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Solar filters


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I intend to purchase a solar filter for 127 Mak.  Any recommendations?  I have heard that some give a false orange colour to the disc, and others render a white image.  To be honest I think I may finf an orange disc more easy on the eye!  I have goto but I wouldn't be able to do a 2 star alignment during the daytime, I suppose it's tricky to get the disc in your fov, and how would the mount be able to track if not set up and aligned?

At least I would know there's something to look at on most days, even if only for a short period, it gets hard waiting up for the clouds to clear night after night especially when they never do!

Cheers

Dave

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I would always recommend the Baader AstroSolar film ND5.0 which is safe for visual observing. If you want an orange image you can always add a filter I guess. I always use a Continuum filter so my sun is always bright green! You get used to it 👍

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8 minutes ago, davekelley said:

I may find an orange disc more easy on the eye!

It's not a matter of taste, film solar filters that give an orange image are made of an inferior material (mylar) that makes the image less sharp and contrasty. Only Baader's AstroSolar film retains most of the telesope's sharpness and contrast. Some makers used to offer (maybe they still do) high-grade glass solar filters flat and polished to the same degree as fine telescope objectives but they cost 6 to 8 times as much as a standard-grade glass filter.

I used to own a standard-grade Thousand Oaks glass filter with nickel-chrome plating, it did produce a nice "easy on the eye" orange Sun but some sharpness and contrast were lost. Buying the higher-grade glass filter was out of the question but switching to AstroSolar solved both the price and quality problem. I made three Baader filters for my scopes, the largest being 300mm across, and several more for club members; all make a bright white Sun with very strong contrast and resolution that remains there at high powers.

By the way, 5-inch is the threshold at which planetary, solar and lunar observation becomes really rewarding, I found.

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The Baader film is the best of the solar films. Tired the Seymour black film that shows the sun in yellow. Used it once then tossed it in the bin. Poor compared to the Baader.. If you want a yellow sun just use a yellow eyepiece filter with the film. Does improve contrast a bit although not as much as a continuum filter. BTW even a continuum filter only improves  contrast by a tiny amount.

You can make your own using a sheet of the film or buy a premade one. And don’t forget about a solar finder. 

Hers’s mine on a 127 mak. Bought a £7.00 flight case on Amazon and fitted the filter with it’s shipping foam into the case.

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Edited by johninderby
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18 minutes ago, Ben the Ignorant said:

By the way, 5-inch is the threshold at which planetary, solar and lunar observation becomes really rewarding, I found.

Each to their own of course, and aperture does help with resolution but the type of kit used makes a difference too. A 4" apo and Herschel Wedge can give excellent and rewarding results on the sun.

I'm sure the 127mm with solar film will be a very good, and good value solution though.

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12 hours ago, davekelley said:

I have goto but I wouldn't be able to do a 2 star alignment during the daytime, I suppose it's tricky to get the disc in your fov, and how would the mount be able to track if not set up and aligned?

Several ways to crack this, assuming you have an EQ mount.

Are you imaging or observing? Probably easier if you're observing.

Set up and polar align the night before, then cover until needed.

Or make marks where your tripod was, and replace in that position on the day.

Or setup earlier in the day and adjust the mount Az and Alt to give best tracking on the sun.

Use Solar tracking rate if you have it.

You don't need to do a 2 star align, the sun is that big bright disc in the sky, easy to find with the manual controls. (weather permitting!)

Michael

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To find the sun, if using basic equipment, I find the best way is to use my phone’s compass to get the EQ mount pointing in the correct direction i.e. North. I then use a bit of card held behind the EP end of the scope and adjust the RA and DEC until the image ( shadow) of the scope is at its smallest/ most round.The sun is then in the FoV.

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