iPhone 8 Plus - Astrophotography Tests
Posted: 22 October 2017
Tuesday, 17 October 2017, I upgraded from my iPhone 6s Plus to the new iPhone 8 Plus. I will be doing astrophotography with the new iPhone and will report on the results. Of course, the sky was cloudy after getting the new iPhone so my astrophotography was delayed for several nights. I did discover one change that may or may not be significant for low-light imaging. When using the iOS app NightCap Camera with my iPhone 6s Plus the slowest shutter speed available was 1/3 second. The iPhone 5s that I had before the 6s Plus had a longer (better) 1/2 second. With the new iPhone 8 Plus the slowest shutter speed is even further reduced to (a worse) 1/4 second. In discussions with the NCC developer, this may actually be a bug in iOS. It should be 1/3sec but shows 1/4sec with both NCC and Adobe Lightroom Mobile. On the good news side, the iPhone 8 Plus is the same size as the 6s Plus so my Levenhuk Smartphone Adapter will still work perfectly. And the Lightning connector Earbuds can be used as a remote shutter release, as could the older headphone jack Earbuds with older iPhone models.
You may be wondering why I decided to skip the iPhone X. When doing astrophotography with an iPhone the phone is mounted either on a tripod or a telescope. When mounted on a tripod the iPhone rear camera is obviously pointed upwards at the sky, sometimes even straight up. When mounted on a telescope eyepiece for imaging through the telescope the rear camera is aimed into the eyepiece. In both of these situations the Face ID camera on the iPhone X would likely have difficulty "seeing" my face with some iPhone orientations. Yes, the phone can be manually unlocked, but that gets to be a nuisance quickly, especially with the phone at odd orientations. And yes, the phone can be permanently unlocked, but that puts information on the iPhone at risk. Touch ID remains the best way to unlock the best smartphone for astrophotographers.
Cloudy skies continued until Saturday, 21 October.
Open: Saturday, 21 October 2017, 1735 MST Temperature: 76°F |
Session: 1152 Conditions: Clear |
Equipment Used:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" 30mm eyepiece
1.25" 15mm eyepiece
Camera:
iPhone 8 Plus
SkyTracker Pro
This session was devoted to testing my new iPhone 8 Plus.
1744 MST: sunset.
1745 MST: LX600 ON, StarLock OFF, High Precision OFF.
1746 MST: viewed the crescent Moon using the 12" telescope, 102X and 81X.
I then took some handheld photos of the thin crescent Moon in the western sky using the iOS app NightCap Camera. This photograph was taken using the 1X normal lens on the iPhone 8 Plus:
Mouseover or tap on image for pointer to the Moon
This photo was taken using the 2X telephoto lens on the iPhone 8 Plus:
Mouseover or tap on image for pointer to the Moon
I added an inexpensive clip-on 8X telephoto lens over the 1X camera lens for this photo:
This is the Moon with the 8X telephoto over the 2X iPhone lens:
These were just some initial tests. For better images the use of a tripod would have helped. It should be noted that the clip for holding the 8X telephoto lens is designed for a single lens smartphone, not the dual lens of the iPhone Plus models. Consequently it slips and is difficult to get full optical alignment.
I returned to the 12" telescope and took this handheld iPhone 8 Plus afocal 81X of the crescent Moon using NightCap Camera:
Switched to the 15mm eyepiece for this handheld afocal 163X photo of the Moon using NightCap Camera:
The Moon was getting lower in the western sky so seeing was getting worse. As a test I used the iPhone 2X telephoto lens for this handheld afocal 163X photo using NightCap Camera:
1820 MST: slewed the telescope to M13 (the Great Globular Cluster in Hercules), which I would image later with the iPhone 8 Plus.
1822 MST: the star Polaris was now visible so I stepped outside of the observatory to polar align the iOptron SkyTracker Pro for later astrophotography of the sky. 1826 MST: completed alignment.
1830 MST: took this handheld iPhone 8 Plus photograph of the crescent Moon and Earthshine with the 8X telephoto lens over the normal 1X camera lens, NightCap Camera (ISO 1000, 1/4sec):
1834 MST: viewed M13, 81X and 163X. SYNCed the AutoStar on M13.
1837 MST: Wi-Fi ON. I had intended to do some tests of the iOS app ScopeBoss. Unfortunately the Wi-Fi adapter could not connect to the telescope. The system had worked perfectly for several years so not certain what the problem was this night. I will have to troubleshoot the wiring connections in the daytime. 1856 MST: Wi-Fi OFF.
1907 MST: mounted the iPhone 8 Plus on the 15mm eyepiece using the Levenhuk Smartphone Adapter. I had to work a little harder to get the 1X normal lens centered over the eyepiece than I had with a single camera lens iPhone. But I was finally successful and could see M13 on the iPhone screen using NightCap Camera. 1932 MST: StarLock ON.
Used the Lightning Earbuds as a remote shutter release and the 1X lens for the following two StarLock autoguided, afocal 163X images using NightCap Camera (Long Exposure, Light Boost, 1/3sec, 1 minute, ISO 8000):
M13 (the Great Globular Cluster in Hercules)
M57 (the Ring Nebula)
1942 MST: StarLock OFF.
Viewed M57 (Ring Nebula), 163X and 81X.
1957 MST: began setting up for iPhone 8 Plus sky astrophotography with the SkyTracker Pro. Using the Levenhuk adapter the iPhone was mounted on a Manfrotto Ballhead, which was mounted on a Manfrotto Geared Head, both for convenience of centering objects:
This tracked NightCap Camera image (Long Exposure, Light Boost, ISO 8000, 1/3sec, 1 minute exposure) was taken using the 1X normal lens. It shows the constellations of Cassiopeia (upper left) and Perseus (below center) and M45 (the Pleiades; lower right).
Switched to the iPhone 8 Plus 2X lens for this NightCap Camera image (Long Exposure, Light Boost, ISO 8000, 1/3sec, 1 minute exposure) of Cassiopeia:
I then centered M31 (the Andromeda Galaxy) and took the following tracked photos NightCap Camera (Long Exposure, Light Boost, ISO 8000, 1/3sec):
1X normal lens, 1 minute exposure
Mouseover or tap on image for pointer to M31
2X lens, 5 minutes exposure
Mouseover or tap on image for pointer to M31
I added the 8X telephoto lens:
8X lens, 1 minute exposure
Mouseover or tap on image for pointer to M31
There is a hint of the spiral arms in the above image!
2111 MST: ended sky astrophotography. I am pleased with the results from my new iPhone 8 Plus. I do wish Apple would allow developers access to a "Bulb" setting or at least a 1 second shutter speed. That would likely improve tracked astrophotography images of faint objects.
Viewed M45 (Pleiades), 81X and 102X.
2119 MST: LX600 OFF.
Close: Saturday, 21 October 2017, 2135 MST Temperature: 59°F |
Session Length: 4h 00m Conditions: Clear |
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