How to create a little planet using Hugin

Ok first things first, we need some photos. We’ll begin by constructing a regular equirectangular panorama, then we’ll turn it into a little planet. An equirectangular pano covers 360 x 180 degrees so we need to shoot all the way around, plus the the nadir (the ground you’re standing on), and perhaps the zenith (the sky above you) though this isn’t too important and I usually don’t bother.

Some tips on taking the photos:

• Shoot portrait, not landscape.
• Try and make sure each photo overlaps the previous one by about 15%.
• Try and rotate around the nodal point (where the light enters the lens) rather than around where you’re standing. Basically try and keep the lens in the same position. Doing so minimises parallax error when you have objects in your near field.
• Shoot with your camera set to manual if possible.
• When shooting the nadir, try and get out of the shot!
• For best results use a panoramic tripod head like the Nodal Ninja.

The number of shots you’ll need depends on the angle of view of your lens – the wider it is the fewer shots you need. With my Canon G7 + Raynox wide angle lens (so about 24mm)  I’d need 10 shots to make the full 360 degrees facing slightly down, another 10 facing slightly up, then one for the nadir, 21 in total. With my Nikon D90 and Tokina 10-17mm fisheye I need 6 for the full 360 degrees and one for the nadir, 7 in total.

For this tutorial you can download all the images I used from here. I actually bracketed the shots (at 0EV, -2EV and +2EV) giving us 3 lots of 7 so that we can make the planet in HDR. This is what they look like:

So when you’ve got the photos, time to get Hugin up and running. Take the first 7 photos (dsc_0001-dsc0007) and load them into Hugin via the assistant panel ‘load images’ button:

The EXIF metadata should be read directly from the images – if not you’ll have to enter the focal length and focal length multiplier values for your camera set up. For the example, the images are at 10mm and the focal length multiplier is 1.5. I used a fisheye lens so select full frame fisheye from the drop down menu. Normally, you can set lens type to normal/rectilinear. When you’ve loaded your photos, hit ‘align’ and wait for the control points to be generated and the images to be aligned. In a minute or two the preview window will pop up:

So now we should have an equirectangular panorama. If the images haven’t aligned properly you’ll have to go over to the images and control points tabs and make some adjustments:

• From the images panel, select all the pairs of image (use control-click) that you know do not overlap. Remove control points that connect these images using the ‘remove points’ button.
• If you have a recent version of Hugin, press the ‘run celeste’ button to remove control points from clouds, as these tend to move between shots which causes misalignment problems. More details on Celeste here.
• From the control points panel, select pairs of images and look at the control points that connect the two images. Remove any which are clearly in the wrong place. It’s also very easy to add some manually.
• When you’re done, hit ‘align’ from the assistant panel and check the preview again.

For full Hugin documentation go here. If everything looks ok, it’s time to make our planet. At the bottom left of the preview window, select ‘stereographic’ projection. At the top hit ‘fit’, and then press ‘update’ (if you have a very recent version of Hugin with the OpenGL preview everything should change before your eyes). Next hit ‘numerical transformation’ at the top. Set the pitch to 90 and hit ‘ok’:

Press ‘update’ again and you should see a a tiny little planet right in the middle of the square. Slide the slider at the bottom to the left and hit ‘update’. Keep doing this until your little planet fills up the square:

Now close the preview window and head over to the stitcher panel. Hit ‘stitch’, choose a file name, and you’re done! Easy eh. But hang on, let’s go HDR. Go to the file menu and save the .PTO file. Click on the ‘new project’ button, then go to file and select ‘apply template’. Open the .PTO file you just saved and you’ll be prompted to select the images. Now chose the next 7 photos in the -2EV brackets set (dsc_0008-dsc0014). Have a quick look in preview and the planet should look exactly the same, but darker. Stitch it, then repeat for the last 7 images (dsc_0015-dsc0021). You should end up with 3 planets that look something like this:

With these three aligned planets, HDR is a quick hop away using this tutorial. Once you’ve tone mapped it you’ll probably need to use Gimp or Photoshop to edit the middle of the planet to remove my tripod; it’s a good idea to shoot from a spot where this isn’t going to be too difficult, so grass/gravel/sand etc is a good choice. Then tweak the colours and levels a touch and you’re done!

This one came out quite well. It’s a shame though; I’d tied the dog to the bench to stop him getting in a fight with a couple of swans. He took this quite well and actually jumped up on the bench and sat facing the pond. By the time I’d got my tripod in place he was off again though. Ah well at least he’s stayed still for his 3 exposures..