Transit of Venus 2012

[ameerat42]

I have posted this here as it is too general to put into Night/Astro.

Is anyone else going to be recording the Transit of Venus across the sun which occurs on 6 June 2012?

I am not necessarily planning a meet-up, as this is something that is best recorded from as many locations as possible to ensure that it is in fact visible.
(Recall the 1976 Total Solar Eclipse, where all the world's scientists got clouded out at Bombala in NSW )

I thought that it would make a good, IF SPECIALISED, photographic opportunity. NOTE THAT there are SAFETY ISSUES involved, as it means photographing and
VIEWING the INTENSE LIGHT OF THE SUN.

At the outset please note that APPROPRIATE HEAVY FILTERING OF THE LIGHT IS REQUIRED.

There are many warnings in the literature about how to observe and photograph the sun properly.

There are many references on-line by using "transit of venus 2012". Below are just a couple:
1. http://www.transitofvenus.com.au/HOME.html
2. http://rses.anu.edu.au/~jcali/eclips...OfVenusp3.html
3. http://www.joe-cali.com/eclipses/PLA...itOfVenus.html

So this is just to kick off the idea, and discuss it, etc.

What I will be trying for, USING PROPER SOLAR FILTERS SECURED ON each piece of equipment and with a friend to help:
1. A photographic record using DSLR and telescope.
2. A video recording of the event using a digicam and teleconverter.

These will be mounted on a tracking equatorial mount.

Just for starters, the type of filer required is proper SOLAR FILTER material that is of very high density and that blocks IR and UV as well. It has been mentioned in a few sun photos threads already.
It is usually designated as a Neutral Density Index of ND 5 or ND 3.8. This means a filter factor of 10^5 or 10^3.8, 100,000X and about 6,000X respectively. The latter is for "photographic only" use.
This is far beyond most neutral density filters for normal photographic use. In terms of f-stops, the ND 5 is 100 stops of exposure difference and the ND 3.8 about 80 f-stops.

Two brands of the appropriate filer are the glass ones, like "Thousand Oaks Solar Filter" and the Baader Film filters. You need to look them up and they're not cheap.

Well, that's the kick off.
Am.

[Bennymiata]

I guess you could also use the glass from a welder's mask, and make sure you only view it using live view.

[ving]

i'll be taking photos if i can!

[farmer_rob]

You can also try a pinhole projection and take a photo of the projection. I did this for the previous transit (sorry, not digital so can't post it) - it worked well, with no filters needed.


Regards,
Rob

[ameerat42]

I guess you could also use the glass from a welder's mask, and make sure you only view it using live view.

No 15 (or 14) is the highest density, but I have been unable to link it with a density index or a filter factor (like 4X), and therefore f-stops. It's also non-optical glass, so I do not know what it'll do to IQ. Nevertheless, there are plenty of sunspots to oblige a try. Be careful (of your sensor) though.

i'll be taking photos if i can!

"I know you can" x 2, of the little red engine.

You can also try a pinhole projection and take a photo of the projection. I did this for the previous transit (sorry, not digital so can't post it) - it worked well, with no filters needed.
Regards,
Rob

Rejoice! Yes you can, Rob, I'd be interested to see it. Just get up close and take a pic of the print.

Am to all.