Wednesday, April 29, 2009

+1, +2, +4, +10

The G9 does macro! OK, in the current use of the term “macro”, all cameras seem to have macro capabilities. A previous post, showed how to get even closer closeups (should that be closer macros?) by using reverse mounted lenses or a +4X diopter attachment on the G9. A key consideration is to getting enough distance between camera and subject to adequately light the subject. Closeup lenses are much smaller and easier to use than reverse mounted 35mm lenses. This post compares four lenses: +1, +2, +4 and +10 diopters; each lens looks like a thick filter and is simply screwed into the Lensmate adapter.

The G9 was set at ISO 80, tungsten white balance, Av mode, maximum zoom, small Flexizone focus frame, auto focus , evaluative metering, raw+jpeg with color saturation turned slightly down for the jpeg, and mounted on a tripod. (To digress a moment, just think about all those options!). The Franiec cable release was used to minimize camera movement. The scene is lit from each side with continuous lighting at roughly a 45 degree angle. The camera is also angled at roughly 45 degrees to the scene. The camera and tripod were manually moved and realigned for each shot by trial and error to obtain a minimum focus distance to the mid point of the scene (the 3” label on the scale).

Knowing that limited depth of field is a problem with close-ups, the G9 was set for f5.6 – even though diffraction would not be minimized.

The image below is the basic scene as photographed with the G9 without any attachments. The front of the G9 camera body is about 20 inches from the scene. This image (and all images in this post) is uncropped but reduced in size from the in-camera jpeg.

Next, the +1 diopter lens was screwed into the Lensmate adapter and the camera moved closer. In the image below, the front of the camera is about 15 inches from the scene.

For the shot below, the +1 diopter lens was removed and replaced with a +2 diopter lens. At this distance, the G9 exposure system was tricked a bit by the black scale so I dialed in an exposure compensation of -2/3. The camera was 12 inches from the scene.

Next, the +2 was replaced by a +4 diopter lens. For the image below, the camera was moved to about 10 inches from the scene and exposure compensation changed to -1.

Next, the +4 diopter lens was replaced by the +10 lens. The camera was moved to 6 inches from the scene and exposure compensation was changed to minus 1-1/3. The two shots below were taken by moving the scene. Notice the extremely short depth of field. In fact, by moving the scene around a bit and playing with manual focus, I found that the subject must be within a distance of 6 to 7 inches when the G9 is at max zoom and fitted with the +10 diopter lens.

For the last shot, I returned to the +1 diopter lens but decreased the zoom. Placing the G9 in macro focus mode, I zoomed in until the “flower” (focus icon on the G9 LCD) turned gray (just short of the yellow line on the zoom display). Then the camera was placed as close as possible to the scene while still obtaining focus. This distance was about 10 inches (had been 15 inches at max zoom).

The built-in macro feature of the G9 is very useful but a simple set of screw-in close-up lenses can improve macro capability and flexibility significantly – and are easy to use. Try it!

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