Long Exposure Photography, ND Filter
I am loving my journey exploring long exposure photography, ND filter. I thought the best way to approach my personal education and maybe yours, was to take a series of images where the ISO and the f-stop remained unchanged, but the exposure time increased. By doing this I figured you would be able to compare the difference each exposure had on a scene; I always find this useful when I am looking at other content.
Long Exposure Photography Using a ND Filter
My kit for this experiment is the Canon 7dMkii, fitted with a 1Canon 10-18mm and a K&F 10 stop ND filter. For a very reasonably priced filter, it is working brilliantly. There is no apparent colour cast or vignetting. Throughout, I have been using manual mode in live view as this allows me to gauge what is happening when I change my settings.
This image of Colemere Lake, Nr Ellesmere in Shropshire was taken on an extremely bright day in June 2021.

ISO 100, f8, 25 secs
Long Exposure Photos – Set 1
Battling against the very bright conditions made it extremely difficult to keep any detail both in the sky and the lake, but I still got some nice cloud reflections in the water. I am now looking at a soft graduated filter to help balance the dynamic range between the foreground and sky.
This first series of long exposure photographs were taken at ISO 100, and at f8, the only difference being the shutter speed for each image. The only processing was done in Lightroom where I simply changed the white balance to Daylight.
As you can see, as I increased the exposure time I lost more and more detail in the sky, but managed to retain colour and detail in the reflection. It would appear that the sweet spot for this particular set of circumstances was ISO 100, f8 at 4 seconds exposure. These settings gave me both detail in the sky and the lake, with a fairly flat appearance on the surface of the water.

f8 3.2 seconds exposure

f8 4 seconds exposure

f8 5 seconds exposure

f8 6 seconds exposure

f8 8 seconds exposure

f8 10 seconds exposure

f8 13 seconds exposure

f8 15 seconds exposure

f8 20 seconds exposure
How to Take Long Exposure Photos – Set 2
So this set was taken at the same time and location, just a slightly different view. Settings were ISO 100, f8 with increasing exposures from 2.5 seconds through to 30 seconds.
It isn’t until you get to 13 seconds that you start to see the loss of detail in the sky. Personally I don’t think there is enough difference in the surface of the lake to justify going beyond 6 seconds in this particular instance. I appear to be losing detail in the sky upwards of 10 seconds.
At 2.5 seconds the image is slightly underexposed but at 5 seconds it is slightly overexposed; I think 3 seconds would have been on the money.

ISO 100, f8, 2.5 seconds exposure

ISO 100, f8, 5 seconds exposure

ISO 100, f8, 6 seconds exposure

ISO 100, f8, 8 seconds exposure

ISO 100, f8, 10 seconds exposure

ISO 100, f8, 13 seconds exposure

ISO 100, f8, 15 seconds exposure

ISO 100, f8, 20 seconds exposure

ISO 100, f8, 25 seconds exposure

ISO 100, f8, 30 seconds exposure
How to Take Long Exposure Photos – Set 3
ISO 100, f8, 6 – 600 seconds
This series of long exposure photos are from a different location and time of day. They were taken in Leominster, the small iron bridge spans the river Lugg at the bottom of town. I was there from about 5pm to 7pm, the light was nowhere near as bright due to cloud coverage plus a lot of overhanging trees cut out a lot of light.
None of the images below have been adjusted, they are straight from camera. In my opinion the 30 second exposure was about right, maybe another 10 seconds might have lifted it slightly.
The final image in this series was taken using bulb mode which I will cover in a separate post.

ISO 100, f8, 6 seconds exposure

ISO 100, f8, 13 seconds exposure

ISO 100, f8, 15 seconds exposure

ISO 100, f8, 20 seconds exposure

ISO 100, f8, 30 seconds exposure

ISO 100, f8, 600 seconds exposure
ISO 100, f9, 9 – 30 seconds

ISO 100, f9, 9 seconds exposure

ISO 100, f9, 10 seconds exposure

ISO 100, f9, 13 seconds exposure

ISO 100, f9, 20 seconds exposure

ISO 100, f9, 30 seconds exposure
ISO 100, f10, 10 – 30 seconds

ISO 100, f10, 10 seconds exposure

ISO 100, f10, 15 seconds exposure

ISO 100, f10, 30 seconds exposure
ISO 100, f10, 30 – 330 seconds
It was getting late now and the light was disappearing fast! I decided bulb mode was now required to give the camera a chance. Entering bulb mode is fairly simple, just find it in your menu’s and enable it. On my Canon I have to use the info button to set the bulb timer. Out of the following images the longest exposure of 330 seconds produced a well exposed image but personally I think I prefer the texture of the water of the 210 second exposure.

ISO 100, f11, 30 seconds exposure

ISO 100, f11, 121 seconds exposure

ISO 100, f11, 210 seconds exposure

ISO 100, f11, 330 seconds exposure
ISO 100, f14 – f25, 90 seconds
In this set I kept the exposure time the same [90 seconds] and moved up from f14 through to f25. For each image I used the auto exposure in Lightroom to see what difference it made to the image.
ISO 100, f14, 90 seconds exposure vs ISO 100, f14, 90 seconds auto exposure

ISO 100, f14, 90 seconds exposure
As you can see in the image below , using the auto exposure in Lightroom has brought a little more detail out in the shadows.

ISO 100, f14, 90 seconds auto exposure
Conclusion
At this stage I have simply been running through a set of exposures at a given f-number to see what the effect is on the image. The camera has been in manual mode with live view operating so I can see what is happening as I adjust my settings.
What is Long Exposure Photography