Comparison, FLIR Boson 640 vs ULIS PICO384 (ThermApp) vs IRAY Xtherm T3S  - Page 1
Forum section: electronics / general

author: cnxunuo
author_rank: Regular Contributor
timestamp: May 11, 2019, 12:01:17 pm
content: noise:t3s wins, by a huge margin, mostly noise even in low contrast days, with its knockoff 17um VOx.Thermapp losed, very bad pixel noise,however BOSON 640is a 12um core, it has extra noise and streak pattern than tau2 etc, but usable. note that this is the industrial (40mK version of boson)lens:t3s is a piece of garbage, its lens is so bad that when you focus on the center, the edge has weird out-of-focus artifact, dot becomes weird smudge.BOSON 640 has weird issue of one corner became noticeably less sharp, which has already happened out of the box when new, very dissapointed.Thermapp wins, its lens is the best.boson uses a NV21 YUV webcam protocol, works without any troublethermapp uses proprietary protocol, needs linux software to trick itt3s also uses YUV webcam protocol, however some idiot decided to permanently put their ugly logo on screen...

author: cnxunuo
author_rank: Regular Contributor
timestamp: May 11, 2019, 12:12:12 pm
content: teardown for t3s, worse quality compared to thermapp, very flimsy, all thats missing is a blob of chinese hot glue....

author: cnxunuo
author_rank: Regular Contributor
timestamp: May 11, 2019, 12:19:37 pm
content: btw, if someone needs 25hz, t3s is default 25 hz, made in china so no itar no wassn****,dont be fooled by that marketing guy on the forum,it cost me 4600CNY which is 675USD to purchase brand new directly from taobao in china, so expect a reasonable price plus international shipping.

author: Ultrapurple
author_rank: Super Contributor
timestamp: May 16, 2019, 11:32:02 am
content: Thank you for this interesting comparison.It may be worth knowing that the Therm-App 384 needs a few minutes to stabilise after power-up. For the first 2 minutes or so after switch-on the image becomes less and less noisy. No-one seems to know why this is the case but it has been demonstrated by several people.

author: cnxunuo
author_rank: Regular Contributor
timestamp: May 16, 2019, 02:25:21 pm
content: Yes, my thermapp also needs many minutes to fully stabilize with no noticeable drift, and I used third party software with manual calibration to achieve best image I could.thermapp also have a better shutterless NUC algorithm, my boson always mistaken blurry out of focus bits as sensor uniformity and correct them, which leaves “burn in until next physical shutter calibration

author: Max Planck
author_rank: Regular Contributor
timestamp: May 16, 2019, 07:04:51 pm
content: Quote from: Ultrapurple on May 16, 2019, 11:32:02 amHave anyone tried to image Therm-App after power-up, using a second camera?Max

author: Ultrapurple
author_rank: Super Contributor
timestamp: May 17, 2019, 07:13:11 am
content: @MaxSeehttps://www.eevblog.com/forum/thermal-imaging/thermal-imaging-gallery/msg2228064/#msg2228064Is that what you mean?

author: cnxunuo
author_rank: Regular Contributor
timestamp: May 17, 2019, 09:02:04 am
content: Just did an exact same thing,https://youtu.be/9U1a0pfCEY4it works! Boson filming therm-app 384, slightly different framerate, so there's a beat.My lens was pulled out of the thread and duct-tape in front of boson, so image quality very bad.

author: Max Planck
author_rank: Regular Contributor
timestamp: May 17, 2019, 02:22:03 pm
content: Quote from: Ultrapurple on May 17, 2019, 07:13:11 amUltrapurple,I meant the surface temperature of the housing of the camera (1) mounted directly on a mobile phone and (2) just connected to a phone using a cable.Never used that camera but from the description, my first idea would be a design flaw in the thermal management atrea. If yes, where exactly and how to mitigate it.Max

author: Ultrapurple
author_rank: Super Contributor
timestamp: May 17, 2019, 03:23:21 pm
content: @MaxAh, I think I see what you mean.On my Therm-App cameras there's a gap of several mm between the camera and phone. It hadn't occurred to me to check what happens, thermally, during the switch-on phase and first few minutes. Perhaps I should take a look and see if we can glean anything.

author: meanie2
author_rank: Contributor
timestamp: August 24, 2019, 10:10:12 am
content: Is it doable to swap thermapp lens to xtherm or thermal expert?

author: Fraser
author_rank: Super Contributor
timestamp: August 24, 2019, 12:50:19 pm
content: Regarding the ‘warm-up’ period required by some cameras before decent imaging is produced. I would suggest that this is due to the manner in which the camera is dealing with non uniformity in the Microbolometer array.My thoughts....1. A Microbolometer array suffers from fixed pattern noise that varies with die temperature.2. Self heating is present in a Microbolometer array due to the readout current and ROIC thermal emission.3. Thermal cameras compensate for fixed pattern noise and non uniformity at a single or multiple die temperature and use algorithms to predict the required corrections at other die temperatures. The further away from the ‘calibrated’ die temperature point you go, the less accurate the compensation becomes. It is advantageous to have multiple non uniformity die temperature calibration points for good NUC performance. Some simpler (lower cost) cameras use just one calibration point. This is normally at the microbolometers nominal operating temperature and is set either by a temperature stabiliser or an open loop natural temperature settling point (equilibrium) in a specific ambient temperature, and is uncontrolled. The best performance in terms of NUC is only achieved whilst the die remains at the same temperature point as when the NUC table was created. On non temperature stabilised cameras, there is a significant ‘settling time’ until the die reaches the nominal temperature operating point. Before that point is reached the image can contain more noise.4. The pixels suffer From output drift over time. To compensate for such highly dynamic non uniformity across the imaging array a method is needed to detect and quantify the drift for each pixel. The most effective method for this is to present a flat thermal scene to the whole Microbolometer array and compare all pixel outputs. A flat field correction flag of known temperature is used and this provides not only a flat thermal scene but also a temperature calibration reference for fine tuning of the cameras temperature measurement capability. For an accurate Microbolometer based temperature measurement camera the FFC ‘flag’ reference could be considered essential. An alternative compensation system deletes the FFC flag from the BoM and uses software algorithms to dynamically compensate for pixel drift using the thermal scene being observed. It may offer a true physical FFC option using the flat thermal scene of a lens cap in order to improve performance before a measurement is taken. Between physical FFC events using the lens cap, the software algorithm does its best to dynamically flatten the field as required. This task is made harder if the Microbolometer die is not at a constant temperature. Such a software based FFC system will likely not cope well in the ‘warm-up’ period when the Microbolometer is self heating to its natural operating temperature equilibrium point. Too much change is happening in the fixed and dynamic noise domains and so a ‘noisy’ image results.5. Calibration time costs money ! Due to this fact, cheaper cameras may use generic pixel temperature drift compensation tables rather than ones created in a calibration rig. This may be done due to the predictability of some modern microbolometers where the pixel drift is relatively uniform across an array at differing ambient temperatures. Such generic compensation is, of course, less than ideal, but it is inexpensive ! A more expensive camera may undergo Microbolometer pixel drift characterisation at different die temperatures and in different ambient temperatures outside the camera. Sophisticated compensation tables may then be used in the camera software to achieve the best possible images without the need for an FFC flag.Any Microbolometer based thermal camera that lacks a FFC flag will be reliant on either regular manual FFC using a lens cap, or a combination of pre-installed compensation tables and dynamic FFC algorithms. The quality of imaging produced will depend, to a great extent, on the effort and time the manufacturer has spent on the characterisation of the particular cameras Microbolometer.Hope this helps and feel free to challenge this viewpoint. It is just my thoughts on the matter based upon my understanding of NUC and FFC in Microbolometer based cameras.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: August 24, 2019, 01:25:54 pm
content: Regarding the column noise in the BOSON images..... this is reminiscent of that seen in A-Si based microbolometers. In the case of A-Si based cameras this is normally due to the lower Signal levels that come out of the array compared to, say, a VOx based pixel array. The BOSON uses those teeny tiny 12um pixels that are less sensitive to the thermal scene presented to them due to their smaller energy collection area. Could it be that we are seeing this low signal output causing a similar effect to that seen with A-Si I wonder.It could also be poor noise processing in the BOSON design of course. The BOSON performance has disappointed me and I cannot help thinking that it I was either released before the hardware and software design was perfected, or that the 12um pixel size is challenging FLIR capabilities to tame its behaviour. DRS manage to produce excellent imaging with 12um pixels but they have employed new technology to do so. An example is the use of thermal energy collection plates above (and thermally bonded to) the microbolometers to improve performance. As I was recently told.....a 12um pixel is the size including the non ‘active’ bridge arms so the thermal collection area is smaller than 12um x 12um.Fraser

author: frogg
author_rank: Regular Contributor
timestamp: August 24, 2019, 04:28:01 pm
content: AFAIK, it's usually more common in optical systems that lens aberrations or optical system alignments are at fault when one has spatial contrast problems (like out of focus corners). With the Boson being a system where the lens as not calibrated as an assembly with the sensor, this seems more likely, especially with large aperture lenses.My understanding is that, apart from noise (as it is strictly defined), microbolometers really have two parameters that are calibrated. One is the gain coefficients, and the other is the offset coefficients. My understanding is that vertical banding is usually solved as part of the offset coefficient calibration.Thermal drift compensation is also necessary, but to be truly effective, the thermal drift compensation has to take into account that thermal drift is non-uniform across the sensor.I'm leaning more towards Fraser's second point: It's possible that the artifacts in the images are related to the physical limitations of smaller pixel sizes becoming much more reliant on excellent noise processing. More to the point, it could be argued that noise processing is the fundamental deciding factor in microbolometer image quality, more so as the pixel pitch declines. The very fact that radiometry is not currently an option for the Boson also underscores this possibility.

author: cnxunuo
author_rank: Regular Contributor
timestamp: August 24, 2019, 11:13:22 pm
content: For lens aberrations, it has been purchased as a unit, from flir directly, it should be quality checked with full field resolutions. although this is a cheap and low-end product compare to scientific instruments, but even a phone camera has to go thru resolution QC.This may be that compare to the QC we used to for cell phones, for example samsung, FLIR is so tiny (samsung revenue in 2017 is 210 billion, compare to FLIR's same year revenue only 1.5billion, they may not have the budget for a full field QC. This has been sort of concluded from the other boson 640 I bought later, they were all fine.

author: Fraser
author_rank: Super Contributor
timestamp: August 24, 2019, 11:32:23 pm
content: Cnxunuo,I have used FLIR Industrial grade thermal cameras for over 2 decades and AGEMA before them. I have seen virtually hand built, calibrated and tested cameras from FLIR. QC and aftersales support was simply excellent. Times have changed though. FLIR’s range of thermal cameras and their target markets have expanded significantly over the last decade. Sadly I have also seen evidence of cost reduction programs and adoption of designs that would never have passed internal scrutiny a decade or so ago. FLIR have bought companies to help expand their internal skill set and capabilities. Some of the companies have been very capable but their knowledge is somewhat squandered on sub par camera designs. To me, the BOSON is an example of such. It was FLIR’s new ‘Baby’, intended to fulfil the needs of customers who demand miniaturisation without loss of performance. I think they dropped the ball on that one though. The TAU2 core is a thing of beauty that, considering its size, was impressive. It could not compete with a high end FLIR camera but that is to be expected. The BOSON is, IMHO, a disappointment. Will FLIR fix its issues ? Well that very much depends upon whether fixes are even possible. They are using an advanced image processor in that little BOSON and they may have bitten off more than they can chew on that front.FLIR are very much a multi faceted organisation these days. They have their Industrial/Professional, Scientific, Prosumer and Consumer ranges. The Industrial and Scientific cameras remain excellent offerings but the other divisions sometimes ‘drop the ball’ and designs leave something to be desired.Fraser

author: cnxunuo
author_rank: Regular Contributor
timestamp: August 25, 2019, 12:28:20 am
content: Dear FraserWe have very similar views about how there quality “appear” to be. back in Indigo photon days, they use proper big image field germanium lens, covers more than the 25um 640 image size, now that its 12um, lens should be smaller, at least the same image circle margin should be kept, however the dark corner light fall off is much more pronounced, results from extremely budgeted lens design even when they already choose cheaper material to start with, why done they just made the image circle a bit bigger ...cost savings has ruined many products.their scientific camera was a leader, but now I saw more people from my field (universities) chose xenics and other smaller brands as they think Flir is a bit overpriced, although gives good performance.maybe a phased array microwave using thermal imaging to steer the beam across cooler spots to evenly heat foods, or self driving car that uses 10+ thermal stereo cameras can bring the quality and performance up and the price down....

author: Bill W
author_rank: Super Contributor
timestamp: August 25, 2019, 12:09:59 pm
content: Quote from: frogg on August 24, 2019, 04:28:01 pmThe vertical banding is very large compared to signal (at least in ASi), each column is an individual, and the offsets are also very temperature sensitive. So correcting a large error that changes a lot is tricky.Gain is almost well behaved in comparison !A single calibration and maths, or even several calibrations at several temperatures, is still going to struggle without a flat flag calibration as well. I am not aware of anyone who calibrates finer than each 10°C and simply interpolates between.Bill

author: Fraser
author_rank: Super Contributor
timestamp: August 25, 2019, 01:27:10 pm
content: Thanks Bill.I personally would choose a Microbolometer based camera with an FFC flag in preference to one without as I am happy to tolerate the occasional screen freeze during an FFC event and want measurement accuracy and small temperature span capability. In some cameras the FFC event can be reduced in frequency or even switched off for video recordings. There will be pixel drift but it may be tolerable in a video recording situation. If you ever want to test a thermal camera to its stability limits, select a temperature span of 2C and observe the displayed image. Poor noise levels are immediately apparent and any drift in the pixels becomes very clear indeed. The FFC flag sorts out the pixel drift correction and then you see the pixels starting to drift again. In a good quality camera the pixel drift is actually quite slow but in an unstable camera the pixels almost immediately start to ‘twinkle’ like a star field after an FFC event.Some manufacturers obscure the cameras pixel stability issues by not permitting temperature spans smaller than 8C or even greater. Such a span allows greater drift in the pixels before it becomes very noticeable to the user. I used to regularly operate cameras at less than 10C span so saw which cameras were stable and which were not. A camera intended to produce ‘pretty pictures’ can employ masses of image processing and limit the minimum temperature span selectable in order to produce nice smooth images that look impressive, but for more demanding applications such a cameras limitations may prove to be a limiting factor. What I must say though is that the FLIR BOSON should be a better performer than I have seen in user reviews. That camera certainly appears to have issues. I am pleased to see that the XTherm is using the conventional FFC shutter approach in its design. A pity about its lens performance though. Lenses can be changed but such might also require recalibration to capture the new lenses characteristics.Fraser

author: cnxunuo
author_rank: Regular Contributor
timestamp: August 25, 2019, 05:38:29 pm
content: Considering the amount of Spamming from xtherm on the forum, and their different pricing strategies, it's looks to be a traditional doggy company who's main market is in Mil and Gov contracts, a common practice in china is spam the f out of every potential costumers.they are retailing in china the 384 (or 320) high fps unit for 500£, but from their spam in those threads, they seems to want way more than that from foreign purchases. I am still waiting for friends review for the new 640 unit, but from the brief video I saw, their denoising seems a bit too aggressive, and recording with extreme compression artifacts, prefer a OTG tau2 or thermapp640 before they remove their permanent logo in video output and get rid off the compression algorithm...from the SDK package, it's a already processed video feed, no RAW data available at all, but I could be wrong since I dont have inside info.

author: Ultrapurple
author_rank: Super Contributor
timestamp: September 16, 2019, 01:40:34 pm
content: I forgot to mention that Jinhua has written a calibration routine for the Therm-App cameras that works insanely well. You need to freeze (<-18°C), then warm (>50°C) the camera whilst the calibration app runs, pointing the camera all the while at a blank subject (a smooth, painted wall is OK). As I understand it, in conjunction with the ThermViewer driver software, the routine calculates new NUC tables for the sensor, possibly several for different temperatures, and replaces the manufacturer's values.Rather conveniently, the Therm-App driver software stores the NUC tables and other correction factors on the phone. They are normally downloaded, just once, when the Therm-App is first used on that particular device.If you transfer the Therm-App camera to another phone the Therm-App driver will download the 'stock' values onto that phone, so you'll have to manually copy the revised data, overwriting the stock files. This only needs to be done once.Jinhua was kind enough to let me use a copy of his software when I had a 9Hz Therm-App modified for a higher (cough cough). For reasons unknown (but easily second-guessed) the calibration was way, way off when the camera came back to me - the image quality was so bad it was essentially unusable. But after running the routine and replacing the data files the IQ was right back up to where I expected it to be.I keep meaning to see if it'll run on the Therm-App Pro 640x480 - mine has a couple of small blemishes in its NUC correction (which are easily nulled out by ThermViewer) but it'd be nice to have a properflatflat field correction. (There were some teething troubles with the Therm-App Pro - mine is serial number 000001 - but these were soon fixed. Opgal kindly offered to take back my camera and recalibrate it for me, with carriage at their expense, however I didn't want to run any potential risk of paying another $800 or so in import taxes).The three images below show my Therm-App Pro face-down on the bench with no lens, using its stock calibration file (left) on the stock app, (middle) the stock files on ThermViewer with no corrections applied and (right) on ThermViewer with the stock cal but on-the-fly correction switched on. The camera does drift - very slowly if the ambient temperature remains constant - but it's very easy to do a manual FFC in ThermViewer whenever required. (Just cover the lens then press & hold the correction on/off button for a few seconds).Note that these images are NOT representative of the quality you're likely to get from a Therm-App Pro that you buy today - as mentioned, mine is serial no 00001 and there were some very early issues.

author: carpin
author_rank: Contributor
timestamp: September 16, 2019, 11:47:22 pm
content: And I am very satisfied with my (one of the first) TS3

author: Hydron
author_rank: Super Contributor
timestamp: September 17, 2019, 06:17:46 pm
content: I would check that there aren't any specks of dust on the top of the sensor causing the circular blobs in the first/second pics. In the absence of dust it's unfortunately probably from small defects in the coating of the FPA window - a known issue with the ULIS sensors, but not normally bad enough to affect image quality in real use (which I guess is why it's tolerated up to a point).

author: Ultrapurple
author_rank: Super Contributor
timestamp: September 18, 2019, 09:02:58 am
content: @Hydron Thanks for that, but I suspect the artifacts are down to the lens that was fitted to the camera when it was initially calibrated. All being well, when I get the time (!) I'll see about running my own recalibration and see what happens. The reassuring thing is that the cal files are easily accessible - and easily backed up - so if I mess anything up I can restore it to its present status without difficulty.