright daylight, as by example it extends the exposure time of 1/125 second to 4 minutes and 22 seconds.
I was quite skeptical if this extremely dark piece of glass would deliver true color rendition and gave the filter a try on my recent trip to the north coast of Spain.
For my test images I used the 150x150mm Version but Haida sells also in 100x100mm size. The filter ships in a secure padded metal box and can be used without a foam gasket in the 150mm Haida filter holder. If you want to use it in the the Lee SW-150 Mark II holder you need to stick a foam gasket on the surface. There are 2 self adhesive gaskets in the box that should work well but I haven’t used them.
My experience with ND filters tells me that in general almost every filter differs more or less from the stated density. This can even change from batch to batch and therefor I always recommend to calibrate your ND filters before first use in the field. This will avoid any over- or underexposed images and increase your image quality significantly. First thing to know is that any dyed filter will lead to increased vignetting (or call it light falloff) the shorter the focal length you shoot. The reason is that light rays towards the corners of the image need to pass a longer way through the filter and get more darkened than rays that pass the filter straight in the center. Therefor I always recommend to use a 50mm lens (35mm Film equiv.) or longer for calibration where the effect gets negligible. If you shoot wider after calibration you simply need to manually brighten the corners of your image which should not be a big deal in post processing. You can learn about how to calibrate your own ND filters in this article.
By testing my Haida ND 4.5 I found out that it darkens by exactly 14,4 stops. So in fact we are talking about an ND 4.3 (21619x) filter. Slightly less than what was mentioned on the box but no deal braker for me. It is simply someting you should know before calculating your exposure time. Otherwise your images would be all slightly overexposed. To give you an example this filter expands your exposure time from 1/125 to 2:53 minutes. Perfect to use at full daylight.
Long story short: Haida has convinced me once again as the #1 ND Filter producer and the 15 stop Haida ND 4.5 delivers great and almost true color rendition as you can see in the comparison below.
These images have been processed in Adobe Camera RAW with almost identical adjustments. The image with the filter was processed with +500K in white balance and +2 in tint. Additionally I have corrected the hue of the blue tones in the SHL sliders by +10. If you are interested in reviewing the RAW files you can download a *.zip file with both images (NEF) and my *.xmp files here.
When reviewing the sharpness please note that it was quite windy when I took the images so that there was always a risk for slight camera movement. However I believe that I cannot see any significant difference in sharpness between the two shots even in 100% magnification.
My conclusion is clear. The Haida ND 4.5 is a highly recommended filter for serious long exposure photography. It allows for exposure times in the lower range of minutes during full daylight and can be used to create artistic effects even in harsh light when most landscape photographers avoid shooting. Well done, Haida!
The following links will guide you to the product pages at amazon.com
Finally I would like to give you a general recommendation as I get asked quite often about it. As an SLR shooter you should always close the viewfinder while exposing your shot. Most cameras are not sealed agains light that enters the viewfinder and can find it’s way through the mirror chamber to the sensor. If this happens you will find magenta artifacts in your images. So please make always sure that your viewfinder is fully covered.