There are many benefits to shooting with the Phase One XF Camera System, with a series of features aimed at achieving the most optimal image quality possible. One of these features is Focus Stack, which has long been popular with product photographers, food photographers, and also has applications for landscape photography. It is not a new technique in itself, however, the fact that the XF can automate this (in conjunction with a Blue Ring Schneider Lens) means that the process is streamlined, optimized, and allows for much more precision.
One really exciting thing about the XF system is that, because it is firmware upgradeable, new features are continually being released by Phase One. Focus Stack is one of those features that users were able to update into their system. People often ask how you can justify the kind of price on this system, but it is this continually evolving ethos that I think most does it.
Why would you need to Focus Stack? When shooting on a medium format sensor, the depth of field at smaller apertures is much shallower than the equivalent on a 35mm. To counter this, you might have to stop down to f/22 to achieve the right depth of field, but this will not be using the sharpest part of the lens, so will lead to diffraction (soft focus). The sweet spot, which is between f/8 to f/11, may give a depth of field too shallow to keep every part of your subject in sharp focus, so by focus stacking, you can get all the detail you need, across the whole field of view without having to sacrifice critical sharpness.
Usually, it would be a case of having to manually adjust the focus on the lens, and taking a series of shots across the whole focus range of the image. This achieves the same result, but is not a quick process.
With the XF, you input the close focus point and save it as a value, then input the far focus point and save it as a value, tell the camera how many captures you want (for smaller items you will need more, for a landscape you might only need 3 or 4). From there, you simply press the rear capture button and the process is dealt with automatically by the XF system. Once you have your shots in Capture One, you output your TIF files to Helicon Focus and in a matter of minutes you will have your stacked image ready to go!
For particular applications Focus Stacking is a huge time saver, so if you think it would benefit your work, get in touch with us and we can arrange a demo for you!