Baader Astro Solar - holes into the film

[N3ptune]

Stub

My pinholes, I can't even see them like that. For me the case is settled, I am going to use it again.

 

 

[Dave In Vermont]

That's a rather cavalier approach to your eyesight.

I forage for wild mushrooms, and I teach mycology to others. One rule I enforce is: When in doubt - Throw it out! So okay, a person says, maybe one wrong mushroom got past me. So maybe only one of my 8 dinner-guests will require a liver-transplant....

Replace the filter.

Dave

[cloudsweeper]

The image in the initial post shows a mighty big area of filter.  On the rare occasions when I view the Sun, the filter I use is no more than a few cms diameter.  I like to be ultra-cautious when it comes to my eyesight.

Doug.

[Stu]

3 hours ago, cloudsweeper said:

The image in the initial post shows a mighty big area of filter.  On the rare occasions when I view the Sun, the filter I use is no more than a few cms diameter.  I like to be ultra-cautious when it comes to my eyesight.

Doug.

I think that's perhaps being a little over-cautious Doug, although of course I understand everyone has different views on risk.  The thing to bear in mind is that you will be losing alot of available resolution by cutting the aperture down so much, so you will see less detail than you would using a full aperture filter (seeing conditions permitting of course)

[cloudsweeper]

Yes, @Stu, you're right about the lower resolution of course.  But not being a great fan of solar, it's a price I don't mind paying.  A few sunspots, transit of Mercury - that'll do for me!

Meanwhile, I'm itching to get some nice panoramic views with my new fast frac!

Doug.

[Stu]

41 minutes ago, cloudsweeper said:

Yes, @Stu, you're right about the lower resolution of course.  But not being a great fan of solar, it's a price I don't mind paying.  A few sunspots, transit of Mercury - that'll do for me!

Meanwhile, I'm itching to get some nice panoramic views with my new fast frac!

Doug.

As a big solar fan, you might be missing out, it's the fine detail in the ARs and granulation which make it fascinating to me.

A Herschel Wedge would go well in your frac ??

[cloudsweeper]

@Stu................hmmmm, you might just be stimulating some further interest here.  But tell me please - is there much difference between using a wedge and using a large area (and carefully checked!) solar filter?

I have spare filter, and could without any more expenditure at the moment.  Mrs. Sweeper's asking awkward questions.

Doug.

[Stu]

44 minutes ago, cloudsweeper said:

@Stu................hmmmm, you might just be stimulating some further interest here.  But tell me please - is there much difference between using a wedge and using a large area (and carefully checked!) solar filter?

I have spare filter, and could without any more expenditure at the moment.  Mrs. Sweeper's asking awkward questions.

Doug.

That's good to hear ?

I have no experience of using film on a larger aperture eg 8" or more. I've used it on 4" refractors and a 6" newt. My opinion is that you will get better results i.e. more resolution by using a larger aperture, although the optimum for best cutting through the seeing conditions does seem to be around 120mm, up to 150 on excellent days.

Again, in my opinion, a Herschel Wedge delivers significantly better results than the film, in particular it tends to be able to take higher magnification and show finer detail around the spots and in the granulation.

so

small aperture film < larger aperture film < Herschel Wedge.

I use a wedge in a 4" apo scope with excellent results. I think one would be pretty good in your 120mm although a Continuum filter would eliminate that completely.

I would give the larger aperture filter a go first and see how you go before spending cash. A used wedge can be picked up for not too much over £100

[N3ptune]

Dave

The problem is that the next new filter might be the same has this one or even worst because they all pass the Baader tolerance tests with minor imperfections. This may be a waste of time and money.

People are saying the filter is inexpensive but it costs actually more then pure gold leaf sheet... it's half a day of work. (Now I am not saying I don't want to replace it because of money, I am contesting the fact it's inexpensive 50 canadian $)

===========

I don't know about the required size or optimal size of telescope to watch the sun but I get a nice and clean view of the spots with my instrument it's a pleasure to watch (:

[cloudsweeper]

48 minutes ago, Stu said:

That's good to hear ?

I have no experience of using film on a larger aperture eg 8" or more. I've used it on 4" refractors and a 6" newt. My opinion is that you will get better results i.e. more resolution by using a larger aperture, although the optimum for best cutting through the seeing conditions does seem to be around 120mm, up to 150 on excellent days.

Again, in my opinion, a Herschel Wedge delivers significantly better results than the film, in particular it tends to be able to take higher magnification and show finer detail around the spots and in the granulation.

so

small aperture film < larger aperture film < Herschel Wedge.

I use a wedge in a 4" apo scope with excellent results. I think one would be pretty good in your 120mm although a Continuum filter would eliminate that completely.

I would give the larger aperture filter a go first and see how you go before spending cash. A used wedge can be picked up for not too much over £100

Thanks, Stu - I might try a full 120mm filter, and use it in conjunction with a variable Moon filter.  And I won't do it for very long, especially at low mags!

Doug.

[Stub Mandrel]

You could look at the pictures @xtreemchaos has been posting he is getting much more detailed pictures with a wedge and a new camera than he was before.

[Stu]

1 hour ago, cloudsweeper said:

Thanks, Stu - I might try a full 120mm filter, and use it in conjunction with a variable Moon filter.  And I won't do it for very long, especially at low mags!

Doug.

Yep, give it a go and see how you get on.

The beauty of a wedge, other than the improved quality of view, is that it's fundamentally safer. If it shatters or falls out, the worst that can happen is either a very poor view or you get slightly hot nether regions! You don't risk your sight.

[xtreemchaos]

yer go for a solar wedge, you wouldnt regret it, and it works out cheaper in the long run. charl.

[cloudsweeper]

22 hours ago, Stu said:

Yep, give it a go and see how you get on.

The beauty of a wedge, other than the improved quality of view, is that it's fundamentally safer. If it shatters or falls out, the worst that can happen is either a very poor view or you get slightly hot nether regions! You don't risk your sight.

OK then - I used the last of my film and made a 90mm dia. filter (for the ST120) in order to have another look at our very own star.

On checking against a strong light, I spotted a largish "pinhole", and dealt with it with a spot of paint.

Finally pinned him down half an hour ago, and used mags between x20 (for location) and x100.  With or without a Moon filter, I could only see a silver disc, plus a few sunspots - no further detail, granulation, etc..  Maybe I should have used the variable Moon filter to get the glare right down?

I stopped after a few minutes, since after my first solar viewing - which lasted a long time - I had slightly blurred vision for a few hours!  (This explains my great caution over solar.)

Well, now I'm saving for a wedge.

Doug.

[Stub Mandrel]

1 hour ago, cloudsweeper said:

 stopped after a few minutes, since after my first solar viewing - which lasted a long time - I had slightly blurred vision for a few hours!  (This explains my great caution over solar.)

Blurred vision MIGHT be caused by the focus being off a bit so your eyes were straining to compensate. It's quite hard to focus on the sun.

[N3ptune]

Cloudsweeper, is your vision restored to normal now?  If so, the blur remained visible for how long?

--> Just for information because I was dazzled while looking at the full moon for almost 30 minutes with no moon filter. The blurry vision spot I had in 1 eye took 1 month to go away. 

[cloudsweeper]

25 minutes ago, N3ptune said:

Cloudsweeper, is your vision restored to normal now?  If so, the blur remained visible for how long?

--> Just for information because I was dazzled while looking at the full moon for almost 30 minutes with no moon filter. The blurry vision spot I had in 1 eye took 1 month to go away. 

I was viewing for quite a while, and the blurred vision then persisted for a few hours.  A bright unfiltered Moon at low mag for a long period could no doubt hurt your eyes as well.   It is certainly well worth exercising caution in these matters.

I was considering a wedge, but £279 (the 2" is recommended for my aperture) is far too steep for the usage I'd get out of it!

Doug.

[Stu]

5 minutes ago, cloudsweeper said:

I was viewing for quite a while, and the blurred vision then persisted for a few hours.  A bright unfiltered Moon at low mag for a long period could no doubt hurt your eyes as well.   It is certainly well worth exercising caution in these matters.

I was considering a wedge, but £279 (the 2" is recommended for my aperture) is far too steep for the usage I'd get out of it!

Doug.

A 1.25" Wedge will be fine in your scope Doug, no need for 2"

[N3ptune]

What about the telescope itself when using a wedge to watch the sun?

Could it be bad for the instrument  to point the sun directly without any filters? (especially for something like a catadiopedic telescope which has sensible mirrors) It's going to get really hot inside after a few minutes, I don't like the idea very much.

 

[DRT]

7 minutes ago, N3ptune said:

What about the telescope itself when using a wedge to watch the sun?

Could it be bad for the instrument  to point the sun directly without any filters? (especially for something like a catadiopedic telescope which has sensible mirrors) It's going to get really hot inside after a few minutes, I don't like the idea very much.

 

I wouldn't point anything other than a refractor at the sun without a filter in front of it. A catadiopedic would create enormous internal heat and a Newtonian is too "open" to be safe for the people around it. That said, I have used an 11" SCT and an 8" Dob with appropriate front-end filters. 

Herschel Wedges are designed for single lens cell refractors (I.e. Not Pertzval or similar which have a second lens cell) and nothing else. 

[Stu]

53 minutes ago, N3ptune said:

What about the telescope itself when using a wedge to watch the sun?

Could it be bad for the instrument  to point the sun directly without any filters? (especially for something like a catadiopedic telescope which has sensible mirrors) It's going to get really hot inside after a few minutes, I don't like the idea very much.

 

As Derek says, a Herschel wedge is only to be used in refractors, not SCTs, Maks, other compound scopes or Newts. The is is largely due to the heat stress created at the secondary mirror which is close to the focal point and is likely to be damaged or even shatter.

Achro or Apo scopes can be used, provided they are air spaced, not oil spaced. Petzvals are also to be avoided, or anything with a reducing/flattening element at the rear of the scope.

The objective of a refractor won't get any warmer than a window in the sunshine so won't be damaged in any way. Rumour has it that a healthy does of UV helps keep fungus at bay so could even be useful in that way.

[DRT]

33 minutes ago, Stu said:

The objective of a refractor won't get any warmer than a window in the sunshine so won't be damaged in any way. Rumour has it that a healthy does of UV helps keep fungus at bay so could even be useful in that way.

I think that's true, Stu. I never use sun cream and have never suffered from fungus

[101nut]

I have been quiet in this thread but thought I should point out what appears to be less-than-obvious.

The main problem with viewing the sun is not exactly "how bright it is" - natural aversion response should take care of that - but the invisible uv and infra-red which actually do the damage.

Clearly I am happy for anyone to do what they feel is correct and take whatever risks they feel reasonable (or economic). However can any poster recommending a permanent marker to others as a fix for a solar filter post an em spectrum absorbance plot of a.n.other permanent markers? Materials that block visible light may be transparent in the infra-red or ultra violet and without that plot observers will have no idea whether they are wasting their time and risking their sight.

Until someone publishes such data, if a filter is no longer within specification, I'd recommend taking safer options than "a black marker".

AndyG

[DRT]

I completely agree, Andy. The very idea of a DIY "fix" to a solar filter horrifies me.

This costs £18.50 and can be used to make a number of very useful and safe white light filters. That's about the price of four pints of beer down at your local pub or a Chinese takeaway for two. How that can be described as expensive by anyone who buys astronomy gear is beyond me. Anyone thinking of a DIY solution to save a few quid should ask themselves how much their eyes are worth to them (and their families).

If in doubt, throw it out

[N3ptune]

The money is not the issue for me here, for sure, I value my eyes more then the price of the filter. The other issue is that the astrosolar comes with pinholes from factory. Baader say it will come with some pinholes and this will cause absolutly no damages to the eyes, they are made like that. I guess they thought about the dangerous UV during the conception.

If I get another baader filter ( for a price higher then pure gold leaf sheets.), I might get the exact same thing or even worse. it's like going outside and trowing 50 bucks in the air.

The solutions seems to be in this order now:

--> Buying a smaller telescope to watch the sun, like a refractor to use a smaller filter, a glass one or a wedge.

--> Finding something else then a AstroSolar Sheet for my actual 203 mm telescope.

--> Continue to use my actual astrosolar sheet on my actual telescope.

--> Continue to use my actual astrosolar sheet on my actual telescope + adding the use of a UV/IR 1.25 filter to my eyepiece to cut the UV's that can come from the pinholes. (Extra layer of safety)