I have performed a filter modification on a Fujifilm X-A1 for a colleague. It involves the removal of the stock UV-IR filter, making the camera more sensitive to H-alpha wavelengths. This modification is helpful only when shooting targets with H-alpha emissions, as Fujifilm’s X-A1’s standard (stock) filter blocks this part of the spectrum.
To view posts on DIY projects and astronomical equipment, click here.
To clean the telescope’s lens or mirror, disassemble the lens or the mirror from the cell, making sure to mark the sides of the glass elements as it is necessary to reassemble them following the correct orientation as determined by the factory. In this video, I used my Sky-Watcher 100ED as an example. Follow these instructions at your own risk and exercise outmost care when cleaning telescope lenses.
To view posts on DIY projects and astronomical equipment, click here.
NOAA 15, 18, and 19 are weather satellites that gather and transmit image data real-time at 137 MHz. Any station with the proper radio equipment could receive this signal and decode it using available decoders. NOAA satellites usually make morning and evening passes, and with each pass, an image of the Earth within the satellite’s view can be received.
To receive radio signals from NOAA satellites, I used an AirSpy Mini Software-Defined Radio (SDR) and used GQRX app to run the SDR. I then connected a DIY satellite tracker with antenna to the SDR through its antenna port, but a simpler DIY satellite antenna would also work fine. Using GQRX, and while tuned to the satellite’s signal, I recorded it and saved it in WAV sound format. I then decoded (converted to image) the audio recording with the NOAA-APT decoder. From May 28 to June 1, I received and decoded the morning NOAA satellite passes and compiled them into an animation.
NOAA satellite images of a weather disturbance affecting the Philippines, decoded from May 28 to June 1, 2021
Receiving satellite images using inexpensive home-brewed equipment could be a worthwhile learning activity. To know more about other projects involving satellite communications, click here.
Sixty girl scouts, troop leaders, teachers, and amateur radio enthusiasts attend a webinar on amateur radio satellite operation co-presented by Manila Girl Scout Council Amateur Radio Club (MGSC ARC) and AMSAT Philippines, Inc. on May 29, 2021 via Zoom Cloud Meetings app. Licensed amateur radio satellite operators Anthony Urbano DU1AU and John Kyl Cortez DW9ILX explained how to use satellites to communicate long distances (Philippines to nearby countries) using only a low-cost handheld radio transceiver and an inexpensive home-brewed antenna. Other topics related to receiving real-time satellite images, talking with astronauts aboard the International Space Station (ISS), equipment and licensing requirements, and relevant information on setting up a satellite ground station were discussed during the webinar.
Total Lunar Eclipse imaged with a 4-inch f/9 refractor and a DSLR camera on May 26, 2021 in Bacoor City, Philippines. To watch our guided lunar eclipse observation (livestream), click here.
For a complete list of astrophoto images, click here.
NOAA 18 weather satellite image received on May 25, 2021 with an AirSpy Mini SDR on GQRX SDR app and a DIY satellite antenna. The signal was recorded in WAV sound format and then decoded (converted to image) with the NOAA-APT decoder. NOAA satellites (15, 18, and 19) transmit weather images in APT (Automatic Picture Transmission) format at 137 MHz which may be received using just a VHF antenna, a software-defined radio (SDR), and an APT decoder.
I have been testing this 2-inch Celestron OIII (oxygen III) narrowband filter, which according to the specifications, isolates 496 nm and 501 nm lines emitted by planetary and emission nebula.
Celestron 93624 OIII filter
The filter looks like a polished mirror that allows some green light that corresponds to the light emitted by emission and planetary nebula to pass through but blocks everything else including most light pollution. It results in enhanced contrast between the sky and the nebula.
An OIII filter reveals an emission nebula in Milky Way’s central region
I have used this filter extensively in visual observation by “blinking” it in and out between the eye and the eyepiece, a technique used in observing emission and planetary nebula. I wanted to know if I could also use this filter to photograph OIII targets with an unmodified DSLR and a telescope and the results look good.
Veil Nebula in OIII, captured with a 4 in f/9 refractor and an unmodified DSLR, 30 minutes single exposure. Image converted to grayscale.
I am only beginning to discover narrowband imaging and I hope to use this OIII filter to photograph targets even in severely light-polluted sky.
To view posts on DIY projects and astronomical equipment, click here.
I’ve built an electronic automatic focuser (EAF) for my Sky-Watcher Equinox 100ED refractor for automated and precise focusing.
The focuser was built with a stepper motor from an old printer, a gearbox from an electronic screwdriver, A4988 stepper motor driver, and an Arduino Uno. It runs on the firmware developed by R. Brown (2021).
The focuser is ASCOM compliant and works with astronomy software such as the Nighttime Imaging N Astronomy (NINA) for automated focusing during unattended imaging. When the autofocus command is called, NINA takes a series of photos (with a Canon 50D DSLR) at various focus distances and measures the diameter of stars for star fields or the highest contrast for moon and planets. It then calculates the proper distance travel for best focus, and then moves the focuser to focus. An automatic focuser ensures that stars remain focused during unattended imaging runs while you are away from the telescope.
Autofocusing with a DIY Electronic Focuser
This DIY electronic focuser attached to a standard Crayford focuser features 50,000 focus positions, with buttons for manual focus adjustment and calibration. The controller keeps track of the draw tube’s current position and saves this information even when the focuser is powered off.
Precise focusing of Jupiter using an Electronic Auto-Focuser
I have tested the focuser on several imaging runs now and it appears to be working fine, especially with planets in which I image at 3600 mm focal length.
To view posts on DIY projects and astronomical equipment, click here. To get a copy of the sketch, please email eteny@nightskyinfocus.com.
I’ve built a simple DIY intervalometer for deep-sky imaging, to enable my DSLR camera to take a series of photos of galaxies and nebula. It features a rotary dial with preset exposure times. When used with an autoguider setup, the intervalometer allows taking unattended exposures, while the telescope tracks a galaxy or nebula.
To view posts on DIY projects and astronomical equipment, click here. To get a copy of the sketch, please email eteny@nightskyinfocus.com.
The Markarian’s Chain imaged under city skies with a 4 inch f/9 refractor and a Canon 50D DSLR on a motorized mount with DIY controller. This photo is a stack of 9 frames at 120 seconds sub-exposure, for a total of 18 minutes, processed in SIRIL.
For a complete list of astrophoto images, click here.
M104 Sombrero Galaxy imaged under city skies with a 4 inch f/9 refractor and a Canon 50D DSLR on a motorized mount with DIY controller. This photo is a stack of 9 frames at 90 seconds sub-exposure, for a total of 13.5 minutes, processed in SIRIL.
For a complete list of astrophoto images, click here.
M101 Pinwheel Galaxy imaged under city skies with a 4 inch f/9 refractor and a Canon 50D DSLR on a motorized mount with DIY controller. This photo is a stack of 12 frames at 120 seconds sub-exposure, for a total of 24 minutes, processed in SIRIL.
For a complete list of astrophoto images, click here.
M66 (left), M65 (center), and NGC3628 (right) of the Leo Triplet galaxies imaged under city skies with a 4 inch f/9 refractor and a Canon 50D DSLR on a motorized mount with DIY controller. This photo is a stack of 7 frames at 120 seconds sub-exposure, for a total of 14 minutes, processed in SIRIL.
For a complete list of astrophoto images, click here.
NGC 5139 Omega Centauri globular cluster imaged with a 4 inch f/9 refractor and a Canon 50D DSLR on a motorized mount with DIY controller. This photo is a stack of 3 frames at 90 seconds sub-exposure, for a total of 270 seconds, processed in SIRIL.
For a complete list of astrophoto images, click here.
Milky Way imaged from a heavily light-polluted skies of Bacoor, Cavite, just 18 km from Manila. Taken with a Canon 1100D DSLR with kit lens on a DIY tracker. This photo is a stack of 5 frames at 90 seconds sub-exposure, for a total of 7.5 minutes, ISO 400, processed in IRIS.
M33 Triangulum Galaxy imaged with a 4 inch f/9 refractor and a Canon 450D DSLR on a motorized mount with DIY controller. This photo is a stack of 2 frames at 90 seconds sub-exposure, for a total of 3 minutes, processed in IRIS.
For a complete list of astrophoto images, click here.
M81 Bode’s and M82 Cigar Galaxy imaged with a 4 inch f/9 refractor and a Canon 450D DSLR on a motorized mount with DIY controller. This photo is a stack of 4 frames at 240 seconds sub-exposure, for a total of 16 minutes exposure time, processed in IRIS.
For a complete list of astrophoto images, click here.
