We woke reasonably late following the feast and free flowing wine the night before. After gathering ourselves and our packs, we headed down to our homestay family’s small dining room for breakfast.
Refreshingly, what was expected of her was the same thing that was expected of Lara Stone: to take a beautiful picture.
We were making our way to the Rila Mountains, where we were visiting the Rila Monastery where we enjoyed scrambled eggs, toast, mekitsi, local jam and peppermint tea.
We wandered the site with other tourists
Yet strangely the place did not seem crowded. I’m not sure if it was the sheer size of the place, or whether the masses congregated in one area and didn’t venture far from the main church, but I didn’t feel overwhelmed by tourists in the monastery.
Headed over Lions Bridge and made our way to the Sofia Synagogue, then sheltered in the Central Market Hall until the recurrent (but short-lived) mid-afternoon rain passed.
Feeling refreshed after an espresso, we walked a short distance to the small but welcoming Banya Bashi Mosque, then descended into the ancient Serdica complex.
We were exhausted after a long day of travel, so we headed back to the hotel and crashed.
I had low expectations about Sofia as a city, but after the walking tour I absolutely loved the place. This was an easy city to navigate, and it was a beautiful city – despite its ugly, staunch and stolid communist-built surrounds. Sofia has a very average facade as you enter the city, but once you lose yourself in the old town area, everything changes.
Clothes can transform your mood and confidence. Fashion moves so quickly that, unless you have a strong point of view, you can lose integrity. I like to be real. I don’t like things to be staged or fussy. I think I’d go mad if I didn’t have a place to escape to. You have to stay true to your heritage, that’s what your brand is about.
Even though most quality PIR sensors have resistance to trigger by white light, all PIR sensors and dual tech sensors are inherently vulnerable to increases in light. In our experience this is especially the case if the changes occur across the entire detection angle – such as when a thick cumulous cloud covers and then uncovers the sun on an otherwise sunny day with light levels of 100,000-130,000 lux.
In the short video above a light change is accompanied by a car top left but there are complications to what’s happening in this scene. The sensor’s sensitivity settings are at the highest level – it will detect almost any movement across its detection fields. This might arguably include movement detected only by the microwave at long range – this car is 35-40 metres from the sensor. Further, the intrusion of the car top left may impact on the rendering of still images captured – but that’s not certain.
“Your best option might be to change the sensor direction”
It’s tempting to say just buy a sensor with white light immunity. However, this immunity is most effective against headlights and strong torch beams – global light changes are still a false alarm threat. The issue with light is that it triggers an electrical signal from the pyroelectric sensor of a PIR – if this voltage is within a particular range, it may be interpreted as an alarm event.
Sensor technologies you’re looking for to resist light changes include optical filtering and signal processing in which algorithms analyse the frequency and pattern of detected signals, ignoring those inconsistent with thermal profiles of human movement.
Dual pyroelectric elements can be configured to detect slightly different heat patterns consistent with human thermal signatures, but they work best against artificial light sources. Dropping pulse count may help, but in our experience, this works best against localised triggers like birds, rather than global light changes.
Your best option might be to change the sensor direction so more of the scene is shaded during the day in order to reduce the impact of light changes. You might also install a PIR camera sensor to deliver alarm verification but it won’t stop alarm events occuring.
A monitoring station can make a decision about an alarm event based on the alarm trigger patterns. Light triggers typically occur occasionally on a single zone – often at the same time of day in a given season. We get them on a front balcony in the morning between 10-12, especially if there are gusty winds. Comparatively, an intruder will cause a cascade of triggers across multiple zones, generally at night.
You can discover a light-resistant dual technology sensor here or read more SEN news here.
