Discussion in 'Amateur Radio News' started by W0PV, Dec 12, 2017.
I am seeing some 6M spots on dx cluster tonight... meteor scatter / tail ionization for sure.
Except on the FT8 mode "channels" , they're FULL !
Jack, very nice with Orion in the background; how long was the exposure time and other settings ?
73, John, WØPV
Thanks. I used a 20 sec shutter, left the aperture wide open at f/1.4, and set the ISO to 200. That probably sounds a bit odd, but there is a method to my madness! Basically I set the camera aperture wide open to f/1.4 to gather the most light from a meteor. Meteors, no matter how bright they are, are usually only visible for a second or less, so the camera has very little time to gather their light. Contrast that with the stars which the camera has 20 sec (in this scenario) to gather their light, and you can imagine why meteors are tough to photograph. Normally I would use a shutter speed of only 10 sec or less with a FF camera and 24mm lens in order to prevent noticeable star trailing. That is, when stars start to look way too elongated because the shutter speed was too long and the stars appear as short lines rather than points of light. But with meteors, I really don't care if the stars trail as I can always take some follow up photos later at shorter shutter speed to use as the background image. Basically, I'm hunting for meteors so I'm setting camera to capture them and not worrying about the stars, but I also don't want to over expose the sky either. The 20 sec shutter is just a nice speed to allow me to set up the camera to take one photo followed by one sec closed shutter and then repeat that 21 sec cycle hundreds of times over a few hours. With the shutter closed only 1 sec out of every 21 sec, I have a better chance of capturing a meteor than if I used 1 sec closed out of every 11 sec. So that is why I used 20 sec rather than 10 sec shutter, it increases the odds of capturing a meteor by keeping the shutter open longer during the elapsed time of the shoot. 20 sec is about as long as I dare go because much longer and it would start to over expose the sky and thus make meteors harder to capture.
So here is the thing. For typical nightscapes I would normally set the camera to f/2.8 (for a sharper image), 10 sec maximum shutter (to control star trailing) and ISO 1600 (because that is the optimum ISO setting for my camera). But using f/1.4 increases the light gathering capability 4x over using f/2.8 which is two stops slower, and with meteors you need all the light gathering capability you can get. So I use f/1.4 and 20 sec shutter for reasons described above, and that means an ISO 200 will yield approximately the same exposure as my typical nightscapes settings (f/1.4, 10 sec, ISO 1600).
I've been photographing meteor showers for several years now, and through trial and error (mostly error) I've developed this method and it seems to work really well. For best results go to a very dark sky location though. I shot these in the southern part of the D/FW metroplex where the sky is way too bright with light pollution, but even here you can capture a few bright meteors.
Back in the 1980's I belonged to the Tampa Area Astronomical Society (TAAS) here in central Florida. We had a nice observatory up on a hill in a dark skies area, a really nice set up. One night at one of our star parties a fireball meteor lit up the sky above us so brightly that it turned to day time for a couple seconds.
Then in less then 30 seconds we were showered by very small sized meteor gravel about the size of peas. It was like a hail storm. It was a once in a lifetime experience.
With the ongoing FT8 frenzy it's becoming harder to make JT65A and JT9 contacts and the ones I do are mostly on 40 and 20 meters, no more on 160, 80, 60, 30, 17, 15, 12 and 10 meters.
Its a real drag that JT modes have fallen out of popularity. But for skeds, JT9 is wide open. But I'm getting really annoyed with ops sending well up into the JT65 section with FT8.
Waiting for a mod to FT8 that gives 26s decodes, 4 sec to react, and 3dB greater sensitivity. Or just take JT9 and make its cycle shorter!
Ref HSMS on 10.. We were experimenting on 28.148 with "JT9-G" fast mode during the 2016 summer on the West Coast. I haven't seen any more activity on PJ Central since. 73, Eric (50.28 MHz, JT9-E+ H)
10m AM- When 10 is open, I work stations right at 29.01, 29.02 MHz.. 73, Eric
I've been having great success with MSK-144 for meteor scatter with my Yaesu Ft-857d and the most excellent PAR Electronics 6m Omni-loop. I get results even when major storms aren't peaking.