Astrotrac antares from astrofest

[h0ughy]

this was taken on wednesday night at astrofest - totalling 1h34min worth of 1 minute unguided imaging using the cooled 40D and 135mm L lens f3.2 using the astrotrac at Astrofest. like my crux shot it suffers a bit of rotation but better than nothing. actually i think the rotation could also be due to the lens or sensor not completely square on to the light path in the focal plane?

stacked in DSS and processed in pixinsight

[LucasB]

That is very enjoyable to look at :thumbsup: Love the dark lanes in this region which have been captured nicely!
Lucas

[h0ughy]

thank you Lucus

[tornado33]

Nicely done and processed.
Scott

[Dennis]

Very nice Dave, a lovely portrait of this richly populated region.

Cheers

Dennis

[allan gould]

Nice one Dave, really like that Astrotrak

[seeker372011]

Nice result...what is your technique for polar aligning the astrotrac?I find it quite difficult myself

I don't believe sigma Octans actually exists

[Davros]

Thats beautiful, very well done. That one deserves framing.

[h0ughy]

thanks SCott - see you tonight at the society's meeting

thanks Dennis - i have several other shots of the area to process yet and stitch up so i hope it works

well Allan - you have seen it in action so you know it works ;) whens yours coming ;)

well that was a bit of a trick to use the polar scope but you line up the crux with the real one then look for the sigma thingy - in the city you would be stuffed by light pollution - it was hard enough in the dark skies at duckadang but the wedge on the pier is brilliant to use to adjust the direction



thanks - think about it after processing the other stuff

[DavidU]

That is one very nice image Dave.

[Ross G]

A great photo David.

Detailed and sharp.

I love the smooth colours.

Is the astrotrac as amazing as the reports I have read?


Thanks.

Ross.

[bokglob]

Another cracker david:thumbsup: You really nailed that dust!

[h0ughy]

thanks David

that they are Ross - i have two ;) but only used one up there



dont know about that - more data is needed i think, but thank you:thanx:

[RB]

Wow great result for 1 min subs Dave.
I can't wait to see the Astrotrac in action at Lostock.

[h0ughy]

soon RB - only a month or so;)

[rcheshire]

David. Was that with the CLS-CCD filter? And did you do a LRGB combination with the extracted L* channel for saturation. Just curious because, it was very difficult on a similar image to retain the nice grey/blue around Rho oph without over saturating, while trying to lift the reds. Still the balance is great. I really like it.

[h0ughy]

no filter except the original modded one, shot without L just processed in PI with histogram and sat in colorsaturation and ACDNR

[Phil Hart]

nice houghy!

i doubt your issues are lens/sensor tilt. i think you can for sure rule out sensor tilt in DSLRs.. they're made to work with f1.4 lenses and i've never seen any evidence of issues in that regard.

i've had a lens element in a 50mm f1.8 get out of alignment before which is why i now use the 50mm f1.4. but i'd be surprised if that was the case with your tele lens.

it looks more like an alignment/stacking issue to me. do you see any issue in the individual subs? if you stack the first and last frames what do you get? can you try alignment/stacking with something other than dss and see if you get same result?

cheers
Phil

[h0ughy]

the lens is the 135mm L glass with a modded and cooled 40D. here are the first anf last shots. one thing to note is that the camera was totally rebuilt for the mod. if you look at that corner its in both shots

[Phil Hart]

hmm.. then can you try taking separate frames after doing liveview focus on each of those two corners. maybe something is tilted. try a different lens too..

[h0ughy]

i noticed once before i used it with the 200mm L lens and had a similar softspot - i could crop it out - makes life difficult. tried to make a mosaic last night as well - took 5 different shots of the area and i have differing light and conditions on each night - including total exposure times. it was really evident. did DBE on each shot but the nights were affected by the conditions of the nights – which were skyglow, smoke of varying intensity, fog, moonlight, and user errors LOL. Can’t really say the dog chewed my homework can I….

as I said to you before with your mosaic the data you collected was great – including the time on each panel. You had flat fielding and a slight vignetting at the corners from memory which were cropped out but essentially I am still learning to get there. I hope to nail the bugger next year – will have a better plan and now having imaged the area I now know what and where I need to position on.

i may have to send the camera back to get Yun to fix the tilt issue:shrug:

[atalas]

Looks great!! houghy, does your camera have regulated cooling ? and If not,does It cause you any problems with your dark's? or do you take your dark's through your imaging run?

[h0ughy]

thanks Louie, i take darks at the end and have a library of temps as well