I mainly have read details about how Canon's IS works but expect that similar issues exist with other manufacturers. Most of the information I have comes from Canon's various publications and from postings by Chuck Westfall (Technical Advisor for the Canon USA Consumer Imaging Group) on various forums and in his Tech Tips Column in the now defunct but archived 'The Digital Journalist'
http://digitaljournalist.org/archives/columns.html.
My conclusions from these articles is that the effect of using IS at high speeds or on a tripod depends upon the particular version of IS fitted to the particular lens. Whilst some of the changes are related to the age of the lens (eg the simplest form is fitted to the oldest design), Canon would appear to also be selecting the type of IS based upon the expected use of the lens, eg is it wide to short-tele zoom, an extreme tele or a macro lens. The comments apply to Canon EF SLR lenses, I don't know how applicable any of this information is to Canon compact or video cameras.
As I understand it Canon have three different kinds of IS in as far as the response to tripod use is concerned:
- those that can't detect the use of a tripod - generally these will degrade the image on a tripod as they do not respond well to the type of vibration likely to be present and the IS should be turned off, IS will probably work with a monopod;
- those that can detect the use of a tripod and switch IS off if detected;
- those that can detect the use of a tripod and change the response of the IS to match the likely vibration on a tripod.
I aso believe that Canon have five different approaches to dealing with panning and IS:
- lenses with no IS mode switch - generally do not work well when panning as cannot separate out panning motion from shake;
- lenses with an IS Mode 2 that can be used for horizontal panning, stabilisation is perpendicular to the panning direction (note I am not certain about this mode - arbitrary panning may be possible for all lenses with an IS Mode 2);
- lenses with an IS Mode 2 that allows panning in an arbitrary direction, stabilisation is perpendicular to the panning direction;
- lenses with an IS Mode 2 that allows panning in an arbitrary direction and an improved response to the start of panning, ie the viewfinder image does not show reverse motion (note this may only be available on lenses that also have IS Mode 3);
- lenses with an IS Mode 3, in addition to the Mode 2, which can better ignore rapid movement between subjects.
The Canon IS generally compensates for angular shake however on the EF100mm f/2.8L Macro IS USM they introduced hybrid stabilisation that can also compensate for camera shift at macro distances.
Different lenses use a mix of these characteristics and also different generations of stabilisation offering claimed vibration reduction performance equivalent to two to four stops.
It is therefore necessary to understand what IS features a particular lens has and perhaps carry out one's own tests.
Regards
Nigel