G1X: Shake Icon

At slow shutter speeds, a blinking orange icon is displayed on the lower left portion of the G1X display.  This icon is to warn you that shutter speeds may be too slow and that a tripod is needed.  Once you know what it is, you realize that the icon is a shaky camera.  So when does the warning appear?

I set up a simple experience in which focal length, shutter speed, aperture, Image Stabilization and ISO were varied and noted the fastest shutter speed for which the shake icon remained turned on.  As suspected, ISO and aperture were quickly eliminated as having an effect.  The shake icon activation logic is a simple function of focal length and shutter speed; however, Image Stabilization (IS) is definitely a factor.

There is an old rule-of-thumb of 35mm photography that says the slowest shutter speed that should be hand-held is 1/focal length.  For example, when shooting a 100mm lens, a tripod should be used if the shutter speed is slower than 1/100 second.  This “rule” was developed before the introduction of Image Stabilization.  Of course, it is not a law of nature – only a rough guide for pointing to the need for a tripod.  A little too much coffee and a tripod is always needed!

In very rough terms, the old 1/focal length rule applies to the G1X when IS is turned OFF.  With IS turned ON, the shutter speed can be 3x slower before the shake icon appears.  All these “calculations” (if indeed they are done) are then rounded off.  Strangely (to me), the effects of digital zoom are not a factor.  Also, the IS effect on shake icon activation is identical whether IS is for single shot or continuous.  “Power IS” does not seem to matter. 

I can remember the simple rule of thumb but here’s a chart of the data.

G9 Shutter Lag

.

I’m one of the complainers about shutter lag with my G9 – even in manual mode – and, in the midst of a debate on a DPReview forum decided to conduct my own tests. But how to do so? At first, I imagined all sorts of timer circuitry, switches, etc. but since I don’t really know how to do that sort of thing, finally decided to try simply taking a photo of my computer screen. This crude approach actually worked surprisingly well – sort of.

I searched for an on screen timer and downloaded XNote Timer . This is a basic and free version of their more comprehensive XNote Stopwatch. The image above is one of the several hundred shots I took of XNote Timer from my LCD. (I know, I know – sort of sad, isn’t it?)

I was especially curious about differences in shutter lag with and without Image Stabilization (IS), the effect of the half-pressed shutter button (sometimes called pre-focus) and the quickness of all manual mode with IS off, display off, etc.

Both Imaging Resource and DPReview publish shutter lag values but their test results did not completely satisfy my curiosity. According to Imaging Resource, the G9 shutter lag is from 0.57 seconds at wide angle to 0.69 seconds at telephoto. When prefocused, the shutter lag is 0.088; with manual focus (but presumably auto exposure) the shutter lag is 0.58 seconds. According to DPReview, the full press lag is about 0.6 seconds; the half press lag is about 0.12 seconds with the LCD turned on but decreases to about 0.05 seconds if the LCD is off. I don’t have any particular reason to dispute these values.

No, the shutter lag of my G9 was never the 40.63 seconds in the picture. After starting XNote Timer, I took a picture every 10 seconds. (I watched the computer monitor – not the G9 display.) So the example represents the 4th shot and the delay was 0.63 seconds. I usually took a dozen shots (2 minutes worth), discarded any obvious long or short times and averaged those remaining. Here’s what I found.

Base Case (my typical setup): Av mode, RAW+JPEG, display on, evaluative metering, small flex frame focus, shot only IS on, AWB. Full press lag = 0.61 seconds.

Same as Base Case (above) but timed from shutter button half-pressed: Lag = 0.15 seconds! In spite of the crudeness of my method, the improvement in shutter lag was obvious. Additionally, I found that the half pressed shutter button reduced shutter lag time to about 0.15 seconds no matter what options were selected in the menu or function settings.

Base Case but with manual exposure, manual focus, IS off. Lag = 0.23 seconds. This test was done with a full length press of the shutter button. Again, lag was reduced to about 0.15 seconds when the shutter button was half pressed prior to completing the press.

In some tests, turning IS off shaved about 0.1 seconds from the shutter lag but other times there was no measured effect on the average time. All these tests were hand held and perhaps I was more steady some of the time. I’d guess that IS probably adds about 0.1 seconds to the lag.

Interestingly, I found that by turning off RAW and using JPEG only, setting white balance (instead of using auto white balance) and reducing resolution to M3 with Normal compression reduced shutter lag by about 0.2 seconds from the Base Case. This was unexpected but perhaps not really correct because by that time I was getting pretty good at taking the shutter lag test. As I got better and better at taking the shutter lag test, I even recorded some negative shutter lag! That is, I jumped the gun a bit while anticipating the 10 second interval. As my own lag improved, the first series of tests had to be repeated.

So I learned some things about shutter lag. The very best technique is, as expected, to first press the shutter button halfway to obtain focus, exposure, set the IS, etc. Complete the shutter button press on seeing/hearing the G9 confirm that it is ready. Full manual mode (manual exposure and manual focus with display off, IS off) is better than I’ve been crediting it.

Granted, this technique isn’t great but it was an instructive exercise and perhaps will be useful to others. My own reflexes are not particularly quick so these speeds should be easily beaten. Try a few variations and learn more about shutter lag.

.