From: Alan Friedman <alan@greatarrow.com>
Date: June 12, 2012 9:18:39 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] a gift of watermelon pickle
With thanks to Darryl Robertson, here is a link to a little movie showing the atmosphere of Venus before second transit. The seeing was terrible at this point. The movie is made from cropped frames from a reference movie containing the best frames selected by AstroIIDC. The original capture was made with my 1600x1200 pixel Grasshopper camera. Even with the YouTube compression, the outward edge of Venus is easy to see.
best,
Alan
Alan Friedman
On Jun 12, 2012, at 12:59 PM, Milton Aupperle wrote:
Hi Alan;
On 12-Jun-12, at 10:40 AM, Alan Friedman wrote:
> Many thanks for your comments, guys.
>
> Milton, the seeing looks very good through the clouds. I find this
> to be the case with light cloud cover, though I'm not sure if it is
> real, of it is the obscuring of the data that makes it appear so.
Seeing was very good that day - as the NAM Forecast 300 millibar map
predictor suggested. It was also good on the other days when I was
testing my rig out on Sunspots - but I can't mosaic them together due
the the filter issues I mentioned previously. We have a very large
dammed lake about 150 meters away and I think that helps stabilize the
local seeing conditions, as I usually have good seeing here.
Cloud cover was erratic to say the least. At some points you could
see the suns disk through the clouds naked eye, then other times
almost no clouds at all. Astro IIDC was adjusting the exposure time
from 33 ms down to 0.1 ms on the fly to balance the exposure times out.
> How do you go about cropping the dimensions of the movie? I've
> wanted to do that recently but couldn't figure out how.
You can't. You have to re-compress the entire movie and crop out the
portions you don't want.