M83, Centaurus A, Omega Centauri & The butterfly

[MGTechDVP (Mariusz)]

Good evening everybody.

I was able to do some imaging for a few nights in the last week and got some results that I'm stoked with... Best galaxy shot I have to date... but my autoguiding, although better, is still iffy.

I placed the mouse cursor over another star and locked off the mouse in the PHD window to see the stability/drift of the guide star. When my guiding is working and its best (best on my unit so far) the star basically moves a pixel or two in both the RA and DEC then returns to its original position (sometimes overshoot by a pixel or so then returns back to the center).

My settings in PHD that seem to work the best are:

RA Aggressivnes: 75
Max RA duration: 2250ms
Max Dec duration: 2000ms
Min motion pixels: 0.05

If anyone has any advise or info on how to get the tracking/guiding spot on please share.

Below are some of the images I took of Omega Centauri 25minutes subs of 60 & 120 second, Centaurus A 50 & 55min subs, M83 (the blue one was 42 minutes of subs, was cut short because the clouds came and the camera was set to the wrong color balance. Any attempt to decrease the blue dimmed the image, no favorable result in increasing red.
The next two M83 galaxy pics were 150 mins of 60, 120 & 180 second subs. Then there's the Butterfly nebula NGC6302, 60 minutes of 60 & 120 second subs. The NGC6302 nebula was taken at F10, all others were through the f6.8 focal reducer.

Clear skies,
Mariusz

[Rigel003 (Graeme)]

Promising images, Mariusz. The guiding doesn't look that bad to me. If you're interested, here's an article by Craig Stark, the creator of PhD Guiding about tweaking parameters when things aren't working well http://www.cloudynights.com/item.php?item_id=2755

[[1ponders] (Paul)]

Nice work Mariusz. You are going about it the right way that's for sure. Get out there and get images. The more you take the better you'll get and you've got some good images there. M83 in particular. Also the longer you can go with your subs (within reason) the better too.

[MGTechDVP (Mariusz)]

Thanks Gents... I wish I had the opportunity to image more often. Thanks for the link Graeme, it was helpful for my next outing.

What do you think of imaging with vs without the Celestron UHC/LPR filter to get the background darker and the objects being exposed longer in each sub to get more faint details? It is blue when compared to without the filter, but I figured that remembering to move the color adjust all the way to the red/magenta on the 40D and set WB to K @ 7300 should counter act the bluishness.

Mariusz

[Forgey (Paula)]

Very nice images Mariusz, looks like you getting the hang of it now.

[MGTechDVP (Mariusz)]

Thanks Paula, next outing or two will show whether I fluked it or it's finally all falling into place.

[graham.hobart (Graham stevens)]

I think your M83 is very good and your Bug Nebula top buddy.
I have read that PHD article as well, and for me the keys are
1. Calibrate at each part of the sky, change subject?, unless its within a few degrees then stop guiding, stop programme. restart and calibrate near your target. Change the exposure to suit the sky but if you haven't calibrated in 15 steps then it isn't working.
2. The Tools drop down menu is a great guide, go to tools enable graph and see how close you are to aligned. If you get a nice EEG looking small bumps around the same axis then you are winning.
3. Don't worry too much about this. It's supposed to be fun right!
Keep em coming!
PS background darker, if you suffer from light pollution use a CLS clip in filter and take stacks of darks and flats, gets rid of that gradient.
Graz

[jenchris (Jennifer)]

Getting close to nailing it.
What's the colour rim round your stars? Processing,tracking or optical?

[MGTechDVP (Mariusz)]

Thanks for the replies, all I can do is play with the setting next time I'm out, but recalibrating at every target is a great idea.

The rings in the stars seems to be from processing, propably over done it a bit.