best camera for scope cam

It depends on several factors such as what you want to do with it (daytime, night time, slow motion, etc.), the mounting system you decide to use, the resolution you want, the FPS (frames per second) you are looking for, ability to take still frames (i.e., pictures versus taking them out of the video), how you plan to use it, where you plan to use it, and what airgun you plan to use it with.

While this may seem like a lot, determining HOW you intend to use the camera will answer the majority of your questions. If slow motion at 30 - 240 fps is required along with portability and 1080p or 720p resolution, you'll most likely be looking at a Casio. However, if you want to do 4K, you may have to look at a Panasonic camcorder or some other brand. When you look at mounting, some systems require you to glue a mounting bracket to the camera before it can be attached to the scope while other systems may hold the camera 3 - 8 inches away from the scope forcing you to hold differently than you're used to as you can't get any type of cheek weld. Other systems may have a camera that mounts directly to the scope, but the display is mounted on top. Lastly, if you're looking at a "sporting" camera (GoPro, RePlay, etc.), you may have to get a special mounting device to mount to the barrel or scope. Since I'm kind of on this topic, let's quickly discuss slow motion.

The best way to think about slow motion is by thinking of a picture book. Every picture book has a certain amount of pages. No matter how fast or slowly you turn the pages, it still is limited to the pages it contains. The same is true with video. If you shoot a video at 30 frames per second, a 10 second video means you end up with 300 pages. However, if you shoot that same video at 120 FPS, you then end up with 1200 pages and at 240 FPS it is 2400 pages. If we edit our 300 pages of video, no mater how much we slow down the footage, all we are doing is slowing down how quickly the pages turn. So if we are trying to track a pellet traveling at 900 feet per second at 20 yards, we may only capture 1 or 3 frames of it in flight, but if we were shooting at 240 FPS, then we may have gotten 8 - 20+ frames. (I didn't do the math so it can be wrong, but the point I'm trying to stress is that you have 8 times more footage shooting at 240 FPS than at 30 FPS.) Unfortunately, the price for cameras starts climbing when you offer more frames per second. Additionally, just because a camera can do 120 FPS or higher, doesn't mean the resolution is good as well. Certain sports cameras offer 120 FPS, but they only record it in 640 x 380 while other cameras may offer 240 FPS at 720p. The rule of thumb is the higher the frame rate and resolution, the more the camera is going to cost. This once again comes back to how is the camera going to be used, as you may be looking for a camera that does 1,000 FPS but it is cost prohibitive so you'll have to rethink what you're trying to achieve.

Getting back to the question, in short if you're using one of the "general" holding brackets (attaches to the scope by a clamp and holds the camera several inches away) you can use almost any point n shoot, DSLR, or Camcorder with a 1/4" tripod thread. Again, this is where knowing resolutions, FPS, stills, etc. requirements really starts to come into play.

For "direct" mounting to the scope (Eagle Vision system), you'll want to keep your camera light in weight but you can use most point n shoots or small camcorders. Just remember that this involves gluing a mounting ring to the camera which may limit what you can do with it in the future.

If you're going to be doing night time video, you'll be limited severely in options (even if supplying you're own lighting source) but the NiteSite unit (SD card recording directly on the camera is coming this spring and can be used in day or night conditions) is a good choice. The one drawback some may have with the NiteSite is that you have to install the IR Illumination / display unit on top of the scope which means shooting from a heads-up position. On the positive side, you can move the unit from one scope to another without having to site-in the scope each time. For anyone not familiar with the NiteSite unit, I have some day and night footage here
and will be adding more shortly. Another option is to use a thermal scope with built-in recording capabilities. The downside to this is it may not give the image you're looking for as it is thermal and you have to site-in the unit each time you move it to another device, but it is still an option.