BB_DF

There's a real art to calibrating the DF. I have two patents for equipment similar to the Ti circuitry, so I have spent a lot of time on the phone talking to the FMA engineers, and also to Mike Dammar, trying to understand how the system really works.

There are a lot of tricks for calibrating the DF, like holding the DF at an angle when you press the arming button, but it's all based on a very thorough knowledge of the algorithms used to determine sky vs. land. The DF can fly over large bodies of water, for instance, if you calibrate it correctly. The main problem that occurs is when the sensors read an abnormal difference in temperature between ground & sky. This can be too great a delta, such as over asphalt, or too small a delta, such as under a heavy overcast.

A general rule of thumb is to try and calibrate it over the coolest patch of land you can find. Thus if the sky is reflecting and retaining a large amount of heat from the earth, you should be able to tell from the green LEDs that the temperature differential is not adequate. My experience: DON'T fly on one LED!

- Bruce

Old Man Mike

Are you running the HD motors?

Mike

Sky High

Have either of you considered making traditional landing struts like on typical helos and the Microdrone? It seems like a few pieces of CF tubing forming two struts would be lighter than foam, create less drag and allow a solid base to raise the airframe to accommodate and protect the camera.

geoffff

No. I don't remember reading that they make much of a difference. But I will if they can boost my payload from 4 to 9 oz!

-- Geoff

BB_DF

A few shots today with the Pana FX-07. Just trying to get an idea of where to hover to get the proper perspective. Main lesson learned today: shooting a property with a wide angle lens works best from a corner of the lot, rather than straight on, for at least two reasons. First, any straight lines like sidewalks will show the distortion of the lens if they're lined up horizontally. Secondly, most people want to print an 8x10, and the corner shot yields a better 4:5 aspect ratio. Also, I think the shots look more interesting.

- Bruce

P.S. I was going to take some shots of the guys standing on the roof and unloading the tiles off a lift truck, but I realized the distraction could cause an accident. Something to think about...

Old Man Mike

Looking good, Bruce. What speed are you shooting now and are you using antishake mode 1 or 2? Can you post some higher resolution pictures than the 800 x 600?

Sky High: Nice looking mount but I suspect it would be considerably heavier than the foam and would not offer as nearly as much vibration isolation. And I think the camera might not survive a 250 foot free fall with that mount.

Mike

BB_DF

Mike,

These were all shot at ASA 400, with antishake mode 1. I haven't tried mode 2. You know, if it ain't broke don't fix it.

Here are some links to the images reduced from 7 megapixel to 1200 x 1600. I just shot the third picture this morning. This afternoon when the light changes I will reduce the angle of the camera and shoot from low across the street. This house belongs to a builder/realtor and I will give her the pictures for free in exchange for possible references.

[link=http://i33.photobucket.com/albums/d85/bboatner/GaryJoans.jpg]Gary & Joan's House[/link]

[link=http://i33.photobucket.com/albums/d85/bboatner/1f1.jpg]Construction at 1170 Riversong[/link]

[link=http://i33.photobucket.com/albums/d85/bboatner/Stancil01.jpg]Stancil House[/link]

PS: Check [link=http://www.helifreak.com/showthread.php?t=41774]THIS[/link] out!

- Bruce

BB_DF

Here's a picture of my high-tech camera mounts, and two pictures that show the difference in the angles.

[link=http://i33.photobucket.com/albums/d85/bboatner/_Stancil02a.jpg]High angle[/link]

[link=http://i33.photobucket.com/albums/d85/bboatner/_Stancil03.jpg]Low Angle[/link]

Old Man Mike

Wow, look at that. Talk about rubbing our noses in your payload capability. That long angle stock of aluminum that probably weighs 3 times what my entire camera mount weighs! What's next, a brick used as a sunshade? [X(]

(Nice pictures anyway)

Mike

BB_DF

Well, when you get done with your OMMM (Old Man Mike Mod), you can meditate on the pleasures of lifting a couple of pounds.

BB_DF

For anybody interested in following OMM's lead in using a high quality camera... Here are three unedited shots with the FX-07, ASA 400, antishake mode 1, and the low angle camera mount. I was practicing guesstimating the altitude & stand-off distance for such a large subject. I made a second trip out there after downloading the first batch of pictures, and got much better shots. This kind of exercise will of course be relevant regardless of what you're flying. Lesson learned today: very smoothly keep changing altitude and stand-off distance, and also continuously slowly pan back and forth. Don't think you've got it nailed and sit there in the same hover for a long time. All it takes is one good shot to make the session work, and there's nothing more frustrating than having 500 frames that are cutting off the edge of your subject.

The wide angle lens makes it look like it's shot from a very high altitude, but it wasn't really. Before you mount the camera on the heli, look through the viewfinder and find how far away you need to stand to frame the subject correctly. This will tell you about where you should launch to give you the correct lateral offset at altitude.

1600 x 1200 pics:

[link=http://i33.photobucket.com/albums/d85/bboatner/_CB1.jpg]Factory_1[/link]
[link=http://i33.photobucket.com/albums/d85/bboatner/_CB2.jpg]Factory_2[/link]
[link=http://i33.photobucket.com/albums/d85/bboatner/_CB3.jpg]Factory_3[/link]

- Bruce

Thumbnails:

BB_DF

I built this mount to test straight-down shooting, like a satellite photo. The mount included highly visible orientation markers, so I can keep the camera aligned with the compass directions at high altitudes. Lesson learned: even with a wide angle lens, it's hard to cover a really large area, like a subdivision. A small amount of tilt in the camera angle would increase the viewable area tremendously.


[link=http://i33.photobucket.com/albums/d85/bboatner/Alt1.jpg]Vertical Shot 1[/link]

[link=http://i33.photobucket.com/albums/d85/bboatner/Alt6.jpg]Vertical Shot 2[/link]

- Bruce

BB_DF

[link=http://i33.photobucket.com/albums/d85/bboatner/GH1203w.jpg]Vertical shot GH1203[/link]

Old Man Mike

This one looks just like a shot from Google Earth. In fact, I would love to see a side by side comparison which should be easy to do with an address or lat/long for that location.

Mike

BB_DF

I used Google Earth to plan for this shot. In the GE picture, the street wasn't even finished yet, much less any construction, but it was helpful for planning my launch point (I'm leaning against the grill of the car in the lower picture). Also at this altitude Google is pretty blurry. So basically Google Earth is not very useful to the real estate developers.

When you get your OMMM DF working, and guys who want to build the Q4 to lift some small cameras, you will find that there is a market out there. People consistently tell me the RC images are better than AP pictures they've paid big money for. It makes sense - they aren't supposed to fly below 500', and some of their cameras probably aren't that much better quality than ours. This kind of vertical shot is good for what realtors call the plot map, which needs to be brought current on a periodic basis (repeat business). If you get your altitude hold working, you will be able to take a bunch of shots and stitch them together into a large wall mosaic. Cha-ching!

- Bruce

BB_DF

Old Man Mike

Cool! It is an very interesting comparison. Although I like the angle shots much better, I can see the value of near vertical imaging. How high do you think you were?

Mike

BB_DF

Mike,
A lot of these ideas will be relevant to the DF after you attain more lifting power with the BL motors. For instance there's no reason you couldn't adapt a more visually friendly orientation system.

I designed this camera mount and I'm extremely happy with it. It doesn't seem to affect the flight characteristics at all because it is very light and well balanced. It gives me a "satellite" vertical mount at the rear, and a tilting mount at the front. The front mount also tilts in the roll axis to compensate for translating tendency in a hover. The "pontoons" are pool noodles over light aluminum angle; they provide excellent help with orientation, and great stability for landing and when carrying the heli in the back of a truck. I've got a very simple gyro stabilized mount for videos designed and on my CAD. I know how much work it's going to be to prototype and test that project, though, so I'm holding off until I can get some real estate AP gigs.

I'm still getting comfortable with the higher altitudes. I just keep climbing until it starts to get hard to see the orientation markers (the pontoons form an 18" x 18" square). It would also be impossible without the horizon stabilizer (Ti). I'd guess it was up around 200 - 300'. How about a similar very lightweight CF version for the DF, maybe using painted cardboard tubes? The markers would need to extend well beyond the downdraft of the rotors.

IDEA DU JOUR: Here's a way to save a lot of time and frustration. Instead of shooting 500 frames and finding out later after you download to your computer that you wish you'd been in a slightly different hover position, you can make a trial run in video mode and evaluate the results right on the spot. It's easy to fast-forward through the footage in the field and see if your shot is set up correctly.

I got this idea the other day when I saw a camera boom operator setting up a shot. They were shooting a TV documentary locally, and I watched these guys running the camera gantry through a simple sweeping motion over and over in the parking lot. The shot was probably only 15 seconds long - some people coming out of the door of a hardware store talking to each other - and I think they practiced the camera and boom motion for over an hour.

Cheers,
Bruce

Sky High

As you know, that's something I can easily identify with.

BB_DF

Sky - That looks like exactly the same rig! Maybe you could throw some light on this. I noticed the camera had about 4 stubby antennas sticking out of it, and also there was a guy walking around with a vest on, like a human antenna farm. What's the deal?

Sky High

Did the camera look something like this? The antennas on the camera were more than likely wireless transmitters for sound like on this one. The person with the vest was more than likely a sound mixer with several wireless transmitters and receivers in a front pouch attached to a vest. I always tell the sound guys that they look like state trooper cars with all of those antennas.

BB_DF

Yep, you pretty much hit the nail on the head!

Dirk Schooner

We seem to have come back down to earth now, thinking about it, why not build a motorised telescopic 300' boom? Should be easy, a few carbon fibre composite rods and a couple of sky hooks

Seriously though, BB_DF those vertical shots are just amazing, I actually said 'wow' out loud!

Sky High

Here are couple of my early satellite images taken from the DF V Ti Pro Eyecam.

BB_DF

I'm trying to get high enough (perhaps I should re-phrase that) to get in the majority of an average sized development. The clarity of this shot is not very good, but it was a successful altitude test. I was shooting too fast (800) for the conditions, which were overcast and hazy. However, on the first flight shooting auto ISO, all the images were blurry. In order to get the necessary speed with the small lens, I think I'll have to shoot on bright, clear days, like on some of the previous tries that turned out better. I'll re-shoot this on a sunny day for comparison.

After a few more flights I'll get comfortable with going a little higher, but this flight just about pegged the old pucker meter. I'd guess this was 400 - 500'. The exact altitude is not really important - I don't think I'll ever be able to get into controlled airspace. The frame is 4' wide and the colored foam pieces are 3' long. Still, it reduced to the size of a small bug in the sky. The overcast was helpful in keeping it oriented, though. It seems to take forever to descend - about 3 minutes! All you have to go on is throttle position. You can't tell visually if it's ascending or descending, and you can't hear it for about the first two minutes of descent.

- Bruce