Ironing out a few problems

[Carole]

One last attempt to see if I can make it clearer.  

There are some faint stars in the same image, so I have now gone back to the full frame and blown them up. Had to stretch the levels for these to show up.

Stars and Mars (with focus mask), before focussing.



Stars (and Mars) after what I had hoped was focus (with focus mask):



top left stars zoomed in (with focus mask):  



If these aren't round I give up!!

Carole

[RobertM]

By the way - focus masks will only work well on stars.

Not quite true.  At shorter focal lengths planets are perfectly usable with a Bahtinov mask but there may be a problem with longer focal lengths where the image scale is much larger.  I reckon that if you can see the spikes then you should be ok - try it and see.  With the image scale you have in those images there's unlikely to be any problem.

Robert

[Mike]

How are you taking pictures of stars in the middle of the day ?

[Carole]

 

How are you taking pictures of stars in the middle of the day ?

a) I went out last night as the skies were clear(ish) at 7.30

[RobertM]

If these aren't round I give up!!

Don't forget the scope will need time to reach ambient after going from inside to the cold outside, maybe up to an hour or so.

[Carole]

Don't forget the scope will need time to reach ambient after going from inside to the cold outside, maybe up to an hour or so.

Hi Robert, I keep the scopes in my conservatory which is very cold in the winter especially now as the dog flap has broken off and there's a cold blast coming through it.  It's DIY built not UPVC and heated.  So the telescope is already pretty cold before it goes outside. 
I don't of course keep it out there in the summer when it is the opposite (like an oven) but I will hopefully have the observatory by this summer.

Also it's normally getting on for an hour setting up and alignment etc etc by the time I get to focus.

[doug]

I have a very large drawing board here, if you want one, Carole.

[Carole]

OK.  I've bought myself a Bahtinov mask, and like every-one else I've been waiting a few weeks to try it out.  

I took some images on Monday evening but they are pretty rubbish as I didn't take enough subs due to (target disappearing behind the trees, or clouds), so I won't be posting them unless you guys really want to see them.  Also did not get the targets centred in the frame.  Lots of lessons learned there.

I managed to focus on my last alignment star and it worked.  So I hope this will solve my problems.



Carole

[Mac]

your mask is round the wrong way.

normally the lines are vertical.

Not that it makes any difference.

Mac.

[MarkS]

Sounds like good progress Carole.

Mark

[Ian]

Nice diffraction spikes there Carole...

Hmm, need a "looking over my shoulder" smilie I think.