From The Beach: A Focus Stacking Test

Using Helicon Focus to merge photos

Liz’s shell project

A few weeks ago Liz and I started working on her shell macro photography project. Setting up a makeshift studio in the saloon, we rigged up three studio lights, made a softbox and, using Panasonic’s focus stacking feature, began the long process of photographing her shells.

The problem was that, with up to 50 images per shell, we were having issues stacking them. If all this sounds gobbledegook…

A stacked composite of around 30 images

What is focus stacking?

When shooting macro (close-up), it is difficult to get the entire subject in focus due to the limitations of depth of field. To get round this, we take multiple images, each with a slightly different point of focus. The traditional way of doing this was to set the camera to burst mode and slowly revolve the focus ring, but modern cameras can now do this for you automatically. Typically, focus starts at the front, or uppermost point, and works backwards.

That’s the easy bit. The problem is then taking these images and choosing the bit that’s in focus from each image, and merging them to make a composite, ending up with one image where the entire subject is in focus. Photoshop can do this but it’s pretty hit and miss, often resulting in unwanted artefacts.

Only the first twenty images were used for this composite, leaving the background out of focus

Helicon Focus

Enter Helicon Focus, a dedicated application designed specifically for stacking photos. It is extremely quick, faster than Photoshop by a factor of ten, and outputs a composited raw file, which can then be edited in your chosen photo editor.

Fun with masking

With the beauty of masking, there’s a lot you can do with these stacked images. You could use them all so that everything is in focus, or isolate the subject and throw the background out of focus. This composite is made up of only three images and then cropped…

Or you can isolate the subject and drop the background altogether. Here’s another cropped composite of around ten images. The remaining forty images (the camera was set to take 50 images per composite) were of the background, so I removed it.

Unbeknown to me at the time, this was a shell Liz had found and then discarded
The flowers and bud here are nettle-like, but it’s not a nettle. Does anyone know what this is?

You don’t need a tripod

Flora is an obvious macro subject and I make no apology for it! This was simply a test, my first time in the field playing with these settings. Today, flowers were quite difficult to capture as there was a light breeze, however, Helicon Focus can handle camera movement and does a good job in aligning frames.

There was a bit of movement between frames in this composite but Helicon Focus handled it well

In fact, many macro photographers shoot handheld, knowing that they can align their images in post easily. All of today’s  efforts were taken on a tripod but the results aren’t bad for a first attempt.

Take A Light

I didn’t have my strobe with me but I did pack my little Aputure light. This helped provide a little fill-in light and increase the isolation of the subject from the background.

Camera and lens

We’ve been using my Panasonic GX85 for both Liz’s shell project and the images taken today. We found this easier to use than the GH5, which is considerably bigger when suspended upside down on a tripod, inside a soft-box!

The GX85 produces images at 4,592px wide (compared to the GH5’s 6,000px), but this is plenty big enough for macro work. If we need bigger, we just upscale the images using Upscayl.

The lens is the Olympus 30mm 3.5 macro for micro four thirds. There’s a better 60mm version but since Liz wasn’t sure if her shell project would take off, we went budget for starters. For social media and even A4 prints, this setup is not bad at all.

Camera Settings

I did consider buying a macro lens for my full-frame Sony but the A7C doesn’t have focus stacking features, whereas the Panasonic does. You simply select ‘focus stacking’ in the menu, set the number of frames and the number of steps, and then decide if you want to focus from front to back, or randomly through the focus range. The ‘steps’ do not correlate to a specific distance, so you need to play with the settings to suit your subject. We opted for 50 images because Liz’s shells are all different sizes and lengths, but 50 is a lot if you opt for the narrowest step number.

The Olympus benefits from being sharp throughout the aperture range so we tend to shoot wide open and adjust the shutter speed, keeping the ISO on the GX85’s native 200.

As for Helicon Focus, we opt for render method B and keep everything else at default.

Shot at a steep angle, this went through the full focus range

Today was just a test and the editing a bit rough and ready for the sake of this post, but expect more macro posts where I’ll be profiling some of Liz’s stacked shell photos.

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