EEVblog Electronics Community Forum
Products => Thermal Imaging => Topic started by: johnelot on June 27, 2020, 07:19:15 am
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i have a flir scout3 sold as a 640 but resolution seems low , is there any way to check the model number in pressing button combinations etc. i know it has fixed focus but i dont seem focused at ant distance , more like a 320 - even on an external monitor it looks better but not like it should be
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Hello,
first check if the diopter is adjusted. See attached picture.
You cand find the manual here:
https://www.flir.com/support/products/scout-iii#Resources (https://www.flir.com/support/products/scout-iii#Resources)
You can also find the software "End User Tool". Go to "Camera Info".
Make a screenshot and post it here.
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i did that now and it looks like the 640 but it is such a poor image - even on an external monitor , perhaps it is just a poor lens , it does not seem focused at any distance
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Yes, its a 640.
Do you have access to a 3D printer?
The lens can be out of focus. The question is why.
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no i have the old stuff like lathe and mill but not 3d printer are you thinking i could make a tool to turn the lens ? i thought it would be in focus at some distance but it seems blurry at all , thanks for helping by the way
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Please upload a picture of the lens that shows its surface condition. It should look like a mirror finish.
Fraser
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the lens is like new - i am thinking its perhaps the non focussing lens and a poor display (cant belive flir would put such a small poor display in a commercial item like this ) i had it on an external screen and its still not very clear .i thought with the tau core in it that it would be good - maybe a good core let down by the rest
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The LCD display is a well respected brand.....Kopin, and it is the full 640 x 480 pixel resolution to match the core. There have been criticisms of FLIRs use of this small LCD panel previously but in truth, it is just a relatively poor implementation of a good panel. The eyepiece optics provide inadequate magnification.
As to why your images a not well focused. It should be born in mind that fixed focus lenses are effectively providing a compromise that is not ‘well’ focused at any point except that used to setup the focus point at the factory. Manual focus lenses provide excellent sharp imaging but require regular adjustment to suit the targets range. They also have relatively small depth of field with the f1 lenses used.
If you upload an image of what you are seeing on your monitor for a target positioned at 3m and one at 10m, I may be able to comment on your Specific units image quality.
For info, the Tau normally produces excellent fixed focus imagery. Adjusting the fixed focus lens will improve the focus at the distance to target that you are using but will degrade its performance at other distances. You need to set such a lens to the Hyperfocal distance.
https://en.m.wikipedia.org/wiki/Hyperfocal_distance
Your lens looks perfect. No problems with the AR coating which is very good news.
Fraser
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I have just had a thought.... I have a 19mm manual focus lens from an ATN Thor rifle scope. It is a custom made lens assembly for ATN to use on their TAU2 based scopes. Apparently the lens element centering is better than a standard FLIR lens and it has a lovely metal manual focus ring :) Whether it will fit the Scout is another matter. I would need to test it on one of my scouts.
Sadly these lenses are not exactly cheap though.
Fraser
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must be a tiny display , maybe a better eyepiece would help it greatly and a focus front lens , i have 1 or 2 but it might be tricky to get this apart to work on it.
seems to be best at about 10 metres . strangely looking thru it there just does not seem to be as much "information" as in detail as i seem to get with the other units i have -perhaps just with the fixed focus - but it must be a 640
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Yes, I can see what you mean. For a 640 x 480 pixel core that does look quite poor to me :(
I am uncertain as to the cause though.
For info, the Scout comes apart quite easily. You just unscrew the outer plastic or metal Ring around the lens and that releases the whole front panel. You can then unscrew the Tau core fixings.
Fraser
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My post from several years ago may be of interest....
https://www.eevblog.com/forum/thermal-imaging/flir-ms-ps-ls-thermal-scope-teardown-by-fraser/msg977520/#msg977520 (https://www.eevblog.com/forum/thermal-imaging/flir-ms-ps-ls-thermal-scope-teardown-by-fraser/msg977520/#msg977520)
And yes, the Kopin LCD display panel is tiny ! They are deliberately small for integration into very small eyepiece assemblies.
Fraser
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i will have a look at it in the next few days , i am suprised it comes apart so easy as they recon its waterproof i was thinking it would be glued of sealed . it should be possible to put a focusing front lens on or even make the existing one adjust but without a better display or more magnifying eyepiece lens in it i dont think it would be improved , i will let you know how i progress - thanks
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i just measured the front lens and it is 23.5mm diameter - i thought it should be 32 or 33mm i know the focal length is 33mm but i thought the actual lens would have been a little larger will this be normal for the 640 ones ?
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I just looked up the TAU2 core and lens specification for your unit.
From what I can see, that lens provides a Hyperfocal Distance of 35m with an 18m depth of field !
No wonder you are seeing poor focus at 3m and even at 10m. I am assuming that your unit has an 18 degree FOV using a 33mm or 35mm focal length lens.
https://www.flir.co.uk/products/tau-2/?model=46640W35H (https://www.flir.co.uk/products/tau-2/?model=46640W35H)
https://www.flir.co.uk/products/tau-2/?model=46640035H (https://www.flir.co.uk/products/tau-2/?model=46640035H)
https://www.flir.co.uk/products/scout-iii/?model=431-0019-31-00 (https://www.flir.co.uk/products/scout-iii/?model=431-0019-31-00)
By comparison, the 19mm lens equipped TAU2 640 provides a 32 degree FOV, Hyperfocal length of 9.5m And 4.8m depth of field.
https://www.flir.co.uk/products/tau-2/?model=46640019H (https://www.flir.co.uk/products/tau-2/?model=46640019H)
Fraser
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yes i see what they have done - since its fixed focus they have used a smaller lens with big focal length so it has a much longer depth of field , just at no distance does it seem to have the crispness of a manual focus lens , inside i suppose there is a very nice core wanting to get out
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i just measured the front lens and it is 23.5mm diameter - i thought it should be 32 or 33mm i know the focal length is 33mm but i thought the actual lens would have been a little larger will this be normal for the 640 ones ?
The rear element will be bigger for a 640 sensor, but the front is not affected by sensor size only by lens aperture. 24mm diameter for a 33mm focal length suggests an f/1.4.
Reducing the aperture should improve focus, at the expense of noise and of course temperature readings are lost.
Bill
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yes, the Kopin LCD display panel is tiny !small displays display a terrible picture. I changed the display along with the eyepiece about the same as in the picture everything changed for the better the picture became large and very high quality
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you can check this by connecting an external monitor to the thermal imager, and you will see improvements
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to focus, you can twist or Unscrew the lens. you need to rest against the 4 cutouts shown by the arrows.
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thanks for the replies , i have a couple of the displays you show in the picture from china - i have bought about 6 but the success rate is 1 good one in three i find but they are a nice display if you get a working one.
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I am using a key to adjust focus. The display means a lot. Some people use video glasses or display video on a monitor. For PS24, I made a video output.