Focus Stacking with Helicon Focus

I’ve recently begun to take my macro photography more seriously, or at least more often and took out a year’s subscription to Helicon Focus with the intention of seeing how much better it is for macro, than Photoshop. In this post I’m going to take us all the way through the process, from shooting using the Canon R5 II to focus stacking with Helicon Focus.

Video

Equipment

Canon EF 100mm L Macro Lens

I’ve owned the Canon EF 100mm L macro lens for a good many years now and have always loved the results, the colour is rich, the detail sharp and there is little fall off towards the edges. Auto stabilisation means you can if you’re careful use this handheld.

Canon R5 Mark II

Relatively new to my photography, I’ve owned this camera for about six months and absolutely love it. Check out my review. The feature that is of particular interest is the automated focus stacking.

Feisol TT-15 Mini Tripod

Very good for macro photography, basically a table top tripod about 6 inches in height, including the ball head (Feisol CB-30D). The legs don’t extend but can be set to three different angles for extra stability if needed.

Process

Camera Settings

Focus Bracketing is found in the fifth submenu of the camera settings (Red).

Switch Focus Bracketing from Disable to Enable

Number of shots – default is 100, essentially the more the better with macro, as the depth of field is so small. I went with 100 and used 70 of them.

Focus Increment between 1 and 10 – I went with 5 to begin with.

Exposure Smoothing set to Enable

Depth Composite – Disable

Flash Interval – 0 (I wasn’t using flash)

What Do These Settings Do?

Enabling focus bracketing means the next time you press the shutter, it will use the rest of the settings to deliver a collection of bracketed shots.

Number of Shots – if you keep your finger pressed on the shutter button it will fire off the selected number of shots or stop at the point it reaches end of focus. The advantage of taking more shots than you may need is that you’ll be able to precisely set the edge of focus in your image by discarding the sharp focus that go beyond that point. This is so simple and so blindingly obvious once you’ve thought of it!

Focus Increment – This setting adjusts the amount of focus shift between shots. 1 is “narrow”, 10 is “wide”. There is no fixed unit attached to this for the very good reason that it is worked out by the camera relative to the depth of the image. A macro might be sub millimetre, a landscape might be metres. You’ll develop a sense of this by experimentation.

Exposure Smoothing –  in macro photography your goal is to combine the images later to create a depth-of-field stack. Exposure smoothing corrects for effective aperture changes caused by focus shifts. The exposure is recorded with the first image in the sequence, and the camera then adjusts the brightness on subsequent images to match that initial exposure, ensuring consistent exposure across the entire focus bracket. 

Depth Composite – if this is enabled the camera will produce the composite image as a jpeg at the time of shooting. It uses the picture settings setting to determine the “look” of the jpeg. I haven’t tried this but I’d prefer to have control over the look of the final image by using Helicon Focus so I leave this disabled.

Crop Depth Composite enable the camera to crop the image. This compensates for the focus breathing that you would have to correct for if you were doing this manually.

Flash Interval – Default is 1 second and this is intended to give. the flash unit time to recycle. If your’e using a Canon flash or other compatible unit then you can set this to 0 and the camera will fire as soon as the flash is recycled. This is obviously dependent on the flash unit used, but in camera it is limited to settings over 1/125 sec for full-frame or 1/200 sec for crop mode. I use the Godox V1C and it works fine.

Shooting

Set up the camera and set focus to the nearest thing that you need in focus. I used aperture priority set to f/5.6 to give me a fairly shallow depth of field, 100 shots to cover a range of a couple of centimetres.

Once you’re set, press the shutter and hold it until it has finished shooting, you’ll hear it. That’s it!

Back in the studio, import the images into Lightroom as normal, select the whole range of images and choose Helicon Focus from the Export Menu. Note that the composited file that Helicon Focus creates is saved to the location of your choice and automatically registered in the Lightroom catalogue when you close Helicon.

Focus Stacking with Helicon Focus

Helicon Focus is a premium, specialist photo processing software that delivers focus stacking seamlessly and intuitively. There are a few bells and whistles added on such as the ability to retouch (most likely needed if something moved during the burst)

Helicon Focus have a very detailed user guide, but these are the highlights.

The focus blending is superlative, it offers a choice of three rendering methods, radius and smoothing controls.

Rendering Controls

The rendering methods include

• Weighted Average
• Depth Map
• Pyramid

Weighted Average calculates a weight for each pixel based on its contrast and then forms the weighted average of all pixels from all source images. This method works well for short stacks and preserves contrast and color.

Depth Map selects the source image containing the sharpest pixel and uses this information to form the “depth map”. This method requires that the order of images should always be consecutive. Perfectly renders textures on smooth surfaces.

Pyramid uses a pyramid approach to image processing, by dividing image signals into high and low frequencies. Gives good results in complex cases (intersecting objects, deep stacks), though increases contrast and glare.

Radius is only available in Weighted Average and Depth Map modes and sets the size of the area analysed to determine sharp focus around each pixel. High values will help to remove noise, unwanted artifacts, and halo, but at a cost of clarity. Low values ie. more precise definition of the pixel is likely to produce clearer, sharper images. As ever, this is a matter of compromise!

Smoothing is available in all modes and smooths the transitions between pin sharp and not quite so sharp areas if there are any. I hoped that by taking so many shots this task would be redundant and the result seems to bear that out.

Preview Mode

One of the better features of Helicon is the preview mode enables you to test the rendering methods in near real time. You don’t have to spend hours cross checking results, simply apply the changes you want and check the result.

Retouching

These controls include Copy from Source, Clone and Erase.

Copy from Source enables you to replace problematic areas on the output image by copying the same area from the relevant source image. This is performed after rendering, so the program shows you the source image selected from all of the source images and the rendered version.

Clone allows you to clone fragments within the output image just as in photoshop.

Erasure enables you to return the image to its previous state if you make a mistake that Undo can’t handle.

I haven’t properly tested the retouch tools so I’ll probably revisit the subject in a month or so when I have some good examples.

Finishing Up in Lightroom

For me, this is minimal, the combination of camera, lens and software produced a stunningly detailed image so all that was left was to delete the 100 input files and export the image produced by Helicon Focus.

Conclusion

I’m very impressed with Helicon Focus. It has substantially improved in the decade since I last used it, or perhaps the whole technology stack has improved but I found it very intuitive, it offers just enough controls to fill out Photoshop functionality and I will certainly be taking out the lifetime license when my year is up.