Railfan Technology > DJI Spark Review (Drone/Quadcopter)

For quite some time, I've had my eye on some of the drone (quadcopter) photos being posted here and on Flickr. Mike Harding's work in Toledo particularly caught my eye, as Mike only uses additional elevation when needed; in many cases his photos look like they were taken on one of those crazy 20' poles.

DJI, makers of many popular quadcopters, recently released a new model called the Spark. A neighbor bought one, and once I saw it in person, I knew it was time. Why?
* Under $1,000 to fully equip, not just the aircraft but a case, extra batteries, etc
* Portable/small size
* Built-in, 12mp camera, 2-axis gimbal stabilized
* Includes a remote control, meaning better radio range
* Real-time video feed using your smartphone

All of the features I'd want to see in a drone for under $1,000. So, after giving B&H Photo all of my credit card info, here we are! I picked up an additional battery, the DJICare insurance (which repairs or replaces your aircraft for a modest charge), a case, and spare propeller blades. In addition, the Spark has "Sport" mode which goes up to 35mph.

The unit has configurable maximum altitude and distance. I tend to stay around 100feet, which helps avoid any unexpected interaction with trees and power lines. The max is 400 feet, which is also the legal limit. Distance range I have set for 1500 feet, and it can supposedly do better than that. (My experience is that you need line-of-sight for the best radio connection.)

When launching the Spark, it's recommended to wait to ensure it has a GPS location which allows it to set a "home point". The Spark will "fly home" to this point if it loses radio signal OR if it determines that it has only enough battery to get home. (Flight time is about 15 minutes per battery. I ended up buying a fourth battery.) You can set the altitude that it uses to fly home, in the settings. This was defaulted to 90 feet, but I increased mine to 120 for safety.

Some photos:
1. Delmarva Central HA-1 returning to Harrington from Clay Siding.
2. Conrail Jordan Spreader at Cresson. It's not always necessary to be very high up. But it is necessary to use common sense and fly carefully - in this case I was sure that I was flying over an access road and not the main line.
3. NS 578 taking coal from RJ Corman at Cresson.

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Some lessons learned (see photos):
1. The gimbal can lock on you when you power it up. This is a known issue with the Sparks; and there are a number of workarounds. Before I learned those, I ended up with this lopsided photo because of the gimbal lock. (It may have been due to overheating, or the case that I have, not sure yet.) If I notice the camera looking cock-eyed when I go to power up, I turn it on upside down and then it's fine. Go figure.

2. Shutter lag. 50mph trains with some video lag = big time shutter lag. Whoops! On this note - the DJI app will notify you of interference detected. You'll want to put other devices in airplane mode and avoid power lines. Also, you can get a cable to connect from the charge port on the remote control into your phone to allow a direct connection - much better than the local WiFi network that you typically have to use. (When you turn on the Spark's remote, it sets up a WiFi network that your smartphone connects to so that you can see the video feed).

Finally - the propellers are sharp and make great weed whackers. That's why the are easily replaced. Use the included propeller guards if you're around people, especially kids. And, the DJI app will give you wind speed warnings if you're in iffy conditions. Don't fly in crap weather!

Questions? Let me know!
-Alex

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Thanks for the info. I've been considering buying a unit in the next year.

A question--a lot of the drone photos I see posted are taken from altitudes that are a bit higher than what I would prefer. I'd like to think of the drone more like a "portable highway overpass" than as a "highly maneuverable airplane". Yet I mostly see airplane angles.

Is this just a matter of my fuddy duddy tastes in pictures, or is there a technical reason for this? Is shooting while too close to the ground riskier for the drone or for bystanders? Or am I missing something here?

I think some folks want to "go big" and do as much as the tech allows. In my experience, there are power lines everywhere, which are a safety issue and they generate electro-magnetic interference to your radio signal. So this often has me at 90-100 feet when I might have preferred 30 feet.

Hmmm, hadn't thought about power line interference with communication. Guess I'll have to experiment when I get one.

Love the first photo. One of my concerns about drone cameras is that they seem to have extremely wide angle lenses. This seems to exaggerate the appearance of height. Do any drones come with less extreme wide angle lenses?

Ken

Ken,
I share your concern - some of the earlier drones had really wide lenses, and the GoPro looks wide even at it's "normal" focal length. I was happy with the Spark, though it does still suffer from some distortion. It's not really a Pentax K1000 in the air... :)
-Alex