The FLUKE “WIDE1 10mm f/1” wide supplemental lens - use on other cameras - Page 1
Forum section: electronics / general

author: Fraser
author_rank: Super Contributor
timestamp: June 24, 2019, 01:14:38 pm
content: I have just taken delivery of a “FLK-LENS/WIDE1 10mm f/1” supplemental lens that is intended to be used with the FLUKE TiR-32 camera.I do not own a TiR-32 so you may wonder why a bought a supplemental lens for such. Well it is not as daft as it may sound. The joy of supplemental lenses is that they are afocal meaning that within certain constraints, they will work perfectly well with other models and brands of thermal cameraI intend to adapt this particular lens for use on my FLIR E40(E60+) camera. The FLUKE WIDE1 is a wide angle adapter that basically doubles the FOV of the TiR-32 and it will do the same on a FLIR Exx series camera as the camera lens specifications are very similar and both the respective FLUKE and FLIR wide angle supplemental lenses are 10mm f1.0 lens blocks. There is the obvious difference in lens mount however. I previously purchased a FLUKE TELE2 lens that provides X2 magnification. That supplemental lens has a FLUKE bayonet mount that I will convert to a FLIR bayonet mount via a 3D printed adapter ring. I will do the same to adapt the FLUKE WIDE1 lens mount to the FLIR bayonet mount. The WIDE1 and TELE2 supplementary lenses have different mount types so I will just need to make a custom adapter for each. Had I found a FLUKE WIDE2 lens I could have used the same adapter ring as for the TELE2 lens. The series “2” lenses are far more expensive in the secondary market though so I went with the otherwise identical spec series “1” lens at £210I hope this all makes sense as I am just brain dumping what I think is the useful information.To précis the FLUKE supplementary lens types that I am able to adapt to a FLIR Exx bayonet mount...Series “1” with ‘slot and pin’ helical bayonet mountFLK-LENS/WIDE1. X0.5 Wide AngleFLK-LENS/TELE1. X2.0 TelephotoSeries “2” with flat interlocking plate bayonet mount.FLK-LENS/WIDE2. X0.5 Wide AngleFLK-LENS/TELE2. X2.0 TelephotoThe prices of these FLUKE lenses vary greatly but, as I have discovered, there are reasonably priced lenses on the market if you search for long enough. I consider £210 a very reasonable price for such a good quality lens. There is the time and effort needed to design and make a 3D printed mount adapter, but I am learning to design objects in 3D so it is good prescribe for meWhat about calibration ?Well adding a supplemental lens in front of a thermal cameras primary lens will most definitely impact upon the cameras temperature measurement accuracy. The supplemental lens adds loss to the system and this needs to be addressed in an offset table, where such is available. Thankfully the Exx series, that still has its Service Menu, provides the option to add a supplemental lens and carry out a calibration for it that is held in a separate supplemental lens offset table that may be selected whenever needed. Some cameras also offer a single offset value that may be used to take account of things like lens protectors of viewing ports in electrical containment housings. A single point offset table cannot take account of a non flat supplemental lens transmission characteristic, but it is better than nothingSome users may have no interest in high accuracy measurements and can either ignore the effect of the supplemental lens or do their own rough measurement offset calculation to account for the effect of the supplemental lens.About the WIDE1 lens.....The FLUKE WIDE1 lens is an interesting design that offers a doubling of the cameras FOV with low distortion and predictable transmission curve. It uses relatively large Germanium lens elements and is a quality product, as would be expected from FLUKE. The front Lens element is an Aspheric type that has a dome that flattens towards its centre. This is used to reduce the number of lens elements required to produce a low distortion lens block. The whole lens block forms an afocal supplementary lens system which is what I need when not wanting to change a camera primary lens block.The rear of the lens uses a slotted semi helix mounting system that engages with three protruding pins around the lens barrel of the FLUKE cameras primary lens. There is a spring loaded pressure ring in the supplemental lens to provide a firm mounting of the lens to the camera with no ‘wobble’ or looseness issues.I attach some pictures of the FLUKE WIDE1 lens taken from the auction listing.If anyone owns one of these FLUKE WIDE1 lenses and still has the SD card that carries the calibration data, I would love to obtain a copy of it to see if I can determine the rough transmission response of the lens.Fraser

author: Vipitis
author_rank: Frequent Contributor
timestamp: June 24, 2019, 02:19:43 pm
content: The mount looks rather simple to adapt, just make sure your print is strong enough. You don't want to drop any lens elements because you cheated on infill or internal structural support.(I recently dropped an element and that ended in me getting some scrap Germanium).Can you post a comparison shot with and without as well as on different cameras? If you still have any operational FLIR One cameras, it would be interesting to know if the fov can be increased even further.

author: Fraser
author_rank: Super Contributor
timestamp: June 24, 2019, 02:34:25 pm
content: Hi Vipitis,Your point regarding 3D print strength is well taken. I use 100% infill for any load bearing parts, especially those with thin sections. When I first got my 3D printer I printed everything with 100% infillI am thinking of printing in Nylon soon and will see how I get on that that instead of ABS which is my usual filament material.These lenses are wide angle supplementary afocal types. As such they offer a set FOV, in the case of the FLUKE Wide1 I believe it is 46 Degrees with an output matching into the 23 Degree FOV of the TiR-32. As far as I am aware such a lens will not match well to a wide angle primary lens block and will not further increase the FOV. I may be wrong though. I have a few FLIR One units around so will test it and see what happens.I can provide a comparison of ‘with and without lens’ on the Exx camera. I have a kitten to look after so it will be when I get a few spare minutesFLUKE Wide 1 instructions are herehttps://dam-assets.fluke.com/s3fs-public/flklens_iseng0000.pdfSeries 2 lens instructions and data is here.....https://dam-assets.fluke.com/s3fs-public/flklens2iseng0000.pdfFraser

author: Fraser
author_rank: Super Contributor
timestamp: July 07, 2019, 09:04:38 pm
content: I just found a few minutes to dig out the FLIR E40(E60+) camera and test the FLUKE Wide1 lens. It works perfectly with the Exx series lens system. No surprises really as the FLUKE and FLIR Wide angle Supplemental lenses have basically the same spec. No modification will be needed to the FLUKE lens mounting as the FLIR bayonet mount ring will be a sleeve around the FLUKE lens barrel.I went to no great effort for this test as it was really intended to just prove my theory that the lens would work with my Exx series camera. I just placed some PVC insulation tape on a mug and filled the mug with hot water. The test is NOT calibrated in terms of the temperature of the mugs surface during the test and, as would be expected, the temperature did drop over time. The test did show the approximate difference in the surface temperature reading between the the standard lens and the addition of the supplemental lens. I can calibrate the Exx series camera to take account of that lens system transmission difference but I would use a calibrated source for thatThe test proved that the lens works well with my camera and provides the expected x0.5 wide angle performance. The wide angle lens also provides an improved close focus capability. In my rough test this decreased the minimum focus distance of the E40(E60+) from around 20cm to approximately 3cmThis distance is in line with the FLUKE Wide1 lens specification for close focus capability. So with the FLUKE Wide1 I also have an excellent close up lens for PCB workThe FLIR's focus ring is used to focus the image just as normally done without the Supplemental lens. In the first test to show the change in FOV, the camera was at the same distance from the mug for both images. Obviously in the second 'close focus' test the camera was set to minimum distance focus and moved towards the mug to achieve minimum distance focus.Pictures attached. Note that in the close up test I was not interested in the temperature measurement so please ignore the readings as the measurement spot is different.I will do further testing of the FLUKE Tele2 and Wide1 lenses later. The next task is to complete the lens mount adapters. They are my first project using Fusion 360Fraser

author: Fraser
author_rank: Super Contributor
timestamp: July 13, 2019, 11:15:00 am
content: I just managed to buy another FLUKE Wide1 lensThese are such nice quality lens assemblies and so easy to adapt to other cameras. There are intended to mate with a primary lens with 24 Degrees HFOV and produce ~48 Degrees HFOV. I am very impressed with the optical performance, including excellent transmission, plus the very useful 30mm minimum focus distance that they provide on my Exx series cameraFor very close focus work, the host camera needs to be a manual focus type.There would be little point in attaching one of these lenses to a host camera like the E4 that already has a relatively wide HFOV, but I will see what happens if this lens is placed in front of an Ex series camera. I am expecting vignetting.A little background on the FLUKE WIDE1, TELE1, WIDE2 and TELE2 lenses that may explain their regular appearance on eBay. A little while ago FLUKE offered a promotion that enabled buyers of their higher performance cameras to choose a Wide or Tele lens as a free gift. Many buyers of the cameras chose a free lens whilst not actually needing it for the intended work of the camera. As a result it is not uncommon to see these supplemental lenses offered for sale on eBay by people wishing to recover some of their investment in their FLUKE camera. Prices vary greatly and in my experience range from around £200 up to £700. I have bought my WIDE and TELE lenses at the very bottom of this price range and advise people to negotiate with the seller on price. When an item has been received as a free gift, sellers are more likely to negotiate on price than if they had paid retail on the item.These lenses use very good quality Germanium lens Elements and from what I can establish, the FLUKE supplementary lenses are basically the same optical specs as the FLIR Exx series supplemental lenses. A very rough transmission test shows the lens transmission to be in the high nineties %. Remember the lens mounts are different though. For me it is the quality of the lens elements that matters and is worth paying decent money to acquire. FLIR supplemental lenses are both uncommon on eBay and usually very expensive. It is therefore worth my effort to adapt these FLUKE lenses to fit the Exx series.It should be noted that these FLUKE lenses should work well on any camera that has a similar HFOV of around 24 Degrees HFOV and an objective the same size, or smaller than that of the Exx series camera. Placing these lenses in front of a larger camera objective, as found on a FLIR PM series camera will not work for obvious reasons.My latest purchase is mint and boxed so hopefully it will include the SD card that contains the lenses calibration file. If so, it will be interesting to see what calibration data appears on the SD card.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: July 13, 2019, 01:17:50 pm
content: Some readers may wonder about the need for these Wide and Tele lenses.The common HFOV on a professional thermal camera is around 24 Degrees. This offers excellent imaging in the common usage scenarios. Sadly no single FOV lens can cover all scenarios presented to the user though.In the case of building surveys, the user often has to pull back away from the building quite some distance in order to capture an adequate area for inspection or reporting. The X0.5 Wide supplemental lens doubles the FOV and allows the required imaging of a building at half the distance previously required. When working within confined spaces or small rooms it can also be very beneficial to double the FOV and also reduce the minimum focus distance. Electrical switch rooms are a common case.There are also scenarios where a user wants to get closer to something that is of interest, but cannot do so due to physical impediment or safety constraints. A typical scenario is the inspection of electrical cables and associated systems in power company sub stations. Safety limits how close the user may get to the live systems and they are also mounted at a height so physical impediment is also involved. By fitting a X2 Tele supplemental lens the user optically doubles the size of the area of interest without having to move closer to it. Such magnification of the target can be very useful as it is superior to digital zoom yet permits the use of digital zoom in addition to optical zoom if desired. Others area of use that are often enhanced by a x2 lens are wildlife observation, building inspection of high areas such as the roof, chimney or upper windows.When using a Supplemental lens, you are changing the optical properties of the camera. This is very different to using electronic (digital) zoom or zooming in on an image on a PC. Optical X2 zoom maintains the full resolution of the camera whereas digital X2 zoom reduces it. That is to say a 320 x 240 pixel Microbolometer camera produces a 160 x 120 pixel image when in X2 zoom. Now that loss of resolution may, or may not be important but 320 x 240 pixel cameras are not inexpensive so it is nice to use the full resolution capabilities whenever possible.Where the Wide angle x0.5 lens is concerned, that optical change does mean that the 320 x 240 pixels are reading a much larger area but the user can often move closer to the target to increase image detail if required. There is a price to pay for gaining a wider FOV. This is true of cameras like the Ex series though and they still perform well in many scenarios. The joy ow owning both a X0.5 and X2 Supplemental lens set is that the user has a very good imaging capability for near or far targets in many usage scenarios.Fraser

author: katzenhai2
author_rank: Regular Contributor
timestamp: March 09, 2022, 11:35:24 pm
content: Quote from: Fraser on July 13, 2019, 11:15:00 amHi Fraser, I'm interested in how it turned out with your lens: Was the data on the SD card helpful? I'm also thinking about buying a cheap TELE1 lens. However, I don't have a FLIR Ex(x). Can this also be mounted elsewhere over the existing lens or do you have to replace the existing lens with it?