On Saturday 2018 June 2nd, we drove over to the Venus transit site south of Newburgh (staying on the public road part and not trespassing) to observe and image the transit of the Sun by the International Space Station. Neither of us have witnessed this event before and it is on both of our observing bucket lists.
She was using her regular Solar scope, a Bausch & Lomb 4000 SC, fl=1200mm and an eyepiece, and a thousand oaks glass solar filter.
I was using the Meade LXD55 mount, Meade DS90 refractor (fl=800mm), the ZWO ASI120MC camera with a 0.5 focal reducer, a windows 10 laptop with firecapture2.6.0.8 , and a baader film solar filter.
The event was set for 20:03:52 from transit-finder.com. We arrived about 15 minutes early, turned on cell data and the atomic clock app to get hopefully sync’d time and started to setup. Last time I used my setup was last August in Wyoming… and I was short a critical part to mount the solar filter.
Kim found some scotch tape and we quickly attached the filter and crossed some finger that it would stay put.
The venus transit site has the only good NW horizon that we know of. The Yarker baseball diamond has a good SE horizon but with some local trees often in the way (had to climb on top of the minivan last time to get a clear shot).
I started the video .avi recording approx 30 seconds before the event.. good thing too as the event seemed to occur 3-5 seconds before prediction. could have been the cell phone time as well.. we forgot to bring the *real* shortware atomic clock.
The other issue with imaging… even with 800mm and a 0.5x focal reducer, the entire disk of the sun did not fit into the Field of View. There was a sunspot, 2712 on the disk, so I focussed on that. The ISS track had been shifting southward over the last few weeks and to get a centreline pass we would have been close to Napanee.. but with no good horizon.
So.. it would be a shorter chord pass but where on the sun? I took a guess and guessed wrong. It did get imaged at multiple FPS but on the top edge of the screen. I think we might have missed 1st contact and 2nd contact but have the middle bits.
The event was *fast*. 3 seconds still.. as it was far away and the apparent motion is fairly slow, compared to an overhead pass.
The video captured was 1280×960 pixels (full resolution) and the 22 seconds captured came in at 1400MB. I used the software AVI-trimmer to cut out the first and last segments and it came in at 400MB for about 6 seconds. The exposure was around 0.3ms /frame.
Then Handbrake to downsize and compress it into just under 2MB.
I want to break out each individual frame next and put them back together in various ways, perhaps blown up a bit as well.
So.. the first video produced is 1.8Mb large, is 1052×720 resolution at 18 FPS and is 7 seconds long or 126 frames.
It can be seen at: https://www.flickr.com/photos/125182848@N03/27689952367/
for now and on starlightcascade.ca a little later.
