stitched aerial photo

Toshido

After reading the aerial photo thread had an idea....


Skydivinig drop zone my sister is active at, and I have gone to take pictures, is wanting a nice high resolution aerial photograph.
So short of renting some sort of 60+mp medium format digital hasselblad or some such nonesense is it possible?

Thinking minimum of 20x30" with 300dpi. Single camera setups only as well.

High wing airplane without a door is no problem, they are skydiving planes after all.

Just curious and an academic problem, to think about for now. But if it seems possible I might approach them with the idea...

ziggy53

The military and CIA have been doing similar things for years. To make it easy on the stitching software you want to use lenses with as little spherical distortion as possible.

pyry

ziggy53 wrote:

The military and CIA have been doing similar things for years. To make it easy on the stitching software you want to use lenses with as little spherical distortion as possible.

Also, remember to do the overlaps well and you should be good to go.

pilotdave

Toshido wrote:

After reading the aerial photo thread had an idea....


Skydivinig drop zone my sister is active at, and I have gone to take pictures, is wanting a nice high resolution aerial photograph.
So short of renting some sort of 60+mp medium format digital hasselblad or some such nonesense is it possible?

Thinking minimum of 20x30" with 300dpi. Single camera setups only as well.

High wing airplane without a door is no problem, they are skydiving planes after all.

Just curious and an academic problem, to think about for now. But if it seems possible I might approach them with the idea...

I think it's possible, but probably not necessary. Dropzones don't generally need to be able to see THAT much detail... just major landmarks. A single shot from a Rebel XT with kit lens is probably plenty for their needs. You can propose it, but don't expect to get paid enough for the time and effort it would take. Might be a fun project though, if that's what you're looking for. I think it would be very difficult though... you really need each image to be looking straight down to avoid distortions.

Here's my home dropzone... if you can find it down there:


(50D / Canon 10-22 at 17mm, about 13,000 feet. Shot last month) Printed nice as a 13x19 and could go a lot bigger.

Here's a crop of the same pic...


Might not work as a CIA spy photo, but it's fine for skydivers.

Dave

FedererPhoto

If you are quick, you can make stitches of quite a few things that wouldn't otherwise seem 'stitchable'. I do them during weddings quite often - people moving, dancing, etc... it works. Just be fast.

Toshido

pilotdave wrote:

I think it's possible, but probably not necessary. Dropzones don't generally need to be able to see THAT much detail... just major landmarks.
Dave

Actually their idea. They would like to get a large high resolution print of the dropzone.

I am thinking easiest and best would likely to get a good aerial shot and use Genuine fractals to upres it.

Maybe get a copy from of the jumpers that has a 5dm2 on his helmet.... Should be plenty of resolution there to upres to a nice print.

aerialphoto

Stitching from that perspective isn't necessarily that simple. Typical pan/stitching software is designed to stitch images shot from a fixed position. Aerials are stitched from moving camera positions. Natural lens perspective-distortion means you can't just butt-match the edges of the images, so it gets complicated.

I had some success with autopano-stitch when using just a couple of frames, but beyond that things started to get distorted. Without using mapping/survey software the best results were with PT-Tools (panotools) and enblend, carefully picking common control points in the overlap areas of each frame. There are tutorials online that discuss using those programs to stitch flat scans together.

The technique carries to a series of images with multiple points of view, but you still have to account for lens distortion/perspective. It helps if you keep the camera as level as possible.

Here's a sample of what can be done. This camera was kept level in a gyrostablized mount and uses the equivalent of about a 14mm lens on an APS-sensor equipped digital camera. Altitude was 12000ft. 7-frames total, each square measures roughly 2600x2600 flown one two adjacent lines:



...and close crop