As I am familiar with some synthesizers, I often user real life circular sliders (e.g. to control the master volume), also called knobs. Like this one:
Sometimes I also find these controls in virtual applications (yes I like extreme minimalism =P):
But most of them are irritating, confusing or just wrong, and simple sliders could be used instead, making the UI much better. What are the advantages of circular sliders like the one in the screenshot above? And when do you use them? Thanks
Circular sliders will gain popularity as multitouch technology improves and users can actually "twist" the knobs with two fingers. I'd be interested if anyone has seen a well designed circular slider for an ipad app.
In my opinion, circular sliders don't have a place in mouse-driven UIs unless you are explicitly trying to make something look like its real life counterpart (i.e. training and simulation software).
IMHO, never. I can't really think of any real advantage besides that you're imitating a control people are familiar with from the real world. And I don't buy that this is worth the disadvantages you named.
When it controls the rotation of something. Of course, one must then make sure that the direction it points in is also the direction of the controlled object.
(I'm not familiar with this actual technology, so please ignore this answer if the knob can't actually be rotated 360 degrees)
Oh and they're handy when space is limited.
Propellerhead Reason uses them extensivly and does a good job of it.
The trick is to make the value go up and down when the user moves the mouse up and down (or maybe left to right) - almost like a slider. Never try to make the value depend on the mouse cursor angle!
Numeric tool tips also help.
As for good usage scenarios: If you need lots of adjustable values (like in a synthesizer) in limited UI space.
hmm, i remember some music software used those knobs, but i guess first of all they used them because they look same like on mixers.
I think the only other reason could be that it saves Space!
you need a square instead of a line that would be longer..
They don't take up much room, so many of them can be added to mixer controls etc.
Positions like 90 degrees left, right, or straight up are easy to see at a glance.
If you're already committed to abandoning the primary advantage of a software-based user interface over a hardware-based one (i.e. the ability to easily resize and rearrange control elements), just so that your program looks like a piece of rack-mounted audio hardware, then you might as well use knobs.
After all, they're no worse than the tiny little toggle switches, or the fake LED displays that can only show one item at a time.