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Eclipse (1 Viewer)
- Thread starter Foss
- Start date
jan van daalen
Well-known member
Don't do that
just get some solar filtersSo long as the solar filters have the necessary EU or US standards marked on them.
Filters have a shelf life of 5 years for the ones used as glasses.
They should be checked for pinholes, and if there are any pinholes the filter should be permanently discarded.
There are unfortunately fake filters.
I would not trust Chinese sourced filters.
If using a welders glass shade 14 or tilted large size 13 these must have permanent markings and certification.
In high very sunny locations welders shade 15 are probably needed but may be difficult to find.
Even shade 14 is difficult to source in the U.K.
The welders glass shades are the 7th root of 1,000. 2.68x per shade.
Projection is the safest method.
Lately, results from US eclipses have been good regarding eye safety, but in the early 1900s large numbers of Europeans suffered permanent eye damage.
There was also a crazy eye doctor who recommended looking at the sun.
His idiocy was widely followed.
There are charlatans everywhere.
Sir Roger Moore was also told to stare at the sun to avoid squinting in movies.
He always wore large glasses after that and had poor vision.
This applied to other actors also.
My astronomer friend, when eleven, made a filter from the lenses of 4 sunglasses, 8 filters.
He put these in front of a one inch aperture telescope. and looked at the Sun.
He was instantly blinded and only had one good eye for the rest of his life.
But he was a brilliant lunar artist using his good eye.
He unfortunately died young from heart problems.
In Vietnam, soldiers looked at the sun for thirty seconds in order to get sent home.
It was obvious to doctors as only the shooting eye was affected.
But these men decided it was better than getting shot.
After decades of solar observing, and taking very careful precautions I have given up solar observing.
When young I was given a large welders glass and used that sometimes.
Unfortunately it had no markings or certification.
I found later that it was shade 8 or 9 and totally unfit for solar viewing.
Whether that has caused some of my age related eye problems, I don't know.
Newton had poor eye sight because of solar viewing.
If using solar filters they should be used for short periods, and not constant viewing.
I think instructions are now given with these certified filters.
I spent years getting a solar filter seller in the U.K. to stop selling his plastic solar filters advertised and sold in U.K. top astro magazines.
A top university tested them and they transmitted 27% in the infrared.
The £1,000 test was done for free.
It took a barrister's letter to stop him.
Yet he surfaced later under a different name selling these orange plastic circular filters screwed into photo filter holders of different sizes.
Unfortunately, as I said above, there are charlatans and snake oil sellers all over the place.
If you want reading, see Hazards of Light, Pergamon press. c.1986.
Regards,
B.
Filters have a shelf life of 5 years for the ones used as glasses.
They should be checked for pinholes, and if there are any pinholes the filter should be permanently discarded.
There are unfortunately fake filters.
I would not trust Chinese sourced filters.
If using a welders glass shade 14 or tilted large size 13 these must have permanent markings and certification.
In high very sunny locations welders shade 15 are probably needed but may be difficult to find.
Even shade 14 is difficult to source in the U.K.
The welders glass shades are the 7th root of 1,000. 2.68x per shade.
Projection is the safest method.
Lately, results from US eclipses have been good regarding eye safety, but in the early 1900s large numbers of Europeans suffered permanent eye damage.
There was also a crazy eye doctor who recommended looking at the sun.
His idiocy was widely followed.
There are charlatans everywhere.
Sir Roger Moore was also told to stare at the sun to avoid squinting in movies.
He always wore large glasses after that and had poor vision.
This applied to other actors also.
My astronomer friend, when eleven, made a filter from the lenses of 4 sunglasses, 8 filters.
He put these in front of a one inch aperture telescope. and looked at the Sun.
He was instantly blinded and only had one good eye for the rest of his life.
But he was a brilliant lunar artist using his good eye.
He unfortunately died young from heart problems.
In Vietnam, soldiers looked at the sun for thirty seconds in order to get sent home.
It was obvious to doctors as only the shooting eye was affected.
But these men decided it was better than getting shot.
After decades of solar observing, and taking very careful precautions I have given up solar observing.
When young I was given a large welders glass and used that sometimes.
Unfortunately it had no markings or certification.
I found later that it was shade 8 or 9 and totally unfit for solar viewing.
Whether that has caused some of my age related eye problems, I don't know.
Newton had poor eye sight because of solar viewing.
If using solar filters they should be used for short periods, and not constant viewing.
I think instructions are now given with these certified filters.
I spent years getting a solar filter seller in the U.K. to stop selling his plastic solar filters advertised and sold in U.K. top astro magazines.
A top university tested them and they transmitted 27% in the infrared.
The £1,000 test was done for free.
It took a barrister's letter to stop him.
Yet he surfaced later under a different name selling these orange plastic circular filters screwed into photo filter holders of different sizes.
Unfortunately, as I said above, there are charlatans and snake oil sellers all over the place.
If you want reading, see Hazards of Light, Pergamon press. c.1986.
Regards,
B.
Last edited:
