Makarian's Chain (Work in Progress)

[MarkS]

Single 5 minute sub of Makarian's Chain. 

Canon 350D (with out-of-alignment CCD) on Tak Epsilon 180ED taken from Riberac.  2x2 binned.  No flats nor darks.  I took 8 before the guiding went haywire and I retired to bed.

[Carole]

Wow, what a lot of galaxies Mark.  Looking forward to seeing the final image.

Carole

[Fay]

Looking good Mark!

[Mac]

Looking good. I like the square stars

Mac

[RobertM]

That thing sure does collect a lot of light.

btw. how close to being burnt out are those galaxy ?

[MarkS]

That thing sure does collect a lot of light.

btw. how close to being burnt out are those galaxy ?

They're already well burnt out.  I need to mix it with some short exposures.

BTW - I have also tried out my other camera - the 300D.  This had star distortions worse than the 350D.  So the problem is not the scope - the problem is the accuracy of the Camera/CCD alignment.  I really need to try out a pristine unmodified camera.  However, I think I've calculated the thickness of shims required to correct the 350D.

Mark

[Mac]

i've got an unmodded 350 if you want to borrow it.

Mac.

[MarkS]

Thanks for the offer Mac.  But I think tonight I've finally located the problem.  The canon adapter ring has a barely perceptible side to side rocking movement when screwed into the focuser - why that should be, I don't know - I'll have to examine it in daylight tomorrow.  Anyway, rocking it to the right I get the distorted stars and rocking it to the left the stars look pretty good.

I also think I've solved my dec guiding problem from 3 nights ago, by pointing the scope at the part of the sky I want to image and then make sure it it balanced in this position.  Guiding is working better tonight.

Now I've more or less solved my problems, it's time to do some serious imaging - shame there's a slight mist in the air tonight!

Mark

[Fay]

I am out there tonight, Mark, i had problems guiding, and after about 3 restarts, thought it may have been the guide camera not being at the correct angle.

It has been going fine & have done about 15x600, will do flats at 12 & call it a day

[MarkS]

Canon adapter ring - made of 2 pieces held together with 3 (slightly loose) tiny grub screws.  I've tightened them now so it no longer rocks.  So now I'm ready for more experiments tonight ...

[RobertM]

Good luck...

[MarkS]

A simple tightening of the grub screws resulted in the CCD being slightly further out of alignment - I think I'll need to do this with the aid of a micrometer to ensure that both faces of the adapter ring are precisely parallel.

Does anyone have one I could borrow sometime?

Mark

[Ian]

yep, somewhere in the cave, probably next to aladdin's lamp... I'll try and find it tomorrow...

[MarkS]

Thanks Ian!

[MarkS]

Ian,

No need now.  I took the adapter ring to bits last night.  The two piece construction gives it one very powerful feature - shims can be inserted into the gap before tightening which means that the camera can be tilted in arbitrary directions to correct for CCD misalignment.

Brilliant!!!!!

I can now completely solve the wonky CCD problem and I can re-install the Peltier mod in the knowledge that I can correct any CCD tilt it causes!

Mark