Canon PowerShot G3 Review
The G2's Color Effect exposure mode is now been removed, the replacement is a selectable Effect FUNC menu option available in all exposure modes. There are six default 'Effect' settings as well as a 'Custom Effect' which allows you to control sharpening, contrast and saturation.
The G3 also provides control over three aspects of the cameras internal processing algorithms. You can alter the sharpening, contrast and saturation of images. Although these settings are available in RAW mode they are not applied to the image in-camera but are stored in the RAW image header as the default settings for Canon's File Viewer Utility.
|Contrast -1||Contrast 0||Contrast +1|
|Saturation -1||Saturation 0||Saturation +1|
|Sharpening -1||Sharpening 0||Sharpening +1|
I'll have the same moan here that I've had before and that is that it's good to see some parameter control but that the range of adjustment should be higher. There should really be plus or minus three or five steps which would give the photographer far more control. It's also worth noting that the G3's default sharpening is lower than most other digital camera's, this seems to be in line with Canon's policy of not over-processing the image.
The G3 and S45 were both introduced with a new feature, the ability to 'focus bracket', that is to take a sequence of three shots at focus distances 'around' the current focus point. Images are shot with focus point of: current position, backwards and forward. You can choose from three different ranges of adjustment - small, medium and large. I'm sceptical of the usefulness of this feature on a compact digital camera.
The example sequence below was taken using a large position adjustment. Crops shown are from the same location in each image and have been enhanced with an unsharp mask (to emphasize the focus position).
|Current position (blue crayon)||Backward (away from camera)||Forward (closer to camera)|
ND (Neutral Density) Filter
An ND filter is a simply a filter which reduces the brightness of light entering the lens (without affecting color balance - hence 'neutral'). In the SLR world an ND filter would typically be attached to the end of the lens, however in the case of the G3 it's inside the camera and can be inserted or removed from the path of light between the lens and the CCD via a menu option. The ND filter in the G3 reduces brightness by three stops (3 EV).
There are three areas (I can think of) where an ND filter is useful: (1) When you want to reduce the shutter speed to blur movement (such as capturing a flowing river / waterfall), (2) When you want to use a wide aperture to reduce depth of field but the camera has reached its maximum shutter speed and (3) When using the camera with studio flash lights which typically have very high power output.
Using the ND Filter to maintain maximum aperture
In the example below we wanted to maintain maximum aperture (to reduce the depth of field and keep the background blurred) but without the ND filter there was too much light and even at the maximum shutter speed of 1/1250 sec the scene was overexposed. Enabling the ND filter reduces the amount of light transmitted to the CCD and now a normal exposure is possible.
|1/1250 sec (max), F2.8||1/500 sec, F2.8 + ND filter|
Using the ND filter to tame studio strobe lights/ internal flash
Most studio strobe systems have far too much power for prosumer digital cameras (because of their limited minimum aperture). My studio setup is normally configured to be used with a digital SLR and normal aperture would be around F13. The G3 was connected to the strobe system using a hot-shoe -> PC Sync terminal adapter. As you can see in the samples below even at F8.0 there is far too much light and the image is overexposed. Enabling the ND filter solves this problem, and the optimum aperture (with my strobes set to 1/3 power) was F5.6 with the ND filter.
The ND filter is also useful when using the internal flash at short subject distances (such as macros), in these situations the flash often has too much power even at its lowest setting. Enabling the ND filter will help.
|1/200 sec, F8.0||1/200 sec, F8.0 + ND filter||1/200 sec, F5.6 + ND filter|
|Morning At Picture Lake by Buzz Lightyear|
from Dawns first rays
|AT-6 Harvard by jarud|
from Trainer aircraft
|Matterhorn by ewng|