Archived posting to the Leica Users Group, 2000/01/19

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Subject: RE: [Leica] Exposure for eclipse of moon ?
From: Paul Chefurka <Paul_Chefurka@pmc-sierra.com>
Date: Wed, 19 Jan 2000 13:18:55 -0800

Oops!  I forgot about the round-trip delay.  So I guess I'll need to use
rear-curtain sync with a 3-second exposure (186,000 mps over a total
distance of ~472,000 miles gives about 2.5 seconds...)  Photographers are so
busy thinking about the quality of light they neglect little details like
the speed of light.

By the way, does anyone know where I can get a sync cord that will connect
an R8 to Leica's Mark 52 thermonuclear-pumped full-spectrum optical twinky
laser? I looked in the box, and it seems they forgot to pack it.  Yet
another example of the shoddy quality control at Solms, I guess.  I just
hope the darn thing goes off when I push the button...

Paul Chefurka

>-----Original Message-----
>From: John Collier [mailto:jbcollier@home.com]
>Sent: Wednesday, January 19, 2000 3:53 PM
>To: leica-users@mejac.palo-alto.ca.us
>Subject: Re: [Leica] Exposure for eclipse of moon ?
>
>
>
>>> Paul Chefurka wrote:
>>> 
>>>> Ted, you'll probably know the answer to this.  If I wanted to
>>> shoot the
>>>> eclipse using twinky flash, what sort of guide number would I
>>> need to expose
>>>> the moon properly on Velvia???  ;-) >>>>>>>
>
>Do not forget that it takes time for the light of your 
>flash/laser to reach
>the moon and get back. Check with NASA but I seem to recall a 
>2 second delay
>during radio contact with Apollo 8. Maybe I will run off some 
>test rolls
>tonight and get back to you.  ;-)
>
>John (never been more serious in his life) Collier
>