Replicating filters in processing

Can you get away without ever actually buying and using a physical filter? Yes and no. There you go, that’s cleared that one up! There are certain filters that you can replicate in software relatively easily and some you can’t, writes Andrew James.

For example, you can’t replicate the polariser’s ability to remove reflections or glare after the shot has been taken. You might be able to tone down the glare but you can’t quite do what the polariser can do. However, you might be able to get around not having a ND Grad filter for a landscape if you think ahead and know what you need to capture in order to process it later.

In this Imaging Skills article you’ll get three video tutorials for the price of one!

My personal rule of thumb is to use physical filters when possible, as these will help me get the shot as near as possible to perfect at the taking stage. There is a satisfaction to this and it can save you time later. But, in times of a crisis, knowing what software can do for you and how to correctly process your image later will be very useful. There’s also a cost issue here. Good quality physical filters are expensive.

There are very few landscape pros these days who aren’t using a combination of physical filters and filters/techniques in processing to perfect their images. Having said that, I also think an image can be too perfect! I see a lot of these types of images on websites like 500pixels where every image seems absolutely flawless. I like a bit grunge here and there! It feels more real.

I expect and hope that you shoot raw for most of your work. Shooting raw by its nature gives you the most amount of information but it does need processing to bring out the best in it. You don’t need to go mad, but you do need to harness the power of software like Photoshop and Lightroom to give your images the edge. If anyone is daft enough (I know you’re not) to think this is cheating is forgetting that back in the dim and distant past when we used film, the film actually did this for you. Velvia slide film, for example, added rich saturation, warmth and contrast to every image you took with it. Now we have to do that bit ourselves but it only takes a few moments in processing.

Even a couple of very minor tweaks will improve a raw file.

By using nothing else other than Lightroom’s Grad Filter I am going to take the flatter raw file and bring out the drama in this landscape shot. Again, the original file was captured using a 2-stop ND Grad to make sure all the detail was there in order to transform the shot into the image I could see at the time, although I have pushed it a little further than normal so the change is more obvious. The following video takes you through the process a bit at a time, as well as demonstrating a new function that’s become available only with the new version of Lightroom. I’m afraid it’s 17 minutes long so grab yourself a coffee, tea, or probably even better, a glass of wine first!

What happens then if we don’t have a physical grad filter because we are a) too strapped to buy one b) forgetful and keep leaving it at home c) too lazy to get it out of the camera bag because it’s a bit fiddly to put on?

The images in this next video were taken just to demonstrate what you can and can’t get away with in Lightroom. The first image has overexposed the sky so the bottom half of the image is correctly exposed; the middle image has exposed to keep the detail in the sky but underexposed the rest; and the final shot is an attempt to expose somewhere in the middle and means that the sky is a little overexposed and the rest if slightly underexposed.

To find out the answer, settle down for another Lightroom session! Perhaps I should have said you needed a bottle of wine instead of just a glass!

Let’s go back to Normanton Church in Rutland and look at another way we could work if we didn’t have a physical filter. This isn’t technically a software filter either, just a way of replicating what a ND Grad filter does when it balances the exposure. I’ve not bothered to label the images below, as you have the hang of this now. One has been processed for the sky and the other for the foreground. They are taken from the same single frame because blending two separate frames where there is water movement would be very troublesome indeed. While this is a split raw file you could easily, where nothing moves, shoot two frames individually. Do this on a tripod though or the images won’t align.

By combining the light image and the dark image together in Photoshop and bringing the detail back through we can finish up with a seamless looking landscape shot that is exposed correctly for all areas of the image. In a higher contrast scene, this might be the only way to achieve a full dynamic range.

Here’s the final video. Second bottle of wine time perhaps?

Final thoughts
Hopefully even if you are a software rookie you’ll now have a much better idea on how to work with the Lightroom’s Grad Filter or play around in Photoshop. As you will have worked out, my simple view is that there is a place for both a physical filter in your kitbag and the ones provided in software. There is nothing scary about Lightroom and if you make a mistake at any time you can just go back or even start again from scratch by hitting reset which restores the raw file to its original state.

Published in Imaging Skills

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