I'm going back in time a little bit, but I am in the studio working on longer term paintings. So to stay a little active with some posting here, I thought that I'd let a little 'kitty' out of the bag concerning nocturnes and the way I paint them. There is going directly to the source and painting from life, a requirement IMHO, and then there's using that experience to draw on to do work in the studio.
This isn't really a secret. Artists like
Whistler,
Maxfield Parrish, Howard Pyle,
NC Wyeth,
Harold VonSchmidt,
Frederic Remington,
Frank Tenney Johnson,
Tom Lovell,
Doug Dawson, and a myriad of other painters and illustrators from the past and in present have painted nocturnes from inside during the daylight hours. Most if not all of them had spent a lot of time in the saddle of a horse, or out observing what happens visually at night, in order to be able to render the effect of the 'lack' of light on the subject that they wanted to paint.
As a side note of interest... At night the rods ( about 120 million, the light and dark receptors ) in our retina take over from the cones ( 6 to 7 million, our color receptors). This is the reason that as it darkens our ability to sense color diminishes. Many scientists think that this makes evolutionary sense. At night is when the predators are out. In our early development as humans, it was very important to be able to see those critters, who were out there to eat us, in order to have a chance for survival. Seeing movement was critical, color not as much so.
Harold VonSchmidt, for instance, painted many, many illustrations and easel paintings of the old west, stampeding horses and cows, the cavalry and their scouts, and much more, at night with a very limited palette of either a blue or green dominant color scheme. For many of his paintings he used a palette of Ivory black, Viridian and Alizarin Crimson. Prussian blue and black with burnt sienna is another popular palette for nocturnes. These are very effective generic palettes for nocturnes due to our inablility to see much color at night.
'Cold Riding' - oil - 30x50 - 1954 Harold Von Schmidt

Painting only in the studio with a generic 'nocturne palette', without the experience of painting from life at night, however, presents the painter with the dangerous possibility of becoming 'formulaic' with the subject. Back when Remington was painting there was often a palette for nocturnes referred to as the 'Frank Tenney Johnson' palette because he had so perfected the luminance seen in the night sky. For an illustrator, that's fine. Their job is to communicate the idea of their client to an audience not necessarily of their choice. It's completely possible to make up a situation on canvas in the studio. To do that takes the right amount of skill, and they are skilled.
For a painter who is trying to paint a response to what they're observing in an honest, objective way, I believe that it's imperative that the work is based on direct 'on the spot' observation. Once that you've understood the principles of a particular lighting situation it is possible to use studies from previous, different experiences to make a complete and meaningful statement.
Just take a look at the quality of work that
Frederic Remington did with nocturnes. He didn't stand outside painting a wolf staring at him in the moonlight. Yet it's totally believable as an image. And I doubt that the native Americans setting the prairie fire would have thought it a good idea to stand there and allow an artist to set up the easel either. He did use a new tool, flash photography, to capture some models and nocturnal reference. And he did do small sketches from life as a base for his reference.
'Moonlight, Wolf' 1909 Frederic Remington

'The Grassfire' (Backfiring) 1908 Frederic Remington

I've been enjoying painting the nocturnes for a few years now, both from life and in the studio from both life studies and from photo references. Another thing that I do and want to share with you, is to take daytime studies and convert them to nocturnes. I've actually done this a number of times and am going to show you a few here. This first image is my reference for the painting below it. I posted this same image in the recent post about the nocturne article.

'Palmetto Island Park' - oil field study, 9x12 © Marc R. Hanson '06

'Palmetto Island by Night' - oil - 16x20 © Marc R. Hanson '08
Another example are these two images. First one is a little field study painted a couple of years ago in spring. I used it as the only reference for the painting below it called 'Spring Night Light'. I'd been painting some nocturnes from life at this point and felt comfortable with translating day into night.

'Spring Painting' - oil - 10x8 © Marc R. Hanson '06

'Spring Night Light' - oil, 20x16 © Marc R. Hanson '06
In the following images I took the idea of this translating a little further and am showing a couple of examples. In both of these cases the only reference was photographic.
The point of all of this is that what we do as artists is make 'paintings', not duplicates of nature. I find this kind of challenge to be one that gets my creative juices flowing. From the source, to the reference photo or sketch, to the finished painting, the similarities between the two change. I move things, shrink, enlarge, emphasize, de-emphasize and employ any number of other alterations to make 'my' point. To me this is where the creativity in my work lies.

'Full Moon Barn' - oil 14x18 © Marc R. Hanson '06

Reference photo

'Winter Solstice Night' - oil - 20x24 © Marc R. Hanson '06

Photo reference