Well Mike I could go on at length about this, but it does depend on what control you've got over the camera. Clive's advice is spot on to avoid camera shake.
*Do you have lighted buildings or lighted rolling stock in the shot, if so start shooting just after sunset at dusk, taking a pic every couple of minutes, don't wait til it's fully dark and at some point you'll get a nice balance between buildings/ loco's and sky and sky
*If it's got an automatic flash, make sure you override it! Otherwise your pics may look like daytime.
*Night settings are usually a way of getting more light into the picture and may not produce what you're after, try a few test shots at dusk with the night setting both on and off. I suspect you'll prefer off unless you're shooting water reflections or whatever!
*Another good trick with all garden rail photography is to position the camera as low as possible. If you're used to looking through a viewfider you might find it strange to hold the camera away from you and just roughly aim at the subject, it's a bit hit and miss but you will get some good shots
*Also, if you've got the memory capacity on your camera, just take loads of shots, despite what you might think professionals will on average shoot over 50 shots just to get one good one. Often people shoot hi-res which lowers the shot capacity, low-res pics are perfectly ok unless you're planning to print A3 or bigger. Most of us just want to publish on the web and CGT I guess.
Best of luck! Look forward to seeing the results!
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