How Effective is Panasonic OIS ?

MICRO  FOUR THIRDS CAMERA PRACTICE

HOW EFFECTIVE  IS PANASONIC OIS ?

Author AndrewS  May 2012

Introduction    I recently conducted a systematic evaluation of Panasonic OIS using a Panasonic GH2 body with Panasonic 14-45 mm, 45-200 mm and 100-300 mm OIS lenses. In standing posture the camera was handheld for all exposures, using the EVF.  I held the camera as steady  as possible for each exposure using the same holding, breathing and shutter release technique for all shots. I photographed the center section of a test chart at shutter speeds from 1/4 sec to 1/1600 sec with OIS off for the first run then on for the second run. I repeated the whole test twice to check for variable results, which I found.

Limitations of method     Before detailing the findings I should say that measuring OIS effectiveness is an inexact process. There is considerable variation in camera shake from one frame to the next and deciding what is sharp and what is not sharp is to some extent subjective. So my second run of tests gave a slightly different result from the first.

Panasonic 14-45 mm OIS lens  Tested at 45 mm.  I was able to get sharp results handheld down to 1/80 sec with OIS off and 1/30 sec with OIS on. The improvement was 1.3 shutter speed steps.

Panasonic 45-200 mm OIS lens  Tested at 200 mm.  I got sharp results down to 1/320 sec with OIS off and 1/250 sec with OIS on, an advantage of 0.3 steps.  If I would accept slightly soft frames, that grew to 2.6 steps. You can see how the subjective factor comes into the equation.  There was a group of frames in the 1/100 sec to 1/200 sec which my notes record as "very slightly blurred".

Panasonic 100-300 mm OIS lens  Tested at 300 mm.  Results with this lens were variable. On my first run there was a benefit of 1.3 steps. On the second run I got sharp frames down to 1/500 sec with OIS off and 1/320 sec with OIS on, for a benefit of 0.3 steps. However if I would accept a slight amount of softness this increased to 1.0 steps. 

On both runs with this lens the OIS produced a markedly bimodal effect. There was a group of quite decently sharp frames from 1/25 sec to 1/50 sec, then a blurred group from 1/60 sec to 1/160 sec with sharpness improving again from 1/200 sec.

Findings 

1. None of the test runs showed a worse result at any shutter speed, hand held, with OIS on compared to OIS off.  The implication is that with these three lenses on this camera body there will be no harm done by leaving OIS on for all handheld shots.

2. The most useful thing about  OIS is it's ability to stabilise the viewfinder image when using telephoto lenses especially at the long end.  The 100-300 mm lens at 300mm with OIS on is eminently usable hand held in good light, which is remarkable considering the angle of view is only 4.1 degrees.

3. OIS does extend the useful hand holding shutter speed range of each lens by a small amount.

4. The most important factors in achieving sharp photos hand held are, in order of importance as indicated by the results of my trials:

a)  Good camera hold and shutter release technique. This includes posture, breathing, holding and finger movement control.

b)  Sufficiently fast shutter speed.  The old rule which says go no slower than  the reciprocal of the focal length (x2 for M43) is still useful.

c)  OIS can provide a small but potentially useful downwards extension of the useful hand held shutter speed range, but it is not a panacea for poor handholding technique.

5. I am at a loss to explain the bimodal effect of OIS with the 100-300 mm lens.