judging distances

Discussion in 'Camera Operating' started by Jose Luis Ocejo, Mar 25, 2013.

  1. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

    Joined:
    Sep 20, 2012
    Messages:
    581
    Likes Received:
    44
    Hello to all I would like to start a new (i think ) thread on the way you guys and ladies judge distance of the flying copter, to close proximity objects from the view of the first person view (FPV) to the view of the line of sight (LOS), we tend to mostly fly with wide lenses that create the visual effect that objects are further away than what they really are, (FPV) you guys know very well the directors direction, "lower lower, closer closer, and you (in your mind) o_O "oh boy, here I go" so here it is, I hope to find out some unique clever ideas.
     
  2. Gary Haynes

    Gary Haynes Administrator
    Staff Member

    Joined:
    Jul 6, 2012
    Messages:
    5,211
    Likes Received:
    460
    Practice practice practice. Have a spotter stand to the side of an object as you fly up to it and call out how far away you are. Pretty soon you should be able to get a least a sense of distance. And make up your own distance minimums. 3m, 6m whatever is right for the conditions.
    If they want you to get closer ask them to write you a check for the full replacement cost of the copter/camera/lost time. Then hand them the tx. (Only kidding).

    Got this question all the time flying hot air balloons. "Why is everyone else taking off and you are staying on the ground"? Answer: There are old pilots and bold pilots. But there are no old bold pilots. If the organizer want's to buy my balloon here's the bill of sale. Never had a sponsor get upset and after they learned of the bad landings due to high winds and people getting hurt they were glad I was an Old Pilot.
     
    Chris Fox and Dave King like this.
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,347
    Likes Received:
    1,159
    For me, the short answer regarding distances is: It is a really hard if not impossible thing to do beyond about 10 meters (well, maybe 30).

    Beyond that it seems that stereopsis doesn't work well and I switch over to relative size/visual cues -- which is not a very accurate way of estimating at all. So as the copter flies away, I tend to rely more on the FPV on-screen display that gives me that distance information -- also, I find that I have to fight the tendency to climb the copter because of illusory descent -- it looks like the copter's getting lower the further away it flies.

    As Gary says, either have a spotter off to one side to avoid flying into the trees, or use a ground marker to determine the "don't go beyond this otherwise you're in the trees" point. (Ask me how I learned about this... :) ) That's another reason why I have a down-looking FPV camera, so I can see when the copter is at the marker. Often I can use a ground feature (fence line, road, etc.) as the marker but sometimes I'll put one or more pieces of neon colored paper on the ground and puts some rocks on them so they don't blow away.

    As you say, Jose, the wide angle lens on the FPV camera certainly distorts the image to the point that it's hard to judge distances -- if you can see individual leaves on a tree, I know from experience that you're probably too close!

    Andy
     
  4. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

    Joined:
    Sep 20, 2012
    Messages:
    581
    Likes Received:
    44
    Thanks Guys this advices are great reinforcement and learning of new tricks and new experiences can be valuable in a similar situations, by the way Gary I love the argument of old pilots and bold pilots Im going to use it some day, and just for fun, have a form kind of there, to say ok, sign in the dotted line... Andy I have been on top of a tree too in my case at the time CS8 2 axis, FPV, I had a spotter that at the critical moment he had a blind spot and lost sight of the copter behind another tree, I, was looking down and to the side of my heading to a beautiful old civil rights church great shot suddenly ......chop, chop, leaves, leaves,... the tree un climbable, I mean all the branches pointing up,.... cherry picker@ $250 the guy verily reach, damage 2 props thats it
    the learning here was: the spotter told me he was afraid to get in the shot that why he did not move to clear his LOS I probably should have told him that from a distance on a wide, people are little ants and that his spotting duties are more important that the chance him been a speck in the shot.
    Idea: I am thinking to carry with my kit a camouflage suit for the spotter so he/she fills more free to move

    Any more ideas.....
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,347
    Likes Received:
    1,159
    I like the idea of a camo suit for the spotter, but, as you say, typically they disappear from the air to ground shot.

    Yeah, the noise a Cinestar makes when it starts to eat its way into a tree is not a good sound.

    If you liked the old/bold pilots, then consider this poster: http://www.check-six.com/lib/Poster_Crash.htm

    Andy.
     
  6. Michael McVay

    Michael McVay Active Member

    Joined:
    Dec 31, 2012
    Messages:
    416
    Likes Received:
    91
    Andy,

    Do you have more than one FPV camera onboard? If so, what do you use to switch between them?

    Michael
     
  7. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,347
    Likes Received:
    1,159
    A two way video switch from DPCAV.com -- uses an RC channel to do the switch. They also sell a three way should that be relevant.

    Andy.
     
  8. Michael McVay

    Michael McVay Active Member

    Joined:
    Dec 31, 2012
    Messages:
    416
    Likes Received:
    91
    Great...thank you.
     
  9. Ralph Chaney

    Ralph Chaney New Member

    Joined:
    May 20, 2013
    Messages:
    3
    Likes Received:
    0
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,347
    Likes Received:
    1,159
    Hi Ralph:

    It's a reasonable question.
    The technical challenge is to get such a device to emit a signal that could be transmitted back down to the ground via telemetry. Now the Graupner line of HoTT receivers do transmit telemetry but they're a closed world. Also the Smart On Screen Display superimposes visual data on a First Person View camera that it gets from the data passed back and forth via the so-called I2C bus between the various Mikrokopter boards -- so the question would then be to ask the author of the SmartOSD how to get the data from the laser distance measuring device into the MK I2C bus data stream.

    I'm afraid my answer doesn't answer your question so much as tell you what the challenges are.
    The good news is that it's merely a money problem -- throw enough money at it and it can be solved! :)

    Andy
     
  11. Ralph Chaney

    Ralph Chaney New Member

    Joined:
    May 20, 2013
    Messages:
    3
    Likes Received:
    0
    Andy,

    Yes, yes. That would be very clean. Makes sense. Takes money. :(

    Hhhmmmm... other more immediate -though not nearly as elegant (or safe?) - partial solution could be
    a distance measuring device that emits a sound at some pre-set distance(s) (something an onboard mic could catch and transmit.. Or the device directly sends some other kind of data that existing signals can handle).

    Just sniffed around the robot world. Found this, for distances up to 5 feet. Many variables to work with, short and long distance sensors.
    http://www.robotshop.com/long-range...ource=google&utm_medium=base&utm_campaign=jos

    This sensor thing is interesting. Perhaps set something up to maintain a set distance to a moving subject/object? Could put a small emitter on the moving subject to make the measurement even more reliable. This may well be something this forum has already beat to death...? I just like brainstorming... and this world of cameras and precise flight is so interesting and gadget-filled!

    -Ralph
     
  12. Josh Lambeth

    Josh Lambeth Well-Known Member

    Joined:
    Jun 29, 2012
    Messages:
    1,312
    Likes Received:
    213
    What about marking your screen in a way similar to the first set of backup cameras on cars? Turn on your camera and such, measure out 5ft, 10ft, ect then look on the monitor and mark the monitor at those distances. Once you see the object at that line you know your within that distance of it.

    Josh
     
  13. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
    Staff Member

    Joined:
    Jul 31, 2012
    Messages:
    10,347
    Likes Received:
    1,159
    Doesn't that depend on the object being at a known angle above or below the horizontal from the copter, Josh?
    I'd need to see the side elevation geometry of what you're suggesting as I might be misunderstanding it.

    Andy.
     
  14. Duane Bradley

    Duane Bradley Active Member

    Joined:
    Dec 6, 2012
    Messages:
    212
    Likes Received:
    26
    i noticed that Hobby King has a sonar board that is made to shoot down under a copter, estimate distance and keep the copter above that. I wonder if this could be modded to shoot forward and give a visual feet or meters from obstacle on the OSD??

    That shouldn't be to hard or too heavy. A worth while addition to the copter for certain shots.
     
  15. Artie Ponce

    Artie Ponce New Member

    Joined:
    Jan 2, 2017
    Messages:
    1
    Likes Received:
    0
    I have a an easy solution to the flying perspective problem. it involves just 4 toothpics and some rubber cement and some nail polish. make 4 small balls of rubber cement, roughly the same size, just big enough to fit onto the tip of the toothpick. rubber cement the 4 toothpics onto the sides of your camera so they stick out in front of the camera with the balls at the tip sticking out way in front of the camera, and try to get them fairly straight. Does not have to be perfect... paint the balls red. This is a training setup for anyone learning to fly these things. It is cheap. It is very visible in the camera. Still gives you most of your screen, and lets you know exactly where the craft is, by giving you something to guage in your mind. It is not just a open sky anymore. almost as if your in a cockpit.. I know I am a newbie, but I dont know how anyone else hasnt thought of this before. It got me flying right.. pretty quickly.
     

Share This Page