Author Topic: Advice on making a solar filter for the Mercury transit  (Read 2849 times)

iam4208

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Advice on making a solar filter for the Mercury transit
« on: May 07, 2016, 11:35:16 PM »
Hoping to see the Mercury transit on Monday and I thought that I could use my 6" Newtonian, which has solar film fitted to a circular cutout on the cover.
It's only a couple of inches in diameter and I read on the British Astro Society website that a 60mm diameter filter would be big enough.
I have a piece of solar film and could make a slightly bigger one, but not full aperture.
Should I make a bigger one or should I just project through an eyepiece onto card?
Would the transit be visible using the same method with my 10 x 50 binoculars?
Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

Lorne

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Re: Advice on making a solar filter for the Mercury transit
« Reply #1 on: May 07, 2016, 11:42:14 PM »
Iain,
The filter on the cut out will be big enough, you wont need much aperture to see it with reasonable magnification. The binos might be a different story mind you, I made 2 X filters for my binos for the last partial eclipse to good effect but Mercury will be a tiny target crossing the surface - may not show up at 10X.

Andy

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Re: Advice on making a solar filter for the Mercury transit
« Reply #2 on: May 08, 2016, 02:00:04 PM »
Hey Ian. I made a full aperture filter for my 6" newt when I had it and it was great. I've rigged up a wee one for my 80mm frac for tomorrow though and I will be just covering the wee cutout as well. I think that will be plenty as I will be using about 50x mag
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iam4208

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Re: Advice on making a solar filter for the Mercury transit
« Reply #3 on: May 08, 2016, 04:06:06 PM »
Well, I was hoping to practice today, but the weather isn't playing ball. Thanks for the advice:-)


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

iam4208

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Re: Advice on making a solar filter for the Mercury transit
« Reply #4 on: May 08, 2016, 04:16:18 PM »
Just managed to see the sun with the little newt. It works - just. I think a bigger filter would just make it easier to find the sun, so I may do that. At least I can look forward to it now.


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

stev74

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Re: Advice on making a solar filter for the Mercury transit
« Reply #5 on: May 08, 2016, 05:47:04 PM »
I think the minimum mag you need for the transit is x50 so binos would struggle. Although there is a nice sunspot on the surface just now that would be visible possibly.  :)

The best way to zero in for the Sun is to look at the shadow of your scope on the ground. Get the shadow of the scope looking like a circle and you shouldn't be too far away. You may want to use your spare solar film for your finderscope Iain  if you don't make a new filter for the front that is.  :)
Steve
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iam4208

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Re: Advice on making a solar filter for the Mercury transit
« Reply #6 on: May 08, 2016, 07:47:38 PM »
Yes, I saw the sunspot today with the 25mm EP. Hopefully, Mercury is a similar size or it could be quite underwhelming. I've managed a bit of alignment practice today, so I think I'll be fine. Oh, and I did use the shadow method, which is given on the BAA website. Good luck everyone[emoji41]


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

iam4208

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Re: Advice on making a solar filter for the Mercury transit
« Reply #7 on: May 09, 2016, 01:04:33 PM »
Got great views of first and second contact today in the car park at work.  It was quite exciting when it started to appear, but once it was on I started to get bored.
Still, it's the first time I've ever seen Mercury.
Came back to my desk to watch the live streams, but they aren't as good as seeing it through your own telescope.
Looking forward to watching the end tonight from the back garden (light pollution won't be a problem for a change). ;D
Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

Killie

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Re: Advice on making a solar filter for the Mercury transit
« Reply #8 on: May 09, 2016, 01:38:49 PM »
I was so excited seeing it through my 80ed this afternoon.


It looked so clear
David
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iam4208

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Re: Advice on making a solar filter for the Mercury transit
« Reply #9 on: May 09, 2016, 08:58:11 PM »
It was a lot clearer at the start than it was the end. Glad I saw it.


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)