Subject: Using a full moon to illuminate landscapes. The object is to use the cameras ability to collect light over time using the natural illumination from the moon to give detail and color to landscapes.
This essay is just a start on a process that I hope to perfect. I started out wanting a milky way shot with moonlit foreground but it is difficult to get the milky way with a bright moon. I ended up deciding that a dark sky with visible point like stars and visible landscape makes a great image. This essay represents what I know so far and I solicit feedback for advice or errors.
Choose your image style.
- Star Trails are one style but are outside the scope of this essay.
- The milky way on a dark night and dark setting with no land or land in silhouette is another.
- A more conventional landscape that includes a dark sky and stars, but which is mostly about the landscape. Individual stars will show but the milky way may not be prominent or even visible as such. This is what typically happens with a full moon. This is the goal of this essay.
- Use light painting to illuminate terrestrial subjects. This can be used for any type, but is outside the scope of this essay.
Note: Some of the techniques described here are useful for all the above styles except star trails. However the main subject of this essay will be type 3.
Choose your subject.
- A snow covered mountain reflecting in a still lake is a great subject.
- The land subject ought to be fairly reflective.
- Bright city lights will look garish when you bump up exposure for other elements. Some is ok, but too much can spoil it.
- This sort of image needs a fairly wide angle lens to freeze the stars, so you need a subject suitable for the focal length.
- When we had the super moon last May, I was able to get an ISO800 50mm image at f5.6 but the star trails were too long. I should have stopped down.
- Avoid including very near subjects unless it is water or something without much detail. At f2.8 your DOF is limited. See table at the end.
- Once while shooting to the east the moon went behind the local mountain and I lost my eastern illumination. But when I looked north, the hillside was still illuminated. It made for an interesting shot.
Some observations on taking the image.
- Have the moon at your back, The full moon usually sets very near to sunrise, so getting on scene about 1-2 hours prior to sunrise works well for east facing shots. West facing shots would need to be done after sunset. It usually takes a couple hours to get really dark and sometimes more for the moon to clear the local mountains.
- Shooting into the moon is tough. The moon is a bright object on a dark night and will be blown out by the time you get the rest of the exposure bright enough. This angle is required for a moonbeam on the water however. You can clone in a well exposed moon but you also need to deal with flare around the moon and its really hard to paint out the bright area on the lighter exposure. I have a sample but the work in post processing was tough and the results ok for web, but not print.
- Use TPE for moon angle and setting times. http://photoephemeris.com/
- If you have mountains, the rising and setting times may be as much as an hour before or after the official time.
- To avoid star trails, use this formula. 600/FL. Example for a 24mm lens, 600/24=25 seconds. This works ok, but still has short star trails so err towards a faster shutter.
- Wider and faster is better to prevent star trails.
- Use the fastest lens you have that that has good wide open image quality. I have the 24-70f2.8 mk2 that is great at f2.8 but 24 falls short on the 600/FL test if you want a bright milky way, but it is good for type 3 styles. I have a Samyang 14 f2.8 but it has distortion issues which you will see in one of the samples. I also have a 17TSE f4 but it is on the slow side for this work.
I have a Zeiss 15 which I have not yet tried and it may be the ultimate night lens.I tried it, and returned it. you can read about here. A great star lens if it does not need to be pointed upward.
- To get lots of sky and just a bit of land, you almost always end up pointing the lens at a steep angle. A lens with lots of distortion may really produce strange results for the land part of the image. Distortion in the sky probably does not matter but can really make a shoreline look funny..
- For milky way shots, vertical works good because it gets more sky less land.
- Try to know where the milky way is for the time of the shot so you can find a good composition that includes it. I don’t know how to do this and the aps I have tried are so confusing I gave up. If you have a tip, please share it. I end up fishing around and generally only find it after it is nice and dark.
- Focus is critical. The focus needs to be at infinity but if it is dark, it will be difficult. The moon is a good target if it’s up. A distant light source is also good using live view. UWA lenses can be focused via the focus dial if you calibrate for infinity.
- You can pre focus before dark but be careful not to touch it later.
- It does not matter if you change position after focus, infinity is infinity east or west.
- You will need a long exposure and probably a high ISO. Set the longest shutter speed you can use per the 600/FL rule. Then set your fastest aperture. Be sure to have long exposure noise reduction on if your camera has it. This will reduce noise.
- After setting shutter speed and aperture, experiment with ISO next. Take one at ISO800. If it does not produce a bright enough image, keep going higher until you get the exposure desired or until you reach the highest ISO.
- My 1DS-mk3 is ok to about ISO1600, and maxes out at ISO3200 at which point it is so noisy I am unhappy with the image. ISO800 is better but ISO1600 will work.
- If you have a lot of ambient light say from a city or from the moon reflecting off clouds, you may find ISO400 is enough. At this point you can start reducing shutter speed or increasing the aperture.
- The final look image needs to be dark, you may find that less exposure is required than first thought. So make some images a bit darker than what you see on the LCD. You want terrestrial subjects to have color and detail, but just enough to show. You want a very dark sky with near black or very dark blue sky and visible white points for stars. Clouds will be white, gray or with just a tiny bit of color. Its not supposed to look like day, just a moonlit scene.
- Post processing
- Preserve the land exposure and probably darken the sky at raw conversion. IE a mask of the sky.
- Run noise probably everywhere for ISO400 and up. Sharpness is not as important for these shots and noise is a killer if viewed full size or printed.
- Mask the sky and perhaps water or other dark areas. Work on dark and light separately.
- The sky can be darkened in the hue saturation dialog selecting the blue channel and reducing both saturation and lightness.
- It can be further darkened with a dupe layer set to multiply and faded to taste. Surprisingly, the stars will stay white while doing this but the clouds and sky will darken. Turn on the land layer so you don’t get too far ahead and mismatch the overall luminance.
- Work the land layer as required to get saturation and luminance as desired. Work back and forth with the sky and other dark layers.
- A water foreground may need different treatment than the sky, but it will be similar. Perhaps allow more blue, or lighter luminance.
- The rest of the processing is per your favorite methods, these are specific things that apply to this type of image.
- After my last trip, I found that there was a heavy yellow component. I desaturated yellow and got what I think is a more pleasing look. See recent additions further down.
The following tables are useful for night photography when using f2.8 focused at infinity.
I used the online DOF calculator with default CoC of .030. We should not have any near detail to preserve so if we get a good infinity focus, the following table shows the nearest acceptable sharpness. Note, I used 10,000 feet as a proxy for infinity.
FL ____Nearest sharp focus
15mm— 8.7 feet
If you want to cut the CoC in half to .015, just double the acceptable focus numbers.
Shutter speed table using the 600/fl rule
FL _____shutter speed
The samples show my learning curve. My more recent samples are getting closer to what I want have a darker sky.
One of my better examples but it can stand improvement.
Into the moon showing a cloned in moon and painted in dark sky around the moon.
This next is an example of a blown out moon.
Example of 50mm f5.6 shot at ISO800. The star trails are too long however and the stars are hard to see at this size, view the larger one in the link at the end.
Samyang 14mm showing excessive distortion from the lens and uptilted angle.
Example of too many city lights.
Moon on north hillside.
New findings as of 11-14-2012
On a recent trip to Zion, Nov 4-6 and with only a half moon, I discovered some more valuable information.
With fairly bright foreground, like some of the Zion Canyon walls, a 1/2 moon provides enough light and allows a darker sky.
Here are some samples:
Samples from November 28th full moon:
I am finding the 17TSE a great moonlight lens. It is very sharp at f4 and the shift feature allows me to get lots of sky without angling the lens upward.
The Samyang 14 f2.8 is pretty good as well but even the slight uptilt I had to apply hears causes a distorted showeline.
You can see large samples here.