my best DSLR deep sky shot to date!

[Robert_T]

Hi All, well it's just boring ol' Eta Carina, but I was stoked to get "a result" in the prime focus imaging with the DSLR. This was taken around 8pm last night with a quarter moon in play.

I'm still having some bizaare guiding woes with PhD in that sometimes it guides fine and sometimes it drifts off into the ether (I'm wondering if it's a periodic error thing... I haven't trained the PEC). Anyway of around 10 x 300 sec exposures with unmodified Canon 40D at 800ISO with the YO ED80 and WO 0.8x reducer plus IDAS-LPS filter (works well :thumbsup:)I obtained five decently tracked lights which I stacked here. This time I took sep Darks rather than use the ICNR. I took flats too before starting but they have a blue tint and I haven't used them in the processing here (done in Images Plus).

Result below touched up in Photoshop CS3 - colour balance and noise reduction.

I've included a very slight crop just to remove field curvature stars and slight vignetting in the first. the second is a zoom in on the Keyhole? area which shows the stars as reasonably circular.

Comments and advice welcome as always.

cheers,

Rob

[AlexN]

Very nice Robert!

The addition of darks seems to have paid off! You'd have to be pleased with that result!

Alex.

[Robert_T]

Thanks Alex, yes, I was surprised and please with how well it turned out. :)If I can recover my flats I want to try a reprocess with those to assess the benefit. cheers, Rob

[Ric]

Well done Robert, Eta is never boring there is always something there to see.

Cheers

[Tamtarn]

Very nicely done Robert. For the small number of images you have posted you certainly have improved with each one. Using separate darks is the way to go. Well done :thumbsup:

[Hagar]

Well done Rob. You could try slowing your guiding rate to 0.5 or 0.25 sidreal rateas this will lower the size of eachmove and will possibly prevent PEC from coming into play. This was sugested to me a while back and I havent had a problem since.

Good luck with it.

[Matty P]

Lovely image Rob, very well done. Nice colour and detail. :thumbsup:

I don't think I will ever get tired of viewing images of Eta.

Keep up the great work. :)

[leon]

Spot on Rob, very nice capture, don't worry about your flats being bule, pink or any other shade, Image Plus automatically changes these as it processes the batch of lights, darks and flats.

Mine with the modded 5d has a very pink shade to them .

Just convert them all to Tiffs in Image Plus and, it is all good.

leon

[Robert_T]

Thanks very much guys for the kind encouragement:)

Doug - thanks for the tip on sidereal rate... did you mean set that in the PhD software or in the mounts controller (autostar in my case)?

Leon - that's good to know re IP correcting for the flats tint... I'm going to run off now and give it a try:D

[acropolite]

Fantastic effort Rob, I always enjoyed seeing your planetary images, your deep sky efforts show just as much promise. :thumbsup:

[Alchemy]

hello rob, couple of things i noticed about PHD

the callibration at the beginning is critical, i usually giude at .5 sidereal ( this is set on the mount) and about 20% RA aggression(set in PHD click on the brain) as i have a reasonably smooth mount (G11) i use the lower setting you will tune yours to suit yourself. On a day with poor seeing i find the phd program cant callibrate proprly at the lower setting so go for a harder and faster setting.
You may find it willl callibrate in one axis and fail the second , what it will then do is guide in one axis only ... this could be why you are drifting away check the guiding and if needed set for force recalibration and it will do it again.

hope this helps Clive.