Has anyone used NDVI lenses (like the one from Peau Productions) for the THP? I am planning on using my THP for Crop Scouting on Rice farms but I wonder if simply replacing the stock lens will do the trick. I know that the NDVI lens (NIR or Red Edge) filters the light spectrum to allow only the ones specific for NDVI calculations so I am thinking that replacing the stock lens will only cost me the lens + another CGO3+ instead of buying the super expensive NDVI cameras. I'm also looking into MapIR cameras but they don't have support for Yuneec products specifically the TH unlike DJI (they have mounts for Mavic and Phantom).
NDVI Lenses
- Thread starter hlorenzl
- Start date
Use the magnifying glass in the top right of each page. It is a FORUM search. Search on "LENS" You will find many threads on that subject..
Hi BobW55! Thanks for the reply. But, yeah.. I kinda used that already before but yielded no NDVI search results. I'm not sure if there is difference in search results between the phone app and when searched in browser which I haven't done yet as I have mostly accessed the forum through my phone app.
I get that discussions here about lenses used as replacement are mostly for regular RGB images only. That's why I started a post and hoped that someone would have actually already tried and used the ones for NDVI mapping. I just need it for crop monitoring purposes, well.. you know, as an alternative to the much expensive cameras exclusively and purposely built for crop health monitoring and analysis.
Individual Farmers in the Philippines tend to have less to no budget when it comes to farm tech, you know.hehe farmers here kinda just wanna stick in their old and somewhat traditional way of farming, so I just wanna spark a change in that mindset of ours so the youngbloods won't get discouraged in investing into farming or agri business. I mean, we're entering into a much more hi tech world each year so I'm thinking why not apply what tech is possibly available into farming so as to reduce cost of production and ultimately cost of food.. and consequently, food may be available to much more people. Anyway, that's just my purpose and I am seeing the THP as a tool to achieve this.
If anyone in this forum is engaged in farming and is considering to mod the THP or CGO3+ for this purpose (believe me this drone is very stable in high winds which is usual in the farm and really reliable even when you do close-ups with plants or trees), maybe they can post infos here.
Hi hlorenzl!
Some clarification... even though there are pages on the web that refer to NDVI lenses, NDVI refers not to a lens, but a type of filter... to pass only the limited bandwidth of light used to do these crop analyses. However, unlike other filters such as ND filters or polarizers, these filters are permanently mounted on the back of the lens, directly in front of the camera sensor. This necessitates that you purchase a separate camera to be used exclusively for NDVI work. So any vendor offering a "NDVI lens", is simply selling you a lens with the filter pre-installed.
If you are going to use the Typhoon H for NDVI work, you will want to install a third party lens. Even if you wanted to use the original lens, the glue that is used on the OEM lens would need to be removed and cleaned before installing the NDVI filter. So at that point, getting the superior sharpness of a lens like the PixAero 3.77 and having a NDVI filter installed at the same time is the most cost effective modification.
I have not yet started my commercial flying, but I intend to incorporate NDVI analysis as part of my offered services. Interestingly, I had bookmarked Peau's NDVI filters page several months ago... on re-checking before posting here, I see that they are no longer offering NDVI filters.
You can also do a search for "UAV Toolbox grid mapping" which will yield threads on previously discussed, upcoming additional functions to Tuna's app... these will be directly applicable to using the H for NDVI work.
Some clarification... even though there are pages on the web that refer to NDVI lenses, NDVI refers not to a lens, but a type of filter... to pass only the limited bandwidth of light used to do these crop analyses. However, unlike other filters such as ND filters or polarizers, these filters are permanently mounted on the back of the lens, directly in front of the camera sensor. This necessitates that you purchase a separate camera to be used exclusively for NDVI work. So any vendor offering a "NDVI lens", is simply selling you a lens with the filter pre-installed.
If you are going to use the Typhoon H for NDVI work, you will want to install a third party lens. Even if you wanted to use the original lens, the glue that is used on the OEM lens would need to be removed and cleaned before installing the NDVI filter. So at that point, getting the superior sharpness of a lens like the PixAero 3.77 and having a NDVI filter installed at the same time is the most cost effective modification.
I have not yet started my commercial flying, but I intend to incorporate NDVI analysis as part of my offered services. Interestingly, I had bookmarked Peau's NDVI filters page several months ago... on re-checking before posting here, I see that they are no longer offering NDVI filters.
You can also do a search for "UAV Toolbox grid mapping" which will yield threads on previously discussed, upcoming additional functions to Tuna's app... these will be directly applicable to using the H for NDVI work.
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Hello Eagle's Eye Video!
Firstly, thank you for the clarification and information. If you are still planning on adding NDVI or other Vegetation Indices outputs (stills, map, and analyses) to your services, maybe we can share our ideas and continue discussions in this thread.
Umm, regarding the terms I've used, thank you for correcting that filters are the ones that "produces" the inputs for making NDVI images and not just the lens itself. But I kinda used the term "lens" because that's what Peau was selling.hehe from what I understand, they actual fixed or "cemented" the filters on their lenses that allows the sensor to only capture NIR, R, G, B, or combination of these like when used in computing NDVI during post processing.
Please correct me if I'm wrong. From what I understand, the light that is reflected from an object is what the camera captures and saves as an image. The regular RGB image that we get is only the captured reflected visible light which is coming from a certain width or range of frequency from the electromagnetic spectrum (somewhere between UV and IR) where our image sensors capture RGB data and record on a specific pixel until it completes the whole map of pixels (or image), while the NDVI is computed only through specific values from a smaller fraction or range in the spectrum (maybe NIR + G, or NIR + B) which is recorded per pixel and is mapped as a whole "NDVI image".
Anyway, the reason why I am saying this is that because of my understanding (not sure if right), it must mean that our CGO3+ can be converted to a NIR camera that can capture the reflected light from the leaf surfaces of crops by buying the lens (with cemented filter) or more simply just a filter like the polar pro filters that can just be placed and replaced every time it's needed. This would be more convenient as this would not require me to buy another CGO3+ just to have the data that I need to compute and make NDVI maps.. any idea if it is possible to have a filter that would only allow NIR or any specific band of light that is needed for the calculations?
Another idea of mine is to add a mounting designed to hold cameras as large as GoPros (particularly the MapIR cameras that have dual lenses and sensors that can capture NIR and RGB data at the same time). I hope someone makes that kind of mounting as the one recently released for the DJI Mavic and Mavic Pro. I'm really jealous on the availability of aftermarket support for DJI..hehe
Anyway, I hope we can continue this thread until we found out what to do to get cheap NDVI images from our TH.
Kind regards
AFAIK, using a filter in front of the lens for NDVI will not work... partially because the light passing through the lens will alter that specific wavelength of light they are trying to isolate. So the best way to ensure that only the desired wavelengths reach the sensor, is to place that filter directly in front of the sensor, on the back of the lens.
This is a very similar setup that is used in my first sub-specialty of ophthalmic photography... doing angiography studies of the retina, using a drug that is injected into the patient's bloodstream to document changes in the retinal circulation. The drug is fluorescent at a specific wavelength of light, and a similar setup was used with a barrier filter mounted behind the lens/mirror system in a specifically modified SLR.
Unfortunately it does require a dedicated camera for this type of work. But from what I've casually searched on NDVI setups... virtually all current cameras and mapping software are geared to DJI products only, and many of these setups cost thousands for the camera itself, not including the additional investment in a DJI platform. About a year ago I asked the folks at Drone Deploy about future support for the Typhoon H... they told me to buy a DJI...
Richk is right in that, this is all predicated on having a quality automated grid mapping solution... I am confident that Tuna will come up with a very usable solution, for those of us looking for that additional capability to be added to UAV Toolbox.
This is a very similar setup that is used in my first sub-specialty of ophthalmic photography... doing angiography studies of the retina, using a drug that is injected into the patient's bloodstream to document changes in the retinal circulation. The drug is fluorescent at a specific wavelength of light, and a similar setup was used with a barrier filter mounted behind the lens/mirror system in a specifically modified SLR.
Unfortunately it does require a dedicated camera for this type of work. But from what I've casually searched on NDVI setups... virtually all current cameras and mapping software are geared to DJI products only, and many of these setups cost thousands for the camera itself, not including the additional investment in a DJI platform. About a year ago I asked the folks at Drone Deploy about future support for the Typhoon H... they told me to buy a DJI...
Richk is right in that, this is all predicated on having a quality automated grid mapping solution... I am confident that Tuna will come up with a very usable solution, for those of us looking for that additional capability to be added to UAV Toolbox.
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