Continuous Cold Moon Streak

This is an advanced full moon photo shoot, where we will atempt to repeat the above continuous moon streak. Please be on-time, starting 10 minutes before the moon comes up (5:31), I will not be able to assist until after the rise.

This meetup needs near-clear skies and may be cancelled if it's too cloudy, but weather forecast is good. No to low cloud coverage, upper 30s temperature, some wind. Dress warmly and in layers, bring gloves, but this will be a short meetup (1 h).

You will need: a sturdy tripod, a camera, a remote control/intervalometer, a long zoom lens of at least 150 mm focal length (better 200, up to 400), a 10 stop or higher neutral density filter for that lens. A second set of equipment (camera, tripod, long lens) makes is more worthwhile. Consider renting a lens if you don't have one.

The ICE 10-stop ND filter can be had very cheaply, it's a great filter with very minor color cast. Buy one for your largest lens and step-down rings for smaller lenses: 82mm (http://amzn.to/1YY3HqZ), 77 mm (http://amzn.to/1YY3Ryz). The Formatt-Hitech 16 stop ND filter can also be had at Amazon now, but it is expensive: 82mm (http://amzn.to/1YY42tC) and 77 mm (http://amzn.to/1YY4ND8). Get some step-down rings (http://amzn.to/1YY4Uyt).

1. We will attempt to shoot a continuous moon streak, which is not clipped, that means: no highlights blown out, the moon will have full color resolution.

http://photos1.meetupstatic.com/photos/event/7/8/d/f/600_444930943.jpeg

Here is how to do this:

• I selected the location to allow for a composition as above. There will be an interesting foreground for the moon to go over or behind (the Boston Logan tower).

• Compose such that about the bottom third is landscape and the top 2/3 are sky. Compose such that the moon comes up in the lower left corner (not too close to the edge) and you may have to make quick last minute adjustments once you see the moon coming over the horizon. Don't fret missing the first seconds, as the moon fills the space as it comes up.

• Plan for a very long, single exposure, around 20-40 minutes (after that it exits the frame), exposure time will be calculated for ambient landscape (with a high ISO preview (http://jmlobert.blogspot.com/2015/01/high-iso-preview-hip.html) - HIP - just before the moon comes up).

• The shot is taken with a long zoom (150mm or more, ideally 200-400mm), which is what makes the moon look "large" compared to the tower you zoom into.

• The lens is equipped with an extreme neutral density (ND) filter, 10 stops or more. 8 stops or less usually does not work. This is done to get the moon correctly exposed and avoid clipping its lights during the long exposure necessary for the landscape through the filter. The moon stays in "one place" only for about 2.5 minutes, so the exposure needs to be right for those 2.5 minutes. After that, the moon is right "next" to its prior self in terms of composition, the light no longer adds to the previous position. An ND filter denser than 10 stops would only make the moon streak darker, the ambient landscape would still be exposed right as determined with the HIP, but exposure time can be extended that way.

• A high ISO preview (http://jmlobert.blogspot.com/2015/01/high-iso-preview-hip.html) (HIP) will give you an approximate starting point for the landscape exposure. Consider that it will get a little darker as the moon comes up. This is one day after full moon, chosen on purpose, because the sun sets 45 minutes before the moon rises.

• The exposure time and aperture are then chosen for the length of the moon trail as well as the surrounding landscape.

• You can adjust exposure by raising the ISO or changing the aperture. The landscape will be far away, so it won't make much difference if you use f/5.6 or f/11, which gives you an easy adjustment for exposure.

• The above is shot at f/5.6 and ISO 400 for 30 minutes (to get the ambient exposure right) and a 10-stop ND filter. However, the moon exited the frame around 30 minutes. The moon also started clipping as it gets brighter, the clouds helped with that, but if it is clear, a lower ISO is advised. I will broadcast my best estimate just before the exposure starts.

• It is important to take a dark frame of the same length, ISO, temperature and with closed aperture and cap on the lens afterwards, because 20-40 minute exposures have a lot of fixed pixel noise. Subtract the dark frame from the image using PixelFixer (http://www.pixelfixer.org/). You can also enable Long Exposure Noise Reduction (LENR), but you won't see the image and can't take a short exposure until another 30-40 minutes after the exposure. You can let that run while you walk back to your car, though.

I chose an easy to get to location: the harborwalk and our zoom-into object is the airport tower 1.6 miles away.

2. Assembled moon streak

• The below image was taken with a second camera (and tripod) with a 10-stop filter, which was not quite dense enough, I had to shoot at ISO 50 (not 100) and f/32 to reduce the amount of light. Exposure time was limited to a few minutes initially, then I had to gradually reduce the exposure time and take multiple shots, 30-seconds at the end. I then stacked all images together for the resulting photo. Overall length is roughly 25 minutes. Easier to do, because you don't need to plan ahead for 30 minutes. The nice thing about this one is that the moon does not exit the frame. The streak is not as smooth and you can see the breaks between exposures as small indents, even though interruption between any two shots was only a few seconds. The moon moves quickly with a long zoom!

http://photos2.meetupstatic.com/photos/event/7/a/c/e/600_444931438.jpeg

3. Full moon rising

If you have a 2nd or 3rd camera, you can also simply shoot the full moon coming up over the horizon, which is substantially easier to do and does not require ND filters. Exposure time is somewhere shorter than 1/90th of a second, ideally shot with mirror up and using a remote control. The challenge here is to not blow the moon out (it has features that you want to show) but also not blur it and to get a composition with an interesting foreground, perhaps with the moon half behind it. Because it is one day after full moon, the landscape will be rather dark when the moon rises (an hour after sunset) and you will have to boost shadows in post-processing a lot.

It will be cold and you will be standing around not doing much. Dress accordingly, bring gloves and head gear. This will be a rather short meetup, about an hour to 90 minutes. Once the moon is way up, it becomes uninteresting and too bright, but you can certainly stay to shoot things around the harborwalk (like the aquarium right behind us) only or zoom in on the moon alone.