About
Acacia (formerly AssCam) is a Camera Assistant's app for Google's Android platform.
It is predominantly aimed at cinematographers shooting on both film and video, but is of some use to still photographers as well.
The current release is v0.5.4 ("Lucy").
Features
- Real-time calculation of:
- Depth Of Field (DOF)
- Field of View
- Hyperfocal distance
- Shot logging.
- Camera reporting
- Virtual slate function
- Equipment management for
There are also some cool additional features in progress. I tend to release things incrementally to get feedback from users, who've had some great ideas so far. Thus you'll find things which are not complete, or even started.
Instructions
Selecting Units
You'll probably want to start by selecting the basic units of measurement in Acacia. Press your phone's Menu key, then select
Settings from the main Menu. A dialog will pop up for you to choose between metres, feet, or inches. Note that regardless of the units setting here, focal lengths and the image plane
always use millimetres.
Managing Cameras
First, tap on the
Equip tab. Here's where you can create and manage a library of your cameras and lenses.
The
Select Camera spinner will be empty to begin with, as you've not added any to the library yet.
To add a new Camera, press the
New button beside the spinner.
A dialog will pop up in which you can enter a name to identify your camera.
Below that is the
Maximum Circle Of Confusion box, and then two boxes that define the width and height of the
Image Plane for your camera. You can set these manually, but typically you'd just use the spinner below them to set all three parameters according to one of the standard formats in the
Standard Guage spinner, such as the Super 16mm film format, the 1/3" sensor common in many digital video cameras, or full 35 mm frame. [If there is a common format you'd like to see, let me know and I can add it].
Once you're happy with your settings, press the
OK button to save them.
Notice that your new camera has been added to the Select Camera spinner. Tap the spinner to select which of your saved cameras to use.
You can edit the parameters of a camera by selecting it, then tapping the
Edit button, which will open the camera dialog for you to make your changes. You can get rid of a camera you don't want any more by selecting it then tapping
Delete.
Managing Lenses
Lenses are managed just below cameras in much the same way.
In the Lens dialog, you can again enter a descriptive name for your lens.
Below that you can enter the
Minimum Focus, or minimum object distance, for your new lens.
Below that is an admittedly
horrible interface
* for setting up the
Focal Length markings (or any other common focal lengths in which you're interested) for your lens. Typically you'd want to add at least the minimum and maximum focal length of your lens. By default, you'll start with a single entry of 50mm. To add new focal lengths, enter it in the box, then tap
Add. The new focal length marking will be added to the string of Focal Length marks. To remove an entry, enter the focal length and tap
Remove. You have to have at least one focal length mark; thus, you won't be able to remove the last one.
Below the focal length marks, you can set the
Minimum and
Maximum Aperture (or f-stop) for the lens. At present, there is no mechanism to deal with f-stops and T-stops
**. For now, use f-stops, since this is the correct measurement on which to base depth of field calculations.
* This will be remedied in the relatively near future. :-)
** This will also be remedied at some juncture.
The Optics Tab
Now we're ready to do something a bit more interesting.
Tap on the
Optics tab to see the DoF diagram.
Above the diagram, your currently-selected camera and lens are indicated. If you have not created a camera yet, the default is to diagram a standard 35mm camera (135 format). If you've not yet set up a lens, you'll be viewing a standard 50mm lens.
The diagram itself shows a variety of information. We'll get to that in a minute; first we'll look below the diagram at the controls available, which correspond to the focus, focal length, and aperture rings on your lens.
Immediately below the diagram are the
Focus controls, to set the Focal Distance. A desired Focus Distance can be entered directly into the text box, or incremented/decremented by the buttons on either side. The inner buttons nudge the distance by 1%; the outer ones by 20%.
Below that are the
Focal Length controls. Again, the focal length can be manually entered into the box, or can be manipulated with the surrounding buttons. The outer buttons move the Focal Length up to the next marking (remember, from the Lens dialog?). The inner ones nudge up or down 1mm at a time.
The lowest group of controls are the Aperture or
f-stop controls. A value can be entered directly in the text box. The outer buttons open and close the aperture by one full stop, and the inner ones move by a third of a stop.
Depth Of Focus, Field of View, Hyperfocal Distance Calculation
The horizontal white axes of the diagram represent the distance from the focal plane of the camera's film or sensor from 0 to infinity. Some reference distances are marked off in gray on the upper axis. Your lens's Minimum Focus Distance is labels in white, also on the upper axis.
Focus Limits: Your current
Focus Distance is marked by the
heavier red vertical line, and its value is labeled along the bottom axis. To each side of this is a lighter red line. These are the
Minimum and
Maximum Acceptable Focus Distance, respectively. Their distance from the image plane is also marked along the bottom axis. Everything that falls between these two distances is considered "acceptably in focus".
Depth Of Field: The distance between the Minimum and Maximum Acceptable distance lines is called the total
Depth Of Focus, and is represented by a
light blue line. The total depth of focus is labeled roughly at the mid-point, above the line. The distances in front of and behind the Focal Distance respectively are marked below the line, along with their percentage of the total depth of field.
Hyperfocal Distance: Along the top axis is a series of
light green ticks. The furthest (right-most) of these is called the
Hyperfocal Distance, and is labeled. The hyperfocal distance is the point of maximum depth of field; a lens focused at this point will acceptably focus everything between
half the hyperfocal distance (represented by the second furthest tick) and infinity.
Interestingly, the Hyperfocal Distance (F
h) yields an entire series of distances F
n = F
h / n, for any n. A lens focus at any F
n will acceptably focus everything between F
n+1 and F
n-1. The green ticks represent this series of fractions of the Hyperfocal Length, and can be used to roughly gauge the depth of field throughout the range.
Angle Of View: Finally, above the little camera icon at the far left are the Horizontal and Angle Field of View for the current focal length,
labeled in yellow text, and roughly diagrammed.
*If you care about geeky things, the scale is based on the arctangent of the focus distance
Managing Projects
(Incomplete).Before logging shots, you'll probably want to set up a project to keep your shoot organized.
Press the Menu key; select Projects from the main menu.
Logging Shots
(Incomplete).
Flashlight
Just a flashlight, which is sometimes useful when fumbling about in the dark.
Don't use this to white-balance your camera!*
This may disappear or be moved in future releases to accommodate new functions.
*One of Acacia's friendly competitors features a gray card feature - which does not make a lot of sense to me. (But other than, it's a very cool app, and you should check it out!)
Trouble-Shooting
The most common issue is a bug that causes Acacia to not restart properly. New installations should no longer get into this state, and I believe the new release should be able to get affected installations back and working. If you still have problems, I'd suggest you uninstall and re-install. Unfortunately, this means you'd lose your configured cameras and lenses.
If you do continue to have problems, please do take the time to let me know!
The Future
A number of enhancements are planned for Acacia, and it's likely that the next version will arrive in a couple of months (unless bug reports from the field warrant a quick interim release). Some of these are obvious incremental improvements - media management, usability improvements, performance improvements. The layout is likely to change in order to accommodate these changes.
Backup options and exporting to a convenient format will be supported soon, too.
I have some ideas for completely new features, that I hope will see the light of day in the not too distant future.
Feedback
I welcome and encourage you to provide feedback on your experiences using Acacia. Bugs and feature requests are important, but I'd like to know what kinds of projects you're using it for, which may help me prioritize the ideas I have for the future - I'm already aware of people using it for things I hadn't thought of.
Drop me a line at android at this domain name!
