Originally posted by Spectre
Rather than UFOs (which I would not object to capturing on tape!) I am going to try and record some meteor showers and Iridium flares*.
I can't advise you on what specific DVR to get, but I can give you some general tips and pointers, since I have been involved with meteors, and been
trying to photograph them for almost one and a half decades.
Firstly, meteors are not easy to capture on camera. Most are dim and are not easily captured on camera, I use multiple DSLRs with mostly wide angle
lenses to increase my chances of catching a bright one during a meteor shower peak. Even so, I rarely catch bright (fireball class) meteors, and most
resemble hair-line scratches on a photograph.
It's not that there aren't any bright meteors - usually there are at least a few, but the cameras never seem to be pointed in the right direction to
Even with medium-wide lenses on the DSLRs, they won't cover the majority of the sky's total area (unless you have lots of them). It is possible to
cover the entire sky with just one camera/lens, but wider lenses are usually slow compared to less wide lenses, and you will only catch very bright
meteors with them.
On top of that, unless the meteor is very long, it will only cover a very small part of your frame/the sensor, and look unimpressive, compared to a
meteor that stretches across the frame.
So you will probably be faced with a choice - either go with a wide but slow camera system, and hope for bright long meteors, or buy a more light
sensitive ("fast") camera system that has a narrower field of view, which will still catch bright meteors, but it will also catch fainter meteors,
and you won't need a super long one to be reasonably close to filling the frame. Obviously, if your camera's FOV is narrow, fewer meteors will pass
through the frame, than a system with a wider FOV, which has to be weighed up against the sensitivity of the system.
There used to be software available called "Meteor Capture Calculator" that would calculate the relative efficiency of your camera system at
catching meteors, if you know the size of the sensor (you will also need to calculate the area of sky the frame covers), but I can't find any links
to download it at this time. U2U me if you want a copy (It's freeware) and cant find it.
I personally like the cameras the ITALIAN METEOR and TLE NETWORK
uses, although I'm not sure what they are. Here's downloadable .avi format
It'll give you an idea what the high end meteor capture systems are like.
Keep in mind that running a camera outdoors all night can present problems, such as the lens dewing up, and the batteries run out quickly, especially
on a cold night. It's possible to buy flexible heaters that wrap around the lens using velcro that will overcome this problem, but if you don't want
to spend much there are alternatives, like taping "chemical hand warmers" underneath the lens, or using a small hair-dryer.
In terms of power, you may find that you need a portable power source to last a whole night. Rater than buying spare batteries for the camera, it's
usually better to power from an AC adapter (if one is available for your camera) connected to a 12 V power-pack or ideally a "deep cycle" battery
via a DC>AC inverter (watch out, some inverters may cause problems with the picture), if you think it's something you will be doing a lot in the
future. There are lots of options available, but not all batteries are designed to take the punishment of being drained near to empty, as the deep
cycle batteries will over time.
Don't forget to budget for a tripod as well.