Flash:

Apart from the effect on the fish, which is an issue which needs to be checked with competent authorities and the aquarium operator or owner, you van often get good results with flash when photographing though glass using the following method. This is also useful for display windows, and glass cases. I can usually eliminate the apparent existence of glass in many cases using this method.

• Approach glass relatively closely. Maybe one foot or less.

• Align the camera's axis at a significant angle to the glass so that reflections from the flash are reflected completely out of the scene. II usually angle it horizontally but angled from above or below also works. This of course limits the angle of shots you can take, but a reflection free angle shot is often superior to a more frontal shot with many reflections.

• Set the camera so that the non flash illumination from reflections will be low compared to the flash illumination level. eg set camera to f8 or small aperture

  Experiment with angle for best effect.

Non flash:

Blcoking the reflections at source works well if you can do it. Cocconing the camera against the glass in a dark refelction free zone can work wonders - and/or get you into trouble :-).

• Work out where major reflection sources are coming from and try to block the light before it reflects. May not be practical depending on environment.

  Position camera close to glass at an angle and place a hood over the camera and the glass around the camera. The more extensive the hood the better. This may get odd looks and/or rude comment - but also may get good photos. Will not be viable or allowable in all cases.

Example - 2000 years! - Through glass - 0.2 seconds, f1.8. ie low light, no flash. Camera lens very close to glass.

Be artistic:

When all else fails you can get some interesting shots with very strong reflections in them. Find or make a dark or darker spot in the reflection field and position yourself so that the subject is in this area. The reflections then become a part of the image - sometimes to great effect. Sometimes not :-)

This was purposeful. Whether it is "any good" is moot. I like it.

As was this ...