Change lens for Seek cameras? - Page 1
Forum section: electronics / general

author: frantzmubarik
author_rank: Newbie
timestamp: October 27, 2020, 11:41:48 am
content: Hello guys.Does Seek camera use the same lens mount across different series? (Compact/reveal/shot/OEM)Where can I get a wide lens? I want >60 degrees HFOV, no upper limit.I see the only native wide angle Seek product is Shotpro with 57 degrees, don’t know if it’s HFOV.There are only few place selling thermal lens without camera, and I can’t seem to find one that fit my needs.The image circle need to cover the whole sensor, and need to be wide enough fitting on the 12 um sensor. (Some lens designed for larger sensers will be narrow when fitting on Seek)The ideal ones should be those for Flir Boson 320, which have similar pixel pitch and resolution as seek Pro. They provide up to 92 degrees HFOV with 2.3mm lens, but I cannot find anywhere selling the lens alone, also don’t know how can I mount it.Any suggestions will be welcome.Thank you.

author: IwuzBornanerd
author_rank: Frequent Contributor
timestamp: October 29, 2020, 11:22:02 pm
content: The mounting is not exactly the same even between versions of the "Compact" models. You can find details on those mounts in the Seek Thermal Lens Repair thread:https://www.eevblog.com/forum/thermal-imaging/seek-thermal-lens-repair/I don't know for sure, but I think the Pro is the same as the XR; I have not cracked open a Pro yet.Fraser has posted teardown photos of the reveal cameras that show the lens nestled in a block but I don't see lens mounting details:https://www.eevblog.com/forum/thermal-imaging/seek-reveal-camera-guess-the-fault-%29/I think it is "fixed focus" so it may just be "stuck" in there.My guess would be that the CompactXR or Pro would be the best Seek candidate for fitting an alternate lens because of the bayonet & the standard 12mm threads. You would need to find a lens that is designed to be mounted with its inner surface no less than half an inch from the focal plane of the sensor as that is about the closest the housing will allow it to get. I believe the "tunnel" in the housing lid will support a lens aperture of F/1.0, but the threaded bayonet will not, and may limit you to the Seek standard of F/1.4.I have fitted cheap ZnSe lenses directly to a Seek CompactXR, but only longer focal length lenses, not wide angle.

author: Fraser
author_rank: Super Contributor
timestamp: October 29, 2020, 11:49:58 pm
content: The Seek Reveal and OEM J3-603 core use a threaded lens mount but the lens is screwed into the correct focus point and locked in place with epoxy. Seek Thermal recommend against adjustment, hence the locking of the lens in place. In Mike's teardown video of a Reveal Pro camera he removes the lens from the metal chassis.https://www.eevblog.com/forum/thermal-imaging/seek-reveal-pro-review-teardown/msg1073767/#msg1073767Fraser

author: coppercone2
author_rank: Super Contributor
timestamp: October 30, 2020, 10:01:54 pm
content: is there a fisheye lens available so you can put it in front without modding the camera (i like it being tactical because I can set up a tiny tripod and take pictures outside and not worry about it being damaged too easily, I think its built well, and the keychain carry case is very good IMO). Actually impressed by how well that thing functions as a phone gadget, it does not feel like a gimmick.Or, does anyone have a road map for grinding your own fish eye lens for a thermal camera? As I understand so long the focal length is less then the focal length of the camera it should work. I see the machines are not horribly difficult to make out of wood and I also noticed the ZnSe lens is pretty resistant to scratches and stuff in terms of not effecting the camera in a meaningful way.. optically my lens look pretty gnarly because they were left in a nasty area for 5 years and I forgot about them (scratchy), but they work just fine for microscopy.Is one of those 20mm lens on ebay possibly a good starting point to throw on some kind of slurry grinding machine made with some cams to make a fish eye lens? I would try it if someone that knows optics would make the calculations for the lens, then I can figure out how to align the cams and grind the thing. I figure its not different then miniaturizing a telescope optic grinder.BTW if you 3d print those thermal lens, try primer + liquid electrical tape to make them snug fit on the seek thermal lens. I tried the thingverse print on a DLP printer and I needed 1 coat of automotive primer and 2 coats of liquid electrical tape to get it probably snug enough, but I went with 1 more coat and it was a but too snug at first, but they have been sitting for another week and now it seems to work very well. I did give the adapter body and the seek thermal lens body a very careful coat of armorall though (it squeeks a bit when you put the lens on). I recommend dripping it in a medicine cup and using a q-tip to apply the armorall.You need to coat it before you glue the lens in, and I used rubberized super glue (not recommended) and I had to clean it up with nitroalkane solvents because it spread over the lens when I pressed it in, but it seems to work fine. Alcohol was not working, you need like nitromethane or maybe the new nitro-something-benzene dichloromethane paint stripper replacement (DCM is bad now). Next time I will try using a paint brush and flowable silicone (windshield sealant). It comes in a tube and you squeeze it out and its self leveling, meaning it flows well, so you can actually paint with it. The super glue is brute force.I have been using liquid electrical tape for the brackets and the lens housings, and it works pretty good. When you apply the liquid electrical tape to a complex bracket or such, that is hanging, you will likely end up with some drops of liquid rubber that do not want to fall off, so instead of waiting to cut them off, what I recommend doing is getting a paper towel corner thats dampened in alcohol and lightly touching them to wick it off (the finish still looks fine). Its not like a nice sleek rubber look, but it is very functional and offers a tight fit. But it grips well and thats what important, I can adjust the focus of my thermal microscope easily now. Also, I use the liquid electircal tape in a can sold in the electrical isle of the hardware store (meant for coating terminal blocks). Plasti-dip might work better and give you a smoother nicer finish, but I don't like it because I HATE throwing it away.. the liquid electrical tape was from 2015 and it worked well, and when I bought a new can a few weeks ago because I went crazy rubberizing brackets, it worked the same.Also, the first coat over your primer will look bad, but the 2nd coat smooths it out if you let the first one partially dry.. don't freak out. I am actually impressed by the overall quality of the part considering it came from resin and spray cans. But for the brackets for the thermal camera itself, I glued the plastic holder to a bend aluminum flat bar to attach it to the tripod, I did not want to go all plastic here because the DLP prints are not tough enough. For gluing I use loctite rubberized super glue (prism loctite) and I apply the hard-to-glue medical primer to the plastic parts I am gluing (stuff is a bit expensive but you basically apply it in the thinnest coat with a brush, 1oz will glue a ridiculous amount of stuff). This stuff is impressive, if you use the primer you can super glue a polyethylene battery case to a plexiglass strip to make a battery bracket that you can screw into a metal chassis. Strong enough so you start to rip the plastic on the battery holder before there is any sign of glue seperation. (this seriously made be interested in AA and AAA batteries, since I could make a chassis mount battery holder that uses AA or AAA on the super cheap, normally they suck because mounting is hard and you need clasps or something, now I can screw em in. Way more convenient then designing lithium power circuits to power stuff! All the lithium battery management stuff is choking to implement into a simple project, wheras alkaline or nimh is trivial.

author: Vipitis
author_rank: Frequent Contributor
timestamp: October 31, 2020, 06:14:20 pm
content: It's already difficult to grind a glass lens at home that is good enough for imaging. I doubt you would be able to do that with ZnSe as it's toxic to some degree.You could buy the elements from a supplier and put them together, but it will be costly. The lenses found in a Lepton based camera are like 1.6-2mm from my calculations, so may maybe they make it, but image circle will be smaller than Seek sensor.

author: coppercone2
author_rank: Super Contributor
timestamp: November 01, 2020, 12:54:21 am
content: why, people make giant ones for telescopes and cameras all the time. it looks like you can put together most of the machinery out of woodAnd it does not need to be ZnSe, it could be germanium. Regardless the whole thing is slurry processing, so if its done right there should be very little toxic dust.It mostly seems to have to do with setting up a cam system to mop cerium slurry across a lens stuck onto a base with wax. From what I have seen I can guess that grinding a small lens would take between 3-6 hours of machine time, since its like 15mm?its not for sale quality, just fooling around

author: Ultrapurple
author_rank: Super Contributor
timestamp: November 01, 2020, 01:44:24 pm
content: I did some experiments on improvised wide angle and medium telephoto auxiliary lenses a while ago. You may find the info relevant (click images for details)You'll see from the first image that I did manage to get a very wide angle, although at the cost of some vignetting. The horizontal field of view was somewhere in the region of 110°.The setup wasn't exactly mechanically stable or particularly repeatable but itwasonly an experiment.There is no reason why something like this shouldn't be set up on almost any thermal camera, including the Seek series.