Sunday, September 20, 2009

G9: Wide Angle Converter Outdoors

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Previously, I showed the effects of using the Canon wide angle converter lens with my G9 indoors in a small room. Here’s a outdoor shot:






Without the wide angle converter, the scene looks like this:




Both shots were taken from a tripod with the G9 set for ISO 80 and manual exposure of 1/125 second at f4.5. Focus distance was manually set at infinity. These images are from the in-camera JPEG and downsized for display.

The purpose of this post was intended to be a comparison of the angle of view but, once again, that bright white fence is difficult to capture. Pixel peeping a bit, the fence is worse with the wide angle conversion lens as shown below.


The comparison above is the 1” x 1” section that would be printed at 300 dpi. That is, each crop contains 300 pixels and is shown here at 100% scale.

In fairness, I have to admit that every picture I’ve taken of that white fence using my G9 on a bright day shows chromatic aberration. Obviously, the wide angle converter makes the result even worse.

Although glad to have it, I haven’t used the wide angle converter as much as I thought but that doesn’t stop me from wanting an easily accessible 24mme lens.
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6 comments:

ajcarr said...

Gordon,

What you are seeing is not CA: it's Moiré fringing. Digital cameras suffer from it, by nature; analogue cameras do not. In front of the sensor on your G9 is an anti-aliasing filter that deliberately blurs the image to try to avoid this, but in this case it hasn't worked.

Interestingly, Leica don't use such a filter: they want maximum resolution, and then deal with Moiré in software.

Alun

Gordon Buck Jr. said...

Many thanks. As I wrote the post, I wondered if this was instead Moire fringing.

I make a small investment each week towards a Leica system but, so far, the result is a net loss. (More difficult than I thought to predict six numbers!)

ajcarr said...

Just regard the Moiré fringing as a testament to the high resolution of the Canon optics on the G9, even with the wide converter. Next time, try smearing some Vaseline on the front element: that should get rid of the Moiré problem. :-)

And of course, we'd all 'like a' Leica :-) However, I can think of better uses for my money (food, for a start).

Bronislaus Janulis / Framewright said...

Gordon,

FYI, I've just discovered that the G9 has a serious flaw. There are two screws that work loose over time, and short out the power system. This is common enough that numerous companies are in the repair business, with flat rate repairs, around $90.00. Guess how I discovered this.

Bron

Gordon Buck Jr. said...

That (loose screws) could be the reason for some of the "dead" G9 questions that pop up from time to time. Are the screws visible? How can this be prevented?

Bronislaus Janulis / Framewright said...

Google it, there are photos of a G9 being disassembled, showing where and how. I've taken mine apart to remove a dent, but I'm unwilling to pull apart the connectors needed to do this, though you may feel more comfortable doing it. Since mine is "blown", I'm just going to ship it to this outfit: http://www.camerasandparts.com/

I've talked to them on the phone; they seem competent, and got good reviews on one of the forums.