PST version and ERF insurance

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
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PST version and ERF insurance

Post by AndiesHandyHandies » Mon Apr 30, 2018 9:15 pm


I have a PST Serial no 97166.

It has a rusty? golden objective.

It seems to work OK. Can see prominences and some small spots one day recently.

I bought a 2" BeloptiK UV-IR blocked KG3 to put on the front as eye insurance, and etalon and filter protection.
The dark spots seems to be a bit more contrasty.

I have a Baader 1.25" 35nm H-alpha which was used to compare with Omega Bobs similar blocker and they seem to work identically. Bobs does have a higher on band transmission. If I added this before the Etalon in the gold tube would I have adequate ERF protection for my eyes and to preserve the etalon and BF from heat exposure and degradation?

Is there any need to take the eyepiece section apart to see if it is a later model with an ITF at the base, before the 5mm BF? Other than for a bino-viewer mod?

Cheers. Andrew.

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Re: PST version and ERF insurance

Post by Merlin66 » Mon Apr 30, 2018 11:32 pm

The original “gold “ objective PST was not fitted with an ITF. There’s no need to add further filters - using an UV-IR upfront is more than enough.
Even with the failure of the original ERF coating, the PST is still safe to use.

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