Thinking about trying to capture sunspots during sunrise and sunsets? Well a dark filter is definately needed.
Days when the atmosphere is so 'dirty' it acts as your filter are rare, so you should have one for all the other days.
An (Nuetral Density) ND400 can be used (2004 USD price $55.00 to $65.00) and images will maintain the natural red/orange colors.
Welders (tempered glass) filter plate is an alternative allowing filtering at various intensity levels but images will be green.
I know of two sizes available as: (1.) a 4 inch square plate and (2.) a 2" x 4 1/4 " plate and have seen them available in
shades numbered #8 thru #12. Other shades may be available. Get the 2" x 4 1/4" size plate.
I chose a #12 that is darker than the ND400. In my area these sizes can be bought for between $2.50 and $4.00 (2004 pricing).
The problem is how to mount the glass to your lens. It would be nice to have some cut to fit into filter rings but being
'tempered' glass, it can't be done. Research found that cutting "tempered" glass is currently impossible; it will shatter.
It must be cut 'before' tempering. Some US university received a grant (2004) to research a possible process to cut it.
If you already have a Raynox Universal Adapter #3500 your half-way to the solution. If not, get one seperate, or as part of
a Raynox Macro Explorer Lens Set. The macro set will cost about $60 but you will get dual purpose use of the adapter.
This adapter clips into any 52mm to 67mm filter or step-ring inner diameter.
The glass is simply held in place with a few short pieces of handy-mans duck tape or a couple of elastics.
In the Next, just one foto is used to show how both are used; both together are NOT neccessary.
Hope this tip leads to some new foto opportunities for you.