For those of you wondering how these wrap-around panoramas are done, once you know, it is pretty simple. If you want to know how to do it and try it yourself, read on. Otherwise skip this post!
When these VR type movies first appeared years back, you couldn't help look at them and wonder, how the SPAMMER do they do that?
The full spherical images where you can't even see the tripod are especially impressive. I had been completely bamboozled by the technique and was convinced there was some special camera, probably mounted on a motorised arm or dollies and I would probably have to hire one at great expense if I was ever to do the studio room.
Anyway, by a happy accident and curiosity, I stumbled across the method and it turns out, you can do it with a regular SLR camera! 8O :8 (You can probably even do it with a non-SLR camera if you are very patient.)
You need two extra bits of kit. One is a tripod head that allows specific positioning not normally possible on a conventional tripod head and the other is a mind-blowingly clever piece of software.
If you want to do it for minimum money, you can frig a setup using a macro rail and free software.
This was how I did my first attempt: the macro rail enables you to position the centre of the camera nearly correctly and you simply disengage the tripod centre column for panning. The only problems with doing it this way is accuracy and that the camera can only be oriented in landscape which means your vertical coverage is limited.
If you look carefully at the mov file I made, you can see problems with the joins between shots but that was my first attempt and I know now I didn't have the camera positioned correctly.
So, to get things really good, you need the correct tripod head. The full head is called a QTVR head and the special trick it performs is that it enables you to position the axis of rotation through the entrance pupil
of the lens. Getting this axis correct is critical as it eliminates parallax errors that are unavoidable when rotating a camera on the normal tripod mount.
For single axis rotation cylindrical projection panos, the setup looks like this:
A dual axis head for cubic projection, ie, the full sphere, requires an extra positioning rail. I've tried doing this by adding my macro rail to the head but have problems with free travel of the camera so this might not be possible.
Anyway, getting the axis set correctly for the entrance pupil is tedious as each lens is different, it changes with focal length on a zoom and depending on the lens design, it changes with focus. Therefore, the point is never marked on the lens itself so the only way is repeated adjustment looking through the eyepiece until you get it right.
Once that is set, calculate how many shots will be needed based on the angle of the lens and so that there is a safe overlap between shots.
Then set your exposure so it is fixed for all shots. Averaging is the best way here. Lens wise, I did mine at 17mm f8, manual focus set to a rough hyper-focal point for maximum DOF.
Now shoot, rotate, shoot, rotate, shoot, etc, until you have the full 360 degrees covered.
Put the camera away. The rest is done in software.
Take all your shots and post-process them into JPGs. I always shoot RAW so use the same conversion factors for each shot.
Now take your string of JPGs and dump them into a stitching program. This is the really clever stuff and I can't get my head round how it works. Somehow, this software takes each image and converts them into a cylindrical or spherical projection whilst merging the borders between shots so the end result looks seamless. There is a free program called Autostitch that works but to be honest, isn't really that good and ghosts a great deal on the overlaps. It might be good for long distance panos but short distance, it can't do it. So the one I used is called PTGui.
Once you have that done, you have a completed panorama which needs one further conversion stage to be viewed in the VR environment.
Again, more software magic. This time, I used a freebie called Pano2QTVR which converts the pano into the VR mov file.
And that is it! No alien technology floating cameras. Just an SLR, a special tripod head and very clever software.
I strongly recommend trying it because it is pretty amazing when you first load up the movie and see your own room in full 360 pan! :8