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Mercury Transit (solar filter bright)

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#1 patindaytona

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Posted 16 October 2019 - 02:00 PM

Anticipating bringing my xt10i to a nearby 5th grade class to show the transit on Nov.11th. My daughter-in-law teaches basic astronomy to them.

I have a 3" off axis aperture right now and it's still pretty bright. Doesn't blind me, but it's bright. Increasing magnification up to say 5.5mm reduces it somewhat though.

I'll bring a large neutral density filter to fit over the aperture just in case. I don't want them to miss anything...me either.

Big question is will too much of that brightness cause what i think they term "halation" where it swallows up something small that's in silouette. I won't know till I see it. That's why the neutral density just in case.

Anyone else using an off axis Badder film (solar film) with the xt10?



#2 DLuders

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Posted 16 October 2019 - 02:14 PM

You could do Eyepiece Projection onto a piece of cardboard -- that won't be too bright to see.  Eyecrazy.gif



#3 siriusandthepup

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Posted 16 October 2019 - 02:22 PM

I am uncomfortable with your words.

 

I haven't heard you say specifically that you are using a solar filter on the front of your scope and specifically "not a photographic solar filter".

 

A neutral density filter is NOT a solar filter. Exception: a hand held welders glass - not to be used on telescope.

 

 

Doesn't blind me, but it's bright.

A proper solar filter will not cause this situation.

 

Baader solar film is recommended (not photographic) as a proper solar safe viewing filter.

 

When you are allowing others to view solar activity through your telescope we all have a triple distilled responsibility to make sure that the public is safe.

 

The proper filters with double and triple redundant fail safes to ensure that the filters can not be dislodged.

 

Your desire to share astronomy with others is commendable! Be safe!


Edited by siriusandthepup, 16 October 2019 - 02:26 PM.

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#4 patindaytona

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Posted 16 October 2019 - 02:57 PM

I am uncomfortable with your words.

 

I haven't heard you say specifically that you are using a solar filter on the front of your scope and specifically "not a photographic solar filter".

 

A neutral density filter is NOT a solar filter. Exception: a hand held welders glass - not to be used on telescope.

 

A proper solar filter will not cause this situation.

 

Baader solar film is recommended (not photographic) as a proper solar safe viewing filter.

 

When you are allowing others to view solar activity through your telescope we all have a triple distilled responsibility to make sure that the public is safe.

 

The proper filters with double and triple redundant fail safes to ensure that the filters can not be dislodged.

 

Your desire to share astronomy with others is commendable! Be safe!

I AM using a Baader Solar Film. The neutral density filter is an addition if i need it (to cover over the Baader S.Film).  Yes, absolutely, I know about the safety thing. I will definitely be right there every second making sure that filter is secured.


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#5 nicoledoula

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Posted 16 October 2019 - 03:04 PM

I AM using a Baader Solar Film. The neutral density filter is an addition if i need it (to cover over the Baader S.Film).  Yes, absolutely, I know about the safety thing. I will definitely be right there every second making sure that filter is secured.

Duct tape it on there. And try a green filter to see if that helps. 



#6 patindaytona

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Posted 16 October 2019 - 03:37 PM

Duct tape it on there. And try a green filter to see if that helps. 

Yes, i had that in mind also about the duct tape. Going to make every precaution.

I have the Meades, all three eye pieces UWA. I don't really like them too much for daytime viewing of the sun because it really has curvature! You have to get your eye smack in the middle of the eye pieces or you get odd distortion (maybe that is what they call "kidney beaning")..hope i got that correct hha

I'm trying to plan on this...I'm thinking of getting some more solar film to rig up my binoculars. That would be a real nice wide field view of the entire sun. Even my 24mm Explorer Scientific 82 degree makes it look like it's just solid white filling up the eye piece with no actual border around the sun because it's black sky. Unless you move the scope you wouldn't know.

So, maybe binoculars in addition for that.

And I'll just use the 5.5mm Meade UWA for the telescope close ups. I have the 14mm Meade UWA also, but it's not really improving anything much. Just slightly smaller view and it's also causing the distortion thing also besides.

Another thing is that I will use my silver reflective shroud for the telescope to just drape over it while viewing. That metal (xt10) gets unbelievably hot! The telescope end cap normally comes off loosely. When it heats up, i have to pry it off.

Besides that, the black enterior of the telescope must cause drastic temp. changes inside to that primary mirror. Way way hotter than the outside ambient is I'm sure. So, that would help too.


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#7 bunyon

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Posted 16 October 2019 - 05:01 PM

Are you using Baader visual or photographic film? 

 

I once made a filter from the photographic film by mistake and new instantly. It was just as you described. And it is to be avoided.  In my case, I made a visual filter and a photo filter and mislabeled them. Double or triple check that what you have is visual film.



#8 patindaytona

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Posted 16 October 2019 - 07:55 PM

Just checked it again. Says "Astro-Solar Safety Film" (Good for production of visual & photo)

So..what it is is what it is?



#9 siriusandthepup

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Posted 17 October 2019 - 02:22 AM

I think you are good. I checked this link: AstroSolar® Solar Films

 

The site describes the different versions of the Baader solar films.

waytogo.gif

 

It still concerns me that you have such a bright image - that should not be the case. With the solar film alone it should present a very comfortable viewing intensity. All the times that I have viewed the sun with white light solar filters (on many different telescopes/filters) never once have I viewed an image that even gave rise to the thought of "This is awfully bright".


Edited by siriusandthepup, 17 October 2019 - 02:32 AM.

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#10 patindaytona

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Posted 17 October 2019 - 07:38 AM

I think you are good. I checked this link: AstroSolar® Solar Films

 

The site describes the different versions of the Baader solar films.

waytogo.gif

 

It still concerns me that you have such a bright image - that should not be the case. With the solar film alone it should present a very comfortable viewing intensity. All the times that I have viewed the sun with white light solar filters (on many different telescopes/filters) never once have I viewed an image that even gave rise to the thought of "This is awfully bright".

Hard to to explain what is "bright". If I use a higher mag. like a 5.5.mm Meade, then it's not bad. As mag.decreases the brightness pretty good. When their are not features to look at ie.sunspots, then it's hard to tell with no comparison how bright it should be looking. I still have yet to be able to see any granulation. I do know that with the brightness I'm seeing, that i won't due to that.

I used a 77mm neutral density filter over the aperture outside (from my photography) and that helped alot. It's a fairly strong N.D. filter.



#11 bunyon

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Posted 17 October 2019 - 08:01 AM

I think the film is correct, too, so long as they labeled it right (and I've never heard of them shipping the wrong stuff). But, to be sure, find in your paperwork the OD value. It should be 5. If it's 3.8, it's the wrong stuff.

 

Are you certain there is no light leaking through, around, under, between, etc? 

 

It shouldn't be uncomfortable, at all. Are you just surprised at how bright it is and not uncomfortable?



#12 SeaBee1

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Posted 17 October 2019 - 08:39 AM

I'll have to echo the rest of the gang here... when using my white light solar filter with my 4 inch scope, the image could never be considered "bright"... it is a comfortable orange disk floating in a black field (I use a Thousand Oaks film filter). I have never needed any additional filter to tone down the image brightness.

 

I understand that you have double checked everything but when you place a classroom full of 5th graders under your responsibility, extra precautions would seem to be in order. We have a saying where I work... "When in doubt... throw it out!"

 

But that is just me... YMMV

 

CB


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#13 patindaytona

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Posted 17 October 2019 - 10:28 AM

I think the film is correct, too, so long as they labeled it right (and I've never heard of them shipping the wrong stuff). But, to be sure, find in your paperwork the OD value. It should be 5. If it's 3.8, it's the wrong stuff.

 

Are you certain there is no light leaking through, around, under, between, etc? 

 

It shouldn't be uncomfortable, at all. Are you just surprised at how bright it is and not uncomfortable?

Checked...yes, it's the 5

Probably more like surprised at the brightness, that's all. It seems that if I'm supposed to be able to see some granulation (which i don't), then it's too bright to see it. It's a solid white.


Edited by patindaytona, 17 October 2019 - 10:29 AM.


#14 patindaytona

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Posted 17 October 2019 - 10:34 AM

The Baader Film 5 is excellant quality. It's the true "color" of the sun. Their is no doubt. I'm using an off axis aperture also. It's safe.

I will bring the neutral density filter just in case I need it, but really doubt that. I just don't want any chance of loosing Mercury by having white light swamp it. But, i think it will all be ok.

I designed my solar filter based on a instructional tutorial. It painted the outside black.

I think about that now, and wonder. It gets very very hot in the sun.

I'm painting it white now and i will paint the inside black just to be sure no extra light is involved with the optical transmission, since it is ALOT brighter than anything at night.



#15 Mike G.

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Posted 17 October 2019 - 10:39 AM

Granulation has always been elusive for me due to seeing conditions.  I've used solar film or a hershel wedge with Baader SC filter and granulation has only been visible on the best of days with the wedge and SC filter on a 4" refractor.  I've never seen granulation using film on a reflector (4.5" or 8") or the 4" refractor.  so, could just be your local conditions.  that said, sunspots have typically been quite well defined with film or wedge and can take a good deal of magnification when visible.  I plan on taking the day off for the transit and have my H alpha scope and my 6" SCT with Baader film. hoping for no clouds....  the H-alpha always provides a show as long as the sky is clear.



#16 bunyon

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Posted 17 October 2019 - 10:57 AM

If you're only worried because you're not seeing granulation, relax. Granulation is tough (suffice to say I agree completely with Mike G. above). It's also tough to evaluate what you're seeing because of the lack of spots.


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#17 patindaytona

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Posted 17 October 2019 - 11:13 AM

If you're only worried because you're not seeing granulation, relax. Granulation is tough (suffice to say I agree completely with Mike G. above). It's also tough to evaluate what you're seeing because of the lack of spots.

Exactly

Looking at some of your astrophotos. Man, those are nice! I hope someday to get a decent quality setup. Their are so many, but for now, i will just have to try using my 400mm (using the 2x) on my DSLR for some shots of Mercury.


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#18 bunyon

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Posted 17 October 2019 - 12:28 PM

Thanks. I only post the good ones. wink.gif

 

For photos, your concerns about "too bright" are valid. It will be easy to overexpose and you'll lose Mercury for sure at that focal length. I think 400mm will be fine if exposed right. 

 

And, of course, it has to be clear. Good luck!


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#19 Special Ed

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Posted 17 October 2019 - 01:34 PM

Yes, i had that in mind also about the duct tape. Going to make every precaution.

I have the Meades, all three eye pieces UWA. I don't really like them too much for daytime viewing of the sun because it really has curvature! You have to get your eye smack in the middle of the eye pieces or you get odd distortion (maybe that is what they call "kidney beaning")..hope i got that correct hha

I'm trying to plan on this...I'm thinking of getting some more solar film to rig up my binoculars. That would be a real nice wide field view of the entire sun. Even my 24mm Explorer Scientific 82 degree makes it look like it's just solid white filling up the eye piece with no actual border around the sun because it's black sky. Unless you move the scope you wouldn't know.

So, maybe binoculars in addition for that.

And I'll just use the 5.5mm Meade UWA for the telescope close ups. I have the 14mm Meade UWA also, but it's not really improving anything much. Just slightly smaller view and it's also causing the distortion thing also besides.

Another thing is that I will use my silver reflective shroud for the telescope to just drape over it while viewing. That metal (xt10) gets unbelievably hot! The telescope end cap normally comes off loosely. When it heats up, i have to pry it off.

Besides that, the black enterior of the telescope must cause drastic temp. changes inside to that primary mirror. Way way hotter than the outside ambient is I'm sure. So, that would help too.

pat,

 

Your XT10i f/4.7 and 24mm ES eyepiece should give you a view of the entire solar disk.  That ep gives you 50x and a TFOV of 1.6 degrees--the Sun is ~0.5 degrees in apparent diameter.  Are you sure you have the Sun in focus?  It can be hard to do with no sunspots.  Put a limb in the field and focus on that.

 

You might even be getting a reflection and not the Sun itself.  Do you have a solar finder or Baader ASF for your finderscope? (BTW, make sure that finderscope is filtered or capped at all times.)

 

I agree with the others--Baader ASF (5.0) should give you a comfortable and not overly bright view of the (in focus) Sun.  You will be able to see Mercury OK at 50x but it will appear very small.

 

I also agree that granulation can be hard to detect.  Something like this filter used in conjunction with Baader ASF can help.

 

I wouldn't use duct tape on your scope--you'll likely get residue on the tube when you remove it.  Use painter's or gaffer's tape instead.

 

Good luck to you and all of us with the weather.  The next transit after this one isn't until 2032.

 

 http://www.eclipsewi.../oh/tm2019.html



#20 patindaytona

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Posted 17 October 2019 - 05:01 PM

pat,

 

Your XT10i f/4.7 and 24mm ES eyepiece should give you a view of the entire solar disk.  That ep gives you 50x and a TFOV of 1.6 degrees--the Sun is ~0.5 degrees in apparent diameter.  Are you sure you have the Sun in focus?  It can be hard to do with no sunspots.  Put a limb in the field and focus on that.

 

You might even be getting a reflection and not the Sun itself.  Do you have a solar finder or Baader ASF for your finderscope? (BTW, make sure that finderscope is filtered or capped at all times.)

 

I agree with the others--Baader ASF (5.0) should give you a comfortable and not overly bright view of the (in focus) Sun.  You will be able to see Mercury OK at 50x but it will appear very small.

 

I also agree that granulation can be hard to detect.  Something like this filter used in conjunction with Baader ASF can help.

 

I wouldn't use duct tape on your scope--you'll likely get residue on the tube when you remove it.  Use painter's or gaffer's tape instead.

 

Good luck to you and all of us with the weather.  The next transit after this one isn't until 2032.

 

 http://www.eclipsewi.../oh/tm2019.html

Yes, I know I can get the entire sun in with that eye piece.  It's just that when you are looking at it, you really can't tell it IS the entire sun. Because of the blackness around it, it appears like it's just solid white filling up the entire eye piece. I need a bit more space around the sun. I'm thinking of getting another solar film and make two filters to put on my 10x binoculars for that. Should really appear as the sun in the sky.

I'll use the telescope just for the 5.5mm. That way, I have good exchange of distances.

Definitely taking off the finder scopes.

It's a metal tube..the xt10, and I already tried to pry off the telrad because i do not want that on when i go and also it's too close to the end of tube. I need a bit more room there for the solar filter to go further on. Alot of residue yes Half off, just leaving it that way for now.



#21 John Fitzgerald

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Posted 17 October 2019 - 05:09 PM

I only use solar projection through a small aperture.  I don't trust any filters with a telescope, certainly not with other people viewing.  Liability is huge.  People will sue a ham sandwich these days.  No actual harm needs to be done either, only perceived harm.

 

Call me overly cautious, but that's the way I see it for myself.



#22 patindaytona

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Posted 17 October 2019 - 05:46 PM

I only use solar projection through a small aperture.  I don't trust any filters with a telescope, certainly not with other people viewing.  Liability is huge.  People will sue a ham sandwich these days.  No actual harm needs to be done either, only perceived harm.

 

Call me overly cautious, but that's the way I see it for myself.

I totally understand what you're saying. I have a bad feeling when I have my daughter in law ask the school for permission to do this they will turn it down.



#23 Myk Rian

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Posted 19 October 2019 - 02:34 PM

I tape the Baader film to the inside of the cover over the small objective hole. Don't touch it as skin oils will destroy the coatings. It does not have to be perfectly flat and ripple free.

A variable polarizer can be used to cut down on the brightness.

Do you have a solar finder?


Myk

Edited by Myk Rian, 19 October 2019 - 02:36 PM.



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