AGA Thermovision 680 - Page 1
Forum section: electronics / general

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 06:48:01 pm
content: Liquid nitrogen seems less of a problem when I look forward to attach AGA IR lense 680 Ge 633/1:2,5/2 (telescopic) to the scanner unit and see what happen. So I am trying to power on my AGA 680 scanner unit without display and control unit.Pinout of the connectors on the rear panel after almost a day-long digging inside the camera:DISPLAY UNITA (ACCESSORIES pin E) - HORIZONTAL TRIGGERING PULSEB - VIDEO OUTC (ACCESSORIES pins H, A) - BLACK LEVEL (?)D (ACCESSORIES pin N) - POWER SUPPLY +50V (?)E - NCF - TO MOTORS M1, M2, M3 (200 Hz 115V ?)G - TO MOTORS M1, M2, M3 (200 Hz 115V ?)H - TO MOTOR M3 (200 Hz 115V ?)J - TO ACCESSORIES pin JK - TO ACCESSORIES pin KL - TO MOTORS M1, M2 (200 Hz 115V ?)M (ACCESSORIES pin F) - VERTICAL TRIGGERING PULSEN - COMP (ACCESSORIES pin P) - COMR - COMS - NCT - TO MOTOR M3 (FOCUSING DIRECTION)U - TO MOTORS M1, M2 (200 Hz 115V ?)V (ACCESSORIES pin R) - POWER SUPPLY -50V (?)The motors are:M1 - V. ScanM2 - H. ScanM3 - FocusingCan anyone revile more detailed info about THV680 system (schematics diagrams)?

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 07:26:52 pm
content: Another lens:

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 07:35:03 pm
content: Camera unit:

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 07:36:55 pm
content: Details:

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 07:41:56 pm
content: Boards (conditioning circuit board for horizontal and vertical scanning prisms position sensors, triggering output signals board):

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 07:51:42 pm
content: Some pages from AGA Thermovision 680 Operating Manual:PS: The were two systems:AGA System 680 (2-5 µm)AGA System 680 LW (8-13 µm)Unit which is discussed and lenses are LW type

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 07:53:47 pm
content: ...continue

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 07:55:18 pm
content: Thermovision microscope:

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 07:57:50 pm
content: ... continue

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 10:43:07 pm
content: Telescopic lens:

author: bangbang99
author_rank: Contributor
timestamp: June 11, 2016, 10:51:17 pm
content: AGA 680 Bayonet:

author: bangbang99
author_rank: Contributor
timestamp: June 12, 2016, 05:00:51 pm
content: I performed a little test with my Flir E4 (hi-res) without original lens which I just lean against the AGA lenses (8 degrees and 45 degrees FOV).1) Test object

author: bangbang99
author_rank: Contributor
timestamp: June 12, 2016, 05:02:34 pm
content: 2) Flir E4 with original lens at distance ~150mm

author: bangbang99
author_rank: Contributor
timestamp: June 12, 2016, 05:06:58 pm
content: 3) Flir E4 with AGA 8 deg fov lens at distance ~2m

author: bangbang99
author_rank: Contributor
timestamp: June 12, 2016, 05:09:57 pm
content: 3) Flir E4 with AGA 45 deg fov lens at distance ~50mm

author: bangbang99
author_rank: Contributor
timestamp: June 12, 2016, 05:32:37 pm
content: Another object. Original E4 lens at distance ~300mm (top) vs AGA 8 deg. lens at distance ~2m (bottom)

author: bangbang99
author_rank: Contributor
timestamp: June 12, 2016, 10:09:04 pm
content: Extension ring. Part of the assembly possibly can be used as an adapter for IR imager. Just think about connection of old AGA 680 lenses with something modern...

author: Chanc3
author_rank: Frequent Contributor
timestamp: June 13, 2016, 08:12:42 am
content: Very interesting breakdown! Thanks for sharing. I must say, I do find it highly amusing seeing such a small handheld camera with massive lens on the front!Reminds me of a retro laser pistol!

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 10:47:45 am
content: I am struggling now with this one:

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 01:51:50 pm
content: Trying to get something like a minimally sharp image putting E4 on AGA 2 deg fov lens.Experimental setup:

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 01:54:52 pm
content: Object 1.Distance ~20m

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 01:59:44 pm
content: Object 2. TV antennaDistance ~60m

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 02:05:08 pm
content: Object 3. Construction craneDistance ~1.5km

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2016, 02:52:57 pm
content: The 680 lenses were large diameter to suit the prism scanning system employed in that particular camera. They will be VERY high quality and if you consider that Germanium, from which their lens elements are made, is worth around £1 per gram, they have quite a high scrap value. I personally would never scrap such lenses as they are too good for that.I use Inframetrics lenses with my FLIR PM series cameras and and experimented with the E4. Those lenses invert the image though.Your 680 camera may really belong in a Museum, but the lenses are suitable for use with modern cameras. You just have to live with the bulk and weightThe AGA 680 comes from the early days of thermal imaging when fine engineering was required and cost was less important than having the imaging capability. This is why it is built like a tank and contains much fine engineering in its build. The motors alone would have been very expensive parts, let alone the Dewar and its associated detector. The bad news is that, having used this type of scanning camera, it produces an image inferior to your E4. Its resolution will be quite limited, say around 128 TV lines, so around half of standard VHS tape quality. It will also be fussy about settings and getting a good picture takes some careful adjustment of the controller.I own the AGEMA 880 which is a descendant of the AGA 680, as AGA became AGEMA, who then were bought by FLIR. The 880 was likely the best of its type and still produced images that are quite limited in terms of detail. Creating an image using horizontal and vertical scanning mirrors or prisms limits what can be achieved. Hence why the staring FPA was such a breakthrough in thermal imaging technology.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2016, 03:13:22 pm
content: Just for interest, I have taken some pictures of my AGEMA 880 which, as i said, is a direct descendant from the AGA 680.I have included a CD in some pictures to provide size reference.The AGEMA 880 is a little smaller than the 680 and uses two scanning mirrors, as opposed to two rotating Germanium prisms as found in the 680.There is also quite a lot of control electronics located within the 880, unlike the very limited electronics found in the 680. The miniaturisation of the detector,motors and all other mechanical parts enabled the 880 to be a portable camera, albeit, for static use due to the power requirements and controller unit.I have the complete tested and functional system, including power supply, controller with built in monitor and the Husky portable computer that was used for ISO thermal calculations etc. It is fully working but I have no source of Liquid Nitrogen or means to store it so it remains dormant in my care.Fraser

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 03:22:44 pm
content: It seems these lenses really worth to build something around them. It is interesting to compare optical resolution of E4 lens with 680 lenses.What about the scanning camera, I anticipate some unused potential in what can be achieved after output signal processing.

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2016, 03:23:09 pm
content: bangbang99,I am very impressed with your AGA 680 leneses. The large telescope is amazing but as you have found, it is quite bulkyI have a special lens for the AGA 680, namely the Thermal Microscope lens with 15X magnificationIt contains a visible light and thermal microscope objective. The DUT is viewed using the conventional microscope lens and eyepiece, for the purposes of alignment, and the thermal lens is then slid into position to replace the visible light lens. All very nice and it was extremely expensive new. You could easily purchase a house in the UK or USA for the cost of that lens when new. That is why I believe we are so lucky to have affordable thermal cameras now. In the past they have been limited to institutions with very deep pockets !Pictures attached.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: June 13, 2016, 03:37:27 pm
content: bangbang99,It pains me to say it, but the AGA 680 really is a museum piece and it is really not worth spending time or money trying to build a controller for it. The results will never justify the effort. In the AGA 680 you are seeing the era of thermal imaging in its infancy. The units size or superb build quality does not mean that it produced amazing images. It was just what was needed to produce an image that was usable. You could compare it to the early days of television and the electro-mechanical Baird Televisor. It worked, but the images were anything but impressive.As thermal imaging detector technology improved it became possible to produce far better images without the need for scanning mirrors or prisms.A breakthrough in portable imaging came with the manufacture of the GEC Pyroelectric Vidicon tube as found in the EEV P4428 and Argus 1 fire fighting cameras.These used a similar architecture to a conventional CCTV camera of the period and produced higher resolution images than the old AGA 680 and AGEMA 880. Things really got interesting when the FPA detector arrays became available in the form of the BST, A-Si and VOx Microbolometers. The AGA 680 looks like it came from the age of steam when compared to such recent developments.Do not get me wrong, I love and collect the old thermal imaging cameras. it is just that I would hate for you to spend a lot of money on the AGA 680, only to find its images very disappointing.Fraser

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 03:48:01 pm
content: AGEMA 880 is much improved version of AGA 680 in terms of everything: electronics, ergonomics, capability etc. And both these models share the same principle of operation.What about the size of 680 optics, I think it relates to the size and sensitivity of IR detector (0.35x0.35 mm). The question is how better the optics is, concerning it was designed for such a large detector?

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 03:58:05 pm
content: I got this almost for nothing so don`t wait any disappointmentJust like to see something working

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 04:09:35 pm
content: For the AGA 2 deg fov lens instantaneous field is 0.26 mrad which is equal to object size of 0.13 m at the distance 500 m. Field of view in this case is almost 18m.

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 04:15:22 pm
content: Angle of view for this lens is 35 mrad (2 degrees). 35/0.26 = 134.6 lines which is almost 128 lines of 680 system resolution.

author: bangbang99
author_rank: Contributor
timestamp: June 13, 2016, 04:27:15 pm
content: Spatial and thermal resolution description:

author: Mashpriborintorg
author_rank: Regular Contributor
timestamp: February 15, 2017, 06:30:18 am
content: I just found a AGA 680 on my local eBay, for 30 euros. missing the display / controller unit too, sadly. But comes with a 556-190-154 lens and extension ring. Usually I purchase stuff for making youtube teardowns, but it my be redundant with with topic photos and infos... however the core parts as the rotating mirors, filters disc and the sensor are not shown here, so I may take mine apart completely to reveal them

author: Fraser
author_rank: Super Contributor
timestamp: February 15, 2017, 12:13:07 pm
content: Hi,Good findIs it a 680 or 680 LW ?If you ever decide to rehome the lens, please let me know.The 680 uses rotating Germanium Prisms rather than the mirrors used in later designs. It is very much a mechanical beast as that was the only way they could generate the required raster image with just a single pixel cooled photon detector. Most of what resides inside the 680 camera head is involved in spinning those two prisms at the correct speed and in sync with the required raster pattern. The detector has a simple interface and 'processing' board that feeds the signal to the controller, along with the required synchronisation signals to form a raster scan.Fraser

author: Mashpriborintorg
author_rank: Regular Contributor
timestamp: February 15, 2017, 02:03:24 pm
content: It is a 680, serial number 4079 according to the blurry eBay photo.

author: Mashpriborintorg
author_rank: Regular Contributor
timestamp: February 18, 2017, 07:49:59 am
content: Fraser May I re-use some of you user manual photos for a youtube video, credits provided ?

author: Fraser
author_rank: Super Contributor
timestamp: February 18, 2017, 09:29:23 am
content: I have no objections but I do not think I posted the manual pictures ?Fraser

author: Mashpriborintorg
author_rank: Regular Contributor
timestamp: February 18, 2017, 10:53:43 am
content: Oops I just noticed it is actually Bangbang99, not you

author: KalleMp
author_rank: Newbie
timestamp: February 21, 2017, 01:23:44 pm
content: Hi,This is my first post here.I like these sorts of scanning cameras.Reminds me of stuff developed in South Africa by Eloptro for the military during the military sanction era when night vision devices were not available for import. They used a hollow rotating polygonal mirror. This scanned the view sideways across a bunch of sensors (perhaps 8-16 not sure) using the inside of the mirror. Each facet of the mirror was at an angle and they would sweep the gaps in between the sensors to multiply the scan lines by the number of facets (perhaps 6 to 16 of those). The outside of the mirror was used to image a row of leds into the view finder optics and used eye persistence to form an image. So it painted it in a comb fashion but used the angular and tilt alignment of the inside and outside of the hollow mirror to synchronise the sensing view with the observing view. The mirror could be spun as fast as the sensors could handle and you could use as many sensors as you could justify price and power for. They later went on to copy 2nd and 3rd generation channel plate image intensifiers as the night sight developments progressed.Not sure if the following article has been mentioned here. I use Sci-hub to breach the paywall. doi:10.1117/12.958943Dual Waveband Infrared Scanning Radiometer For Use With Rocket Motor Plumeshttp://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1230080It has some nice details about the cameras. Mentions 235 kHz nominal max pixel rate. They chose 207ksamples/s for a 60 x 90 field. The dynamic range is or the order of 60 to 80 dB and they used a 10 bit ADC to quantise the data and save to high speed tape for later retrieval.They mention that the fuzzy interlacing takes 6 frames to repeat and is not hard synchronised but I got the feeling that two frames would give a pretty full image.The shutter (possibly optional) seems to be well synchronised to the vertical scanning and reflects the sensor back for a cold reference.That is all for now.EDIT:I forgot to mention that I thought it might be possible with modern sound card and super software to decode the data with just the video signal. The slow scan TV , the HAM radio people have been doing it for a while and it might make these nice old cameras more usable if no special control box (besides PSU would be required to get data out.RegardsKalle

author: Mashpriborintorg
author_rank: Regular Contributor
timestamp: February 24, 2017, 03:52:30 pm
content: Here is the teardown of my AGA 680https://www.eevblog.com/forum/thermal-imaging/aga-thermovision-680/

author: Fraser
author_rank: Super Contributor
timestamp: March 05, 2017, 11:23:51 am
content: Teardown video is here:https://youtu.be/pLYQXTdspe4

author: bangbang99
author_rank: Contributor
timestamp: December 10, 2017, 04:57:24 pm
content: Is this unit MW?

author: bangbang99
author_rank: Contributor
timestamp: December 10, 2017, 05:01:18 pm
content: This is clearly LW

author: Fraser
author_rank: Super Contributor
timestamp: December 10, 2017, 06:11:15 pm
content: As far as I can recall, the Medium Wave 680 was marked as just '680' and the Long Wave version had the addition of 'LW' to show it to be the less common LW version. The LW version also had LW on its side casing label. The optical blocks can be simply tested using a LW thermal camera as the MW optics are opaque at LW.Fraser