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Hello from Germany

Multispectral Filters LWIR
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#1 WiSi-Testpilot

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Posted 18 September 2018 - 22:26

Thank you for accepting me. I got the link to this very interesting forum from David Kennard and have already read a lot. Many contributions concern NIR. Until now I made NIR photos with my multicopter/drone using a low cost camera, see the attached image. In the next days I will get back my converted Sony A 6000 for IR and UV photography. I hope to enhance the quality and that UV photography from the drone will work too.
I am also interested in taking pictures with a thermal camera, see the screenshot. The two dots are hot-air balloons.
Best regards,
Wilhelm

Attached Images

  • Attached Image: d950-cumulus-cirrus.jpg
  • Attached Image: Screenshot_2018-08-12-19-56-56.png


#2 Andy Perrin

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Posted 18 September 2018 - 23:53

That is nifty to see the drone photography showing up here now! I like to play with thermal photography and near infrared (and UV and SWIR) also. You should try white balancing that NIR shot.

#3 WiSi-Testpilot

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Posted 20 September 2018 - 12:06

EDITOR'S NOTE: I found the deleted first introduction and merged it with the second introduction that Wilhelm wrote. Thank you, Wilhelm, for your patience while I got this sorted. A merge was chosen because the 2nd intro had two new photos and a new link. :)



I had introduced myself 2 days ago, however my contribution and one answer were accidentally deleted. Because it cannot be re-established, I do it again:
Thank you for accepting me. I got the link to this very interesting forum from David Kennard and have already read a lot. Many contributions concern NIR. Until now I made NIR photos with my multicopter/drone using a low cost camera, see the attached image. Yesterday I got back my converted Sony A 6000 for NIR and UV photography, see the first UV test image (1/5s, f3.5, ISO3200) and a BG3 image (1/250s, f9, ISO100).
At the moment I own only the kit objective SELP1650 containing 9 lenses. The UV filter is this one:
http://www.optic-mak...missionskurven/
SP2 UV-400N
However I will look here for other equipment to shorten the shuttertime for copter application.
I am also interested in taking pictures with a thermal camera, see the screenshot. The two dots are hot-air balloons.

The answer to my post:

That is nifty to see the drone photography showing up here now! I like to play with thermal photography and near infrared (and UV and SWIR) also. You should try white balancing that NIR shot.

This was the answer I got, but did not save the author's name. My comment: I am interested in SWIR too, but the cameras are not cheap.

Best regards,
Wilhelm

Attached Images

  • Attached Image: d950-cumulus-cirrus.jpg
  • Attached Image: Screenshot_2018-08-12-19-56-56.png
  • Attached Image: k_370nm_A6000_19_9_2018.jpg
  • Attached Image: k_BG3_A6000_19_9_2018.jpg


#4 Andrea B.

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Posted 20 September 2018 - 17:09

Hello, Wilhelm and welcome to UVP!

First of all, please accept my apology as one of the Owner-Admins of UVP for the loss of your first post and comment. Please be assured that I will try to find out what happened. It is a little bit mysterious to me, but there must be some explanation which I hope I can find. I did see your first post and the comment last evening as I was working to catch up to all the new topics after having been on vacation and then having to go through some dental work.

I'm really excited to see some UV/IR and SWIR drone work. Our member Andy Perrin has some SWIR work on UVP. You can use the search tag SWIR to find it. Also look for LWIR.
Andrea G. Blum
Often found hanging out with flowers & bees.

#5 Andrea B.

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Posted 20 September 2018 - 17:17

Found the deleted topic.

I am going to merge the two introductions.
Andrea G. Blum
Often found hanging out with flowers & bees.

#6 Andrea B.

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Posted 20 September 2018 - 17:35

OK, back to normal.

Wilhelm, I am worried that your UV-pass filter (link in Post #3) has too low a transmission rate. At only a 30% transmission peak, any exposures will be rather long. I am thinking that long exposures are not useful when using a drone. Granted a drone can hover, but it is not still. There will be vibration, yes?

You might want to look into stacking a UV dual bandpass filter with a blue-green IR-block filter or investigate a commercial UV-pass filter with a high transmission rate such as the BaaderU or the StraightEdgeU.
Andrea G. Blum
Often found hanging out with flowers & bees.

#7 WiSi-Testpilot

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Posted 20 September 2018 - 18:46

Andrea, thank you for sorting my posts and for your proposal. Yes, I have to reduce the shutter time. First I will read your/the posts about filters.

I see a lot of work has been done in the last years.

Best regards,
Wilhelm

#8 WiSi-Testpilot

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Posted 21 September 2018 - 09:27

In these pictures you see a field of barley. The bright stripe is only visible in the ripe crop, not in the green and NIR. The reason is unknown, probably an old street. It would be very interesting to see an UV image.
The stripe is also visible on the harvested field in the Vis and LWIR region.

Question: do you agree, that the SEU Gen2 filter is (in relation with the other limiting factors) the best filter to get a high UV-light yield?
Best regards,
Wilhelm

Attached Images

  • Attached Image: Gerstenfeld.jpg
  • Attached Image: Gerstenfeld_2017_2018.jpg
  • Attached Image: enhanced_sw.jpg
  • Attached Image: Feld_26_8_2018.jpg


#9 Andy Perrin

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Posted 21 September 2018 - 13:23

Provided you are after the 370-400nm UV I think you are right about the SEU2 based on results shown here on this forum by Andrea. I have not tried that one myself.

As far as bringing out hidden patterns in fields, I did quite a bit of work on that this past summer using a computational method called Independent Component Analysis. I did a ICA writeup here:
http://www.ultraviol...ng-ad-with-ica/

My field photos using a visible/NIR filter (Tiffen #12 yellow filter) have not been shown here yet, I think. I’m away from home until tomorrow but I can upload them then.

Edited by Andy Perrin, 21 September 2018 - 13:26.


#10 WiSi-Testpilot

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Posted 22 September 2018 - 07:50

Andy, thank you. I am very interested in your field photos. On my hard disk are yet some too. I think, we (you) should create a new thread for that.
Best regards,
Wilhelm

#11 Andy Perrin

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Posted 22 September 2018 - 22:35

Wilhelm, please see the new thread!
http://www.ultraviol...lized-with-ica/