Another Cent A

[Peter.M]

I had another go at Cent A while testing all my gear for this weekend where I will be taking it away with me. I still have some gradients that im working on but overall the image isnt too bad.

I am hoping to get some nice images while I am away despite the moon, at very least the seeing should be far greater where I am going.

[multiweb (Marc)]

Very nice details and colors. That's a tiny one to image. Well done.

[Peter.M]

After trying various methods to remove gradients in photoshop I came up with this, not entirely happy with it but at the moment it will have to do.

[Paul Haese]

Gradient aside Peter, you need to watch the focus a little more. There is some coma showing in the images and this is most likely more evident because focus looks just a little off. What are you using for addressing collimation? Do you have cats eye collimation tools? If you get these issues under control you will start producing some cracking images.

[Peter.M]

I have some problems with collimation at the moment, I have cats eye tools but to get them to work the autocollimator needs to be at the focus point. Because of my large backfocus this means I need an extention tube, and this nullifies any collimation that I make as the extention tube may not be perfectly concentric in the focuser.

The focus issues are probally because I didnt refocus at all this night so later subs may be a little off.

I am assessing my options at the moment, collimation issues may be due to my tube flexing, or my larger secondary being too heavy for the holder/veins. I have enquired about a carbon tube with heavy duty spider but I think at the moment it might not be cost effective, might put the money into the new scope fund.

[Paul Haese]

With the cats eye tools you should be able to still get collimation sorted or very close even if you in focus quite a distance. While it is not optimum the collimation would have to be better than at present. Yes do look into sag related issues. Sometimes it can be a minor thing that is making things sag.

Focus should be checked every hour when imaging. Minute focus changes occur all night long as you will be aware and this means a good practice of hour checks is preferred. Therefore good pointing is a must for imaging.

Not to worry, when you come down to Clayton we will get you in the swing of things.