My first little DIY thermal camera project... - Page 1
Forum section: electronics / general

author: Lambda
author_rank: Regular Contributor
timestamp: February 19, 2021, 09:18:41 am
content: Hello,Just a little post for presenting to you my first little DIY "thermo camera"... A first attempt for help me to learn more in this domain.It is based on:- a thermal core Indigo "micro" A10:160x120,Vox pixel 51umx51um,NETD <=85 mK (i am not sure with which optics it was estimated in the factory) in "sensitive mode" (range of measured temperature in this mode <= 150°C),and optics included with the core: 8mm, f/1.2.working in automatic mode: "power in"/"video out".- a viewfinder receiving video signal (NTSC or PAL standard: 640x480) (Modèle VF-2C not anymore produced, but easily repleacable by more recent modele Chinese module to be found on E-Bay, Banggood, Ali...., and so on...)- a small powerbank 5V, i do not remember the capacity, few thousands of mAh, double output, for feeding the view-finder and the thermal core.- wires, one old switch, salvaged usb plugs, tape, sushi sticks... glue, one table corner,...Nothing ambitious, but happy i am to have been successful to "build" my first thermal item.Here is the little Guizmo (photos at the end of the post).And here just two photos from the item in actions, showing warm water tubing embedded in my floor and thermal scene from inside of a warm living room and cold outdoor visible from the open window-door.We can see warmth for the embedded tubing coming through the carpet, the opacity to LWIR from the plastic cover, and windows of course, the non intuitive (for a beginner like me) view of the opaque windows and thermal contrast between outside and inside.The 640x480 viewfinder allows to benefit completly from the resolution (640x480) from the sensor.I will investigate to learn more and optimize this small system: finding a faster optics for increasing the global NETD, and with a bit longer focal length, thinking about slightly cooling, refreshing the jacket of the lens, from external side, and so on....Thank you for your patience for reading my small fantaisies...Best regards.Stéphane

author: Lambda
author_rank: Regular Contributor
timestamp: February 19, 2021, 09:46:15 am
content: Here, just a photo from the front side of this item...The assembly is a bit crude, i am not skilled in that also...Cheers.Stéphane

author: Bill W
author_rank: Super Contributor
timestamp: February 19, 2021, 11:49:03 am
content: Quote from: Lambda on February 19, 2021, 09:18:41 amAlways good to see what can be done with the older cores.An NETD is almost always based on f/1 optics, or the measurement rescaled to f/1.Bill

author: Lambda
author_rank: Regular Contributor
timestamp: February 20, 2021, 05:47:44 pm
content: Hello.Thank you Bill for this indication.I keep on learning how to use this little Guizmo, and how to "read" the delivered image...Here some additional exercices with this little camera, during my night promenade before the curfew here.... Walk through some woods on the edge of the Nord Sea, some Rodents, rabbits, other people with dogs in promenade... pee form the same dogs.....Quite a deep night, cloudy sky....moon barely visible time to time...The magnification of the camera, for the eye is around X1, which allows me to walk quite easily with the camera near my eye.Sorry for the quality of the shootage.... screen filmed with a handheld phone.... I have to investigate for a good compact DVR unit to integrate in this system...Small shy rodent...https://youtu.be/yfD2o8FW9hUPee tree from a dog and one more rodent behind said tree...https://youtu.be/8HVfDl-gMKoEncounter with night walkers and their dogshttps://youtu.be/eWsB81jNRnAGrassy dunes and beach on the Nord Seahttps://youtu.be/cpXDETNYXHsOnly with the genuine optique 8mm/1.2, it is already very nice to see such things! I think it will worth, in the future, to investigate for finding and using a different objective with longer focal length and with F/D<1.2....Cheers.Stéphane

author: Lambda
author_rank: Regular Contributor
timestamp: February 22, 2021, 11:18:18 am
content: Hello.With this core came from the seller also a nice Germanium Lens, but without any specifications.In the goal to replace the genuine lens from the Indigo Core (8mm/1.2) i wanted to know more about this lens.Physically, the lens is housed in a kind of ceramic (i suppose) sleeve or jacket.The lens is apparently, when observing my own reflexion, a plano-convexe element (i suppose single, i was measuring rear distance from the edge of the tread and front distance from the front edge of the jacket/sleeve, and i obtained just 2 or 3 mm of thickness on the periphery of the lens itself, roughly).- Convexe side in forward direction, and plane side in backward direction.- The clear diameter of the lens is around 40mm.- Length of the brown ceramic sleeve/jacket (without the thread), around 83 mm.What i was missing is the focal length of this lens.Today being a sunny day, i decided to simply aim the Sun, which i believe to be a good source of LWIR, and i fixed the lens on a tripod with behind a brown card-box screen which had apparently some decent emissivity. And i used my Guizmo as a monitoring tool for finding, by moving the screen, the focal plan of my setup wherein the sun was appearing the most brillant and with the smallest spot or projected image.My wording is a bit vague, because, with the resolution of my thermal camera, i had to repeat several times the experience, moving back and front the screen, the image being not super defined as you can imagine, and i had to average my brightness illumination, from that.But finally, when considering the lens as roughly equivalent to a thin lens, i obtained a focal length around 40mm.Therefore, i suspect my unknown lens to be a 40mm/ "around f/1". Which would be a nice replacement lens for my DIY camera.Later on, i will precise my measurement by comparing the FOV given by the genuine 8mm/1.2 lens with the FOV provided by this other lens.Here some photos of the "experimental set-up". a crude, rudimentary one, but at least giving some indications for me....It is always fun and rewarding to be able to use a non finished project as an already more or less functional tool for investigating further aspects for itself....Cheers.Stéphane

author: Lambda
author_rank: Regular Contributor
timestamp: February 23, 2021, 10:11:43 am
content: Hello.This tread being to be considered as a simple "logbook for experiments and note", i keep on feeding it...What i was noticing is that the Indigo micro A10 core, when working in automatic mode, provides a kind of AGC:- when the general level of LWIR light provided by the whole scene is elevated, AGC increases the "gain" of the system for allowing the best contrat and limiting as much as possible saturation/washing of the image.- when the general level of LWIR light provided by the whole scene is low, AGC decreases the "gain" of the system for allowing the best contrast and bringing the highest contrast and extracting the max of information form the image.But- when there is a mix of bright targets and low background, sometimes, targets are saturated but background well defined...Shortly said i tried to imagine how to mitigate this problem, and when reading numerous of posts here, i learned that for BST core having a limited dxnamic range, it was commonly used iris. Therefore, i wanted to test that also with my Vox bolometer core.Fortunately, i was collecting some iris form old DSLR discarded lens. I therefore took one from my junk box and settled it in front of the objective of the core.And i did some tries with good results.....Normally, the core works in my case (power in/video out) in high sensitivity mode [0-150°C], meaning that it saturates for example when watching a gas fire on a cooking plate (almost white image, with red pixels in the highest warm zone, no valid temperature measurement (but i do not care, i am for now not interested in radiometric measurement)). But with this little add on, i was able to see the fire again, with more details in its development, and immediate very warm surrounding....I did tests with also simply my warm keyboard, with open iris and close iris...It works and allows me to extract more details from scenes when high and low LWIR emitting target are co-existing together in the same scene.I know it is nothing new for you but for me, as a beginner, it is very interesting to see that i can improve my observations with such means.Thank you for your patience of reading.Cheers.Stéphane

author: Lambda
author_rank: Regular Contributor
timestamp: February 26, 2021, 10:37:12 am
content: Hello.Yesterday, i was able to properly dismantle the front flange supporting the lens, from my core.I was a bit anxious, especially i had to "machine" a Allen wrench with a dremel, from the smallest i had available in my tool box, this smallest being still to big for the 4 Allen bolts fixing the front flange on the body of the core.To be sure to not do mistakes, i was watching several times, these references (thank you to their authors!):from Connor Wolfandhttps://www.eevblog.com/forum/thermal-imaging/flir-micron-a10-160-x-120-hiding-in-disguise-bought-for-$100-)/msg2334615/#msg2334615from Fraser, with the specific post from Cat.From that, i was testing, hand held in front of the naked sensor, the brown lens i was mentioning above in this thread, and it works quite well, the image is nice with a bigger magnification than the one provided by the genuine 8mm/1.2 lens. This is interesting because i would like to use this core for "long range" observations.Therefore, now, my idea would be to simply "manufacture" a DIY whole front flange supporting the replacement lens. which could be easily replaced on will by the genuine bloc with genuine lens, and vice versa, depending the purpose of my using (walking in wood with the camera hold by hand, or observing at long distance on a tripod).My question would be about the material to use for the front flange replacement. I am poorly equipped for machining, but can do lamiated structures with epoxy resin for instance..... For the internal surface of this DIY flange, i would like to use a material with low emissivity for avoiding to blur my image by receiving unwanted radiation from the immediate proximity of the sensor....Would it be possible to use for example, as an internal surface of my flange, simple domestic alu foil (emissivité < 0.1 if o do not mistake myself) ? Or would you advice me more suitable material?Here is a summary of this step in my DIY project....Thank you for your lights on this subject.Best regards.Stéphane

author: Lambda
author_rank: Regular Contributor
timestamp: April 08, 2021, 09:30:35 am
content: HelloJust a small update on my current project.I received from Bill a wonderful spotless Ge lens (3 elements) 15mm, F/1 for replacing my genuine ZnSe lens 8mm, F/1.2.http://www.fire-tics.co.uk/spares.htmThe result is excellent, with a crisper, clearer and more resolved image (better sampling, or better said, less under-sampling).I manually use the integrated iris which allows me to spot very warm source like a gas fire in kitchen.I had just to create a flange for welcoming with two screws, the lens, and i had also to adjust the helicoidal system from this lens to adapt it to my A10 core.To be finally able to fine focus on a target is really pleasant.The circle image provided by this 15mm, F/1 lens (made for a BST sensor 320x240, for Argus 2/3, is it correct Bill?) is very generous and allow me to illuminate without problem the disc shape Vox sensor from the A10 core (around 15mm diameter, from memory...).I made a crude but solid housing, and let's play now.For the time being i leave the whole rectangular platen from the lens untouched, because to have the 4 screwing holes and a very nice flat aluminum front surface would render easier further modifications in the future.Here is a image summary... urban image made during a grey day, no Sun having warmed buildings during the whole day, temperature around 8 deg C.Photos taken with a smartphone hand held, sorry for the poor quality....Thank you.Stéphane

author: MikeNC407
author_rank: Contributor
timestamp: April 08, 2021, 11:45:36 am
content: I’m really digging the look of your camera as it’s coming together! I’ve got the same core with the 8.5mm lens as well (did you get yours from an MSA Evo 5K as well?) and have been trying to figure out what to do with it, those viewfinders are just so expensive on eBay still!I haven’t taken the lens off my A10 before, do you happen to have any pictures of the sensor? I had no idea it wasn’t rectangular but that’s very interesting.

author: Lambda
author_rank: Regular Contributor
timestamp: April 08, 2021, 12:30:27 pm
content: Hello Mike!Thank you for your interest. I found the core originally equipped with this lens on E-Bay, second hand, the offer was comprising the core with this lens ZnSe 8mm/1.2 and an additional unknown/no name lens (i am still investigating on it).It is true that ready made spotting units are really expensives generally speaking, the second hand market + DIY path gives more acceptable options in term of budget, for sure.For taking of the lens, if your core and lens are similar to mine, you have first to remove the front flange holding the lens (the lens can not simply be directly "unscrew" from it), by removing the 4 Allen tiny screws. Then the lens can be taken apart by removing 4 additional even tiner screws from the back of this flange (internal side).Here is a (blurred, sorry) photo of the naked sensor, with its shutter...Hoping it can help bit!Good luck for your own project! Do not hesitate to share!Stéphane

author: Fraser
author_rank: Super Contributor
timestamp: April 08, 2021, 01:50:42 pm
content: Lambda,Nice workThose lenses from Bill_W are great for experimentation and projects like this. You get real solid Germanium optics that are likely high quality due to the era from which they came and their likely high cost when supplied. Bill is actually underpricing such a lens but he is a very generous chapMikeNC407,Regarding sources of a viewfinder, you might wish to consider old camcorders as a cheap source of monochrome high resolution viewfinders ? The older camcorders often used a totally self contained CRT based EVF that just needed power and composite video for operation. Some later LCD types were more challenging to use as some were direct driven from the cameras main PCB and not composite video. Early LCD EVF’s were also relatively low resolution so were inferior to the CRT based units. I have bought many 1990’s era JVC camcorders that were equipped with a colour LCD EVF that was self contained and wanted composite videoI bought these because they are what AGEMA used in their Thermovision 570 thermal camera. They just placed the whole EVF, case and all, in a metal outer casing ! Decent resolution and a colour display.Time to start looking for a bargain old camcorder at a charity shop or on eBay. I paid around £15 each for the JVC units as they are VHS-C and no one wanted them. Working condition was not an issue as the EVF is normally OK.Sorry I forgot which model of camcorder I was buying. Look for the old 1990’s VHS-C units with all black cases and a rectangular tilting EVF with the word color on it ! If you see a bump on the top of the EVF, it is the monochrome CRT version but still a composite video EVF for project useFraser

author: Fraser
author_rank: Super Contributor
timestamp: April 08, 2021, 02:03:17 pm
content: I just dug out a couple of the camcorders that I bought for just their viewfinders. They contain useful screws and PCB’s that are good for soldering rework practice ! Well worth the £15 I got them for. You need to buy the correct NTSC or PAL camcorder for your project as the EVF is not multi standard (it can be modified to another standard in its hardware though).My advice is to find the service manual for these camcorder types (there are several models with a colour EVF) and study the EVF connections and circuit to ensure that it meets your needs. The EVF contains Sony LCD driver IC’s and a Sony LCD panel.Fraser

author: DaJMasta
author_rank: Super Contributor
timestamp: April 08, 2021, 08:05:54 pm
content: If you're looking for a size up from a viewfinder, look into a used "field monitor", basically a small LCD screen used to monitor video camera output for a cameraman when the video signal itself is going off to the main switcher. They range from 3-8 inches or so and while most of the newer ones are digital only, older models often have composite video input (even passthrough), so get a larger view but still keep the video output if needed. An LCD is going to run a higher current if you're on batteries, but it can be useful (or just more comfortable) to have a small screen than using it as a monocular.

author: Bill W
author_rank: Super Contributor
timestamp: April 08, 2021, 09:49:47 pm
content: Quote from: Lambda on April 08, 2021, 09:30:35 amYes that is right, designed for BST 320x240 50um. You have an Argus3 one, but it is mainly the mechanical format that is different. The Argus2 had an exposed front element and so that had a 'durable' coating, although looking at a few repairs now it was not THAT durable.You may also find a use for the sliding back element on its' own, it is something like a 12mm focal length so does as an auxilliary lens magnifier in front of any camera. They tend to survive even if the front element get trashed.Thanks for the kind words,Bill

author: Abbott242
author_rank: Regular Contributor
timestamp: April 09, 2021, 02:16:21 am
content: Nice job, that's looks awesome! Very functional and affordable compared to purchasing a similar product How is that little viewfinder working out for you? It looks very similar to one I'm thinking of getting. (Analog 640*480 off eBay/alibaba/etc)

author: MikeNC407
author_rank: Contributor
timestamp: April 09, 2021, 02:24:28 am
content: It’s funny you mention those color viewfinders Fraser, I just happened to be trying to find one on eBay a few months ago for this very purpose! I was pretty set on finding one of the rare ones with a color CRT for a little extra retro aesthetic even though it would have been more than a little bit bulkier. I ended up buying an RCA CC017 that looked like it came with a color viewfinder but had a black and white one instead and kind of gave up on the project for a while. I didn’t have any luck getting the viewfinder that it came with to power up either unfortunately, it was a bit beyond my skill set to get any further. I suppose it might be time to start looking again, the Indigo is the only core that I haven’t done anything with yet and it’s the right size for a monocular!In the meantime I’ve settled for car back-up cam monitors from Amazon as a cheap source of composite displays. I did stick an RCA to HDMI converter on the side of one of my L3 Thermal Eye 4500 cores so I could use a bigger 7” display stuck to one of those magic-arm pivots, the hdmi converter does some upscaling that actually looks pretty good in this case.

author: Lambda
author_rank: Regular Contributor
timestamp: April 09, 2021, 09:06:21 am
content: Quote from: Bill W on April 08, 2021, 09:49:47 pmOk Bill, good to know!Anyway, as much as i can, i will preserve this lens in its whole. It really worths! At least, for showing respect to the designer/enginer who creates this very nice piece of optics, in his time!Quote from: Abbott242 on April 09, 2021, 02:16:21 amThank you Abbot242, for the viewfinder it is a model called "VF-2C" (monochrome 640x480, accepting automatically video multi-standard PAL/NTSC...) I bought few years ago for previous night vision project, from this UK shophttps://www.sure24.co.uk/But unfortunately, they are now discontinued..... :/ they were really nice compact units, with contrast and brightness manual control, running under 4.5V-5V, but with a on/off switcher working in the "dead man" principle..... I have to admit that they were at their time quite expensive (around 100-130 Euros, from memory....)But easily transferable from one project to another...The EFV salvaged from old camcorders, as indicated by Fraser, is a very good cheap alternative, and providing viewfinder with often excellent resolution. Just to manage power supply, and video input. I played also with some of them.You can find also this kind of kit which may be interesting to investigate....https://www.ebay.com/itm/AV-Input-DIY-Night-Vision-Viewfinder-Monocular-Micro-Display-Video-FPV-Display/283696427174?hash=item420d9ff0a6:g:rz0AAOSwXMhd5O9oCheers.Lambda

author: ianspy1
author_rank: Newbie
timestamp: October 16, 2022, 06:07:40 am
content: Heyo, just saw your post and thought I´d share what I have built based on a Flir Photon 320 30hz. (will also be making a post with some links) Took me a couple of months. Recently gave it some waterproofing and a paint job along with a 3D printed J-arm for mounting !

author: Lambda
author_rank: Regular Contributor
timestamp: October 16, 2022, 04:00:50 pm
content: Hi Ianspy1 !Awesome job you did there! Thank you for sharing that with us. Neat results, definitively!This very tiny and compact viewfinder is extremely convenient for such project. Well done.

author: ianspy1
author_rank: Newbie
timestamp: October 16, 2022, 11:55:46 pm
content: Hey thank you !My post is also up now if you want a bit more of how I got to this.Also I found this viewfinder as well :https://de.aliexpress.com/item/1005001426576019.html?spm=a2g0o.productlist.0.0.6cb456afRtoB0V&algo_pvid=4edcf620-fa51-41e5-a3f7-bf2c6fb2b7d8&algo_exp_id=4edcf620-fa51-41e5-a3f7-bf2c6fb2b7d8-1&pdp_ext_f=%7B%22sku_id%22%3A%2212000016064639949%22%7D&pdp_npi=2%40dis%21EUR%2181.43%2175.73%21%21%21%21%21%402100bb4c16659644842296703e2783%2112000016064639949%21sea&curPageLogUid=HGmfd3Qu4QUEKinda asking my self if that maybe would have been a better choice...Oh welll I will be getting a silicone eyecup for it and cant wait to get it on a helmet !

author: Lambda
author_rank: Regular Contributor
timestamp: October 17, 2022, 08:12:30 am
content: Hi!For all this kind of projects, i like also gathering this kind of "vintage" analog video viewfinder, scavangered from old camcorder....https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.leeland.info%2Fsocaviasdi.html&psig=AOvVaw1SHKIbMRIQYPkrpE0DvN4T&ust=1666080510666000&source=images&cd=vfe&ved=0CA0QjRxqFwoTCMDJ4dnn5voCFQAAAAAdAAAAABAGFor instance... They are good piece of kits delivering quite nice image with a pretty decent resolution. And time to time, not too expensive.Cheers,Stéphane

author: ianspy1
author_rank: Newbie
timestamp: October 17, 2022, 01:14:19 pm
content: Love to see stuff being reused !I also had a Idea to just use a VR display. But these are not cheap ! But honestlly I dont have a complaint with the resolution, only thing I really would like is a better lens at the back. If the center and most of the image is clear, the temperature in the bottom right is basically unreadable.What I am also looking for now is a way to get my AV out signal to my phone. That way I could take my friends with me on night hikes in discord xD.