a really poor image of the horsehead

seeker372011 (Narayan) · #1 07-10-2005, 10:51 PM

there are many words to describe the attached image of the horsehead but because as Mike and the moderators remind us this is a family forum, the word rubbish will have to do.

I post it only to share my frustration at a massive stuff up..and as a warning to others!

This was on Sunday night..after the grand final. Focus was spot on..checked with DSLR focus. Polar alignment was great-drift aligned as best as can be expected. No moon. CLS filter to fight light pollution..got four 10 minute images of the horsehead and was absolutely chuffed with the way the raw images looked on the screen. guiding looked to be perfect, bit of coma around the edges but you get that anyway

My mistake? didnt take a dark frame that night.

It was much much warmer than any night this year. Result...massive noise. My dark master could not compensate, and nor could frequent passes through Neatimage.

So in the end this is a write off

This is resized down for posting but noise is still apparent.

Herein lies the lesson, at least for me..take a dark frame -one for every light-every single time!

and dont wait for the end of the night because temperature changes

h0ughy (David) · #2 07-10-2005, 11:04 PM

hey that is still a great shot, i like it a lot. it gives me a target to aim for, and a lession in astrophotography

davidpretorius · #3 07-10-2005, 11:33 PM

wot you talking bout willis?????

i was able to see the bottom left nebula last last night thru the eyepiece, and that is the first pic i have seen from the forum of the horsehead.

well done!!

ballaratdragons (Ken) · #4 07-10-2005, 11:53 PM

I can see it. I just zoomed in about 50%, brought the Brightness up a tad and the contrast up half a tad. Great shot. Your right david, no Horseheads in here till now. (not that I can remember)

beren · #5 08-10-2005, 12:10 AM

Wow high standards think its a top effort , last thing i tried a couple weeks back and failed completely

asimov (John) · #6 08-10-2005, 03:36 AM

Seeker.......your a perfectionist, great job mate! I totally understand your frustration about the dark frame though.

gbeal · #7 08-10-2005, 05:27 AM

Nice shot, and like the others I can't really see what is griping you. Be proud.
What is wrong with getting the gear out again, and if the temps are similar taking a few darks.
When I had a "real" CCD camera I made a library of darks, and simply used the one that corresponded to the exposure time, and temperature. Not perfect but a darn sight easier.

#8 08-10-2005, 06:11 AM

I think that's an excellent attempt too!! well done!!

regards,CS

Striker (Tony) · #9 08-10-2005, 08:10 AM

I agree.....looks to be a nice shot anyway...be proud

Robby · #10 08-10-2005, 08:49 AM

Great shot seeker. The horsehead is a tough target... I have yet to master it after 1/2 a dozen attempts! Getting a couple of narrowband filters soon so that should help. Otherwise it needs a very dark sky!
Cheers

atalas · #11 08-10-2005, 10:01 AM

Still looks good Narayan ! well done

Louie

seeker372011 (Narayan) · #12 08-10-2005, 10:52 AM

You guys are very kind...fact is at the scale I have shrunk it to, you cant really see all the noise

the real reason I was whingeing was because I thought I had nailed it..till I started to process.

Gary's suggestion makes sense...problem is last Sunday was so warm that it will be difficult to replicate those conditions again.

A library of dark frames certainly seems to be the way to go and maybe even keep track of ambient temperature, if that's not being too anal.

anyway you learn from mistakes so they say. I hope never to replicate this again!

josh (Luke) · #13 08-10-2005, 02:06 PM

Youll get it next time. Still your "stuff up" stands well above my success at the moment so that aint so bad.

Itchy · #14 08-10-2005, 05:18 PM

Quote:

Originally Posted by seeker372011

You guys are very kind...fact is at the scale I have shrunk it to, you cant really see all the noise

the real reason I was whingeing was because I thought I had nailed it..till I started to process.

Gary's suggestion makes sense...problem is last Sunday was so warm that it will be difficult to replicate those conditions again.

A library of dark frames certainly seems to be the way to go and maybe even keep track of ambient temperature, if that's not being too anal.

anyway you learn from mistakes so they say. I hope never to replicate this again!

I think you are being a little hard on yourself too. It is a great image of a very difficult object.

What are you using to do your calibration?

The Library idea is a good one, however I have just started to use the latest ImagesPlus Beta. It has an automatic darkframe matching routine designed to take account of temperature differences in your light frames. So far so good. So it might be possible to have a small library of darks and use IP to scale them to match!! I'll let you all know how it develops.

Cheers

zipdrive (Dave) · #15 08-10-2005, 05:43 PM

Pretty good shot though!!

I had a go at the horsehead lastnight for the 1st time and it sure is a tough one to capture.

just curious, what iso setting did you use with your 300d? and which scope?

seeker372011 (Narayan) · #16 08-10-2005, 06:37 PM

Quote:

Originally Posted by zipdrive

just curious, what iso setting did you use with your 300d? and which scope?

ISO 400 -each sub was of 10 minutes

The scope was my ED80, the 5 inch was the guidescope.

seeker372011 (Narayan) · #17 08-10-2005, 06:39 PM

[QUOTE=Itchy

What are you using to do your calibration?

I have just started to use the latest ImagesPlus Beta. It has an automatic darkframe matching routine designed to take account of temperature differences in your light frames. So far so good. So it might be possible to have a small library of darks and use IP to scale them to match!! I'll let you all know how it develops.

[/QUOTE]

I use IRIS..but the more I'm hearing about ImagesPlus the more interesting it sounds

seeker372011 (Narayan) · #18 08-10-2005, 06:41 PM

Quote:

Originally Posted by Itchy

What are you using to do your calibration?

The Library idea is a good one, however I have just started to use the latest ImagesPlus Beta. It has an automatic darkframe matching routine designed to take account of temperature differences in your light frames.
Cheers

I use IRIS..but the more I'm hearing about ImagesPlus the more interesting it sounds

rumples riot · #19 08-10-2005, 07:20 PM

Do you want to send me the stacked image without ps processing? I think I can bring out the nebula better. You got the HH there on the image posted but I cannot do much with the current image.

seeker372011 (Narayan) · #20 08-10-2005, 09:20 PM

Quote:

Originally Posted by rumples riot

Do you want to send me the stacked image without ps processing? I think I can bring out the nebula better. You got the HH there on the image posted but I cannot do much with the current image.

For sure..big file though..we are talking 32 meg as PSD .. I could convert to jpg but still will be a pretty big file ?is that OK?

its a 7.5 meg BMP, will be much smaller as jpg