Solar eclipse observation by projection

Off topic discourse and banter encouraged.
User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 968
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Solar eclipse observation by projection

Postby JohnD » Sun Aug 20, 2017 4:28 pm

I've used projection - a pair of binoculars or telescope directing an image of the Sun onto a white card - to observe a partial solar eclipse and the Transit of Venus (twice). It makes discusison and exposition of the event more social and lively as a whole group can see what's happening, and point out features to all at once. It's also completely safe.

But a total? At totality, can the corona be seen on a projection? Does it need the screen to be under cover to keep out ambient light? The corona is the unique sight of totality - be a pity to miss it.

John

User avatar
geckzilla
Ocular Digitator
Posts: 8573
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: Solar eclipse observation by projection

Postby geckzilla » Sun Aug 20, 2017 4:45 pm

It is my understanding that during totality it is safe to look directly at the corona. In fact it may be one of the most important reasons for traveling to an area of totality, because to witness it with one's own eyes is like something out of a dream. Alas, I'll have to wait for some other time to see for myself.
Just call me "geck" because "zilla" is like a last name.

User avatar
bystander
Apathetic Retiree
Posts: 16094
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

Re: Solar eclipse observation by projection

Postby bystander » Sun Aug 20, 2017 6:56 pm

NASA will have live coverage of the event starting at 9am PT/12 pm ET. It will be covered on NASA TV and CSPAN1. Check your local providers for the channels.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 968
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Re: Solar eclipse observation by projection

Postby JohnD » Sun Aug 20, 2017 9:20 pm

That is not what i asked for.
As I said, projection is 'totally' safe. There is a risk of looking too early or late at the corona. If it were visible by projection, then for instance children could be safe guarded better.

John

User avatar
Chris Peterson
Abominable Snowman
Posts: 13124
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: Solar eclipse observation by projection

Postby Chris Peterson » Sun Aug 20, 2017 9:49 pm

JohnD wrote:That is not what i asked for.
As I said, projection is 'totally' safe. There is a risk of looking too early or late at the corona. If it were visible by projection, then for instance children could be safe guarded better.

Obviously, children should be supervised. But it takes a number of seconds of staring at the Sun to do damage, and it's very apparent when totality begins and ends. Nobody should ever be denied the chance to see it; it's truly one of the greatest things a person can ever see. And it's far to dim to see with anything other than the naked eye.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 968
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Re: Solar eclipse observation by projection

Postby JohnD » Mon Aug 21, 2017 10:16 am

"Far too dim"
Thank you, Chris!
John

User avatar
neufer
Vacationer at Tralfamadore
Posts: 14193
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: Solar eclipse observation by projection

Postby neufer » Mon Aug 21, 2017 12:09 pm

Art Neuendorffer

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 968
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Re: Solar eclipse observation by projection

Postby JohnD » Mon Aug 21, 2017 5:03 pm

JohnD wrote:"Far too dim"
Thank you, Chris!
John



Not you, neufer!
John

User avatar
geckzilla
Ocular Digitator
Posts: 8573
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: Solar eclipse observation by projection

Postby geckzilla » Mon Aug 21, 2017 5:53 pm

I mean, you didn't specify what kind of projection. Art did provide a second answer. I don't see a corona in that cloud cover projection, do you?
Just call me "geck" because "zilla" is like a last name.

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 968
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Re: Solar eclipse observation by projection

Postby JohnD » Mon Aug 21, 2017 6:02 pm

Quote, my OP, "I've used projection - a pair of binoculars or telescope directing an image of the Sun onto a white card - to observe a partial solar eclipse"
idDo you want a diagram, geckzilla?
John

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 968
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Re: Solar eclipse observation by projection

Postby JohnD » Mon Aug 21, 2017 6:02 pm

Quote, my OP, "I've used projection - a pair of binoculars or telescope directing an image of the Sun onto a white card - to observe a partial solar eclipse"
idDo you want a diagram, geckzilla?
John

User avatar
geckzilla
Ocular Digitator
Posts: 8573
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: Solar eclipse observation by projection

Postby geckzilla » Mon Aug 21, 2017 6:08 pm

We have no way of being sure that your question, in the second paragraph
At totality, can the corona be seen on a projection?

has any relationship to your binoculars or telescope, as you didn't specify. For all we know, you could be asking about weather projections. For future reference, yes, I would like a diagram. If you could provide a diagram for each post you make, I'd be grateful.
Just call me "geck" because "zilla" is like a last name.

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 968
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Re: Solar eclipse observation by projection

Postby JohnD » Tue Aug 22, 2017 9:15 am

I 'watched' the eclipse on the NASA live stream from Idaho Falls, saw splendid solar prominences at totality and diamond ring as it broke, but no corona at all! Was the camera aperture not reset for totality?

Today's EPOD reminds me of another property of the projection method. During a partial eclipse, 'dappled shade' through the leaves above, instead of casting shadows of the tree cover, shows up as crescents. Nice pic of this on a clapboard house at: https://english.stackexchange.com/quest ... ugh-leaves

John


Return to “Open Space: Discuss Anything”

Who is online

Users browsing this forum: CommonCrawl [Bot] and 0 guests