The dangerous sun

A cautionary tale.

I was observing the sun at lunchtime today, I observe with a 100mm refractor and a home made mylar filter. When I had finished I removed the filters from the objective and the finderscope. Putting them to one side I proceeded to put on the caps on both objectives and on the diagonal. Having covered the finder I placed the small cap on the diagonal, I then got distracted and moved into the house for a moment. When I came back out the cap over the diagonal was smouldering, literally a column of smoke. I quickly moved the scope out of the suns path and then I realised that I had neglected to attatch the objective cap. I quickly removed what was left of the cap and to my horror plastic had melted onto the diagonal mirror rendering it useless.

Thankfully I had another diagonal that I had purchased only recently to replace the old one.

A clear demonstration of the power of the sun, I am normally so careful, and check the filters with the naked eye before attatching them. My children are often in the garden when I'm orbserving and I'm carefult o move the scope from the sun when I'm finished. This time a simple distraction could have been disastrous.

Enjoy the sun, but never take it for granted, treat it with the respect that it deserves and always be on your guard.

I've learned my lesson and I hope others can learn from this too.

Paul

You think that's bad? I had set up my 20" f/4 outside during the day to muck about with collimating the top cage. It being overcast I thought it would be safe enough. While I was working, the sun crept out from bwehind the clouds and partially illuminated the mirror which was pointing away from the sun. I made the mistake of walking past the scope on the opposite side from the sun and got the hair on the side of my head singed from the tangental focus coming through the side of the open truss! Scared the life out of me! Just for kicks, after I dismantled the scope, I propped up the mirror against a wall facing the sun and waved a rolled up newspaper in front of the cofus. It erupted into flame immediately!

Way cool, but a strong reminder of just how dangerous optics can be during daylight hours.

Phil.

I'm sorry Phil, but I had to laugh when I read your piece, even though it is a serious topic, it's unfortunate that we only learn by such drastic examples.

I'm sorry Phil, but I had to laugh when I read your piece, even though it is a serious topic, it's unfortunate that we only learn by such drastic examples.

Did the same here! You can't do much except laugh! Good cautionary tales all the same guys.

Seanie.

Here is another (almost) horror story.....

The day of the Ecplise in March this year I brought a pair of binos
to work and set them up to see the event by projection onto a card.

I also had a few pairs of ecplise glasses from the ecplise in '99
and brought them in to give some of my co-workers a chance
to see it by direct viewing also.

So during coffee break around 11, I set up and and showed anyone
who cared the event.
Making sure to point out the reason for the projection method
was because of the dangers of looking at the sun through binos etc.

While some were delighted to see
'the moon take a bite out of the sun',
one or two were flat-out un-impressed.
I left the canteen with my binos and glasses and asked
(lets call him Mr.X, one of the facinated ones)
to drop back the other pair to my desk when he was finished his break.

Roll on to 2 pm.
I return from lunch and to my horror see the pair of glasses
with 2 very obvious scorch marks on the lenses. Big on the
front but tiny pin points on the reverse!

I immediatly went with them to Mr X's desk to see what had happend.
He was very embarresed he had 'ruined my ecplise glasses' by
borrowing my binoculars from my drawer and trying to look at the sun through them with the glasses on!

He told me,
''I reckoned there was somthing odd alright
when I could smell something burning''

I dont have to tell you the conversation that followed but
as you can imagine the air turned a little blue for a while.

I reckon from looking at the damage on the glasses he was
about a tenth of a second away from permanent blindness.
Lucky sod.

It tought me a lesson, you can
A., never underestmate some people's stupidity,
B., Never understate the dangers of solar viewing.

I guess he learned a lesson too......
don't go snooping in other people's desks at lunchtime!

Yup, it's easy to make that mistake.

I've a a half melted Meade finderscope from where I went inside while clouded over and the cap fell off. Mustn't have put it on right. :oops: