Nerdliness

The 2012 annular solar eclipse is just two weeks away. We are still scheduled to witness this magnificent event from Page, Arizona, almost exactly on the centerline of the annular eclipse path. The eclipse will occur about an hour before sunset, so the sun will be low in the western sky at the peak of annularity.

I took a minute yesterday afternoon to check the SOHO website for active sunspots and found that large spot 1472 was showing midway between the center and the limb of the sun. I went outside with the SX-40 and the solar adapter to take some practice shots. For the image at the right, I used the filter (of course) 1/1600′ shutter speed and F8.0 aperture with a film speed of 3200. Sunspot 1472 shows up at about 7 o’clock on the solar disk in the image.

I wanted to make sure that my earlier experiments would work when we are in Page on May 20th. I think that using the filter, a very fast film speed, a fast shutter speed and a normal aperture will enable me to capture the lunar/solar images just fine. Now, if the weather will cooperate, we have it made. 😉 Click on the solar image to enlarge.

I ordered some solar filters for all of our cameras so we can try to get images of the annular solar eclipse in May. The filters aren’t very substantial since they are made with cardboard tubing and have polymer filters, but they are cost-effective (~$10 each) and they work.

Image: Solar filter over Canon SX-40 with inset of solar photo I took – click to enlarge

The filters come with an adhesive felt liner that you install to allow a snug fit when you slip the filter over the objective lens of the camera. Once installed, the filter doesn’t interfere with the auto-focus mechanisms nor with any other camera function.

After some experimentation, I found that trying to use the cameras in auto modes (other than auto-focus) does not give good results; camera motion would blur most images. I tried using a tripod, but getting the image centered in the camera was taking too long. The eclipse would be over before getting all the proper adjustments.

I finally settled on using the camera in manual mode where you can independently set the film speed, aperture and shutter speed. I settled on ISO 3200 film speed, F5.6 for the aperture and 1/1250 second shutter speed. Holding the camera in my hands, the image was good enough to resolve sunspot 1445 currently transiting the solar surface. I uploaded a large image of the sun to the image viewer. Click on the link to view.