Long Exposure Photography

13th of January, 2022

Taking advantage of a recent lull in the misty rain I headed for the local hills to visit a waterfall I've been keen to see for a while. It was an ideal opportunity to get out and practice some long exposure photography. Haven't done any for a while and I like the effects you can get, especially with water. Blairskaith Linn waterfall and caves, Glasgow. 

For this trip I was using my trusty Sony A7iii, with an 18-105mm G lens fitted, and a tripod. It's essential to have a good tripod for trips like this; you need a good, steady base to shoot from. Any slight movement creates a blurry image, which is not what we want. 

This initial shot was taken at f8 on a 15 second exposure and ISO100. I have a variable ND filter on the lens over my protective UV cover. It can sometimes give a strange tint to an image, but that's why God invented LightRoom. Investing in a good quality set of ND filters for this kind of work is pretty important. I use them mainly for filming, but they obvioulsy have their uses in photogrpahy as well. The variable ND just gives me the flexibility to change the camera setings without the faff of removing and fitting new filters. With the small, delicate screw threads on the camera lenses and filters, the fewer times you can remove and fit them the better. 







I was also trying to experiment with different shutter speeds and ISO settings to get example images for a course I'm writing for budding drone pilots. It will be the bigger brother of the course we released specially for the Confederation of Roofing Contractors annual magazine. More details here: Practical Drone Flying

Some of the examples are below.

These are the same composition, just at different settings. The first image is f7.1 at a 1/200th exposure and ISO 5000. You can probably see the image is 'noisy' due to high ISO number. Lightroom can smooth some of that out, so I don't worry too much about grain in my images, unless I'm at a ridiculously high ISO. The Sony A7iii is capable of an ISO of 204800, which I'd probably only use if I was stuck in a cave in a bin bag. 

The second, middle image, is again at f7.1 but an exposure of 15 seconds at ISO 100. You can see it starting to get the distinctive smooth effect of a long exposure shot. Using the Variable ND filter meant I didn't have to disturb the camera to change to exposure of the image, just simply rotate the bezel to get a lighter or darker set of 'sunglasses' on the lens. 

The final image is f7.1, 30 seconds exposure and ISO 100. You can now see it just shows a curtain of misty water as opposed to individual droplets of streams of water. It's just a matter of testing and adjusting for the effect you want. The darker the filter (or the higher the number on your filter) the longer you can expose for without overexposing the image. Comes in useful when you're using the BULB feature on your camera.

I also took the wee DJI Mini 2 drone up with me as well. It made for some interesting flying as the GPS signal was particularly weak. Not a problem in itself, but it's something you need to be aware of if you're thinking of buying a drone for things like this.

Places like this cause problems for drones as the GPS signal can bounce off the terrain and cause something called Multi-path Interference. Which basically means your aircraft gets the GPS confused and, as you can't switch the GPS of in most models of drones, it'll start to drift or not reposnd to your inputs. Or the GPS signal just won't reach your aircraft. Again, without the facility to switch off your GPS it can lead to a few problems. 

Having said that, I think the Mini is a great bit of kit. For such a small sensor it does deliver a decent image. Even the 4k video looks good, which makes it a must for any budding photographer, in my opinion at least. It's a great little workhorse for smaller jobs in built up areas like property shoots. 

Unfortunately, due to the lack of stabilising GPS, I didn't get a chance to properly try long exspoure from the aircraft, but it's only January, so there's plenty of time this year. Plus it was cold and I would have had to try and stand absolutely still for the whole exposure, so maybe next time. 

This photo is a bracketed shot from the Mini which I then stitched in Lightroom in a few seconds. With minimal editing it'll produce a decent HDR photo like this. Much easier than exposing for all the lighting conditions then trying to mush them together later, especially if the drone is bouncing about in the conditions. 

All in all a good wee trip out into the countryside that I aim to repeat in more locations around the local area as soon as I can. Next time I'll be heading to the Loup of Fintry, a personal favourite, and the Campsie waterfall just down from the car park on Crow Road. 

Any suggestions for good places to go are always welcome.