1. TRANSIT OF VENUS
(Venus moving in front of the Sun when viewed from the Earth)
Talk by:
Aditya Ravi
Saturday, 27 April 13

2. WARNING
Never look at the sun through a telescope/binoculars/finder scope without a
proper solar filter!You not only blind yourself but also may end up damage your
equipment optics.
Saturday, 27 April 13

3. WHAT DO YOU MEAN BY
“TRANSIT OF VENUS”
“When Venus passes directly between earth and the sun, we see the distant planet as a small dot
gliding slowly across the face of the sun.”
The last transit of Venus occurred June 6th, 2012. The next pair of Sun-Venus-Earth alignments will
be December 2117 and 2125.
If Venus and the earth orbited the sun in the same plane as the sun, transits would happen frequently.
However, the orbit of Venus is inclined to the orbit of earth, so when Venus passes between the sun
and the earth every 1.6 years, Venus usually is a little bit above or a little bit below the sun, invisible
in the sun’s glare.
A similar thing happens with our moon. Every month the moon passes between the sun and the
earth, yet we do not see a solar eclipse every month. That’s because the moon’s orbit is also slightly
inclined to earth’s orbit, so the new moon is usually a little above or a little below the sun.
The pattern of 105.5, 8, 121.5 and 8 years is the pattern followed by these transits in a 243-year
cycle.
Saturday, 27 April 13

4. METHODS OF
OBSERVING THE SUN
A good quality solar filter is required
Observing Visually
Eye-piece Projection on a board.
Photo Credits:Adarsh A.Srivatsa
Saturday, 27 April 13

5. REQUIREMENTS FOR IMAGING
THE TRANSIT OF VENUS/SUN
Telescope or a telephoto camera lens with a tripod.
A white light neutral density 3.2 filter or H-alpha solar filter or Calcium K filters.
A DSLR/Webcam for prime focus photography or cellphone and point and shoot camera for a-focal photography.
Saturday, 27 April 13

6. COMPARISON OF IMAGES OF SUN WITH
DIFFERENT FILTERS
White Light ND 3.2 Filter
Saturday, 27 April 13

7. COMPARISON OF IMAGES OF SUN WITH
DIFFERENT FILTERS
H-Alpha Solar Filter
Images taken by and credits to: Steven W. Ramsden
Director,Charlie Bates Solar Astronomy Project
Saturday, 27 April 13

8. COMPARISON OF IMAGES OF SUN WITH
DIFFERENT FILTERS
Calcium K-Line Filters
Saturday, 27 April 13

9. WHAT I USED DURING
THE VENUS TRANSIT
Skywatcher 8” F/5 Newtonian Telescope
Baader ND 3.2 white light solar filter.
Canon 500D on prime focus.
Skywatcher NEQ-6 Goto Mount
Solar Tracking Mode On
Saturday, 27 April 13

10. THE PREVIOUS NIGHT WE HAD
AMAZING TRANSPARENCY
Saturday, 27 April 13

11. THE NEXT DAY OUR BEST
FRIENDS JOINED US (CLOUDS)
Saturday, 27 April 13

12. THE FIRST SHOT CAPTURED
AND THE EXCITEMENT BEGINS
Saturday, 27 April 13

13. TECH SPECS
The Baader Solar solar film reduces the intensity of
sunlight by 99.999%
Exposure time: 1/4000s
ISO 100
Exposure biasing was used in few images to control
the brightness of the image.
The photos were taken at prime focus hence aperture
cant be controlled.
Saturday, 27 April 13

14. RESULTS
Saturday, 27 April 13

15. RESULTS
Saturday, 27 April 13

16. A-FOCAL MOBILE PHONE
PHOTO
Photos are
taken by
Sanath
Kumar with
his cell-
phone
Saturday, 27 April 13

17. Any questions?
Hope you enjoyed this presentation.
You may also contact me at adityaravi1210@gmail.com
Saturday, 27 April 13