Tech Article: Multispectral Imaging: UV-A experiments...

Full spectrum cameras are all the rage, but if you capture an anomaly, can you determine the light band it was captured in? UV sensitivity is often mentioned, but what does it really mean? In reality, UV sensitivity for most modern full spectrum cameras out there means a slight sensitivity to the UV-A spectrum of light. This is the spectrum of ultraviolet light that is least harmful to sight and tissue and is also responsible for making your t-shirt or other florescent materials glow in that groovy way. The deeper spectrums of UV (UV-B and UV-C) are generally hard to image without expensive systems, and I will explain why momentarily.

Back to anomaly identification by spectrum. I believe that by "narrowbanding" by filtering, you can get a better idea of where anomalies are showing up at. Everyone knows about IR, but few experiment with UV. I find UV to be very intriguing, so I have been researching a way to narrowband image UV on a shoestring budget. The sliver of UV-A spectrum that I can afford to concentrate on is the area between roughly 380nm and 400nm. Tiny section, I know. At any rate, I have been looking at various options, such as lifepixel conversions, and filtering. The trick to successful UV-A imaging is extended exposure. Most full spectrum cameras have imaging chips that are horribly inefficient at UV wavelengths. You can over come this by extended exposure. I then remembered I had a monochrome astronomy imager that had pretty decent efficiency (roughly 55-58%) sensitivity in the UV-A neighborhood. I decided to through a cheap computar lens on it and test it out... and I am pleased and excited for what it may show for paranormal imaging applications.

Let's talk for a second about why I selected UV-A as my sliver of the ultraviolet spectrum to image with. First off, UV-A illumination sources are plentiful and cheap. I am currently using a 51 LED UV-A (395nm) flashlight as a strong and narrowband illumination source. Secondly, image dimming from lower chip sensitivity, lens attenuation, and possible anti-UV coatings can be overcome by extending exposure. At UV-A wavelengths, glass is still mostly transparent, allowing most light transmission to reach the chip. This is not the case the deeper into the ultraviolet spectrum that you go. Glass becomes opaque in UV-B, and virtually no light is transmitted through in UV-C. It is for this reason that when you want to experiment in imaging these wavelengths, you must purchase specialty lenses made of quarts to retain some light transmission to the imaging chip. These special lenses are very cost prohibitive, and usually require a host of adapters to mate to your imaging platform of choice. Lastly, illumination sources in UV-B,C spectrums can cause eye and tissue damage, even with short exposures. This is why UV lights in these wavelengths are used for germicidal and antibacterial purposes. UV-A illumination is generally pretty safe as long as you do not stare at the light source. I believe there to be a treasure trove of UV paranormal anomalies residing in the UV-B,C bands, but at this point the cost of admission for good imaging there is definitely a roadblock.

Initial testing with this setup pictured above is proving good, I need to get a Hoya UV pass filter to cut or severely attenuate any visible or infrared components. Here is some results from my quick experimentation today. I draw your attention to the calendar on the wall. Each picture set has two pictures, one where I illuminate the calendar and one where I don't. The spot illumination source is a 51 LED UV-A flashlight with peak emission at 395 nanometers. False color was added during capture on some to accentuate the UV-A illumination. Results look promising, can't wait to try this in the field!

Tech article: Review of the Seek Thermal Imager

When team member Kay purchased one of these devices, I could not wait to give it a shot. On a recent trip to St. Louis, I got the opportunity to put her Seek Thermal imager to the test. I was so impressed, I had to have my own. Here are my impressions.

First off, I should start out by saying I am no stranger to thermal imagers. I have owned several, and used many different ones from Raytheon/L3, FLIR, Hughes, etc... I have owned a FLIR B2 and a DCI (argon cooled digital upgrade to the Hughes Probeye series) and the performance of this unit rivals all of them. 

First, the good aspects of this imager. It is small, utilizing a 206x156 resolution sensor, which is very good considering the price point. As a point of comparison, FLIR budget imagers right now only boast 80x60 resolutions when using the Lepton core. They compensate for reduced resolution by overlaying a software image layer from a visible light camera and employing an edge-enhancing algorithm. When using in a dark location, this software enhancement is nullified and all you can view is the bare thermal resolution. It is for this reason that I think that the Seek thermal unit exceeds any FLIR device using the Lepton Core. 

Another positive of this device is the app that is available for it. It has a nice array of many color palettes and allows for multi-point temperature alarms and the ability to take still shots as well as video. The app is very intuitive and easy to use. This is made even better by the fact that the software development kit for this device will be available later this year allowing app developers to make better apps with more functionality.

This imager is compact, easy to use, and very versatile. I really only have two gripes about it, one of which will be addressed in a coming app update. As it currently ships, when using the Seek with the app, the temperature span is auto-ranging and cannot be set manually. If you are looking at an image with ambient temperatures, a warmer target can wash out those details. If you had the ability to manually set your span, you could adjust for the best display of ambient or thermally acclimated targets and that display would remain the same even if a hotter target traversed the field of view. Seek advised me that this will be a feature included in an upcoming app. upgrade.

The second gripe I have about this imager is really not that big of a deal. In order to comply with ITAR regulations regarding internationals sales and shipment of this device, the image refresh rate is locked at 9hz, or 9 frames-per-second. My old FLIR B2 would functing at 30hz or 30 frames-per-second, ensureing no choppy motion. 30fps is the agreed upon standard for "real time" video. That being said, 9hz is not bad, and the image video is only choppy when making wide sweeping motions quickly, and honestly not that noticeable. 

Despite having much lower resolution, the FLIR Lepton core does beat the Seek when it comes to thermal noise, but again that is not that noticeable and I would rather have the resolution vs. slightly less thermal noise. 

These are exciting times when it comes to thermal imaging devices. I never thought that I would see such quality devices in an affordable range for average consumers.  The Seek comes in several flavors, the regular fixed-focus Seek and the adjustable focus SeekXR. Seek is available for iOS devices with the Lightening interface as well as Android (KitKat or newer) with one caveat for Android devices: The device MUST support USB OTG (USB on-the-go hosting). Only certain devices support this, and most manufacturers are less than forthcoming with this specification. Samsung Galasy S3,4,5,6, devices *usually* support it, larger Galaxy tablets support it (not entry level Galaxy Tab in 7 or 8" flavors), Galaxy Note, Motorola Moto-G, Moto-X, and many LG and HTC devices. Unfortunately there is not a realiable list of what will work for other devices not listed on the Seek website. I have personally tested this device on the Galaxy S3, S4, LG Flex 2, and HTC one. Buyer beware. As of this writing there is not any Windows compatibility. Here is the device being used on an HTC One (2nd gen). The orientation of the port dictated I used a USB-OTG extension cable. 

Should you include one in your investigative toolkit? At this price, absolutely. You must familiarize yourself with thermal imaging principals before doing so though, and know what will affect the picture. Watch this video to cleanse any misconceptions about the application of this technology in paranormal investigation. How much is this little jewel? The fixed focus version comes in around 249.00 and the XR version is around 299.00. There is not any price difference with regards to phone platform.

https://youtu.be/KvRvB1pwy3M

Here are some real-world samples of the Seek thermal imager in action:

Introductions...Andrew

NEOPS is comprised of veteran researchers of paranormal phenomena. It's members are diverse in their disciplines, research methods, belief systems, and talents. We have been investigating paranormal occurrences independently for years, but decided to form an actual organized team recently and expand our resources and apply them uniformly.

NEOPS members are Mary F., Kay K., and myself, Andrew S.

My name is Andrew. I have been actively researching the paranormal since 1998. I formed one of the first groups in Oklahoma, the Paranormal Investigators of Central Oklahoma when I started my quest for answers. I soon found out that group management is not my forte and after a divorce, PICO was disbanded. I was about the research, not membership and group dynamics. I joined the Oklahoma City Ghost Club in 2003, and remained a part of it's membership until around 2006.  I then joined the Central Oklahoma Paranormal Studies group and then rejoined the OKCGC in 2009. In 2011 I elected to be an independent researcher of ITC on my own, retiring from group-based investigations. I also participated in the Abandoned Hospital Research Project and was a member of the project group, OKC-PRG, from 2000 to 2008. I have decided to step back out into case-based investigative projects thanks to Mary and Kay.

I have had the pleasure of conducting paranormal investigations all over the country (RMS Queen Mary, Waverly Hills Sanitarium, Pythian Castle, etc...) as well as investigating in Scotland.  Every location is unique, with it's own challenges and rewards.

I am a very technically-inclined investigator. I enjoy prototyping new gear and technical experimentation. I believe that in order to paint an accurate picture of what is happening, we must first do our best to record environmental conditions so as to easily debunk common natural causes. I also believe that presented findings should be of the best quality possible evidence. I don't have what I would classify as a developed psychic intuition, but do rely on my instincts.  I also like to dabble in subjective Instrumental Transcommunication and imposing as strict controls as that discipline will allow. I have had the privilege of being a contributer to Paranormal Underground magazine from 2009-2011 with regard to technical articles. I am a geek by nature and love the technical aspect of this research.

I have had the honor of working with many groups in Oklahoma and across the country, and hope to do so again. I am currently very excited at some projects coming up to get to collaborate with some greats in this field. I have teetered on the edge of returning to field-based investigations and research for several years now, and believe that now is the time.

My contributions to this blog will include many tech and how-to articles and budget-minded adaptations that anyone can replicate. It is my sincere hope that the readers enjoy my submissions and perhaps can adapt them to their own use.