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Triangulum Galaxy (M33)


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Been a while since I have posted an image here, weather and work but last night was a great night, best in a long time.


Having now upgraded to a Lodestar X2 and have managed to get at least some guide stars though my OVL OAG on the EdgeHD 8", this scope is a real challenge to guide not helped by the design of the iEQ45 as get a lot of backlash with the weight.


This is the result of a difficult night getting everything running, first sub not in till 1.30am.


M33-EdgeHD8-V1_zps52bcdec1.png


Kit

EdgeHD 8" / OVL OAG Guider with Lodestar X2 / QHY8L / Hutech IDAS P2 filter all sitting on an iEQ45 Mount


Captured in SGP and processed in PixInsight


20 x 300s Subs

59 Darks /Bias

29 Flats



Thanks

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Been a while since I have posted an image here, weather and work but last night was a great night, best in a long time. Having now upgraded to a Lodestar X2 and have managed to get at least some guid

Hi Louise, Tonight is a loss again in rainy Manchester. I ordered a WO Star 71 Ian King in July and I got it just before I went on Holiday so last night was the first light for this little beauty. A.G

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Nice capture, M33 is hard.

I always fractionally unbalance and misalign the polar so as to maintain a very slight drift and keep the gears meshed.

There appears to be a little colour speckle noise when viewed at full resolution, is this hot pixels or just the top of the background noise?..  though even printed A4 you're not going to see this, only if you wanted to print bigger than that...  which if fully polished I'm sure this could do.

well done

Derek

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@rfdesigner  They are most likely hot pixels, would normally dither to remove them but that threw things way out last night so just went with it.

@cfpendoc Yes, native f/10 - a few people have showed surprise at that, did not really think about as was more testing the Lodestar with the OAG and this was a target that I could get a guide star on and did not hit meridian till after 4am thus avoiding the flip! 

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Hi

Really nice - I've been trying to get M33 too! 1200s subs but still not showing up much... I can only get one a (imaging) night :( Still good to see the results from another qhy8l - please do more to further inspire me!

Louise

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Hi

Really nice - I've been trying to get M33 too! 1200s subs but still not showing up much... I can only get one a (imaging) night :( Still good to see the results from another qhy8l - please do more to further inspire me!

Louise

Thanks, surprised 1200s don't show much, this screenshot from PixInsight shows what I had for single 300s sub, the one on the left is the raw sub and the right hand one is a calibrated and debayered version, both auto stretched.

Screenshot2014-08-25102319_zpsf0fb9ada.p

Most of my images are here, virtually all with the QHY8L bar the planets and Solar - http://www.astrobin.com/users/trevorn/

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Worth the trouble you went to getting everything sorted as you've nailed a tough target there.

Thanks, nearly gave up at one point but glad I carried on - setting up each session can be a real pain at times.

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Thanks, surprised 1200s don't show much, this screenshot from PixInsight shows what I had for single 300s sub, the one on the left is the raw sub and the right hand one is a calibrated and debayered version, both auto stretched.

Screenshot2014-08-25102319_zpsf0fb9ada.p

Most of my images are here, virtually all with the QHY8L bar the planets and Solar - http://www.astrobin.com/users/trevorn/

Hi

My main problem is light pollution which kills the contrast and gives a severe gradient :(

Here is a single 1200s sub (one of 2 x 1200s subs I did last night) which I've stacked with calibration frames and stretched:

post-33532-0-65510500-1409001086_thumb.j

I know PI has DBE but I'm currently using StarTools. I think it's possible to remove the gradient without destroying the dust lanes using ST but I need to sit down and figure out how to do it! I have 10 x 600s and 7 x 900s though they don't seem to add much when I stack them all together in DSS using entropy-weighted stacking.

Louise

Edited by Thalestris24
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Hi

My main problem is light pollution which kills the contrast and gives a severe gradient :(

Here is a single 1200s sub (one of 2 x 1200s subs I did last night) which I've stacked with calibration frames and stretched:

attachicon.gifM33_1x1200s_flip.jpg

I know PI has DBE but I'm currently using StarTools. I think it's possible to remove the gradient without destroying the dust lanes using ST but I need to sit down and figure out how to do it! I have 10 x 600s and 7 x 900s though they don't seem to add much when I stack them all together in DSS using entropy-weighted stacking.

Louise

Hi Louise,

I did a quick play with Gradient Xterminator in PS, 3 passes only. You have an IDAS D1 which is about the best that you could get as a broadband LP filter so I wonder why your signal is so weak for 1200s subs. If you wish you could put the unmolested fits file in Drop Box and I could have a go at it with StarTools and see what could be done.

Regards,

A.G

post-28808-0-45480500-1409005354_thumb.j

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Hiya

Thanks - great you got rid of the gradient! I think it's the lack of dark skies combined with a poor atmosphere around here :( I used to have similar problems with the 1100d. At the moment the position of M33 is a problem because of a nearby street light. Other parts of the sky seem not so bad - at least for stars... I tried to grab an image of the California Nebula last night too - got 3 x 1200s. It's a bit big for my scope but here's a jpg:

post-33532-0-97424100-1409006465_thumb.j

Star clusters come out better! I did this Starfish Cluster last night too:

post-33532-0-69707600-1409006573_thumb.j

Apologies to the op - I don't mean to hijack the thread!

Edit: I need to spend more time studying and practicing the processing!

Louise
 

Edited by Thalestris24
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Hiya

Thanks - great you got rid of the gradient! I think it's the lack of dark skies combined with a poor atmosphere around here :( I used to have similar problems with the 1100d. At the moment the position of M33 is a problem because of a nearby street light. Other parts of the sky seem not so bad - at least for stars... I tried to grab an image of the California Nebula last night too - got 3 x 1200s. It's a bit big for my scope but here's a jpg:

Star clusters come out better! I did this Starfish Cluster last night too:

Apologies to the op - I don't mean to hijack the thread!

Edit: I need to spend more time studying and practicing the processing!

Louise

No problem with hijacking the thread, it's sort of linked.

Have you gone though the process of setting Gain and Offset on the camera? 

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No problem with hijacking the thread, it's sort of linked.

Have you gone though the process of setting Gain and Offset on the camera? 

Hi

Yes - I have gain set to 13 and offset at 118. I set them when I first got the camera. How do those values compare to yours?

Louise

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Hi

Yes - I have gain set to 13 and offset at 118. I set them when I first got the camera. How do those values compare to yours?

Louise

I am at G5 and O119, the Gain seems a little high, my dark images have a mean of 808.  

How long ago did you do them, and assume the camera was at operating temp when you did the calibration?

I check/redo my settings every 6mths or so, a pain as have to redo my bias and dark library again.

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Hi

I've only had mine since mid-March so not 6 months yet. Yes, did it at cooled operating temp. I'd have thought if my gain was set higher, the resultant images would, if anything, be brighter?! Not sure what my mean dark values are. It's puzzling - I mean I image at F5 so I should get more photons in a shorter time compared to you! But I know my local lp is limiting - 1200s is probably on the long side. Maybe I should try getting more 900s subs? It should be clear here tonight :) though looks like being misty after midnight :( But I'll see how it goes.

Cheers

Louise

Edit: I redid my darks library a couple of weeks ago - with same gain and offset. I did the gain/offset back in March/April.

Edited by Thalestris24
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Hi

I've only had mine since mid-March so not 6 months yet. Yes, did it at cooled operating temp. I'd have thought if my gain was set higher, the resultant images would, if anything, be brighter?! Not sure what my mean dark values are. It's puzzling - I mean I image at F5 so I should get more photons in a shorter time compared to you! But I know my local lp is limiting - 1200s is probably on the long side. Maybe I should try getting more 900s subs? It should be clear here tonight :) though looks like being misty after midnight :( But I'll see how it goes.

Cheers

Louise

Edit: I redid my darks library a couple of weeks ago - with same gain and offset. I did the gain/offset back in March/April.

I was thinking f/5 should be giving you better signal than you appear to be getting hence asking about the gain offset, what light source did you use when setting the offset?

High gain should capture more faint stuff but at the expense of more noise, all the QHY8Ls are different so can't really compare. You can check the mean dark value by dropping a dark sub into FITS Liberator, QHYY suggest between 500-1000, I went for the low end of the scale.

Suffer for LP here as well, n the middle of a housing estate though they switch the local street lights off between Midnight and 5am which helps, though even then imaging west is still at problem as get LP from the town, have the same LP filter as you though also use a 7nm Ha with then TS65Quad

As an aside the TS65Quad, QHY8L and 7nm are a good match, LP is a lot less of a worry and you can get some good mono shots.

Heart-Ha_zps5681686f.png

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Hi

I used a monitor screen with Notepad window for setting the gain/offset via EZCap. I use the same screen for flats.

Your lucky to get the lights switched off! Unfortunately I live close to the city centre... :(

I have a set of Baader NBs and a mono dslr - currently being repaired. I could try attaching the 7nm to the 150pds but I don't want to disturb anything at the moment.

A 1200s dark gives a mean value of 717.8 in FITS Liberator.

Getting dark here now - well, will be when the turn the nearby all-weather pitch floodlights off! Should be off about 10pm.

I think I'll try getting more of the 900s subs and manually dithering a bit. I had a fiddle earlier and was able to get something that resembled a galaxy but it wasn't at all satisfactory:

post-33532-0-23306300-1409085197_thumb.j

That's a crop of the galaxy region saved as jpg.

I still have a lot to learn with the processing side!

Louise

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Hiya

Well the above pic could be called 'artistic' - impressionistic, perhaps! I'm imaging now - on my 3rd 900s sub :) I can't see any of the galactic stars in my subs like those in yours :( Maybe that's just a lack of resolution with the 150pds. Not sure, and it's the only proper scope I have any experience with. But, again, the atmosphere here tends to be moist and I think that reflects a lot of lp.

I hope it doesn't get too misty though the visibility is forecast to drop after midnight. Still, I'll see what else I can get.

Cheers

Louise

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