I Thought He Came With You is Robert Ellison’s blog about software, marketing, politics, photography and time lapse.

Golden Gate Bridge Timelapse

Golden Gate Bridge from near Fort Point

Shot from the Marin headlands, the Golden Gate Overlook and near Fort Point. I used an RX10 IV with an ND3.0 filter. Raw images were captured every four seconds with a one second exposure time. Edited with LRTimelapse and scored with Filmstro Pro.

I was expecting a pretty sunny day but ended up with regular showers and some pretty wild swings between sunshine and cold soggy overcast weather. I think the occasional raindrop and the mood swings work quite well, although the wind caused a bit of wobble on the long zoom onto the deck of the bridge.

(Previously)

3D Printing a 72-58mm step down Camera Filter Adapter

Thingiverse render of 72-58mm adapter

3D printed 72-58mm adapter in action on Sony RX10 IV

I have a 58mm ND5 filter that I bought to photograph the 2017 solar eclipse. It worked pretty well for that with my Sony RX100 V, but now I want to use it with an RX10 IV (which has the advantage of a 600mm equivalent zoom). The RX10 accepts 72mm filters and I want to try and photograph an ISS transit which is happening sooner than I can get hold of an adapter.

I figured someone must have done this before, but I can't find a file anywhere. It's a reasonably straightforward part - as the filter is smaller than the thread on the camera I just need a small cylinder which has a 72mm thread on the outside and 58mm on the inside. A step up adapter would be slightly more complicated to accommodate the larger filter size.

To build this I used OpenSCAD and this thread module. Open the thread module file in OpenSCAD and then you just need to subtract the inner thread from the outer thread like this:

This makes a simple 10mm tall adapter and you would just need to change the thread sizes to make it work for pretty much any combination of camera and filter (most filter sizes use a 0.75mm pitch as shown above). The vignetting is pretty extreme with the smaller filter and the size of the adapter. For this application I don't care, I'm only using the center of the image. If it's a problem for your application then it might be worth reducing the height of the adapter, at the expense of making it harder to detach from the camera.

Here is the adapter STL file on thingiverse.

After all that, I missed the transit by a couple of seconds. I thought the clock on my phone would be accurate enough but turns out it's 5 seconds off. So memo to self for next time - shoot over a longer window, or just take a video.

Philippine Tarsier

Tarsier on Bohol

(Recent Photos)

Comparing the Atmosphere to the Population of the United States

Composition of Earth's Atmosphere

If the atmosphere was the United States here's how it would break down:

Thor, Iowa is Hydrogen. Thor is the birthplace of John K. Hanson, founder of Winnebago. 179 people.

Florence, South Dakota is Krypton. 371 people.

Butterfield, Minnesota (home of the Butterfield Steam and Gas Engine Show) is Methane, 586 people.

Lewisport, Kentucky is Helium. Abraham Lincoln was unsuccessfully tried for operating a ferry without a license here in 1827. 1,706 people.

Maquoketa, Iowa is Neon. As of the time of writing Maquoketa Caves State Park is closed for bat hibernation. 5,921 people.

Gainesville, Florida is Carbon Dioxide. It's ranked by the National Coalition for the Homeless as the 5th meanest city. 132,567 people.

ChicagoCorpus Christi and Kimball, West Virginia make up Argon. 3,042,217 people total.

All that adds up to around 1% of the atmosphere, mostly Argon.

Oxygen is about 20%, that's California, New York, Oregon, Louisiana, Lake Station, Indiana and Cedar, Kansas. 68,225,139 people.

If you're not listed then you are Nitrogen. Close to 80% at 254,334,562 people.

(Population figures from the US Census 2017 estimates. Atmosphere composition from Wikipedia. Water vapor not included.)

Newsletter Improvements

It turns out I'm not great at getting a monthly newsletter out. Starting with the January 2019 newsletter I've put in place a new system - I'm storing summaries of new articles when I write them and also collecting a few links that might be of interest to ITHCWY readers. These should be sent out automatically on the first of the month so I should only skip the newsletter if nothing happened. Apologies in advance if there are any teething issues with the new format.

Surfing Dolphins

Dolphins off Ocean Beach

A pair of dolphins enjoying high surf off Ocean Beach, San Francisco

(Recent Photos)

Global Temperature Anomalies Animation, 1850 to 2018

Global temperature maximum anomaly from Jan 2010 to Nov 2018

I made this animation to visualize climate change based on the HadCRUT 4 data (specifically the ensemble median gridded data) from the Met Office Hadley Centre.

HadCRUT 4 provides temperature anomalies in a five degree grid by month and year from January 1850 to November 2018 (as of this post). Anomaly here means deviation from the 1961-1990 average.

In the animation I wanted to capture the full timespan of the data but also show long term trends. Each frame is a month of data and each five degree grid of longitude and latitude is colored based on the maximum cumulative anomaly (positive or negative) for each decade. The range for color is 0 to +/- 20.85 degrees, red for warmer and blue for cooler. This means there is a reset at the start of each decade, the first few years are mostly random noise but by the end of each decade you're seeing the range of extremes.

Spoiler alert - you can spot something happening in the last three decades.

As well as the change in temperature it's interesting to watch the increase in global coverage over time. It's surprising that even the most recent years have no readings for Antarctica. Here's a paper (PDF) discussing the impact of the missing data. The HadCRUT 4 FAQ has more detail on how the temperature anomalies were assembled.

(Previously)

Hummingbird 2

Hummingbird

A hummingbird at the Marine Cemetery in the Presidio.

(Previously)

(Recent Photos)

Treasure Island

San Francisco from Treasure Island

A timelapse from Treasure Island in the San Francisco Bay.

The first half of the video is looking west from Treasure Island and pans along the San Francisco waterfront. The second half was shot east towards Oakland and includes a storm sweeping in from the north.

Elephant Seals at San Simeon

Elephant Seals at San Simeon

Elephant Seals at San Simeon

Elephant Seals at San Simeon

Elephant Seals at San Simeon

Elephant Seals at San Simeon

Elephant Seals at San Simeon

Elephant Seals at San Simeon (Piedras Blancas elephant seal rookery).

(Recent Photos)