Do I need graduated filters?

There’s a groundswell of opinion that the way to deal with the extremes of contrast in sunset and sunrise images in particular is to use a graduated ND filter. The principle is simple – set the filter so the darker part covers the brightest part of the image – usually the sky, and this then ‘holds back’ the light, giving a more balanced image. Sounds simple, but not so easy in practice. A tripod is essential to hold the camera still while the filter is correctly placed. That’s after you’ve worked out how strong a filter to use, and whether its a hard ‘grad’ (i.e. a quick transition from light to dark) or a soft ‘grad’ if a gentler transition is required. There’s also the small matter of carrying around the filters (up to 6 in a set) and the holder and adapters for different lenses, not to mention the cost of the filters themselves – could be £200 +.

Most decent digital cameras allow you to store the RAW image from the chip, and its generally possible to get quite a decent dynamic range by careful post processing – however with a really wide exposure range like the image below, that’s still not going to do the trick.

A very practical alternative is ‘exposure stacking’ – take one image exposed for the lighter parts of the scene (the sky here) and another exposed for the darker foreground detail. Then combine the two images in a programme like Photoshop to take the best bits of both. The image below was from images with 5 stops difference in exposure – far more than even grad filters could easily copy with, and was merged together in just a few minutes. Its a really practical way to cope with wide exposure differences – just remember to use a tripod so the 2 images correspond!


EDIT: Since writing this blog back in May 2014, I’ve actually invested in a set of grad filters. I don’t use them that often as its possible to wring a lot of detail out of Fuji RAW images, but there are times when they definitely help.

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