Old 12-22-2009, 10:39 PM   #1
Mark Gayman
Member
 
Mark Gayman's Avatar
 
Join Date: Jul 2008
Location: Utah
Posts: 95
Thumbs up Simple, accurate sun angle charts

Since the sun angle can be a key factor in shots, I researched the web for sun angle calculators or tables. I found a useful source for printing free, custom sun angle charts at:

http://solardat.uoregon.edu/SunChartProgram.html

I find the 6 month, one page chart (select radio button for Plot dates 30 or 31 days apart, between solstices, December through June) to be the most useful since it also works in reverse for the months of December to June. As well as tracing the sun angles, the chart also indicates sun rise and set times and azimuths.

Explanations can be found here: http://solardat.uoregon.edu/AboutSunCharts.html

A sample PDF from the charting program can be seen here: http://www.californiasolarcenter.org...mple_38lat.pdf

The charts from this source are graphical.
__________________
Rath copy 6 east Wood copy 3 west (Form 19 is my way to run a railroad)

---------------------

Last edited by Mark Gayman; 12-23-2009 at 04:44 AM. Reason: Added links to chart details and a sample chart.
Mark Gayman is offline   Reply With Quote
Old 12-22-2009, 10:43 PM   #2
cblaz
Senior Member
 
cblaz's Avatar
 
Join Date: Jan 2005
Location: Marlboro, New Jersey
Posts: 1,007
Default

Here's the one I use, just punch in the day and nearest town and off you go.

http://aa.usno.navy.mil/data/docs/AltAz.php

- Chris
__________________
- Christopher Blaszczyk
My shots on RP: http://www.railpictures.net/showphotos.php?userid=284
cblaz is offline   Reply With Quote
Old 12-23-2009, 02:24 AM   #3
JimThias
Senior Member
 
JimThias's Avatar
 
Join Date: Feb 2007
Location: Grand Rapids, MI
Posts: 9,843
Default

Quote:
Originally Posted by cblaz View Post
Here's the one I use, just punch in the day and nearest town and off you go.

http://aa.usno.navy.mil/data/docs/AltAz.php

- Chris
Does it give you a graphic representation? I punched in the day and nearest town and all I saw was a list of numbers. I want to SEE how the sun angle is and not have to computer a bunch of numbers.

Actually, I think someone posted a link on here during this past year that had something simple like that. It might have been John Ryan. Hmm...
__________________
.
Rhymes with slice, rice and mice, and probably should be spelled like "Tice."

This pretty much sums it up: http://www.urbandictionary.com/define.php?term=Thias
JimThias is offline   Reply With Quote
Old 12-23-2009, 03:51 AM   #4
cblaz
Senior Member
 
cblaz's Avatar
 
Join Date: Jan 2005
Location: Marlboro, New Jersey
Posts: 1,007
Default

Quote:
Originally Posted by cblaz View Post
Here's the one I use, just punch in the day and nearest town and off you go.

http://aa.usno.navy.mil/data/docs/AltAz.php
Quote:
Originally Posted by JimThias View Post
Does it give you a graphic representation? I punched in the day and nearest town and all I saw was a list of numbers. I want to SEE how the sun angle is and not have to computer a bunch of numbers.
The first column is the time. The second column (altitude) is the angle of the sun above the horizon. Anything above 0.0 means the sun has risen.

The third column is the angle of the sun in relation to direction. 0 is North, 90 is East, 180 is South and 270 is West. To go further, 45 is NE, 135 is SE, 225 is SW and 315 is NW. So if the sun is at 135 and the line you're railfanning runs NW-SE, a train heading south/east will be nose lit at that time of day.

- Chris
__________________
- Christopher Blaszczyk
My shots on RP: http://www.railpictures.net/showphotos.php?userid=284
cblaz is offline   Reply With Quote
Old 12-23-2009, 10:03 AM   #5
John Craft
Senior Member
 
Join Date: Apr 2007
Location: Atlanta, GA
Posts: 238
Default

Quote:
Originally Posted by JimThias View Post
Does it give you a graphic representation? I punched in the day and nearest town and all I saw was a list of numbers. I want to SEE how the sun angle is and not have to computer a bunch of numbers.
Plot the 'angle' number on a map of the location you're interested in.

Actual example: this was a spot (actually two spots a bit over a mile apart) I'd thought about trying for a while, a bit different than the usual sunrise silhouette.



Using numbers from the Navy site, coupled with a compass-equipped visit to the spots about a month before the date we'd be shooting, confirmed that it would probably work:



The results:

Image © Rod Myers
PhotoID: 300613
Photograph © Rod Myers


Image © Sam J. Botts
PhotoID: 304968
Photograph © Sam J. Botts


Image © Appalachian Railfan
PhotoID: 300263
Photograph © Appalachian Railfan


Image © Dane Reynolds
PhotoID: 300211
Photograph © Dane Reynolds


Also, by playing with the dates, you can use it to find when a particular location is lit the way you want.
John Craft is offline   Reply With Quote
Old 12-23-2009, 02:30 PM   #6
willig
Senior Member
 
willig's Avatar
 
Join Date: Oct 2007
Location: Manchester, UK
Posts: 473
Default

For the UK there is this rough and ready calculator.

http://www.trainspots.co.uk/ts-s-dial.jpg
willig is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT. The time now is 04:45 AM.


Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.