As Grahami suggests, there is probably a split based on
why someone might consider the photograph to be a good one, basically:
- photographs which are intended as a record, thus should be clear and evenly lit (and possibly with an example of scale :bored: )
or
- photographs which are intended as 'good photographs', where lighting and subject matter will play the important part
I'd agree with the idea that a photograph which includes well-lit areas as well as dark areas is likely to appeal: contrast does appear to improve images.
Something well-framed is likely to look better than something where half the subject is missing, but that's pretty simple stuff and not peculiar to underground photography.
One thing which is - to my mind - very important is subject matter: it has to be recognised that there are a lot of chambers etc. which are simply not interesting and will never make a decent photograph.
Colour is also a pretty critical component, particularly the inclusion of some contrast within the image - this can, sometimes, be improved by lighting (or post-processing). I'd offer as an example something like this:
🔗Rhiwbach-Trip-4th-October-Image-024[linkphoto]Rhiwbach-Trip-4th-October-Image-024[/linkphoto][/link]
Hello again darkness, my old friend...