Olivia, Jack and Papa Build a Camera Obscura Out of a Bedroom!

Last week, our granddaughter Harper stayed with us (see previous post). This week, it is her brother Jack and cousin Olivia. They are also attending Dallas Parks & Recreation Outdoor Adventure Camp during the day and in the evening we're having other adventures with them. While Harper's camp was focused on photography, this week the focus at camp is on archery. Linda and I don't have a lot of archery experience so our evening adventures are things that are more in our wheelhouse. One of those is photography. :-)

Optics: the principle of the camera obscura.
Engraving, 1752. Wellcome Collection

Tuesday evening, the project was to build a camera obscura. If you aren't familiar with the term, it's an ancient discovery that by having a darkened room with a small hole in a wall or window, a view of the outside scene is projected onto the opposite wall. The image is inverted (sky below, ground above) and in practice is pretty dim. In this digital age, as an alternative to sitting for a long period for your eyes to become dark-adapted enough to see the image, you can capture it with a camera capable of taking long-exposure photographs. 

 There are various tutorials available online on how to create a camera obscura out of a room in your house and capture the image on a camera. We used this one from the George Eastman Museum. It's very clear and easy to follow.  

Outside view of Camera Obscura

In choosing a room to use, we went with the master bedroom. Not only does it have a window with a reasonably interesting view (our backyard) but there is just that one window and although the room has glass doors facing our patio, there is a storm shutter that (mostly) blocks all the light from it.

While the kids were at camp, I masked off the outside of the window which was simpler than trying to tape plastic over the inside. Using cardboard, a black tarp, some plastic bags and gaffer's tape it was pretty quick and easy to block out all light from the window. It ain't pretty, but it's functional. 

The next step was to make lens boards with pinhole lenses. After the kids got home, we sat down to fashion them from cardboard, washers and gaffer's tape. Olivia's has a smaller hole (aperture) which would potentially give a sharper image but requiring much longer exposures; the aperture on Jack's was a bit bigger. 

Next, we finished prepping the bedroom. Initially, we just used towels on the floor to block light coming in through doors and a towel hung over the bathroom door since it had a bigger gap, let more light through. Later, we tried painter's tape. 

As I mentioned, the image in even a darkened room is a bit dim. Given that it takes about a half-hour for our eyes to become dark-adapted after being in a brightly lit room, it wasn't really practical to stay locked up in the bedroom for that long given the kids still needed to get showers after a hot day at camp and we hadn't yet had dinner. Not to mention the impatience of a 12 year-old and a 10 year-old. :-D

Instead, I pulled out my Nikon D750 with a wide angle lens and we captured the view with exposures ranging from 30 to 55 seconds. Of the images below, the first was taken before dinner while it was still pretty bright outdoors; you can see there is still direct sunlight on the fence. It was also taken with Jack's pinhole lens with it's slightly larger aperture so the image is nice and bright. The other two were taken after dinner so it was getting a bit darker outside; there is only a sliver of direct sunlight on the fence. The first one is with Olivia's pinhole lens, the second with Jack's. 

These images have been inverted vertically to emphasize the "normal" view of the backyard but that means everything in the room is upside down with the bed on top (lit blue by the sky) and the ceiling fan down "in the grass". Also, notice that the entire inside of the room is the "camera". Pretty cool!

Shot early evening with larger aperture

Shot later in evening with smaller aperture

Shot later in evening with larger aperture

We have a few other ideas for the camera obscura, interesting alternatives to explore, so stay tuned... we might have more to share soon!

As always, click on an image to see it large.

Harper and Papa Chasing the ISS

UPDATE: Keep reading for the "rest of the story" but here is the same image as below but cropped vertically to focus attention more on the ISS trail. Enjoy!

Our granddaughter Harper stayed with us this week. During the day, she was attending Dallas Parks & Recreation Outdoor Adventure Camp and the theme this week was photography. As I am an avid shutterbug I also spent a little time each evening with her, messing around with cameras, talking about how to take good pictures, etc. 

As I was checking to see what the evening weather would be with the idea that we could maybe take some night sky shots, I noticed that Tuesday evening the International Space Station (ISS) was going to be passing over. Even better, it would be rising just over downtown when seen from up by White Rock Lake. That night around 9:00 pm, we headed up to Winfrey Point and set up my Nikon D750 with an Irix 15mm wide angle lens. Once the camera was set up on the tripod, I let Harper take all the test shots and then we set the camera to shoot a sequence of 20 second shots. ISS was going to be visible for about 7 minutes, only 3 of which would be visible to the camera facing due west. After it passed overhead, we also tried capturing shots to the northeast but lights and trees were in the way.

The next day we loaded the captured images into Lightroom and I did some basic edits for exposure, contrast, etc. and then we loaded them as layers in a single image in Photoshop. As each layer contained a section of the ISS flyover, our goal was to follow instructions from this online article to stack all the images to end up with one image with a full track of the ISS, from when it was first visible (about 10 degrees above the horizon) until it passed out of the camera frame. 

Unfortunately, while the weather report had been for clear skies, there was actually a lot of haze on the horizon and clouds across the path of the ISS. Here is the result of just stacking all the images.

Harper thinks this version is kind of cool and I agree. The streaks of the clouds are pretty surreal and the airplane trails and the few star trails convey a lot of action.  The problem is that you can only get glimpses of the ISS trail as it is mostly obscured by the clouds. Even where it might have been clearly visible in one frame, once we stack all the other frames on that then some or all of it is obscured by the clouds. 

That led us to research other ways to achieve what we were after. With the help of ChatGPT, we learned some Photoshop techniques that allowed us to selectively mask out everything but the ISS trail, stack those and combine them with a base image that included the foreground with the lake and downtown Dallas and in which most of the clouds were to the right. We also removed a couple of airplane trails so that the ISS trail is the "star" of the image.

Here is the end result. It's not exactly what we intended to shoot - the ISS trail is spotty and the gaps don't always match the cloud gaps in the base image - but we are pretty happy with it. 

This was just the start, though. Now we are watching out for other nights when the ISS will fly overhead where the skies are clear and it will pass over an interesting foreground like the lake and downtown in this image. More to come!

If you are interested in finding out when the ISS flies overhead where you live, there are many resources but one of my favorites is the Heavens Above. Here is the ISS Visible Passes chart and here are the details for the flyover we captured. 

As always, click on an image to enlarge. Clear skies, y'all!

Reasons to Be Cheerful

I am a big fan of the Talking Heads and David Byrne. I admire not only his music but also his passion for social consciousness, which is evident in his music, art, and writing. In 2018, he launched the web site and lecture series Reasons to Be Cheerful. Over the years their articles have been a great source of hopefulness and inspiration. 

The title of one of their latest articles, West Texas Oil Country is Revealing a Sky Full of Stars, caught my eye as my son Brian and I visited Big Bend National Park and McDonald Observatory back in April and had driven through the Permian Basin. Imagine my surprise to find that the article showcased a photo taken on that trip, the one I now use as the header for this blog and described in the post The Road to the Stars. Thanks to the author for including my image and for providing proper attribution. 

The article itself discusses the encouraging progress being made to reduce light pollution in West Texas, with the assistance of the oil industry. If you haven't been to Big Bend, you should definitely put it on your bucket list as the night sky there is truly breathtaking and must be witnessed firsthand. And make sure to attend a star party at McDonald Observatory, where scientists are conducting valuable research and the visitor staff excels at explaining the wonders of the night sky. 

Personally, I feel protecting the dark skies of West Texas is something worthwhile. In addition to the article above, you can find out more about dark sky protection in the area at web sites for the Greater Big Bend International Dark Sky Reserve and the International Dark Sky Association.

I still have addditional images and some video from our trip to share. Here is one of the Milky Way over Casa Grande taken from the Chisos Basin. This was captured with using the incredible Night Sight feature on my Pixel 7 phone. 

As always, click on images to see full-sized.