My interest in railroad photography has been shifting more and more towards low light conditions and having an interesting sky is a must. I feel that there is much more depth of emotion and a deeper feel captured in low light settings. This is one reason I have been drawn to low light photography. Learning how to capture moments in this type of light is by far the easiest part of the photo process. The more difficult part of the photo process is processing. It can be fairly difficult to bring out your image as envisioned when shot is low light. This is especially true if you captured the image while trying to preserve the high lights in a bright sky. This can result in a overall dark image which can reveal a lot of noise when the exposure is increased. If the image can be used, the next challenge is being able to bring out details in the highlights and shadows. This part of processing can take time with the use of a program like Photoshop. With Photoshop, you are able to use layers and masks to edit the image in parts rather then as a whole or globally. One program I have just started using is Photomatix. Photomatix is aHDR (high dynamic range) program that can help save a lot of time and work while achieving close to the same results. HDR is best done with three or more images exposed at higher and lower exposures which can be hard to do with a 
moving object, like a train.Photomatix can also work with a single RAW file with good results while saving the work of dealing with an object that has moved during the multiple exposures. Photomatix can also do this 3 different ways with different results from more HDR looking to more realistic, which all can be fine tuned. One of the most important parts of post processing to me, is adding some pop. This pop is what makes the whole image worth all the work you put into it. Now while using Photoshop, Photomatix, and getting some pop in my images is hard enough, making them appear 100% real can and still is a challenge to me. The photo on top is of two Soo Line EMD SD60s running through Dayton’s Bluff with the sun setting behind the St. Paul, MN skyline. This photo was was processed first inPhotoshop with layers and masks. Then to recover some highlight and shadow detail and add the pop was done with Photomatix. I believe this photo came out with a very near real appearance. The other photo of the Union Pacific led coal train in the Powder River Basin was first run through Photomatix. After it was processed by Photomatix I did very little work to it in Photoshop. This photo has a little more of a HDR look. I did not attempt to make this more realistic since I enjoy a moderate HDR look. Many railfan photographers do not like the look of HDR photos, period! This is one issue that I will live with. So, with the use of photo programs and a lot of practice, a lot can be done to make your low light photos end with a pop.