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#1 catheleen


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Posted 04 November 2013 - 06:13 PM

Hi, I have an old Helios D:120 and would like to have a go at white imaging of our nearest star.
I would be grateful for any advice on filters to make this satisfying.
I could do with advice on the most suitable eye piece and filters. I have been reading about it but can't quite understand whether I need a front end foil filter, continuum, UV/IR cutter and herschel or whether on my budget I might as well just go buy a welding mask and a pair of binoculars?

#2 sullij1


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Posted 04 November 2013 - 09:19 PM

Hello Catheleen,

Sorry it took so long for somebody to answer you.

"For imaging only" use the Baader 3.8 density solar film.

For visual only buy the Baader 5.0 density solar film.

It is important to keep track of which is which. Your eyes count on it so mark the rings. I am linking you to a Canadian site that explains how to measure and gives a choice of ring type or their version. I recommend the safety ring type. You will see the difference on the Canadian website. Once you know the size, you will be able to find the same product in the UK, no problem.


For photography just the film will do. Some people like to add red or green filters to the camera end to help bring out contrast.

This is the cheapest entry level route.

With the 5.0 density for visual use just the film will do. Some folks add a yellow or green filter to the eyepiece to help with visual contrast.

The eyepiece can be any one you choose. Usually 20mm down to 10mm depending on what you are trying to see.

If your budget allows you can forget the film and buy a wedge that come with various neutral density filters so you can find a view that is comfortable to the eye and useful for photography. This is an expensive option though.

I recommend starting with the film to get your feet wet and decide if its something you want to pursue.


#3 catheleen


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Posted 05 November 2013 - 11:32 AM

Many thanks Sullij1, sounds like very practical advice.

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