What do I need to know before attempting to photograph Venus in transit?

Question

This Tuesday will be the last chance to view Venus in transit for the next 100+ years, so I'm planning to make the most of it. I'd also like to capture what I see for posterity, but this type of event is decidedly something new to me. I suspect that I can't simple aim at the sun and fire away. If a simple magnifying glass will kill an ant and cook a hot dog, surely my lens would concentrate the sun's rays to a disastrous effect on the lens/camera internals. Surely the shutter, sensor, etc. would be in danger of frying.

Are my suspicions correct? If so, is there anything I can do to mitigate the effect to a safer level--via a ND filter, smoked glass, etc? What other considerations do I need to make in attempting to capture such an event?

Good question, although probably a lot of it is covered under How to take photos of a solar eclipse without damaging one's eyes or camera? — mattdm, Jun 02 '12 at 23:27
@drewbenn, not a telescope, but I have a 300mm lens; on an APS-C sensor, that's equivalent to something like 480mm. Would it be too small to be visible even with that? — Ray, Jun 03 '12 at 01:20
The disk of Venus will be 58 arcsec in diameter. With a real focal length of 300 mm, Venus will be (300 mm)(1000 micron/mm)(58 arcsec)/(206265 arcsec/rad) = 84 microns on the focal plane. Typical APS-C DSLR pixels are ~5 microns, so it should certainly be visible on the image. — coneslayer, Jun 03 '12 at 02:13

score 3 · Accepted Answer · answered Jun 03 '12 at 01:27

This looks like an excellent place to start.

A Checklist for Photographing the Transit of Venus

That was for the 2004 version, so times and date are of course wrong.

He covers procedures and equipment including cameras, optics, filters & more.

He notes that you can practice in advance by taking sunspot photos. Re sunspots - enjoy them while you can. You may not be seeing any for some while after a decade or so from now.

In NZ the transit is on Wednesday June 6th, starting at 10:15am, solar-middle at 1:30pm, and with Venus reaching the far edge of the Sun by 4.25pm and exiting the sun's disk completely by 4.45pm.
Take 12 hours off that for UTC.
Adjust relative to UTC for where you are.
Be pleased if your local time is well ahead or well behind UTC!

UTC:
Start Tue 10:15pm - hard to see if that's your local time as well :-)
Middle Wed 1:30am
End 4:45am.

What do I need to know before attempting to photograph Venus in transit?

1 Answers1