Orpington Astronomical Society

Astronomy => Technical => Topic started by: Carole on Mar 04, 2011, 22:54:53

Title: Oh Gawd, give me strength..............
Post by: Carole on Mar 04, 2011, 22:54:53
As if almost constant cloudy skies and my intermittent guiding problems were not enough, my DSLR (or the EOS Utility) has started playing up.  I noticed earlier when I was doing a test sub that it failed to switch itself off, but then did 7 x 6mins subs no problem.  I had to stop to change the battery so dithered while I was at it.

Went back half an hour later to find it had only taken one sub, which was disappointing.  I then noticed it had taken 1 sub of 1325 secs!!!!!! (see later post, was actually 1625 secs)

:alien: :alien: :! :boom:
Title: Re: Oh Gawd, give me strength..............
Post by: Fay on Mar 04, 2011, 23:30:11
Sorry Carole, but you are funny!!!!
Title: Re: Oh Gawd, give me strength..............
Post by: Mike on Mar 05, 2011, 00:04:29
Yeah but what does that 22 minute sub look like?!
Title: Re: Oh Gawd, give me strength..............
Post by: Mac on Mar 05, 2011, 00:08:51
noisy,  :cheesy:
Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 05, 2011, 00:16:06
I've never been told I was funny before, I just had to let off steam otherwise one could go completely mad with all the frustrations of this hobby.

I'm wondering now whether it was because I plugged the DSLR cable into a different USB port because some-one suggested there might be a clash with the guiding with the DSLR in an adjacent port.  Bloody guiding, one minute it won't calibrate in Dec and then several tries later it starts working OK.

Anyway glad it made you smile.  I got 42 minutes imaging out of it at least.  

QuoteYeah but what does that 22 minute sub look like?!
Crap

Better watch out for the Forum police with all these expletives.

Carole

Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 05, 2011, 08:32:06
Correction it was a 1625 sec sub not 1325 i.e 27 minutes!!!

Carole
Title: Re: Oh Gawd, give me strength..............
Post by: RobertM on Mar 05, 2011, 10:08:00
Well done Carole, wow a 27 min sub!  Was that guided?

That sure must have caught some light !!!
Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 05, 2011, 11:04:25
Yes Guided.  

This is it (processed in DSS only with incorrect length of dark - I miscalculated how long 1625 secs was in minutes and secs), guiding not too bad for 27 minutes.  The result I got after photoshop was not very good.

(http://www.caroleastronomy.webspace.virginmedia.com/_wp_generated/wp4c1491ad_0f.jpg)

Title: Re: Oh Gawd, give me strength..............
Post by: mickw on Mar 05, 2011, 11:39:25
Wow - That's your best yet  :o

:lol:


Seriously, you seem to have nailed the guiding - What was the target ?


Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 05, 2011, 12:31:27
Hi Mick,

The guiding works well - when it feels like it, it's so frustrating and time wasting.

The target was M1 crab nebula.  I am hoping that I will be able to get more Sunday evening which currently is looking promising, although the weather forecasts keep changing. 

What a waste this sub was of half an hours imaging time!!!!! :(

Carole
Title: Re: Oh Gawd, give me strength..............
Post by: mickw on Mar 05, 2011, 14:13:27
The guiding will be fine now you've told the mount it lives in the Northern Hemisphere  ;)

I guessed it was M1 - (I had a play with PS) - There's quite a bit of stuff around it, unfortunately pink stuff  :(

It wasn't really a waste of time, you now know you can't do a 27 min exposure in Bromley  :)
Title: Re: Oh Gawd, give me strength..............
Post by: Mac on Mar 05, 2011, 14:13:45
Looks a tad pink, ;)

I take it you were using the dslr,

Try using photo shop to look at the individual colour channels,
and make the adjustments there to reduce the overall colour,

Any chance of posting the original sub as well.

Guiding does look bang on.

Mac
Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 05, 2011, 15:15:30
QuoteThe guiding will be fine now you've told the mount it lives in the Northern Hemisphere
That was a red herring Mick, as it seems it won't tell you which hemisphere it is in until you've actually done an alignment.  So when I looked at it to check I did just that, bypassed the alignment and looked at it.  So seems like it was in the Northern hemisphere all the time.

Guiding is NOT consistently fine unfortunately, it took about 5 goes at trying to calibrate last night before it would start guiding, it kept failing in Dec.  Then when it started guiding the Dec Red line went off the graph quite a bit, but it did seem to settle down eventually.  But if I can't get it to calibrate in the first place it's a real pain.

QuoteTry using photo shop to look at the individual colour channels,
and make the adjustments there to reduce the overall colour,
It's not the colour that's the problem Mac, it was just really noisy with no detail.  

QuoteAny chance of posting the original sub as well.
Do you mean the RAW file as that was just the one sub, I don't think you can post RAW on the Forum, I think it needs a jpeg.  I can put it in my drop box if you want to look at it.

Let me know.

Lastly, having examined the flats from my new scope, it looks like the misalignment on the flats we discussed in the past must have been the Megrez as it's perectly central in the new scope.

Carole
Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 05, 2011, 15:22:20
QuoteLooks a tad pink
Mac, my DSLR subs are normally purple.  Blue from the CLS filter, red from the mod. 
I just have to process it back to the correct colours.

Now with this one above being exposed for so long, the purple washed out as pink.

Carole
Title: Re: Oh Gawd, give me strength..............
Post by: Mac on Mar 05, 2011, 16:02:32
I wouldn't mind having a look at the Raw if possible,
I think you should be able to post the raw into the gallery, There is a section for it.

Mac.
Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 05, 2011, 17:07:41
QuoteError Message
1. IMG_0003.CR2 Forbidden file extension.

Didn't work Mac as above I'll stick it in drop box and send you the link.

Carole
Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 06, 2011, 12:29:17
Hi Mac,

Did you look at the RAW sub yet, and what was it you were looking for?

Carole
Title: Re: Oh Gawd, give me strength..............
Post by: MarkS on Mar 06, 2011, 17:34:20
Quote from: Carole
QuoteLooks a tad pink
Mac, my DSLR subs are normally purple.  Blue from the CLS filter, red from the mod. 
I just have to process it back to the correct colours.

The colour of that background is pretty much what I get from a CLS on a Canon.  It's more intense in this example because of the incredible exposure length.  It will also depend, to some extent, on the exact mix of lighting causing the light pollution (high/low pressure sodium, mercury, incandescent).

Mark
Title: Re: Oh Gawd, give me strength..............
Post by: Mac on Mar 06, 2011, 18:25:43
I've had a very quick look at the sub,

Very easy to pull all the three colours back into one, with the latest version of photoshop.

When I've got some spare time, after next week, i'll have another play with it,
There were quite some nice colours around the crab.

Mac
Title: Re: Oh Gawd, give me strength..............
Post by: Carole on Mar 06, 2011, 20:02:54
That would be nice Mac, thanks.  I've tried re-doing it and although I can get the colours back I can't get much out of the Crab.

Carole