Josef “Jeff” Sipek

2017-03-23

The million dollar engineering problem — Scaling infrastructure in the cloud is easy, so it’s easy to fall into the trap of scaling infrastructure instead of improving efficiency.

Some Notes on the “Who wrote Linux” Kerfuffle

The Ghosts of Internet Time

How a personal project became an exhibition of the most beautifully photographed and detailed bugs you ever saw — Amazing photos of various bugs.

Calculator for Field of View of a Camera and Lens

The Megaprocessor — A microprocessor built from discrete transistors.

Why Pascal is Not My Favorite Programming Language

EAA Video — An assortment of EAA produced videos related to just about anything aircraft related (from homebuilding to aerobatics to history).

The Unreasonable Effectiveness of Recurrent Neural Networks

The Mobile Cat

About three weeks ago I got the idea to put a phone in front of the cat and use it to light her. It took a while for everything to align (she needed to be resting just the right way, it had to be dark, and I had to notice and have my camera handy), but I think the result was worth it:

D750: A Year In Statistics

It has been a year since I got the D750 and I thought it would be fun to gather some statistics about the photos.

While I have used a total of 5 different lenses with the D750, only three of them got to see any serious use. The lenses are:

Nikon AF Nikkor 50mm f/1.8D
This is the lens I used for the first month. Old, cheap, but very good.
Nikon AF Nikkor 70-300mm f/4-5.6D ED
I got this lens many years ago for my D70. During the first month of D750 ownership, I couldn’t resist seeing what it would behave like on the D750. It was a disaster. This lens just doesn’t create a good enough image for the D750’s 24 megapixel sensor.
Nikon AF-S Nikkor 24-120mm f/4 ED VR
I used this lens when I test-drove the D750, so technically I didn’t take these with my camera. With that said, I’m including it because it makes some of the graphs look more interesting.
Nikon AF-S Nikkor 24-70mm f/2.8G ED
After a month of using the 50mm, I got this lens which became my walk around lens.
Nikon AF-S Nikkor 70-200mm f/2.8G ED VR II
Back in June, Nikon had a sale and that ended up being just good enough to convince me to spend more money on photography gear.

Now that we’ve covered what lenses I have used, let’s take a look at some graphs. First of all, the number of images taken with each lens:

Not very surprising. Since June, I have been taking with me either the 24-70mm, or 70-200mm, or both if the extra weight is not a bother. So it is no surprise that the vast majority of my photos have been taken with those two lenses. The 50mm is all about that first month when I had a new toy (the D750!) and so I dragged it everywhere. (And to be fair, the 50mm lens is so compact that it is really easy to drag it everywhere.) The 230 photos taken with the 70-300mm are all (failed) attempts at plane spotting photography.

First, let’s look at the breakdown by ISO (in 1/3 stop increments):

This is not a surprising graph at all. The D750’s base ISO is 100 and the maximum native ISO is 12800. It is therefore no surprise that most of the photos were taken at ISO 100.

I am a bit amused by the spikes at 200, 400, and 800. I know exactly why these happen—when I have to adjust the exposure by a large amount, I tend to scroll the wheels a multiple of three notches.

Outside of the range, there are a couple of photos (52) taken at ISO 50 (which Nikon calls “Lo 1”) to work around the lack of an ND filter. There is actually one other photo outside of the native ISO range that I did not plot at all—the one photo I took at ISO 51200 (“Hi 2”) as a test.

Now, let’s break the numbers down differently—by the aperture used (again in 1/3 stop increments):

I am actually surprised that so many of them are at f/2.8. I’m well aware that most lenses need to be stepped down a little for best image quality, but apparently I don’t do that a third of the time. It is for this kind of insight that I decided to make this blahg post.

Moving on to focal length. This is by far the least interesting graph.

You can clearly see 4 large spikes—at 24 mm, 50 mm, 70 mm, and 200 mm. All of those are because of focal length limits of the lenses. Removing any data points over 500 yields a slightly more readable graph:

It is interesting that the focal length that is embedded in the image doesn’t seem to be just any integer, but rather there appear to be “steps” in which it changes. The step also isn’t constant. For example, the 70-200mm lens seems to encode 5 mm steps above approximately 130 mm but 2-3 mm below it.

I realize this is a useless number given that we are dealing with nothing like a unimodal distribution, but I was curious what the mean focal length was. (I already know that the most common ones are 24 mm and 70 mm for the 24-70mm, and 70 mm and 200 mm for the 70-200mm lens.)

Lens Mean Focal Length Count
24-120    73.24138 87
24-70    46.72043 6485
50    50.00000 1020
70-200    151.69536 4438
70-300    227.82609 230

Keep in mind these numbers include the removed spikes.

Just eyeballing the shutter speed data, I think that it isn’t even worth plotting.

So, that’s it for this year. I found the (basic) statistics interesting enough, and I learned that I stay at f/2.8 a bit too much.

Flying around Mount Monadnock

Last week I planned on doing a nice cross country flight from Wikipedia article: Fitchburg. Inspired by Garrett Fisher’s photos, I took my camera and the 70-200mm lens with me hoping to get a couple of nice photos of the landscapes in New Hampshire.

Sadly, after taking off from KFIT I found out that not only was there the stiff wind that was forecasted (that’s fine) but the air was sufficiently bumpy that it wouldn’t have been a fun flight. On top of that, the ADS-B unit was having problems acquiring a GPS signal. (Supposedly, the firmware sometimes gets into a funny state like this. The good news is that there is a firmware update available that should address this.) I contacted KASH tower to check if they could see my transponder—they did, so I didn’t have to worry about being totally invisible.

Since I was already off the ground, I decided to do some nearby sightseeing, landing practice, and playing with the Garmin GNS 430 GPS.

First, I headed northwest toward Wikipedia article: Mount Monadnock. While I have seen it in the distance several times before, I never got to see it up close, so this seemed like a worthwhile destination.

As I approached it, I ended up taking out my camera and getting a couple of photos of the hills and mountains in New Hampshire. It was interesting how the the view to the north (deeper into New Hampshire) is hilly, but the view more east (and certainly south) is flatter. (Both taken near Mount Monadnock.)

While the visibility was more than good enough for flying, it didn’t work out that well for photography. In all of the photos, the landscape far away ended up being heavily blue-tinted. No amount of playing around with white balance adjustment in Lightroom was able to correct it. (Either the background was too blue, or the foreground was too yellow/brown.) That’s why all of these photos are black and white.

I made a full turn around Monadnock, taking a number of shots but this one is my favorite:

Once done with Monadnock, I headed south to the Wikipedia article: Quabbin Reservoir in Massachusetts. This is a view toward the south from near its north end:

At this point I started heading to KORH to do some landing practice. Since I was plenty busy, there are no photos.

I’ve never been to this airport before and landing at new airports is always fun. The first interesting thing about it is that it is situated on a hill. While most airports around here are at 200-400 feet MSL, this one is at 1000 feet. The westerly wind favored runway 29 which meant I got to see a second interesting aspect of this airport. The beginning of runway 29 is on the edge of the hill. That by itself doesn’t sound very interesting, but consider that the runway is at 1000 feet while the bottom of the hill (a mere 0.9 km away) is at 500 feet MSL. That is approximately a 17% grade. So, as you approach the runway, at first it looks like you are way too high but the ground comes up significantly faster than normal.

I am still hoping to do my originally planned cross country flight at some point. Rest assured that I will blahg about it.

Plane-spotting in Manchester, NH

Last weekend I got to drive to Wikipedia article: Manchester, so I used the opportunity to kill some time near the airport by watching planes and taking photos (gallery).

The winds were coming from the south, so runway 17 was in use. I think those are the best plane spotting conditions at KMHT.

It is relatively easy to watch aircraft depart and fly directly overhead:

Unlike all my previous plane spotting, this time I tried something new—inspired by Mike Kelly’s Airportraits, I decided to try to make some composite images. Here is a Southwest Boeing 737 sporting one of the Wikipedia article: special liveries:

It was certainly an interesting experience.

At first I thought that I would be able to use the 7 frames/second that the D750 can do for the whole departure, but it turns out that the planes move far too slowly, so the camera buffer filled up way too soon and the frame rate became somewhat erratic. What mostly ended up working was switching to 3 frames/second and taking bursts. Next time, aiming for about 2 frames/second should give me enough images to work with.

Even though I used a tripod, I expected that I would have to align the images to remove the minor misalignment between images due to the vibration from the rather strong wind and my hand depressing the shutter. It turns out that the misalignment (of approximately 10 pixels) was minor enough that it did not change the final image.

Here’s an American Airlines commuter taking off from runway 17. (I repositioned to get a less head-on photo as well.)

For those curious, I post processed each of the images in Lightroom, exported them as TIFFs, and then used GIMP to do the layering and masking. Finally, I exported the final image and imported it back into Lightroom for safekeeping.

As a final treat, as I was packing up a US Army Gulfstream took off:

As far as I can tell, they use this one to transport VIPs. I wonder who was on board…

Visiting Helsinki

Back in July and August I got to visit Helsinki. Needless to say, I dragged my camera and lenses along and did some sightseeing. Helsinki is a relatively new but welcoming city.

July

My first trip there was in early July (7th-10th). This meant that I was there about two weeks after the summer solstice. At 60°10’ north, this has been the northernmost place I’ve ever been. (I’m not really counting the layover in Reykjavik at 63°59’ north, although I do have an interesting story about that for another time.) If you combine these two relatively boring facts (very far north and near solstice timing), you end up with nearly 19 hours of daylight! This gave me ample time to explore. Below are a couple of photos I took while there. There are more in the gallery.

Approaching Wikipedia article: Senate Square and the Wikipedia article: Helsinki Cathedral:

The cathedral:

Not far from this (Lutheran) cathedral is an Eastern Orthodox cathedral—Wikipedia article: Uspenski Cathedral.

And here is its interior:

Like a number of other cities in Europe, Helsinki is filled with bikes. Most sidewalks seem to be divided into two parts—one for walking and one for biking. The public transit seems to include bike rentals. These rental bikes are very…yellow.

Suomenlinna

On Saturday, July 9th, I took a ferry to the nearby sea fortress—Wikipedia article: Suomenlinna—where I spent the day.

Of course there is a (small) church there. (You can also see it in the above photo in the haze.) This one has a sea-fortress-inspired chain running around it.

The whole fortress is made up of six islands. This allows you to see some of the fortifications up close as well as at some distance.

There are plenty of small buildings of various types scattered around the islands. Some of them are still used as residences, while others got turned into a museum or some other public space.

August

The August trip was longer and consisted of more roaming around the city.

The Helsinki Cathedral in the distance.

There are a fair number of churches—here is the Wikipedia article: Kamppi Chapel.

Heading west of the city center (toward Wikipedia article: Länsisatama) one cannot miss the fact that Helsinki is a coastal city.

Finally, on the last day of my August trip I got to see some sea creatures right in front of the cathedral. They were made of various pieces of plastic. As far as I could tell, this art installation was about environmental awareness.

I took so long to finish writing this post that I’ve gotten to visit Helsinki again last month…but more about that in a separate post. Safe travels!

Septemberfest 2016 - Birds of Prey

This past weekend, the Dunstable Rural Land Trust had its annual Septemberfest event (yes, it ended up being in early October this year). Holly and I went to it armed with the cameras hoping to get some nice images of birds from the “Birds of Prey” program. We were not disappointed.

So far, I have managed to sift through only the bird photos. I still have to go through the other ones (e.g., the colorful autumn shots) and figure out which are the keepers. I set up a gallery which I’ll update with the non-bird photos in the near future.

Without further ado, here are the birds!

The peregrine falcon:

The screech owl:

The great horned owl:

The Harris’s hawk:

The red-tailed hawk:

The American kestrel:

The golden eagle:

This is only a fraction of the photos that are in the gallery, so make sure to check it out for more avian goodness.

First Attempt at Food Photography

Yesterday evening, I decided that making dinner and photography should be combined more often. As a result, I dragged my camera, the 70-200mm zoom, the flash, and the tripod to the kitchen to try my hand at taking some photos of scrambled eggs—or to be more specific, scrambled eggs as they were cooking.

The fully extended tripod left the Arca-Swiss plate about nose-level. With the D750 with the 70-200mm on top, the LCD on the camera was just above my head. The swiveling LCD on the camera was rather useful and made it significantly easier to review test shots, and mess with the flash output.

As far as the food itself is concerned, I prepared two bowls—one with five cracked eggs, and the other with some shredded ham slices and swiss cheese slices.

Here is a (terrible) diagram showing the setup from above to better explain it.

The four-circle thing in the middle is the stove, with the skillet on the bottom right burner (the scribble with a handle sticking out). The camera on the tripod is in the bottom right corner of the diagram. To the left of the stove is the flash. It’s on top of a cardboard box that the 70-200mm came in. Above the stove is a stove hood with a couple of lights pointing down at the stove top.

I used a wooden spatula in the otherwise empty skillet to have something to focus on. After I got the focus right where I expected the food to be, I switched to manual focus. In the process of taking those test shots, I ended up concluding that I need both the flash and the stove hood and kitchen lights to get something resembling the right kind of lighting. Of course the kitchen light color temperature did not match the flash, so I grabbed the orange gel and put it on the flash. (This is the first time I used a gel on a flash!) It worked.

It was time to start cooking! Once the bacon grease on the skillet got hot enough, I poured the eggs in, and quickly moved to the camera to get some more test shots—to make sure that the exposure, focus, and composition were good. I ended up tweaking the focus and flash output.

After I scrambled the eggs a little, I dumped the ham and cheese on top and moved it around a bit to avoid a large mountain of ham and cheese. Then it was time to go back to the camera—to get the final shots.

Even though I was zoomed in near 200 mm, I ended up cropping significantly to get the shot I wanted. I suppose this would have been a good time to use a macro lens (which I do not have).

I set up a gallery for my food photography, but so far the only image there is the one above. Obviously, this means that I have to take more food photos. :)

Sunset over Mount Monadnock

Back at the end of June, I hiked up the nearby Gibbet Hill in Wikipedia article: Groton to watch the sunset and get some nice shots of the western sky. (gallery)

Both times I went, I arrived about 20 minutes before the sunset, and got situated. Once the actual sunset started happening, it was a matter of a minute or two before the sun was gone.

Just before sunset @ 24mm:

Sunset @ 70mm:

The peak that the sun sat behind is Wikipedia article: Mount Monadnock—about 50 km from Groton.

I took a couple of panorama shots. I like this one the best (6 shots):

While hiking up the hill, I spotted this tree against the colorful sky. I had to get a silhouette:

I was surprised at how little time the entire trip took. From leaving the house to getting back, it was about 70 minutes. This is certainly a quick photo shoot compared to the day-long trips like the one to Boston in early June ([1,2,3]).

Stellafane (2016)

Last weekend we drove to Wikipedia article: Springfield, VT to attend the Stellafane Convention. In short, it’s two and a half days of camping, astronomy and telescope making talks, and of course observing. I brought my camera (D750), two lenses (24-70mm f/2.8 and 70-200mm f/2.8), and a tripod. Over the two and a half days, I ended up taking 400 shots of just about everything of some interest. I post processed about 60 and created a gallery. I’m going to include only some in this post, so make sure to check out the gallery for more shots that just didn’t fit the narrative here.

Thursday

Thursday was mainly about arriving in the late afternoon, setting up the tent, and doing some observing once it got dark. Photography-wise, my primary goal for Thursday was to get some sky images at 24mm. I tried some long exposure (657 seconds) to get some star trails:

There was a decent number of people walking around with red lights (so as not to destroy night vision), so a number of my shots ended up with some red light trails near the ground. (That’s that wobbly red line.)

I also took a decent amount of short exposures (10-16 seconds). At 24mm on the D750, 13 seconds seems to be just about when stars start to turn into trails.

This is the only staged shot—I intentionally left one of our red flashlights on in the tent to provide something interesting in the foreground.

Here is our tent-neighbor and friend looking up at the sky. He didn’t actually know that I was taking a shot of the milky way, and I didn’t realize that he managed to sneak into the frame. The trees got lit up by some joker driving around with headlights on. I expected that to ruin the shot, but it actually worked out pretty well.

Friday

Friday is the first full day. I started it by hiking to the other side of the site, which not only sports a nice view, but also nonzero phone and data coverage:

The original club house is there as well in all its pink glory:

The last, but not least, building there is the turret solar telescope:

Right next to it is the location of the amateur telescope contest. Yes, people build their own telescopes and enter them into a competition to see whose is the best. This year, the most eye grabbing (in my opinion) was a pair of scaled down reconstructions of the 8-inch Alvan Clark refractor. Here’s one of them:

I couldn’t resist taking a couple of close-up shots:

Heading back toward the main site, I walked past the observatory set up in such a way as to be handicap accessible:

After a breakfast, it was time to go off to the mirror making tent. I think that every year, there is a series of talks and demos about how to make your own telescope mirror.

The speaker letting an attendee give mirror grinding a try:

And a close-up of the eventually-to-be-mirror on top of the grinding tool:

Fine grinding demo using a glass grinding tool instead of the plaster one:

After lunch, there was a series of talks about a lot of different topics—ranging from digital imaging, to “crowd-sourced” occultation timing.

Between talks, I noticed that one of the attendees erected Federation flags in front of his tent:

Once night rolled around, it was time for more observing. I took a number of milky way shots. They all look a bit similar, with the only real difference being what is in the foreground. Of all of them from this night, I think this is my favorite—there were a couple of people standing around a telescope talking with their flashlights on.

Saturday

The second full day of the convention began with mechanical judging of the telescopes.

Somehow, I ended up drawn to the twin-scopes; here’s another detail shot. You can see a little bit of motion blur of the governor:

The day program was similar to Friday’s—the mirror making talks and after lunch a set of talks on various topics.

The evening program consisted of the keynote, raffles, competition results, and other customary presentations. The sky was completely covered with clouds till about 1am at which point it started to be conducive to stargazing. Oh well. Two clear nights out of three is pretty good.

Sunday

Sunday is all about packing up and heading home. During breakfast time, I ended up walking around a bit and I got this image—with the food tent in the foreground, the handicap accessible observatory near the background, and the McGregor observatory with a Schupmann telescope in the very background.

So, that’s how I spent the last weekend. I’m already plotting and scheming my next astrophotography adventure.

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