ZS30 Using iZoom


Using iZoom with the ZS30/TZ40

When using iZoom, which is essentially “processed cropping”, the images are automatically upsized to the full 18MP image size by in-camera interpolation.  That is undesirable, and therefore I always downsize the 18MP (4896x3672 pixels) iZoom image by the iZoom ratio.  That is, for a 40x (maximum) iZoom image, I downsize it to 20x, which means downsizing by a linear factor of two, to 2448x1836 pixels (4.5MP).  A 40x iZoom image actually represents a 4.5MP crop.

The resulting image is then quite comparable (except for the effects of iResolution as discussed above) to a crop from a full-sized 18MP image shot at maximum optical zoom (480mm) but with some posssible additional benefits.  Using iZoom may enable better framing of a very small, distant subject, as well as possibly better focussing/metering, than by simply using maximum optical zoom.

Using iZoom instead of EZ Zoom

As implemented on the ZS20 and ZS30, EZ Zoom (essentially a central crop of the sensor) is not very “user friendly”.  It is necessary to decide in advance a setting from a choice of 12MP, 8MP, 5MP or 3MP as the EZ zoom image size in the Picture Size menu item.  That takes some time to perform and in the meantime the desired subject may have moved, or the chosen EZ zoom setting may prove to be too small to encompass the particular subject.

iZoom is much simpler to use than EZ Zoom, because with iZoom ON, the zoom bar on the LCD is extended (in a paler colour blue).  Any iZoom setting from 20x up to 40x (plus any setting within the optical zoom range) can then readily be made using the zoom lever at any time and without needing to delve into a menu.

A Better Way

If a full sized 18MP image of a very small distant subject is required, and the use of maximum optical zoom (480mm) is insufficient, then it is preferable to use an attached teleconverter.  I have discussed using an adapter with the ZS30/TZ40 for attaching teleconverters and other lenses in another section here.

iZoom in Practice

Below are two iZoom images taken hand-held using my ZS30 (click on an image to see the full sized version).

Plane with daytime moon: ZS30 at 40x iZoom downsized; f/6.4, 1/250s, 100 ISO

Pelican: ZS30 plus Olympus C180; 40x iZoom downsized; f/6.4, 1/400s, 100 ISO

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