Solar observing first time

[tripleped]

Tried my first solar observing and it was a flop.  Using a skywatcher goto 10” DOB f4.7.  Baader solar film over the inside of the aperture hole on the plastic cover. Hole is about 50mm.  With no ep in focuser tube clearly saw white solar disc and had it centered in the aperture hole but with ep just total white out no image at all. Used televue 25mm plossl. Read somewhere that this method works albeit not as good as a full aperture filter. Suggestions? Was I mislead into thinking this would work?

[tripleped]

Oh and the cover was placed on outside of optical tube

[Stu]

@tripleped, that should work fine. Did you try through the full range of focus? Using just the small aperture will limit the resolution of the image you see, it might be worth creating a bigger aperture that just fits between two of the vanes, or even a full aperture mask. Have another go with it though, no reason why it should not focus as normal and show you a sharp white disk, there are a few active regions about currently too which is a bonus.

[Peter Drew]

Most likely a focusing issue although the reflection from the filter suggests that it might be a little tight, the film needs to be completely relaxed and floppy.        🙂

[Rusted]

Unless you focus slowly you may well have passed the sharp focus point.
47-50x is quite a big disk. Remember that the filter has no real effect on the focus point.
So the telescope should focus exactly where everything else does. Stars & planets, etc.

Even a distant tree should be somewhere near the focus point or usually just outside of it.
The moon will be at the same focus point too if it is available.
Presently East in the early evening and rising high to the south. You can't miss it.

I sometimes use a pencil mark on silvery drawtubes to save fiddling about.
A narrow magic marker would do if a pencil mark won't show up on chrome.

[tripleped]

Thanks. I will try again focusing very slowly. That’s probably it. I was kind of zipping along with the focuser. Thanks everyone for the advice 

[Ricochet]

How have you attached that solar film? Is it just selotaped to the underside of the cover? I think that is a very dangerous way to do things. Under the heat of the sun the plastic cap will heat up, the tape can begin to unstick and the film could fall off, blinding you instantly. In addition, when you just remove the cap for night-time observations, there is nothing to protect the underside of the film from damage.

If you really want to only use the 2" hole, you should build a solid filter cell that slots over the outside of the hole so that gravity is pulling it down onto the cap, and you should have secondary fixing methods to 

1. Prevent the solar cell/filter from coming off the cap
2. Prevent the cap coming off the telescope.

When not in use the cell can then be stored in an airtight container to protect the film from damage.

However, using a full aperture filter should give much better resolution than just the 2" hole.

[tripleped]

Wow that’s a lot to consider. Thanks Ricochet for the advice. Think I’m gonna order a glass full aperture from Orion after reading your response. Sounds like it will be better and safer 

[Jamgood]

I got a Baader Astrozap Solar Filter from FLO this week. Link

Covers the full aperture of the scope. Focus was barely changed from the previous nights imaging. Just a little fine tuning as normal.

Only took a couple of images on the first outing as I spent most of the time watching the screen in awe. Seeing the Sun and Sunspots for the first time was quite mind blowing. I got this single shot though.

You should be able to focus as normal.

[Neil H]

Hi i will be joining you soon just got my hands on a kendrick filter for my 8 inch Newtonian 

Quick question  some say you need an filter for the eyepiece as well ? 

[Merlin66]

Neil,

adding a green or Continuum eyepiece filter behind the Solar filter, will enhance the contrast.

 

[Neil H]

Ok i have s green filter i will try that if not i will get the other filter

[Stu]

I’ve used an OIII filter before as a substitute which does tighten things up too, although a Continuum filter is better.

[RT65CB-SWL]

On 28/11/2020 at 17:44, tripleped said:

Wow that’s a lot to consider. Thanks Ricochet for the advice. Think I’m gonna order a glass full aperture from Orion after reading your response. Sounds like it will be better and safer 

Glass solar filters need to be checked before each and every use too for scratches and pin-holes. I have a Thousand Oaks one.

[JOC]

There is a relevant thread here that might be of interest