I have had some good outcomes with small areas of 2Km x 2Km with around 100 photos.
I am trying to get large areas such as 100km x 100km from a high altitude. Here is an example photos:
3840x2160 ~3MB per photo
The photos have exif data (GPS lat/lon/alt meters).
These are captures from a flight simulator so visually slightly different than real earth images, but lat lons match up and these are real areas on earth.
I use WebODM, I upload the normal 100-200 photos flow in a zig zag pattern at a naidir angle (90 degrees down). I have also flow the route twice, second time offset 90 degrees to get a perpendicular routes. I have also tried flying one route nadir, then another at ~80 degrees.
Majority of the times, WebODM will take 1-2 hours and stuck and fail due to multiple reconstructions found. Other times, the maps appear distorted/incorrect GPS positions.
I have verified all the images have EXIF data, and smaller sets at lower altitudes work a lot better. But I am hoping to cover large spans of area.
Any suggestions for a first time ODM user? I have read the ODM uses Point Cloud Maps, and for more high altitude images there are other applications that use stereo imagery and are more commercial oriented products.