LED astray

I paid a visit to the Frankfurt Dippemesse on the 5th of May to get some photos of the fireworks and the fair at night. Generally I got some decent long exposures using a tripod and settings with low ISO and 2 to 4 second shutter. There are a lot of bright lights so f stop can be f8 to f11 and even f16 for more starry effects in the bright spots.

glittery white lights

One thing that I noticed when looking at the photos is that most of the lights on them did not produce constant blur lines in the photo. Most of the lines of light are composed of dots when you look at them closely. I have noticed this phenomenon more over the years and finally realised the cause after blaming my technique, camera and other superstitious reasons.

dots are visible at fast speeds

In the olden days, lights were almost all incandescent bulbs or halogen. Nowadays, everything is LED. LEDs are cheap, efficient, don't produce heat like halogens and last longer, so they are now find everywhere in torches, home and automobile lighting and even fun fairs. The downside to LED lights is that they pulse (for cheap ones) at a much slower rate than incandescent lights or florescent tubes. As far as I can tell from reading on the internets an old style light bulb pulses at twice the frequency of the power supply current, while a cheap LED pulses at half of the frequency. This is measured in Hertz. Let's pretend the power supply is 50 Hertz, a florescent light would pulse at 100 Hertz, an LED at 25. Apparently, all lights on AC flicker but the effect is made more prominent with LEDs as photon are not emitted when they are flickering on and off. While a regular light bulb is in an off state it still produces heat and some light. If the LEDs are dimmable, this is achieved not by lowering the amount of voltage as in the case of a light bulb, but by increasing the time the LED is off per flicker cycle.

Digital dots of the break dancer ride

Does any of this matter?

Health-wise, lights that flicker at a slower cycle can cause seizures in some people.  For long exposures, lights with slower flickers on fast moving objects are easy to spot as a series of dots rather than a single line as in the examples here. Photographers have long been aware of the effect of florescent lighting and shutter speed causing issues at certain rates. The LED issue is a newer version of this but I also found recently that if a room is predominantly lit by LED, my Sekonic flash meter doesn't function properly as it thinks a flash has been fired when it is actually the room lighting flickering. It was unable to get a reading at all while the LEDs were on. This even occurred when a regular light was the dominant light source. The only solution was to turn off the offending lights while reading for flash exposures. Seeing as LEDs are not going away any time soon, I guess we will just have to get used to seeing lines of Morse code instead of smooth clean light trails during long exposures in future.

DEAD HOT PIXELS!

This is not nearly as glamorous as it sounds. Products like TVs and LCD screens are covered in millions of pixels and as they are not all guaranteed to work by the manufacturer, sometimes you just have to live with a dead one or two on your massive TV screen. The same is true for camera sensors but somehow seeing bright spots in photos that I know should be completely black irks me a lot more.

Try it with your camera. Take the lens off and put the body cap on then take a photo on a manual setting at 100 ISO for a couple of seconds. The whole image should be black. If you have any pixels on your sensor that are misbehaving you will see a bright white or red/green/blue spot. I was originally looking for ways to fix dust on photos taken before using the "Dust Delete Data" tool on my Canon, but glad I stumbled on this youtube video for beating hot pixels - How To Fix A Hot or Dead Pixel (Canon 7D & 5D & others).

After following the tip in the vid and taking another photo the same way as before and checking on my camera's screen, all of the hot pixels appear to be gone! So try it out if you have been plagued by any stuck pixels on your camera too.

No regrets!

If there is one piece of advice I would recommend to everyone is never go anywhere without a decent camera. When the voice pops into your head that says 'I won't need it, I'm only going to the shops/pub/put for a moment,' ignore it, or better yet overrule it. The opportunities for photos is practically infinite and I only regret not taking the photos I wished I had.

If your main camera is too big to carry all the time, go smaller and get a compact for emergencies.  Last night I was out in the countryside trying to get a good sunset. I got a couple of OK shots but nothing great. Tonight I decided to go out for a meal without my camera and to my dismay the whole sky was filled with flaming whisps of red cloud on a perfect turquoise that faded into a light yellow below. Such moments are never repeated again exactly the same way, so I will suffer the extra baggage for the chance of the right photo in future!

Modern technology

I've been using old film cameras for a while. They are generally heavy, made of cast iron and could be used as air raid protection for your pet mouse if necessary. At the very least, if you drop one, you expect more damage to be done to the floor than the camera. Luckily, I haven't dropped any cameras yet (touch wood! And thanks to the after market straps I use from Amazon).

This morning I was using my Nexus 7 tablet in bed and dropped it. It slid off me and onto the floor, falling only about 30cm. When I picked it up the screen was black and lifeless. It's a horrible feeling when you know you may not see your photos or unrecoverable data again and face being cut off from the outside world. Sure, I have a PC but it takes 15 minutes to start up and nobody has that kind of time to wait any more.

Incidentally, the Nexus is great for transferring photos via WiFi from my Canon 6D. Especially as Canon have finally fixed it so that I can download full size images within seconds. It takes much much longer using my PC so I only like to use it for making back ups to my hard drive.

Luckily, I had bought my now lifeless Nexus within a year and expected I could get a free repair from the German electrical goods store (Saturn) I bought it from. However, two clerks refused to take my receipt and instead said that a chip on the corner (that had been there for ages) meant that they would not take it and I would have to pay for it to be seen at a minimum cost of 150 Euros (not including parts). They said it would be cheaper to buy a new one and gave it me back.

I was on the brink of sending it straight to ASUS but stopped when I got to a clause that said ASUS repairmen are allowed to delete all data in order to fix an issue. I really wanted to keep my data so didn't want to risk losing it all over a screen issue. So instead I turned to YouTube. After watching this video for 3 minutes, I already had what I needed to check my tablet out myself. 

It took me only a couple of minutes to pop the back off and find a cable that had become unconnected. It just popped right back in place and then I just repeated everything in the video in reverse and squeezed the back on before being overwhelmed by relief at my tablet turning on normally and that caveman making fire with told feeling of triumph. Luckily, I didn't even need to replace the screen but I found you can buy them on Amazon for around 50 Euros which is much less than the fee I was quoted and about as risky concerning whether you will ever see your data again or not.

So next time your German shop won't honour it's guarantee, why not try fixing the problem yourself too? Best of luck! As for fixing old cameras, it is something I need to do in the near future. My Mamiya 645 Pro became stuck recently and needs repairing. They are generally built to last unlike modern throw away technology, but when they do go it can be hard to get replacement parts. Perhaps modern technology can help with 3d printing new parts. It's something I will research and might give an old camera a new lease of life!