Omega Centauri

[Slawomir (Suavi)]

Hi Paul,

Very nice photo and certainly beautiful round stars

I stopped using OAG because it was a pain with an ED doublet, not so much in regards to finding suitable guiding stars but because I needed to refocus the guide camera for each filter; I had a basic OAG and it was just too much fiddling in a dark at night...

Now struggling with flex...got the flex down to 1arcsec per 8minuts 20 seconds...would love to halve it though...

[DJT (David)]

Originally Posted by Slawomir

...I stopped using OAG because it was a pain with an ED doublet, not so much in regards to finding suitable guiding stars but because I needed to refocus the guide camera for each filter; I had a basic OAG and it was just too much fiddling in a dark at night...

Wondering why you need to refocus the guide camera with the OAG?

[Paul Haese]

Nice work. Nice colour and resolution looks good. A bigger image would be nice to see the resolution better. When you say RC8 are you referring to a GSO RC8? If so, that is another tick for their scopes.

[strongmanmike (Michael)]

Originally Posted by DiscoDuck

Thanks all.



Well, still struggling with the OAG to find guide stars sometimes. Find I have to plan in advance in Stellarium/Cartes du Ciel, even to the point of working out the orientation of the camera to get one. And a meridian flip causes headaches with having to find one the other side or rotate the camera and refocus! Tips appreciated!

So, you are operating at 1600mm FL is that right? I am only at 1120mm so my Lodestar and the SX pick off mirror has a bigger field than it would have at 1600mm but (to date) I always have a guide star available in a 2.5sec exposure (without any specific framing) which is my standard now, so I'm not sure how I can help you? What guide camera are you using? What guide exposure length can you get to and maintain good guiding with the EQ6?

Mike

[Slawomir (Suavi)]

Originally Posted by DJT

Wondering why you need to refocus the guide camera with the OAG?

Don't want to steal the thread, so in short: when changing a filter for the main camera I need to refocus it (I use a doublet so focus adjustements between filters are relatively substantial) and that always significantly stuffs up the focus for the guide camera. Solution: need too get a triplet or an OAG with easy and reliable focus adjustement.

[DiscoDuck (Paul)]

Originally Posted by Slawomir

Hi Paul,

Very nice photo and certainly beautiful round stars

I stopped using OAG because it was a pain with an ED doublet, not so much in regards to finding suitable guiding stars but because I needed to refocus the guide camera for each filter; I had a basic OAG and it was just too much fiddling in a dark at night...

Thanks Slawomir. Re OAG refocussing, I know what you mean. Had to refocus it on another image as was using an Ha filter. It's just a simple screw holding the stalk in position, so fine adjustment is almost impossible. Seems to be a case of close enough is good enough!

Originally Posted by Paul Haese

Nice work. Nice colour and resolution looks good. A bigger image would be nice to see the resolution better. When you say RC8 are you referring to a GSO RC8? If so, that is another tick for their scopes.

Thanks Paul. Yes, a GSO RC8. I'll dig out a higher res version and send you a link.

Originally Posted by strongmanmike

So, you are operating at 1600mm FL is that right? I am only at 1120mm so my Lodestar and the SX pick off mirror has a bigger field than it would have at 1600mm but (to date) I always have a guide star available in a 2.5sec exposure (without any specific framing) which is my standard now, so I'm not sure how I can help you? What guide camera are you using? What guide exposure length can you get to and maintain good guiding with the EQ6?

Mike

Mike, yes 1600mm. I'm using a QHY5L-II. With 3-4 seconds exposure, guide stars of 10-11 mag seem fine, but they're not that common in the fov I find, unless planned in advance. Perhaps I can expose longer and/or focus the guide cam better. I need to experiment I guess to determine that maximum exposure time. This hobby is always a learning curve! I presume the Lodestar is more sensitive than the QHY too??

[Ross G]

Excellent photo Paul.

Nice colours.

Ross.

[DiscoDuck (Paul)]

Thanks Ross.

Paul