My first thought was that it was some vibration from the mirror and shutter, but as you say, it doesn't happen on the stars. Still, if the ISS is much brighter then any little vibration artifacts will be brighter too.
Next time, you could try holding a black card in front of (but not touching) the lens. Then open the shutter, wait a second for everything to quiet down and then pull the card away.
I thought I read you used a D90? You can also use the mirror lock up function. There's more vibration from the mirror flipping up than from the shutter opening. The mirror lock up function pulls the mirror up out of the way, waits for a second for vibrations to settle down and then opens the shutter. The it flips back down when the shutter closes. It's worth a try.
73,
Ken Alexander VE3HLS
On 2016-07-20 2:26 PM, PA3GUO wrote:
Hi John,
Also in the past my ISS photo's (with longer exposure, few seconds) had the same. I expect a ---- but I get a `----. Not a straight line, but at the start a curly curve. It is on all pictures. I expected it to be related to movement of the camera, eg the pressing of the button. But why does the ISS stripe have it, and none of the stars?
Yesterday I took all pictures with an IR remote. Effect is still there. Maybe the flipping of the mirror internally, but then again, why not the stars? Maybe because ISS is that bright ?
Frank answer: no clue. Anyone ?
Henk
-----Oorspronkelijk bericht----- Van: John Brier [mailto:johnbrier@gmail.com] Verzonden: woensdag 20 juli 2016 19:42 Aan: PA3GUO CC: AMSAT BB Onderwerp: Re: [amsat-bb] Spectacular views: Dragon and ISS clearly visible over The Netherlands !
Congratulations. That is really cool.
I see the Dragon streak far behind the ISS, but what is the dot/star looking thing right behind the ISS?
On Wed, Jul 20, 2016 at 12:42 PM, PA3GUO pa3guo@upcmail.nl wrote:
Last 2 nights both the ISS and SpaceX's Dragon cargo capsule were clearly visible over my location (Waalre, The Netherlands).
I got great help of two friends setting up the camera & tracking the spaceships.
In the night of July 19th they were still separated 4 minutes. ISS already passed when Dragon showed up.
However, in the night (early morning 03:35 local time...) of July 20th they were separated only 15 seconds / 115km.
One really sees the two 'following' (trailing) each other (ISS is followed by Dragon).
We had a bit of a challenge with the full moon. Fortunately, the basketball field helped out a bit as you can see on this picture: http://www.pa3guo.com/DSC_7644.JPG ISS is the bright stripe, the more dimmed stripe (below) is Dragon. Exposure (lens open): 10 seconds. ISS was approaching.
Subsequent pictures are here: http://www.pa3guo.com/DSC_7645.JPG http://www.pa3guo.com/DSC_7646.JPG http://www.pa3guo.com/DSC_7647.JPG http://www.pa3guo.com/DSC_7648.JPG (here you see Dragon best) http://www.pa3guo.com/DSC_7649.JPG
Then my two friends noticed during the final period of the pass that the Pleiades ("Seven Sisters") were accompanying them: http://www.pa3guo.com/iss_dragon_waalre_20jul2016.jpg
Well, I finally saw a cargo ship and the ISS passing by together, it was truly a spectacular view !!
Best regards, Henk - PA3GUO
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