DIY Thermal - it can be done!

built your own thermal unit?.....or done some d.i.y modding on/with your existing unit. post them up here
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blueeyes
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Location: Bonny Scotland

Re: DIY Thermal - it can be done!

Post by blueeyes » 19 Nov 2014, 15:52

Unbelievable well done that man :clap:

phoenix
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Re: DIY Thermal - it can be done!

Post by phoenix » 19 Nov 2014, 16:07

OK, couple of quick vids.
Both recorded on a Newton (Yukon) CRV640 DVR at (supposedly) 800x600 resolution and then uploaded to Photobucket where there was some processing going on -but I have no idea exactly what
Both thermals were mounted side by side, aiming at the same area across the road from my garage
First vid is the Guide
To get some idea of the resolution, look to the right of the horizontal crosshair line but just before the bush. You should see a blurry blob a bit lighter than the background.
That's a stone about 4 inches wide on a roof 100 yards away.
You'll notice a couple of birds flying through the FOV.
The trees in the background are 180 yards away
Mine is one of the older Guides with the lower resolution display (320x240) and the video is actually better than what is seen through the eyepiece.
Image
Second vid is the new thermal
The stone on the roof is much more easily discerned and the general sharpness and clarity of the picture is, in my opinion, much better.
For some reason, the video crops off most of the menu which is displayed across the bottom of the screen, but I'm basically running through some of the options to show their effect
White hot/black hot
Zoom x1, x2, x4
Cursor position
Note that the cursor has a flashing single pixel at it's centre - I reckon that would be a reasonably good shooting reticle if the thermal could be gun mounted
Notice that the FOV is bigger than the Guide - probably because although they both have 50mm lenses, the sensors are different physical sizes
Image
You see some small birds sitting in trees, but I'll try and get some video of proper animals in the next day or so.

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

phoenix
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Re: DIY Thermal - it can be done!

Post by phoenix » 19 Nov 2014, 16:10

PeteL wrote:Bruce,
Brilliant, an excellent piece of work. :thumbup: Congratulations.
What material is the lens, as a matter of interest?.
Peter

Peter,
Like most thermals at the moment, the lenses are made by single point diamond turning a solid single crystal of Germanium - that's why they're so expensive.

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

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paulham
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Location: Potters Bar, Hertfordshire

Re: DIY Thermal - it can be done!

Post by paulham » 19 Nov 2014, 16:36

phoenix wrote:
PeteL wrote:Bruce,
Brilliant, an excellent piece of work. :thumbup: Congratulations.
What material is the lens, as a matter of interest?.
Peter

Peter,
Like most thermals at the moment, the lenses are made by single point diamond turning a solid single crystal of Germanium - that's why they're so expensive.

Cheers

Bruce
So the sensors are nothing 'special', and they can come down in price a lot more?

I read that its the germanium that has to be polished from 1 piece and the failure rate is high currently leading to expensive end products.

PeteL
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Joined: 09 Apr 2014, 14:35
Location: Swansea

Re: DIY Thermal - it can be done!

Post by PeteL » 19 Nov 2014, 16:45

Bruce,
Both Pilkington and Schott make Thermal lenses from elements other than Germanium. These lenses(unlike Germanium) can be made by moulding and grinding just as are glass lenses. Whilst I do not have any prices, I guess that because of this they would be significantly cheaper (only a guess, mind you). I had some references from the manufacturers website but can't locate them at the mo'.
As to what sort of lens is needed, how you'd go about finding out and from where they are obtainable, I dunno.
Here's a few references I could find:
http://www.axis.com/products/video/came ... ens_ta.htm
http://www.laserfocusworld.com/articles ... aging.html
Hope they are of interest
Peter

phoenix
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Re: DIY Thermal - it can be done!

Post by phoenix » 19 Nov 2014, 16:57

This is how the prices broke down
Camera £2700
Lens £495
I think it's fair to say that the camera is still a "bit special"
They do a camera with 388x284 pixels which costs £1350 and apart from the number of pixels is exactly the same as the one I bought
A camera at £1350 and a lens at £495 gets you the same performance as a Guide costing over £4k and a pulsar HD50S costing over £3k
Obviously you still need to do some serious fettling, but with an Oriscape type 640x480 near eye display costing around £100 you could put a working device together for just about £2k
They do a range of lenses from 13 -100mm but there's a big jump in price between a 50mm and a 75mm with the 75mm costing £1050
The sensors will come down in price, because they are made from silicon and the whole semiconductor industry is based on making very small circuits from silicon.
FLIR use a Vanadium oxide sensor which is more difficult to with smaller pixels
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

phoenix
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Re: DIY Thermal - it can be done!

Post by phoenix » 19 Nov 2014, 17:14

PeteL wrote:Bruce,
Both Pilkington and Schott make Thermal lenses from elements other than Germanium. These lenses(unlike Germanium) can be made by moulding and grinding just as are glass lenses. Whilst I do not have any prices, I guess that because of this they would be significantly cheaper (only a guess, mind you). I had some references from the manufacturers website but can't locate them at the mo'.
As to what sort of lens is needed, how you'd go about finding out and from where they are obtainable, I dunno.
Here's a few references I could find:
http://www.axis.com/products/video/came ... ens_ta.htm
http://www.laserfocusworld.com/articles ... aging.html
Hope they are of interest
Peter

Peter,
There are several different materials that have good transmission properties at thermal wavelengths, and I've searched extensively for potential suppliers.
The lenses used are not a single piece of material, but, rather like normal visible light lenses, have multiple elements which have to be aligned with each other and at least one element movable so as to focus the radiation on the sensor.
There are no standard mountings for thermal lenses in the way that exists for camera lenses (e,g C, M42, Nikon etc) and every thermal camera manufacturer wants to sell you his lens with it's proprietary fitting.
As an example, here's the back of the lens for the new thermal showing the attachment to the camera
Image
Not exactly standard!
Chalcogenide lenses will bring down prices, but at the moment they are only made in small diameters because that's where the bulk of the market is

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

Snapper
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Location: East Sussex

Re: DIY Thermal - it can be done!

Post by Snapper » 19 Nov 2014, 18:27

My god that is something special.

I'm not saying you're a NV god but if ever my hat blows into the middle of a pond, I'll ask you to walk over a pick it up.....

keeperjim
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Joined: 05 Jul 2014, 09:21
Location: Norfolk

Re: DIY Thermal - it can be done!

Post by keeperjim » 19 Nov 2014, 19:06

Hi I got some geraniums in the garden if you want to make me one :lol: ,awesome build well done and I was feeling smug as I just made a digital mp3 caller but now I'm feeling abit useless ,keep up the good work mate

Radagast
junior librarian
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Location: Sydney Australia

Re: DIY Thermal - it can be done!

Post by Radagast » 19 Nov 2014, 19:30

Stunning. I really can't express how impressed I am without sounding like a squealing teenybopper.

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