Pine Mountain Observatory: Program and Milky Way Photography

We will head to Pine Mountain Observatory (PMO) to attend its first public viewing night for 2025 and to photograph as a group the mountain campus for night and Milky Way photography.

ABOUT THE PMO PUBLIC PROGRAM

Pine Mountain Observatory is operated by the University of Oregon for astronomical observations and scientific research. For many years the University has provided community outreach through public programs on the darkest weekends throughout the summer. In the past, more formal programs were presented in a large tent on the celestial campus before visiting the telescopes. Now, informal learning stations are found in the permanent telescope buildings and on the grounds at telescopes set-up and operated by astronomy volunteers. These stations provide visitors the opportunity to learn about and view through the telescopes at planets and other wonders of the universe. The observatory requests a $5 donation for these public events.

ABOUT NIGHT PHOTOGRAPHY

Night sky photography is quickly becoming possible for photographers using their phones or camera and lens combinations customized for low light photography.

Photographers using more advanced phone cameras are increasingly more successful using their phones. As low light capabilities vary between phone makes and models, please refer to the documentation of your particular phone to best utilize its low light, night photography features.

For photographers using discrete cameras and removable lenses, night sky photography typically requires a large aperture (aka "fast") lens that captures more light. Lenses with smaller aperture openings that let in less light are considered "slower". Slower lenses (f/3.5 or f4) can work for night photography but they greatly limit the available light captured by the camera sensor.

The focal length of a lens determines the field of vision and how much of the night sky can be seen in one image. Wide angle and ultra-wide lenses (rated 24mm capture or smaller) are generally used.

Success when photographing low light images at night involves finding a balance between the physical abilities of your equipment, high ISOs that increase your cameras sensitivity to light, and the duration (shutter speed) of your photograph. If the ISO is too high, an image may have too much noise. If the exposure is too long, the movement of the stars as they travel across the night sky can appear in the image. It's good to experiment until you know what is best for you. In addition, other photographers are happy to help too!

NIGHT PHOTOGRAPHY PREREQUISITES

1. Finding Infinity

In order to achieve sharp focus on stars, the most accurate focus for infinity for a lens must be identified.

On most DSLRs, the infinity mark on the lens barrel may not be the true infinity focus of your lens optics. You will need to find, identify, and then preserve the true infinity setting on your lens for the sharpest star images. It's easiest to find infinity in the daytime using your autofocus then turn off your autofocus and preserve the exact focus setting for infinity by taping your lens, use rubber bands, or photographing the lens barrel and reset the lens to that mark prior to night shooting.

On lenses without infinity marks, in manual mode zoom in to a star using Live View, and adjust the focus of your lens manually until it looks very sharp. Keep the camera in manual. Physically secure the focus setting by using rubber bands or blue tape on the lens barrel (optional).

2. Red Light District Etiquette.

Red or green lights are used for night photography as they interfere less with eyes sensitivity to darkness. Eyes mostly adjust in five minutes but take 45 minutes to be fully sensitive.

However, improper use of red lamps greatly impair image quality. Thus, a few guidelines.

1. If you have brightness settings on your light, turn the red light to the dimmest setting.

2. Always point your red light towards you and not the scene. Hold your headlamp to view camera/intervalometer settings. Don’t wear your headlamp. Hold it in your hand over the lens barrel facing you and your camera/intervalometer.

3. If you finish photographing before others, point your red light away from the scene to gather your belongings and to leave the shooting vicinity before using white lights again.

4. These basic practices will help photographers to transition from being inexperienced to experienced night sky photographers.

3. Rule of 500

Because we're taking long exposure images of a moving night sky, calculations are made to determine maximum time the shutter can be open without blurring the stars. To get crisp stars with no blur, here are basic formulas:

Full Frame Sensor
Basic 500 Rule: 500 Divided By the Focal Length of Your Lens = The Longest Exposure (in Seconds) Before Stars Start to Trail.
Ex. 500/24= 20.83 sec. or 20 seconds before trails/elongation of stars

Cropped Sensor
Basic 500 Rule: 500 Divided By the Focal Length of Your Lens Divided by the Crop of Your Sensor (eg Nikon 1.5; Canon 1.6).
Ex. 500/24/1.6 = 13.02 sec. or 13 sec. before trails/elongation of stars.

TENTATIVE TIMELINE

08:45 pm: Meet outside the Barnes and Noble Cafe (Highway 20 location)
09:00 pm: Carpool to PMO.
10:00pm: Arrive at PMO
10:47pm Night Begins (end of Astronomical Twilight)
10:48 pm: Galactic Core of Milky Way rises
12:00- 01:00am: Finish and drive back to Bend

THINGS TO BRING

Since we'll be at 6300 feet expect and dress for cold temps and possibly breezy conditions. We will be walking a short distance from the PMO parking lot to the domes.

• A head lamp with a red light only or green light only setting.
• a flashlight,
• a sturdy tripod,
• fresh and extra camera batteries,
• an empty memory card,
• an intervalometer is useful to fine tune the length of your exposure but not required.
• proper footwear as we could be walking across desert scrub brush,
• "Little Hottie" Hand warmers: use 1 package to keep dew and frost from accumulating on our lenses.

SAFETY CONSIDERATIONS

Night photography has inherent risks as low light conditions increase the possibility of encountering unseen obstacles and hazards. Personal safety has to be the constant focus as locations with unmarked level changes, abrupt drop-offs, and cliffs without warning signs or protective handrails can be fatal. Always SAFETY: before, during, and after shooting.

PLAN B

Bad weather backup date: Saturday 5/24/25