The full spectrum camera conversion
A full spectrum camera conversion is a modification where the camera’s internal IR cut filter is removed and replaced with a clear filter, making the camera sensitive to UV, visible, and IR light. At this point, the camera is useful for astrophotography and low light applications where having as much sensitivity as possible is helpful. On it’s own, it is also useful for some B+W photography and can lower the noise in the shadows.
Why convert a camera to full spectrum?
The big benefit of full spectrum is that it allows you to put external filters on the lens to narrow the sensitivity to a certain range. Putting an IR filter on the lens will still allow for handheld infrared photography, just like a converted camera. Alternatively, using a hotmirror filter you can use the camera to take normal pictures. Putting a UV bandpass filter lets you take ultraviolet pictures (provided you use a good UV lens). Filters are available here. This is the most flexible conversion you can get, giving you 7+ options in one camera. Most importantly, it lets you still shoot normal color photography by using our hot mirror filter, meaning that you only have to carry one camera with you.
Best cameras for a full spectrum conversion
Full spectrum has some problems specific to a DSLR. Because most infrared filters are opaque, you will not be able to compose with the viewfinder with the filter on the lens. The autofocus and exposure systems also rely on visible light, making them inaccurate when the filter is on the lens. While exposures will be short, the obstructed viewfinder still makes shooting challenging.
To get the most out of a full spectrum conversion, it is good to choose a mirrorless camera or a camera with live view. With live view, you can compose and shoot regularly even with the IR filter on the lens. With that combination, it is possible to use a filter for normal photography, the best filters for color IR photography, another filter for B&W IR, and even filters for UV photography. DSLRs with live view and mirrorless cameras are very good for the full spectrum conversion because of this added flexibility. Some point and shoots have threaded lenses that will accept filters, others have adapters available, either in the form of an adapter tube or a stick on thread adapter, such as the one Lensmate makes. It is also possible to glue a filter adapter onto the lenses of most compact cameras to let them accept external filters.
Choosing a Filter, DSLR and Compacts Color Performance, Choosing a Camera, CDHK