Solar Filters

[pmrid (Peter)]

In tidying up my cupboards of astro bits and pieces (most of which has not seen the light for ages), I found a Thousand Oaks Solar filter Type 2+. I've never used it either visually or imaging and have no other experience with solar imaging so I am going to ask for a bit of guidance.

It is a 4" (115mm ID) glass filter and ought to fit my BD80 well enough. But I am unsure whether I should also be thinking about using a Ha filter as well. This means using a good imaging camera - probably my SBIG STF8300M and I rather not cook it's innards if I can avoid it.

I could also just use an old Canon 40D I have here which would not be quite the same sort of loss if I damaged it. And a remaining question would be about the use of barlows. Is the TO filter going to adequately (safely) reduce the heat from the sun to make this feasible?

Peter

[astro744]

Thousand Oaks no longer have the Type 2+ listed on their web site. I suggest you email them to make sure it is still suitable.

See http://thousandoaksoptical.com/faqs/

(email address at bottom of page)

Explore Scientific have the Tyoe 2+ listed (may be an old image).

See https://explorescientificusa.com/pro...for-telescopes

I have a Type 2 from the late 1980s and it has a few pits which can be masked but I no longer use it. The life is typically 15 years but can last longer if properly looked after. I believe there were both visual and photo models. The visual model could also be used for photo but the photo model could not be used for visual as it was unsafe for this purposes it let in more light for shorter exposures.

These filters were made of glass with a nickel chromium allow coating. They produce an orange-yellow Sun image and are known as white light filters. Adding a visual Ha filter will not make them safer. Safe Ha observing is done with a completely different method.

I suggest you contact Thousand Oaks directly for advice.