Re: ATM Experience in solar filter for amateurs

[Brian Nestel <blast@aloha.net>]

Jose Amaury Pereira wrote:
> 
> For visual secure solar observations in Refractors, I adapted in my ocular focus
> "sandwiched" welders # 8 filter and LPR Celestron with one # 80A (blue)
> Vernoscope filter. This result is just one excelent view blue solar image
> ideal for sunspots
> observations. Secure, no retina damage, I tested in refractors of the 60mm
> and 80mm aperture. Scheme for adapt in refractors:
> 
>                l - welders filter # 8
>                2 - LPR filter
>                3 - Filter # 80A (blue)
>                4 - Eyepiece
> "sandwiched"  into diagonal prism.
> 
> Clear skies!
>                J. A. Pereira, from Olinda, Pernambuco in Brazil.
Hi Jose:
I'm sure that your filter setup is dark enough to protect you eyes.
the bad thing about having a filter a ocular focus is the heat. you are
concentrating the sun on these filters and they get hot! and the danger
is that a filter will shatter and blind you with concentrated sunlight 
that comes through the broken filter. The best thing is to get a filter
to cover the front of your scope. These are the safest, as you can
usualy
detect damage to the filter before you use it. The other option is 
sun projection on a screen.
Aloha
Brian

_________________________________________________________
|         NESCOMP         |          K.E.A.S.A.         |      
|    Computer Services    |Kauai Educational Association| 
| Box 73, Lawai, HI 96765 |  for Science and Astronomy  |          
| Voice/Fax 808-332-7709  |  Box 161, Waimea, HI 96796  |

    "He who flaps one wing flies in circles"