Article

Introducing Slicing
also known as Image Stacking

Slicing, some call it image stacking, is a photographic skill or technique that allows you to get expanded depth of field. It is of use in many areas off photography, although probably best known in the areas of macro and extreme macro photography, as well as photography through microscopes. It can be useful used in many other areas from landscapes and scenic photography through the more specialist areas like food photography, property photography and many areas of advertising or product photography. So it is part of the range of skills that every professional photographer should know and most enthusiasts should at least have tried. The concept behind this is quite simple, you take a series of photographs with your camera on a tripod or locked in position in some other way, where each of these is the same except that the focus point changes. You therefore have a series of photos where everything that you want in focus is in focus in at least one photograph. You then put these photographs through a programme that selects the most in focus area from each and creates an overall photo with everything in focus. Photos right:- Taking a photograph close up into a lily is difficult. The central parts are near the camera and the petals some way back,  we cannot get them both in focus at the same time. Similarly the distance from the nearest petal to the furthest from the side presents a similar problem. Using slicing we can achieve the impossible in both situations.

By using slicing we are gaining control of depth of field, now its our choice what is and is not in focus, we can break boundaries that many do not realise is possible and achieve near magical results. It means we can take images now in situations that have a shallow depth of field and combine them, to produce any depth of field that we require.

So we are going from images like this:-

To this:-

Without changing anything except the focus point and taking a number of photos that are then combined.

Clicking on the above photos shows far larger versions, showing better the difference in detail in focus between these two.

Another example, from this:-

To this:-

While this may sound complicated it need not be, the process can be undertaken in a way that is predictable, reliable and with no difficulties and in the article Depth of field magic we have an actual project that you can try, using shareware that you can download and try without cost, and several sets of slices I have taken including both of the examples above, so to start you can just get to see the effect and how it is achieved. In the article what we can do with Helicon Focus,   I look at the programme being used in a little more detail and in capturing slices with a Nikon DSLR, I look at how I captured these slices.

I have produced a number of sets of slices, so you have some images to play with, if you want to have a go with Helicon Focus, but also included in each case the end result photo I produced and an animation sequence so that you can see what is happening.

• Slices - Coins   - the set used in Depth of field magic

• Slices - Chips  - another similar project using casino style chips and coins, spread over a larger distance. Some of the screens as taken while this set was being captured is shown in capturing slices with a Nikon DSLR.

• Slices - Red flower  another set showing how it can be used in photographing flowers so as to get every part in focus. Plus goes on to select which slices to include so as to control the depth of field that you want.

Programs to put the slices together

There are two programs that I am aware of that can convert slices into these all in focus images, Helicon Focus, we have mentioned above and covered in more depth in what we can do with Helicon focus. You can also see examples and collect some more sets of slices from the HeliconSoft website.

The second program is called 'Combine ZM' sometimes referred to as CZM. I have not at the moment written this up, but you can get to the developers home page at CZM,   they also have have a help manual available. While the Helicon version handles large images, 16 bit and more, Raw files and is straight forward to use, CZM cannot. CZM is often said to be more for enthusiasts who want to experiment, while its other attraction is that it is free. I suggest you try Helicon Focus first and then if you wish, also then try CZM once you understand what is happening and how to get the results you want.

More examples

There are, you will find, many examples of bugs, some very small, some very highly magnified. If these interest you then take a look at this link,  it contains well over 70 bugs and other small items all created with Helicon Focus. There are quite a few individual examples within the Helicon user forums, take a look at Helicon Forum Index . Another site you may like to take a look at is available here. On the same site is an article for those who like to experiment using a camera bellows and microscope objectives with slicing or image stacking as they call it. With 48 images to get the eye of an ant, and 99 to get part of the eye of a fly, this is entering a world few have seen before.  It has some impressive results and is an area I will be experimenting with when I have few days available.

Tethered shooting

Shooting tethered, with your camera connected to a computer is possible using a variety of programs, some of these are just storing the resulting images, where some allow you more control over the camera. While there are a lot of entries that come up when you search for variants around tethered shooting, there are far fewer when you look for tethered shooting and Liveview. Nikon cameras with Liveview can use Nikon Capture Control 2, but I haven't been able to identify any program for other cameras that can do as much.  If you have experience of others software that use real Liveview, so that you can see, focus and control the image live on the computer screen for any make of camera please let us know. If you don't want Liveview then there are a variety of programs available.