The other day someone commented on the irony of having a very complex image in my book on the page opposite my claim that images should be simple. In fact the image he was concerned about had a very limited colour palette and all the lines worked together and reached upwards to a single point and there wasn't a single extraneous detail in the image to distract from it's strong design.
This then leads to how to make complex multi element subjects work in a photograph. You may well be able to look at your image and discount all the elements that don't help the composition, while concentrating on those that do, but can someone who isn't familiar with the subject or the image do so easily?
Apart from the image features that I referred to in the first paragraph, how do you assure yourself that your images are going to be 'understood'?
1) Survey the image for elements that don't add anything to the story or the composition. If you can't reduce their effect (through darkness or contrast), then you may not have a good image here despite all the good things it has.
2) Is the placement of all the elements of the image (which do work for the story) optimal?
3) If you can't keep things simple in one way (say the number of items or their positions or directions or disparity in shapes) can you keep things simple in other ways? If not,... Sometimes simply switching to black and white can solve the problem.
4) If the many and complex items of your image can be arranged so that there is a virtual 'pathway' around and through the image, then your viewer might well be able to handle the complexity with aplomb.
5) Sometimes complexity can be handled through layering - that is arranging the camera position so that classes of elements are in different planes. Obviously in a two dimensional image this means nothing except where elements overlap so that is what you have to use to simplify the complex design. Two rocks may well be different distances from the camera, but if they don't look it, it complicates things. If one overlaps the other, then the arrangement is made clearer, which if not actually simplifying things, has the same effect in making the image more readable.
6) We tend to assume that smaller things are further away so that even if they aren't further, they tend to be treated as 'background'. Should they overlap something larger though, then you can't pretend they are background material.
7) Sometimes when an image has many elements to it, the elements naturally or with effort on your part can be made to fall into groupings which can simplify the reading of the image and strengthen composition. Four blocks of four is easier to 'read' than 16 random scattered items.
8) Consider the possibility that a complex image will look better in a big print, in which the elements have breathing space and aren't a jumble. This only works sometimes, but when it does...
9) Consider reducing overall contrast in a complex image so that the viewer is left with the impression of a group rather than of a lot of separate elements. In some ways this completely contradicts # 8 suggesting a large print - you just have to see what works in each situation.
10) In the end, if an image is really complex, but you are convinced it works, show it anyway. Who said everyone has to like every one of your images anyway? If all your images are too complex for your audience, you either have to change your pictures or your audience. If the occasional image is important to you and you want it seen, go for it. You might not choose to do it this way when submitting for a contest or hoping to be published, but if you already are, then why not sneak in the occasional challenging image.