Re: [APML] OT: Penumbral eclipse

["Taras R.Hnatyshyn" <tarashnat@earthlink.net>]

Stan,

The focal length doesn't change if you crop a photo, it was still taken 
with the same lens, so it doesn't change if you use a smaller film/chip 
size. It is just the apparent FOV that changes (one can use the term 
equivalent focal length, but that can also cause confusion, because 
then you need to state equivalent to what, though most people use 35mm, 
when that film size is no longer popular, then what will that mean?). 
With a small film/chip size, the moon will cover a larger percentage of 
the area of the detector. There is quite a bit of detail for such a 
short lens on the moon. The darkening of the northern limb is more than 
I expected.

Taras


On Apr 24, 2005, at 11:32 AM, Stan Richard wrote:

> Stuart, thanks.  The focal length was actually about 330mm, forgot 
> about the 1.6x crop factor.  This is 100% crop, sharpened up in PS.  
> The image is just as the moon appeared to me visually looking thru the 
> viewfinder, suppose I could try to reduce the dynamic range but I 
> don't think it would look right.
>
>
>
> Stan Richard
> Events in the Night Sky
> www.nightskyevents.com
>
>
>
>
> ----Original Message Follows----
> From: "Stuart Heggie" <Stuart.J.Heggie@sympatico.ca>
> Reply-To: Discussion of Film Astrophotography <astro-photo@seds.org>
> To: <stan.richard@hotmail.com>,"Discussion of Film Astrophotography" 
> <astro-photo@seds.org>
> Subject: Re: [APML] OT: Penumbral eclipse
> Date: Sun, 24 Apr 2005 08:17:28 -0400
>
> Stan - nice one! Very sharp for a short focus camera lens. The image 
> seems
> to have a very wide dynamic range - the brightest parts of the moon 
> are too
> bright. Is this pretty well what came out of the camera? If not, you 
> might
> try to reprocess it to retain the details in the brightest parts of 
> the moon
> without losing them in the penumbra.
>
> Stuart
> ----- Original Message -----
> From: "Stan Richard" <stanrichard@hotmail.com>
> To: <astro-photo@seds.org>
> Sent: Sunday, April 24, 2005 7:02 AM
> Subject: [APML] OT: Penumbral eclipse
>
>
> > I hope it's ok to post this here as it is digital, got up early 
> anyway so
> I
> > went out and grabbed a shot of the eclipse.
> >
> > http://www.pbase.com/image/42489471/original.jpg
> >
> >
> >
> > Stan Richard
> > Events in the Night Sky
> > www.nightskyevents.com
> >
>
--
                         <end of message>
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* Taras R. Hnatyshyn                     tarashnat@earthlink.net *
*    http://homepage.mac.com/tarashnat/astrophoto/welcome.html   *
*  73°59'18.4"W 40°43'37.2"N    or    74°25'24.4"W 41°40'42.0"N  *
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