Total Eclipse: Fun Fact, Aug 21

[ItemB]

I bought some solar glasses at north Walmart in Bismarck in the vision center. They cost $1.

I am dumb to this but do regular sunglasses work? What does a dollar pair of glass have that a good pair of sunglasses doesnt?

 

[dean nelson]

Level 14 welding glass. You need a filter that you cant see anything through but the sun IN The Middle Of The day. so sunglasses are way way to clear.

 

[Bed Wetter]

I'm thinking park my vehicle facing south, put on polar lenses, view through sunglasses and blue tint at the top of my windshield. What could go wrong?

 

[guywhofishes]

I am dumb to this but do regular sunglasses work? What does a dollar pair of glass have that a good pair of sunglasses doesnt?

you can't imagine how little light shade number 14 filter glass (the recommended sun viewing shade number) lets into your eye:

What do the numbers in welder's glass specifications mean (e.g., #14)?

The shade number (SN for short) is based on the optical density of the glass in the visible region. If the fractional transmission of light through the glass is T, then
OD = -log T
SN = 1 + (7/3) OD

Consider, for example, a filter that blocks 99.9% of the visible. T = 0.001 and hence OD = 3, and SN = 1 + (7/3)*3 = 8. This would thus be typical for a #8 welder's glass.
If you plug SN=14 into the formula above, you can show that the OD is 39/7, or 5.57... A #14 welder's glass transmits about 3 millionths of the light hitting it.
Note that this formula only applies to transmission in the visible; for IR and UV the specifications are a little more complicated, and not given by a nice neat formula like this. In the US the requirements for welders' glasses are given in the ANSI publication listed in the references. In general the tolerances for UV and IR are not quite as strict as those in the visible, which is part of the reason astronomers recommend the darkest shades of welders' glass for solar viewing.

 

[tikkalover]

^^^^^^^HUH?

 

[ItemB]

Interesting and this light blocking ability is able to be produced in $1 pair of glasses made in china sold at Walmart.

 

[martinslanding]

Hurry and get your limited edition once in a life time solar eclipse viewing glasses customized for the liberal masses:

 

[NodakBuckeye]

you can't imagine how little light shade number 14 filter glass (the recommended sun viewing shade number) lets into your eye:

What do the numbers in welder's glass specifications mean (e.g., #14)?

The shade number (SN for short) is based on the optical density of the glass in the visible region. If the fractional transmission of light through the glass is T, then
OD = -log T
SN = 1 + (7/3) OD

Consider, for example, a filter that blocks 99.9% of the visible. T = 0.001 and hence OD = 3, and SN = 1 + (7/3)*3 = 8. This would thus be typical for a #8 welder's glass.
If you plug SN=14 into the formula above, you can show that the OD is 39/7, or 5.57... A #14 welder's glass transmits about 3 millionths of the light hitting it.
Note that this formula only applies to transmission in the visible; for IR and UV the specifications are a little more complicated, and not given by a nice neat formula like this. In the US the requirements for welders' glasses are given in the ANSI publication listed in the references. In general the tolerances for UV and IR are not quite as strict as those in the visible, which is part of the reason astronomers recommend the darkest shades of welders' glass for solar viewing.

You really Neaned it!

 

[guywhofishes]

hee hee hee

 

[WormWiggler]

you can't imagine how little light shade number 14 filter glass (the recommended sun viewing shade number) lets into your eye:

What do the numbers in welder's glass specifications mean (e.g., #14)?

The shade number (SN for short) is based on the optical density of the glass in the visible region. If the fractional transmission of light through the glass is T, then
OD = -log T
SN = 1 + (7/3) OD

Consider, for example, a filter that blocks 99.9% of the visible. T = 0.001 and hence OD = 3, and SN = 1 + (7/3)*3 = 8. This would thus be typical for a #8 welder's glass.
If you plug SN=14 into the formula above, you can show that the OD is 39/7, or 5.57... A #14 welder's glass transmits about 3 millionths of the light hitting it.
Note that this formula only applies to transmission in the visible; for IR and UV the specifications are a little more complicated, and not given by a nice neat formula like this. In the US the requirements for welders' glasses are given in the ANSI publication listed in the references. In general the tolerances for UV and IR are not quite as strict as those in the visible, which is part of the reason astronomers recommend the darkest shades of welders' glass for solar viewing.

so if 14 is good, is 16 better or worse... in other words, dumb this down bitch

 

[guywhofishes]

you can use binocs or spotting scope

first pic is the two circular images of full sun - binocs are angled slightly to put image into shade - but binocs own shade works

2nd pic is tree limbs/leaves directly in sun's path maybe 50yd away - a different focal point than the sun so sun outline is fuzzy

you just adjust focus to get clear outline of sun then just watch the ecclipse - perfect image

in real time you can see leaves rustling etc.

easy way for entire family to watch without dumb glasses etc.



- - - Updated - - -

pinhole camera thingy works too - ha ha

 

[Stan's Dad]

I'll just wear my babe winkelman uv blockers

 

[AR-15]

If you want to see something really cool, load up and head to Idaho Falls, Idaho ,suppose to be clear sky's on Monday, I think we will only see about 75% of it here in ND

 

[Kentucky Windage]

https://m.youtube.com/watch?v=lcOxhH8N3Bo

 

[Brian Renville]

I can't wait for the first freeloader to sue someone/something for damages from looking at the sun.

- - - Updated - - -

Actually how many people will be on public disability for the rest of their lives after this?

 

[bucksnbears]

Just hoping gst takes off his rose colored glasses and stares at for the duration

 

[guywhofishes]

I can't imagine international travelers coming to Hobunk town midwest to watch... and a cloud effs the whole thing up moments before, then drifts away after

that exact thing will happen to lots of people - the odds demand it

geez what a pisser - I couldn't take that risk

 

[dean nelson]

The smart people rent a plane.

 

[Ericb]

Only if your a Hilary supporter.

BS... Hillary supporters don't work.

- - - Updated - - -

The smart people rent a plane.

Did you have filter 14 put in the Windows so you don't have to wear those silly glass?

 

[dean nelson]

Definitely could....make landing more interesting that's for sure!