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Mapping with X5, zoom lens, and bird? O MY!

Discussion in 'Surveying & Mapping' started by Zak, Mar 12, 2018.

  1. Zak

    Zak

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    So I have found myself with a conundrum at work. First off background. I study beach nesting birds. We deiced to test whether we can more efficiency, more accurately, and more safely count colonial bird nest with a drone then we currently do.

    Currently we have ~6 people walk transects through the colony and count the nest they see. This is very disruptive to the birds and also run the risk of stepping on a nest. It can also take upwards of an hour. That being side the area is rather small, ~3-5 acres.

    I think a drone could do better. The problem with this experiment is me......

    I have done a series of test using fake wooden eggs and decoys. I thought first I better get an idea for what altitude I can still ID the nest by species. So I did a vertical test. Starting at 50 ft I would take a photo capture at 25 foot intervals up to 300 feet. I did this test with the DJI 15mm and also the Oly 14-42. Of course at 42mm I could see the eggs at greater altitude, up to 200 feet. With the 15mm it was about 75 feet. I'm sure everyone is saying why not the Oly 45mm or fly lower? I have a reason for both. My employer will not buy me the 45mm lens yet and I can't fly lower because that is what I have determined is a lowest safe altitude to avoid bird collusion. Usually what happens is the birds will flush just because of our presence and then settle at the waters edge away from the nests.

    Alright, I have figured out at what altitude and which lens I can use to maps the area. Now the problems start. First off I had to find a mission planner that will work with the zoom lens. There are a few and they seem to work. But when I create an stitched image or ortho map (drone2map) I can not see at the same zoom level or clarity.

    So....
    1. Does ortho and stitched images give the same zoom capabilities as a jpg at the same AGL?
    2. I have overlap set at 70/80%. Too low?
    2. I can not get consistent focus with the x5 while mapping, the zoom lens has made it worse. Do people use manual focus while mapping with the x5?
    3. Am I looking at this all wrong?

    Sorry for being long winded but that is all the marbles.

    I should add that I do have my part 107 and this is being strictly monitored by US Fish and Wildlife Service and State Wildlife Agencies.

    Thanks ahead of time for any insight,
    Zak
     
  2. fasterpastor

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    You have discovered a reality, the X5s does have focus issues sometimes, most people I know do not use the x5s for mapping for that reason. The x4s seems more reliable in that regard. I have just started a mapping resolution test, and so far I cannot see more detail on the x5s, to the phantom 4 pro, or Yuneec H520. SJust an idea here, if you sell the zoom lens on ebay (or whereever
    - it would not cost much more to get the 45mm?? - don't have that so I cannot promise better results.
     
  3. Zak

    Zak

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    I would love to sell the zoom lens but it has it uses. I am able to remotely check trap lines during our predator control work. Zoomed out (14mm) I can figure out where I am related to the point and then zoom in to make sure the leg hold or snare is still set. I will work on getting the 45mm to test but it might be a couple of months before I can get approval.

    I assume if I set the focus of the zoom lens in DJI Go and then switch to a mapping app that always manual focus it should stay in focus, as long as I do not change the altitude. Correct? I have question about that tho. If i set the camera in GO do I also need to set interval photo taken in the GO app and not use the mapping app other then more flight or can I set focus in GO and still use the mapping app to control the shutter without changing the focus?
     
  4. drz1972ss

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    Anyone 1 you know have a Inspire 1 with a Z3. You will be amazed at what that cameras capabilities are with the zoom
     
  5. Zak

    Zak

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    Do you use the z3 for mapping? I have read somewhat poor reviews on the camera. I know it has a smaller sensor and less pix then the x5. The zoom is about the same but the x5 is optical were the z3 is 2x optical and the rest is digital, right?

    It would be nice to get what I have to work instead of trying to fix the problem with more money and risk running into the same problems.
     
  6. Jesseg138

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    I have never tried mapping with my 14-42 but it should work just fine as long as you get the overlap plsnned correctly. I would say UGCS would be your best bet at getting a good flight plan with propper overlap since you can customize your focal length. Since 70 side and 80 forward overlap should be enough to stitch I suspect that your flight planning apps are planning for 14mm when you're flying fully zommed in at 42mm which is creating your problems. As for focusing you have to set focus in djigo when airborne at your flying altitude and then set to manual so it holds the same focus and doesn't try to autofocus while flying. An ortho is basically just a puzzle made of pieces of your original images so the resolutions should be identical as long as your stitching software isn't compressing them. Your flight planning software should be the program triggering your shutter so you shouldn't need to set it to intervals in djigo and yes focus should hold once set in djigo.
     
  7. Zak

    Zak

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    JEsseg138, thanks for the reply. I should note that the focus problems are happening most often with the 15mm DJI lens. I have been setting the zoom lens in manual in GO but they still do not look sharp even after calibration.

    I have never heard of UGCS. I found that GSPro also let you set the focal length.

    Thank you for answering the the resolution question that is what I thought but haven't seen that when looking at the ortho and individual images. So it is driving me nuts. I think the problem is with the soft focus is magnified when stitching.

    My latest problem is the drone will not let me fly to AGL set focus with GO>Close>open map planner anymore. Map planner will not connect to drone or sometimes it will not let me load the mission. This is new for me and across the board (many planner apps). I often take off manually and switch apps in flight because I am taking off from a boat and even what to get some shots before flying a mission.

    I can't tell if the drone world frustrates me or keeps me entertained.
     
  8. VisionAir

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    The X5 is digital and the Z3 is 3.5X optical with a digital double to 7X
     
  9. Jesseg138

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    Right on the mark about the z3, but digital zoom on the x5? Not sure how you came up with that...There's no digital zoom on my x5 with any of my prime lenses and the zoom with my olympus 14-42mm and Panasonic 45-150mm is completely optical.
     
  10. VisionAir

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    Yes not many people are aware that the X5 and the X5S have 4X digital zoom but only when you are shooting in 1080, if you are in 4K there is no zoom, how you do it is while you are in 1080 place your index finger and your thumb together on the screen then slide them open to zoom in and pinch them together again to zoom out. How it works is a single frame of 1080 X1920 is 2 meg and a single frame of 4K is 8 meg so you have 4 times the info in the 4K hence 4X digital zoom, however on saying that I always shoot in 4K and do the zooming ( cropping) in post production, I use FCPX. I hope all this made sense.
     
  11. Jesseg138

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    Oh right, there IS the pinch zoom while shooting 1080 video but its not available in photo mode...sorry, since this is a mapping thread I didn't think about video as it probably wouldn't be useful for what the OP is trying to accomplish.

    To get back on track...
    @Zak I forgot that GSPro does support different focal lengths so I'm at a loss why you can't get the images to stitch. If you want you could send me some of your data set and I can run it through Photoscan to see if it will stitch. For the focus, have you tried calibrating the 15mm lens that is having focus issues? I usually have to calibrate about 5 times before it hits perfectly for infinity(less so with my Olympus 12mm). Once a lens is calibrated correctly I find it easiest to set the focus before take off. Keep in mind that infinity focus is achieved once you are beyond 100 feet or less depending on focal length so just focus on something at least a hundred feet away and call it good, turning on "peak focus threshold" can help you nail it down since checking focus on a tablet or phone screen can be challenging. I'm curious what shutter speed and aperture you are shooting with? A shutter speed under 500 could give motion blur that could seem like focus issues and using a aperture that's to big or small can make images soft so I try for an aperture of around 5 and a shutter speed around 1000 as a starting point.

    UGCS is a very capable flight planning program that I highly recommend. Its like $65 for a license but it has alot more options than GSPro and other apps like terrain following so you maintain a consistent AGL and overlap. My biggest gripe with GSPro is that it keeps the drone heading one direction during all flight lines so it flies nose forward one line and then sideways and tail forward for the next instead of turning and keeping the drone always heading nose forward. This induces more error since most photogrammetry software that corrects for rolling shutters(like the x5) heading in the forward direction. It also means that if you want to fly a typical double grid mission with your gimbal set to anything other than nadir(straight down) you have to make 4 flights instead of 2 to get all 4 angles. Those issues0, probably wouldn't bother you since you won't be chasing error like I do with land surveying.