In the interests of safety certain popular online forums [like CN] do not condone discussing the modification of solar telescopes nor their use. This is a highly specialized area of DIY or ATM [amateur telescope making.]
We live in a world where idiocy is rife. Litigious idiots regularly make the headlines as if their own idiocy was meant to be capitalized. Further countless idiots prove their drooling idiocy every time they go online.
Read the warnings at the top of all the pages dealing with my solar telescope modification.
Don't blame me if you are permanently blinded by your own drooling inadequacy! Even with well over 50 years of amateur telescope making experience behind me I still take every possible precaution because I am so well aware of the very real dangers. Concentrated infrared and ultraviolet can be completely invisible and still blind you instantly and permanently!
My solar telescope has a large, specially designed Baader D_ERF [heat rejection ] filter behind the objective. Many solar telescopes put the filter in front of the objective to reject heat, IR and ultraviolet before they even enter the telescope. Skilled telescope makers have discovered you can cheat to some degree on the size of the filter by placing it securely inside the instrument. The heat falling on the highly reflective filter is pushed back out of the objective.
I have used the original refractor baffles to ensure no unfiltered light can possibly sneak past my multiple, highly professional, high tech, filter defenses against instant blindness.
There follows the vital PST H-alpha etalon. Which narrows the bandwidth of the remaining light passing through the rejection filter.
Then there are two more special solar filters: The PST/Maier ITF and the PST Blocking Filter in series. These remove yet more of the heat and light intensity in the already filtered image.
All of these special solar filters are well proven and made by the top manufacturers of solar telescopes and equipment in the world. There is nothing remotely amateur about their equipment and their filters. Their very high cost ensures very high levels of quality control for user's safety. Anyone who thinks they can mix'n'match these very specialized tools, had better do some serious homework first!
The Coronado/Meade PST [Personal Solar Telescope] currently costs nearly £900 new for a modest 40mm aperture. The Baader D-ERF costs several hundred pounds to several thousand pounds depending on size. Larger solar telescopes cost from nearly £2000 to tens of thousands of pounds. The high price reflects the need for total quality control of very high tech specialized equipment always used in unison by knowledgeable users.
Without these special filters a 6" aperture refractor lens can instantly set fire to wood or similar materials. Not only would the focused beam cause instant blindness, if you were daft enough to look into the telescope. It would probably completely destroy your eyeball, if it didn't boil or explode! IN AN INSTANT!! Consider yourself warned.