When asked what a grad filter is most people will have a good understanding of what that is, but I thought I would just pop together a post to explain in a little more detail what my favourite type of grad is, how to use, the benefits of using it and why I prefer the hard grad over the soft. These are the type of things we talk about and show on the workshops I run.
As always with any of my posts, writing is not my strong point as a dyslexic and these points are all formed from my own experiences of using equipment out in the field/beach.
There are 3 types of Grads to consider. Soft, Hard and Reverse. We will take the reverse out of the equation straight away as that is something a bit more specialist, typically used at sunset or rise, just as the sun is sitting on the horizon.
Why not the soft grad though?
It is a very simple reason why I don’t favour the soft grad, I do own a fair few of then ranging from 1-4 stops and also have plenty of them in my training kits for workshops and for people to borrow if needed and I do use them when the time is right.
I live in Norfolk, the area known for big skies, you can see for miles on a clear day. Pop up to one of the church spires or the lighthouse and you will see for miles, around 20+ on a good day.
With nothing on the horizon to block the views and my main subject being landscapes my horizons are fairly straight forward with nothing protruding in from the sides of the image like rock pinnacles, large cliffs or mountains.
When you have a clear and mostly uninterrupted horizon line where the sea meets the sky, that area where the 2 meet normally is very noticeable in that one is lighter/darker than the other, hence we are using a grad filter to try and balance the 2 out.
If you placed a soft grad in the holder that has a gradual transition from no ND effect to the ND effect then the horizon line above/below where the image is darker will actually end up being overexposed.
This is due to the soft grad effect transitioning over a 4-5cm area on a 100x150mm filter as shown in the image below.
Now imagine the same shot looking straight out to sea, but this time you are using a Hard grad, the transition from no grad to grad is only 1.5 cm on the 100x150mm filter as shown in the image below.
That black line you see on the filter will drop right on the horizon, it is where the dark and light part of your image is going to be noticeably different and where you need to have the filter doing its job.
As you slide it into the holder, if you use live view or even look through the viewfinder you will see the filter doing its job as you push it down. As soon as the filter hits that horizon, you want to stop there.
As you can see from the images below the effect of one filter over the other is noticeable, the image top half appears to be darker with the grad and typically there are more details retained in the sky, I know they are not the best examples, but I am writing this during what is pretty much a worldwide lockdown, plus when I go out to shoot, being used to filters I know what ones to use as part of my set up process, or at least and starting to think about what to use, so I don’t tend to shoot many images with blown out skies and no filter or the wrong type, but I have done a few on some trips as learning tools.
You can see the difference in detail that is preserved by using the hard grad over the soft grad from the shots below. You have a more defined line of effect, but mostly you see all the extra detail the soft filter will have missed
The following images of Brograve wind pump give an example of what an image would look like at sunset if you used either no filters or a soft grad or a hard grad with a poloriser and also just for fun also a 10 stop ND as well. Each image says what it is if you hover over it.
Looking at the 1st image with no filter you will notice straight away that the in order to get the foreground to an acceptable exposure, the sky is burnt out and there is no recovery you can do for that in post-production apart from sky replacement, something I won’t do.
I have then placed in the 3 stop soft grad and adjusted the shutter speed slightly to allow for the exposure to be correct as it also had to allow for the poloriser filter, in this image go can see the difference in the sky to the left of the windpump, there is a lot of blown-out detail in the top of the sky and to the right-hand side of the wind pump. This was as much detail as I could recover from post.
In the next image the 2 stop hard grad, you can see the difference is much the same as the last shot, but the overexposed highlight area is now less and the sky has started to retain more details, the thing to note here is that the 1st image was shot using a 3 stop, this was done with a 2 stop filter and the amount of light stopped is 1 whole stop of difference.
The final image and the one I was most happy with was the one with the 3 stop hard grad. When you look at the sky you can see how much balancing it has done on the image being received by the sensor of the camera. This is what the filter is designed for, maximize everything you can from a scene and get it correct in-camera, a massive part of image-making for me. The exposure from the green foliage on the river bank blends well into the sky, it is not a case of one is brighter than the other and distracting the viewer’s eye from the shot.
To show you what can happen if you do use a hard grad in the wrong place, this following shot from in Snowdonia was taken on a rainy evening after the sun had dropped below the edge of the Devils Kitchen in the background of the shot. The still bright sky was a lot brighter than the dark valley floor, so I had to get as much of a filter effect on the top sky part of the images as possible, I knew I wanted the darkness of the hard grad, so the only option was to drop it in and slide the edge of the grad effect over the tops of the mountains. You can notice it, but only if you are looking for it, and with a little bit of editing you can then recover the shadows a bit to disguise it.
I hope this has answered a few questions for you, but as always with my posts, if something is unanswered or you want some more information then please do just ask.
The following images are some of my favourite images that may not have looked as nice unless I had the hard grad filters in my kit. All of these were taken between October 2019 and March 2020 and are some of my favourite places including the Overstrand on the Norfolk Coast, London and the Thames Barrier, Chrome Hill in the Peak District and Cummingston on the Moray Coast in the North East of Scotland.