Don't leave home without your graduated filter!
If you're a fan of shooting sunrise or sunset, you shouldn't consider leaving home without your graduated filter. Of all the filters in your landscape photography kit (a circular polariser and ND filters being the other two components), this one is the one you will be most grateful for shooting in high contrasting scenes or at the beginning and end of the day.
Example on left: no filters vs using a graduated filter on the right
What does a graduated filter do?
A graduated filter has a part of the glass that is darker with a soft, medium or hard transition to a clearer part of the glass below. The goal of using one is to darken the brighter part of your image to the extent that you prevent your highlights from being blown out, as pure white information in your sky is impossible to recover. It acts to reduce the total dynamic range of your scene (i.e. the difference between the darkest and lightest part of your image), improving your in-camera result and making post-processing much simpler.
What are the different types of graduated filters?
There are various types of graduated filters available depending on the scene you are shooting - soft, medium, hard and reverse and these are also available in different strengths, usually 2-5 stops (0.6 - 1.5).
If you could only buy one graduated filter, we recommend the 3-stop soft graduated filter since is the most versatile for many different situations since it has such a gradual transition it doesn't seem to negatively affect objects that might be the horizon. The 3-stop seems to be about the right amount of darkening to cope with the difference between light and dark around sunrise and sunset, and it is our favourite filter for this reason.
Even better, we have recently added the convenience of a dual filter to our lineup of graduated filters - there are two options, a double hard/soft graduated filter and a double medium/reverse graduated filter, it certainly saves carrying two filters around!
Square or circular graduated filters - which is best?
The goal with a graduated filter is to provide a very even transition across your image both vertically and horizontally. The best way to do this is with a square graduated filter within a system like the Kase K9 kit that more than overlaps the outside of your lens, and is fully adjustable up/down to suit the scene.
Magnetic circular graduated filters have the benefit of being much smaller and more compact as well as being easy to attach, and you can stack these magnetically with other filters like a CPL or ND filter. They do tend to provide less even results, often producing a bit of vignetting in the corners in the middle of the scene. They are also limited since you can't adjust them up or down depending on your composition without having to move the whole camera up and down.
However, Kase's new Magnetic Graduated Master Kit or Magnetic Holder options have overcome this problem by offering a fully adjustable graduated filter that is magnetic. We love using this set when hiking as it is a lot more compact than taking a full square set.
Are there any alternatives to using a graduated filter?
Some photographers will tell you that they prefer to exposure bracket their images rather than using a graduated filter, for this you would need to take at least two images, one exposed for your darker foreground and one exposed correctly for your lighter sky. These can be merged in post-processing to create an HDR (high dynamic range) image.
If you have large RAW files, space is a consideration. If you shoot multiple exposures to create one final image, this takes up considerably more disk space. More importantly, if there are moving objects in the scene (think clouds, trees or water), you may find it difficult to blend these raw files together both automatically or manually.
That's why we prefer to get it right in camera using a graduated filter.
Should I still use the filters in Lightroom (or other editing tool) to further adjust the exposure in my image?
Absolutely! In fact, it would be silly not to do so. More often than not, it is only when you get home and see your image on the full screen that certain parts of the image will call out for refinement whether that's using a linear filter, radial filter or a targeted brush.
Using a graduated filter in the field gives you a great starting point, but you should definitely take the time to review, and further edit all or parts of your image to improve the overall exposure of all the elements in your scene using the filter tools within your editing software.
Now that you know just how important a graduated filter is for shooting in high contrast scenes, we hope you decide to add one to your photography kit!