Helicon FB Tube – Configuration Utility
Configuration principle:
the tube arrives pre-configured, i.e. the default step is already pre-set, so once you mount the tube on the camera and set up the camera and the lens as described, you will be able to focus bracket. The main parameter for successful focus bracketing is the size of the step between the consecutive shots. If the step is too big, the DoF areas of consecutive shots will not overlap and once you merge them in focus stacking software you will see the blurred zones – a pattern typical for a wrong step size during focus bracketing. If the step is too small, the DoF areas of consecutive shots will overlap too much. In this case you will make more shots than needed for a good stack. So the main task is to determine the step that will allow the DoF areas to overlap to the extent sufficient not to leave any areas out of focus and not to cause excessive shots.
Such optimal step size depends on the lens, on it’s internal mechanics, on the aperture, since the DoF area differs depending on the aperture, and the distance to the object. That’s why we recommend to determine the right step experimentally: set the step – configure the tube – shoot a stack – merge the images in a focus stacking software and evaluate the result. You can find more details on how to find the optimal step at the Setting the step page.
There’s a number of lenses that have been tested and the step for them has been determined – we’ve included them to the Lens list in the Configuration Utility. If your lens is not on the list, you’re welcome to add it, find the optimal step size and save this value in the Configuration Utility. This will allow you to choose your lens from the list next time you will need to re-configure the tube, for instance, when you decide to shoot at a different aperture.
Main controls:
In order to set the step for your lens, aperture and shooting conditions, please install the Configuration Utility.
Camera type – choose between Nikon or Canon
Lens – choose your lens from the list of lenses or add one if it’s not on the list yet. The lens list includes the lenses that have been tested to determine the optimal step size.
Adding user lens
If your lens is not on the list, you need to determine the optimal step for your lens yourself and add this lens to the list for further convenience of configuration. Here’s the general algorithm of adding a lens shown for Android version of the utility, versions for other operation systems have similar functionality:
- open the lens list and tap the ‘plus’ sign in the bottom right-hand corner of the screen
- enter the lens name
- set the min and max aperture values for your lens
- press Save
- choose your current aperture value
- determine the optimal step size for this aperture
- once you found the right step size, press Save. The step size values will be automatically recalculated for other aperture values
- if you would like to change the step size you determined before, enter new value and press Save again
Editing or deleting user lens
The list of predefined lenses can’t be edited.
In order to edit the name or the aperture range for a user lens or to delete it, tap and hold on the name of lens and choose Edit or Delete.
Aperture – set the aperture you plan to shoot with. The step size depends on the aperture, since the latter influences DoF
Recommended step – the size of the step between two consecutive shots
Focusing steps of the tube is the value proportional to rotation of the focus ring of the lens, and not to the linear movement of focus in mm.
It's called ‘Recommended’, because for some lenses we’ve determined the optimal step, i.e. the one that will allow consecutive shots to overlap and not to leave areas out of focus, and on the other hand, for them not to overlap too much causing excessive shots.
We recommend to determine the step experimentally through successive refinement of the step size. The general algorithm is described at: https://www.heliconsoft.com/helicon-fb-tube-setting-step/
If, for one reason or another, you would like to set a different step size for one of the predefined lenses, choose the lens, the aperture, enter new step size value and press Save. You will see the ‘ * ’ symbol appear next to the lens name in the Lens window.
If you open the Lens list, you will see this lens with the ‘ * ’ symbol in the User lenses section of the list, it means that all the predefined lenses and their pre-determined steps will stay intact and all the changes will be made to their ‘ * ’ copies. In this way you will always be able to go back to default preset step values for predefined lenses.
Please note: Recommended step does not set the number of shots, but the size of the step. With Helicon FB Tube you focus on the initial shooting point and control the number of required shots by holding down and releasing the shutter button.
Direction
In course of focus bracketing focus can be shifted in two directions – from camera towards infinity, allowing you to focus on the nearest focus point and to move focus from front to back of the object, and vice versa – from infinity towards camera. In this case, you start shooting from the back of the object and the lens focus is moving to its front.
Suppress focus
Configuration No. 3 for Canon cameras requires suppressing focusing commands, so Suppress Focus option in the Utility should be checked if you want to use it. For instance, this Configuration No. 3 might be needed for some third-party lenses, like some Sigma ones.
