Hello,
I just wanted to share some of my initial results for mapping. I am using a Go Pro 4 Silver with a 5.4mm lens from Peau Productions. I swapped the lens out yesterday. I plan to fine tune the focus tomorrow to see if I can get better results. This was flown at 300 feet with 5 second intervals between shots. Next flight I will shoot at 2 second intervals. The profile I used was a Canon S100. I mounted the controller on a quick release tripod. I hope to start processing orthomosaics this coming week with Pix 4D. I live on 20 acres in Texas so plenty of room for trial and error. Any feedback, questions, or advice much appreciated.
Martin
Replies
Kudos Martin thats a good start.
I map with my Iris using an S100 and I work as a commercial photographer.
Two things that helped me get better final results
1. Fly higher, this minimizes motion blur caused on frames affected by ground speed.
It also helps minimize blurry frames when the bird turns at the same time it takes a photo.
The idea here is that the closer an object is to the lens the more dramatic and evident will
be the effects of the birds speed in the air.
2. Consider running your imagery through Lightroom/Photoshop and correcting some of the
color fringing (purple/blue) that shows up on the edges closest outward areas of the frame.
Alternatively, if you swap back your original Gopro lens you can have the software do it
for you automatically. In programs like Adobe Lightroom, the necessary lens profile corrections
can be enabled just by checking a box. Below is still photo from the Hero3+ that I corrected
in post-production. You'll notice it's not perfect because the edges show heavy signs of blurring
due to the wide angle lens. Ideally you would crop this area out and work with the center area
which is typically the area where most average optics perform best. Most modern software will
also be able to simply copy & paste your changes from one image to the whole batch. That makes
things go so much quicker.
Regarding focus:
Aerial imagery is typically shot with focus at infinity.
Assuming the machining standards are the same for the 5.4 lens as the
original gopro lens; to set infinity screw in the lens all the way.
Regarding MP/Tower Settings:
According to the specs on the lens you bought, the 35mm equivalent
for your lens is 30.5mm. When your ground station calculates coverage
it does so based on the the camera you tell it. The s100 has a 24mm lens,
which means it sees a greater field of view. You would want to pick a camera
that has something closer to 28mm. You won't necessarily benefit from the
change bc your triggering the exposures based on an interval timer
and not a set distance. To do distance you would have to use hack your solo
to trigger the gopro over it's wifi connection via the cameras api.
Not to worry, you can still get a solid end product by flying higher,
increasing to every 2 sec, and increasing the overlap between your shots
by tightening up the grid.
If you want to learn w/o spending ton of $ on software, check out the opendronemap project.
It has matured so much in the last year and is very comparable to Pix4D.
Fly safe!