Acclimatising to aperture

I wrote this post long-hand in the 20 minutes I had to hang around after getting my flu jab. A version of it was actually supposed to go up yesterday on my regular posting day, but it didn’t, and there’s a good reason why.

My camera ended up at Jonathan’s Photo Warehouse here in Dunedin for a sensor clean. It’s a pretty new camera, so I was a bit worried (which is something I do), but it turns out this is just something that happens.

Let’s go back a bit, though, to how it ended up there in the first place. Well, I was doing my homework.

My first photography class was last week. We looked at a bunch of different camera settings, just as a beginner’s overview, talked a bit about aperture, shutter speed, and ISO, and had a go at using some of these in the online environment of Canon Play. It was a great start to the 8-week course, and we left with the task of getting used to the aperture mode on our cameras before our next class.

The aperture is basically the opening that lets light in, and it’s measured in f-stop numbers. When the f-stop is low, the opening is big, and when the f-stop is high, the opening is small. My lens is a f2.8, which means it’s a relatively wide-angle lens. From playing around with it, it looks like I can get it to an f22. Each of these different numbers give a different effect.

At f2.8 there’s a blurring around the focal point, like what’s happening to the other produce around the orange below.


At f22 all the fruit is in focus, but the image is a bit grainier overall.


I had a good play at the low, mid-range, and high numbers, just to see what happened, which was a useful exercise. Then, the next day, sitting in the library and working on my blog post, I put the images on my computer.

That’s when I noticed the spot. (“Out, damned spot!” etc., etc.)

Faintly present at f11, it really stood out at f22 (note: you can’t see it on the portrait image above because of the carpet, but when I tried these same shots in landscape, it was annoyingly present). It showed up in every picture, and in exactly the same spot. Which could only mean one thing. There was something – probably dust – on the sensor.

Now, I get pretty anxious about things like this, so I went to Jonathan’s to pick up a basic cleaning kit. I didn’t have my camera with me, so I brought the kit home and spent about an hour trying to blow out the dust from the mirror and the sensor using my new wee air blower friend.

Alas, to no avail. Well, that’s not totally true. It got rid of some of the problem, sure, but not all.

The internet reliably informed me that a wet clean was likely required. I know that at some point this is something I’ll need to do myself, especially if I’m taking this camera on the road (which I will be), but for now I was pretty happy to leave it with a professional. (I think $30 is a good price for my peace of mind.)

I’ve been able to do some limited testing since I got it back today (in the form of photographing the back of my immunisation consent form!) and it looks way better now.


So, to recap, while doing my homework, I not only learned about aperture, but I also learned a great way to check the state of my sensor (i.e. photographing something white with the aperture set at f22 to see what spots show up), how to do some basic cleaning, and where to go if I need professional help.

Not bad for my first week!


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