Oooops! I'm on fire!

[Knighty2112]

46 minutes ago, JOC said:

I had already decided that a filter for the eyepiece wasn't going to work for me - I think this confirms my decision.  On my Dob if I fancy a look at the sun a full aperture filter seems recommended and I've got the instructions to make one from my Wanted posting - it sounds a nice rainy day project.  However, I also think reading above that I will have to remember to not to put on the finder scope!!  Or do people make little solar filter for the ends of these too?  I do have a right angled lens finding scope so wouldn't need to risk catching my eye on the sun away from the finder EP as a straight through finder might do.

To be fair my accident occurred because I was trying to compare the views with the Lunt between two scopes and using the same mount to do so. In normal practice the Lunt wedge would only be used in one scope, and never taken out whilst observing the sun at all during a session. 

[Knighty2112]

18 minutes ago, Macavity said:

Now persuaded to leave SOLAR setups in one (dedicated) piece.
Probably the BEST for me (and my memory re. such things)! 

Yes, this will be done always now so no silly mistakes can be made. The only time the Lunt wedge will be taken out of the scope again is when it is safely back indoors again out of the sun!  

[Stub Mandrel]

1 hour ago, JOC said:

I had already decided that a filter for the eyepiece wasn't going to work for me - I think this confirms my decision.  On my Dob if I fancy a look at the sun a full aperture filter seems recommended and I've got the instructions to make one from my Wanted posting - it sounds a nice rainy day project.  However, I also think reading above that I will have to remember to not to put on the finder scope!!  Or do people make little solar filter for the ends of these too?  I do have a right angled lens finding scope so wouldn't need to risk catching my eye on the sun away from the finder EP as a straight through finder might do.

You can make a solar finder, a simple 'pinhole camera' five or six inches long works really well.

 

[JOC]

1 minute ago, Stub Mandrel said:

You can make a solar finder, a simple 'pinhole camera' five or six inches long works really well.

As a scientist I am ashamed to say that I've never made a 'pinhole camera'.  I've often wondered if they would really work, but the fact that you have made one suggests that carefully done they must function as I've often read they do.  So in the setup you have there where do you see the sun's projection - do you just hold up a white sheet of paper behind the finder or does it have a white sheet of something like tracing paper at the back?  In fact I do have a spare finder-scope shoe and the straight through finder-scope that came with my set-up so I could easily remove the old one and gain a shoe, and I have a brother who is into welding who could probably find me a suitable piece of piece of pipe to make one from.

[Macavity]

29 minutes ago, JOC said:

As a scientist I am ashamed to say that I've never made a 'pinhole camera'.

I have made (fairly sucessful!) "Pinhole" solar finders. But after a LONG
wait for delivery, noted that a standard Lunt Solar Finder was actually
a relatively SIMPLE beast with a large-ish hole! The screen, made from
"tracing" film or something similar.... Basically "semi-opaque stuff" etc.  
 

In fairness, it does have the right Screws - Plus nifty adjusters!
AND the correct hole spacing for the scope! Worth it for me... 

[Stub Mandrel]

The screen is just a bit of translucent white plastic. Black plastic for the pinhole. Any type of tube will do, useful to be able to see both sides of the screen but not essential.

[JOC]

I shall certainly have a go with this I think.  A big full aperture filter (home-made with that special filter material for the scope - then I am protected if I wish to change EP's providing they don't catch the sun as I move them around, and a pin-hole home-made finder.  I'm already on the hunt for materials but probably won't order the film until I'm ready to go so it doesn't get damaged in storage.

[David Smith]

Been there, done that, got the scorch marks on my T Shirt sleeve to show for it

[sophiecentaur]

On 10/03/2017 at 11:28, Macavity said:

I have made (fairly sucessful!) "Pinhole" solar finders. But after a LONG
wait for delivery, noted that a standard Lunt Solar Finder was actually
a relatively SIMPLE beast with a large-ish hole! The screen, made from
"tracing" film or something similar.... Basically "semi-opaque stuff" etc.  
 

In fairness, it does have the right Screws - Plus nifty adjusters!
AND the correct hole spacing for the scope! Worth it for me... 

Trying to line up the scope shadow on the ground to get it to point in the right direction was driving me mad. I looked around on Google and found a load of alternative designs and prices for solar finders. I spotted one design which totally suits my Baader ASTF80 filter. It cost nothing. All I have done is to mount a long M3 screw, facing forward (perpendicular to) on the front plate of the filter. There are three spare holes on the plate so no drilling was necessary, even. It throws a shadow onto the filter plate. When the sun is on boresight, there is no shadow. That's more than accurate enough for my 32mm EP lens to locate the Sun. It will only work for filters that have a flange of some sort. I can see no safety issues and it lives permanently on the filter in a deep box. You could do the same thing on a spare lens cap for the finder scope - or any other suitable flat surface.