The initial thought is to use a tripod, but some cathedrals do not permit them! Fortunately, many cameras have excellent image stabilisers, preferable to whacking up the ISO value causing noise. A traditional technique is to stand correctly and like a marksman; breath in, take the shot and breath out. Not high-tech, but it works!
Other problems connected with lowlight abound and perhaps surprisingly contrast, even on a dull day. The classic situation is a low-lit interior with a bright stained glass window that often gets overexposed. If you have a tripod you could try HDR, but I am playing 'devil's advocate' even inside a church, so we have to look for another answer.
With film photography, especially colour transparencies for projection, we were stuck with whatever could be achieved in camera but digital, with the help of computers, takes us more than one-step forward. Modern sensors and software give the photographer considerable latitude to take images knowing what can be done in post-production by correcting overexposed highlights and underexposed shadows. That is how these images have been created, take a look at: -Photo-soundbite 14
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