Re: [APML] Rising Emu

[Matt BenDaniel <matt@starmatt.com>]

At 04:59 PM 5/20/2002, Axel Mellinger wrote:
> > Another question (because I´m in Namibia in July too): how do you plan such
> > mosaic shots? Do you look for the center of the area for every shot and how
> > much do you overlap the frames?
>
>In the text below the mosaic, there is a hyperlink titled "4-frame mosaic"
>that will open a little JPEG file with the four raw images. As you can
>see, I try to get about 20% overlap. Sometimes this is not trivial to
>achieve, especially in areas with few bright stars (when it is hard to see
>anything at all in the viewfinder). It is always a good idea to sketch the
>frames in a star chart, especially when your exposures are several nights
>apart.

Volker,

It helps if you can compose each shot with the frame edge aligned exactly 
north/south. This aligns the frames. If they are askew you have to crop more.

In Axel's Emu mosaic, he did not compose north/south. He aligned the edges 
according to the galactic equator. But he had lots of bright stars to align 
with.

If you make printed charts with TheSky, it makes it relatively easy to 
compose. It's important to have a viewfinder in which you can actually see 
5th or 6th mag stars near the edge of field.
--
Matt BenDaniel
matt@starmatt.com
http://starmatt.com


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