I can't find the sun!!! I no I'm daft lol

[KerryAnn23]

Ok so with observing the night sky out for me at the moment due to how late it needs to be I decided to buy a solar filter for my 8' truss dob..... Problem is I just can't find the darn sun with it and it's really making me question weather my love of the universe is enough to actually get me learning the tools I need at night and now even during the day to see the sun. Iv all but given up in all honesty now. I have a solar finder but need to figure where on the scope to fix it plus how to align it without blinding myself with the sun (if I actually managed to find it lol). Guess I need an idiots guide or something :-(

[Stu]

The simplest way to find the sun with a scope is to look at its shadow. When pointing directly at the sun, the shadow of the OTA will be at its smallest, and round. This is easier on a mounted refractor than a dob but the same principle should apply.

With the sol finder, I would work backwards ie find the sun with the scope (as above), then align the sol finder once the sun is centred in the eyepiece. That's how I do it anyway :-)

Stu

[Robny]

The simplest way to find the sun with a scope is to look at its shadow. When pointing directly at the sun, the shadow of the OTA will be at its smallest, and round. This is easier on a mounted refractor than a dob but the same principle should apply.

With the sol finder, I would work backwards ie find the sun with the scope (as above), then align the sol finder once the sun is centred in the eyepiece. That's how I do it anyway :-)

Stu

I use same method and works very well, especially the shadow method. In addition make sure to use a wide eye piece initially to give you the best shot of getting itin the FOV, then you can narrow down.

Don't give up, it will be worth the effort

Sent from my GT-I9505 using Tapatalk

[Fozzie]

I used to struggle, some days it was easy.. others seriously frustrating! In the end I bought a solar filter sheet and modded a spare finder to a small easy to use solar scope... works every time now... and you'd have plenty left over for making a smaller filter if you ever buy a frac or something..

Good luck and clear sky's.

[itmo]

first minimize the size of the shadow, then look into the focuser hole without eyepiece (assuming you are using baader film or some such front mounted filter) and turn the tube until the sun is centered, then put a wide eyepiece in, center, then increase magnification. 

[ronin]

First thought is I would be a little careful of a truss newtonian and the sun, there just seems the oppurtunity for light to get past the filter to the mirror and then to your eye unfiltered.

Concerning the general usage I am afraid a dobsonian mounted scope is not the easiest to get going with. I have seen them referred to as a specialist scope. I guess you really need some time to get familiar with them and learn their vagrancies and from older posts 2 or 3 months of reasonable usage seems about "normal".

[KerryAnn23]

I do have some of the film and did think of the idea of making a little filter for the main finder but wasn't 100% if it would work. I have tried the shadow method before with no luck but I think it's just me. I was also thinking about getting a shroud for the truss, would this help do you think? My lowest power eyepiece is a 40mm so I guess it's just attempting it again and seeing what happens, but wud really love to find the sun and use the filter that is nearing a year old and cost a fortune to buy. I think I make things more difficult in my head tbh, but you guys always seem to make it sound so easy which is why I feel so stupid lol

[Cornelius Varley]

I have to agree with Ronin, truss dobs are not ideal for solar viewing. Unfiltered sunlight could hit the primary mirror and reflect back up to the eyepiece. There was a thread some time ago showing what happened to the underside of the eyepiece, lucky no one was looking through the eyepiece at the time. The shroud would have to be totally lightproof to ensure safety.

[Stu]

Best to be careful using a truss, quite easy for a reflection to burn part of the scope or worse.

I'm sure you could make a shroud if your sewing skills are up to it :-)

Would it be easier looking at the shadow of the finder? Make sure it is capped obviously but it may be easier to see when this is round/minimized than the main OTA?

[ronin]

Everyone will make it sound easy, especially if it is not.

The thing about a dobsonian is all you can do is push/pull/nudge/kick it to something.

In some respects the "easy" bit is the simplicity of moving it, that is however not the same as saying that getting a target in view is simple.

I cannot understand the problems people have with goto's.

You need a few bits of data, follow the setup and off you go.

Never yet have I had a real problem, equally I am happy enough to reset everything and start from the bottom up.

At a local club the others there send people with goto problems to talk to me to sort them out. Perhaps I have just worked in software systems for too long to be bothered by them.

More then once on SGL a person will say they entered the data, then asked the scope to goto X.

When asked "did you do the alignment?" the reply has been "What alignment?"

Usually the answer is Page 20-23 of your manual.

A 40mm eyepiece is a good start, I have one for the same reason, but an utterly different scope.

If you have one then pair the 40mm with a 25mm and simply start with the 40mm to work out what is where, then get a bit closer in with the 25mm. Forget anything less, basically play with the more forgiving ones for a while.

If that fails then the only path left is the decent into goto's. :eek: :eek:

Looks like Bertha has started to make her presence apparent down here.

[Stu]

Quite possible with a dob, I think Shane uses his 6" f11 on the sun.

I only ever use manual Alt Az mounts when solar observing (with fracs), the same principle applies though, minimize the shadow and the gentle circle around that area until you find the sun. The other option is some kind of sol finder, home made perhaps, or as was suggested, cover your finder with a piece of Baader film and away you go.

Stu

[NGC 1502]

Bit of "thread drift" here but - the question of go-to versus manual is not clear cut.

I've seen technology competent people really struggle big time with go-to, and equally others find it a breeze.

I've seen others struggling with manual scopes, and equally others find it a breeze.

It's a case of finding what suits the individual.  I love basic manual equipment, but I'd never try to "sell" the idea to others 

Regards, Ed.

[Moonshane]

I do use the shadow method and it works for me. You can use the shadow method to get close and then look with no eyepiece in the focuser down the drawtube and you will probably see the haze of the sun. Centre until the secondary is Michael Barrymored (all white) and put in your low power eyepiece and voila!

On a serious note I agree about a shroud first. It is ok to use a truss when the sun is on axis but when it drifts out of view can be seriously dangerous. A cut camping mat would be ok.

[Earl]

I struggled with my first try on my 250px getting the smallest shadow got me pretty close then just a case of tweaking, marking a refernace point on your focuser for your focus posistion once you get it is worth doing also.

[Fozzie]

Agreed with the need for a shroud, it's amazing that even the smallest bit of light seepage can have consequences... i used a astro zap filter for a 80mm frac whilst on holiday, however it must have been splashed by pool water at some point.. I noticed when I got home the smallest section of "rust" on the filter.. A few mm across.. tried cleaning it but the contrast and amount off light getting through means the filter is pointless... Can't see any details and the image is too bright and washed out...

Don't want to think about the damage off axis light on a truss might cause... A good shroud, good for day and night I believe!

[ollypenrice]

Do be careful with large aperture and the sun. Keep it shrouded, as stated. Cap your finder.

A Dob's convenience or otherwise, for solar viewing, is very dependent  upon both your latitude and the season. The further you are from the equator the lower it gets and a low winter sun is least convenient of all.

Worse, the best solar seeing is often early in the morning before the land has heated up again. Clearly this means the sun is low and not easily Dobbable - to coin a term!

Olly

[KerryAnn23]

Ok so I guess I make a shroud first and try the shadow method again. My scope is goto but didn't think about using that to find the sun as I didn't think I could align it with anything because of it being day time. If that doesn't work I will make a little filter for my finder I guess and hope to god that works instead. If I focus the scope on something in the distance before I search for the sun that should help a little too right? Arghhhh seriously feel useless not having anyone local to talk me thru it. I'm a visual learner more so than reading something and being able to do it. :-(

[nightfisher]

Kerry, the baader solar filter is really easy to make for a 9x50 finder, a simple card ring with some film double sided tape

[KerryAnn23]

Yeah I remember from making the filter for the other dob, just have to find where I put the actual filter sheet. At least with this Rubbish weather I can make it in advance lol..... I am determined to at least find this blumming sun if I can't navigate at night lol

[Moonshane]

Next psp I will help you if you remind me. Do you have a red dot finder and an optical finder?

If you csn afford a telrad or perhaps a rigel it makes a massive difference to finding stuff. Dont get frustrated as you are so keen it would be a shame

[Fozzie]

If you csn afford a telrad or perhaps a rigel it makes a massive difference to finding stuff. Dont get frustrated as you are so keen it would be a shame

110% agree... Putting a Rigel on my scopes increased my object find by an unbelievable amount... I'm actually lost without it... You'll be amazed if you get one the difference it can make.

[Cath]

Preezoom you live in the UK? .. not being able to find the sun is normally a consequence of living in the ....

[itmo]

and be careful when using a truss dob for sun observation (I do). Basically make a pilot-type checklist for setup/teardown, because if you do something in wrong order something is going to burn or break. 

1. set up mount

2. set up scope with endcaps on AWAY from sun

3. take endcaps  off  in a position where sun cannot hit the mirror. 

4.  extend and collimate 

5. shroud 

6. check solar filter against sun to see there are no holes in it. 

7.solar filter + sun shade for the observer + preferable an "extra collar" for the sun shade which will make sure no sun can peek in if the shroud has wrinkles 

    -sun burns observers every day, shield observer from sun. also eyes get tired faster if you have to squint. you will get a nice tan if your left side is to the sun for 1 hour while right cheek is to the shade. 

    -make sure the solar filter is attached and stays attached, avoid windy days. avoid kids. 

8. turn telescope to sun, observe

Add to the list if i forgot something. teardown in opposite order, remember to FIRST turn the scope 90 degrees away from sun, only then take filter off and start teardown. 

[KerryAnn23]

Thanks guys, Shane, I don't think il be at PSP this year, didn't book when I should have and soon starting a new job so not sure if il get time off :-(( . I do have a telrad but got to find somewhere to add it to the scope lol. My next project now I guess is making the filter for my finder and making a shroud and hoping the sun will be out once I get round to it!

[Astrosurf]

first minimize the size of the shadow, then look into the focuser hole without eyepiece (assuming you are using baader film or some such front mounted filter) and turn the tube until the sun is centered, then put a wide eyepiece in, center, then increase magnification. 

That's what I do. It works a treat.

Alexxx