• Welcome to Orpington Astronomical Society.
 

News:

New version SMF 2.1.4 installed. You may need to clear cookies and login again...

Main Menu

Wonderful evening with a sting in the tail

Started by Carole, Oct 26, 2009, 08:56:30

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Mike

Don't try to run before you can walk. Practice using your equipment first. Forget about getting pretty pictures, just get to know how to sue the equipment and get your technique right first. Once you have mastered that, then step outside to get the images.
We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology. Carl Sagan

RobertM

Carole,

There's nothing wrong with autodarks at this stage but you don't want to be applying darks you've taken manually as well - it's either one or the other.  You will find however that spending half your imaging time on the autodarks (in camera noise reduction) is not a viable option as it wastes too much time as well as being unnecessary for longer sessions.  As Mike has just mentioned, familiarity with your kit and technique is essential.  I've spend numerous wasted hours so can vouch for that first hand.

btw. That's a very nice Pleiades, you must be dead chuffed!

QuoteI am finding the post-processing a huge challenge

Join the club !!!

Robert

Jim

Carole

Well done, that's a great picture

JohnP

Carole that is really very good for your first image & only 30secs... Great start - John

Fay

Very nice image, Carole, lots of nice subjects around to do now
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Simon E

That is way cool. Well done, I'm gonna have to get out some more, to try and catch you up..... you are way ahead of me ;)

I 'll be learning off you.

si
SW 130DPS reflector main imaging scope, SWST80 refractor Guide scope, HEQ5 Mount with syncscan
ZWO ASI 120MC 1/3" colour camera Guide camera, Nikon D5100 + D3100 Imaging cameras

Daniel

Carole, that really is excellent, the stars are wonderfully round, and the nebulosity is coming through nicely. If you want a hand with the processing techniques I could show you some stuff if I have some time some weekend.

Daniel
:O)

Carole

Many thanks every-one.

QuoteI 'll be learning off you.
Well that will be a first, but like every-one else, always happy to help where I can, but if you want really expert advice I'm not the one to ask. 

QuoteIf you want a hand with the processing techniques I could show you some stuff if I have some time some weekend.
Yes please Daniel.  I do have a certificate in Photoshop, but of course the techniques for Image processing are quite different.  I can then come back and show any-one else who wants to learn what I've learnt and give something back.  i.e. 
QuoteI am finding the post-processing a huge challenge  Join the club !!! 

Carole


Carole

QuoteI've spend numerous wasted hours so can vouch for that first hand.
Yup, have had quite a few of those already.

Carole

Tony G

Carole,

Great image, and glad to see that you are not giving up the easily. I hit a few hurdles when I started and it put me back, but you are now encouraging me to have another go with the canon and with the advice people are giving you, it is also helping me.
Keep up the good work, and I may be asking your advice soon. ;)

Tony G
"I'm normally not a praying man, but if you're up there, please save me Superman." - Homer Simpson

Carole

Thanks Tony. 
Quoteglad to see that you are not giving up the easily
Yes there have been times when I've been close, but I didn't want it to beat me.

Quotewith the advice people are giving you, it is also helping me
Yes it is always a good idea to keep notes of things being told to some-one else, thats what I have been doing at times. 

Carole

The Thing

Better than my best effort at the Pleaides and I've had a few goes.

Great stuff, keep at it Carol!

Carole

Thanks Duncan.
Would never have got this far without all the advice I have had from every-one.   

Carole

Carole

While the skies have been awful I have been practicising post-processing.  When I originally processed this image (see above) it looked absolutely vile in colour, so I cheated and converted it to B&W and then added back some blue.

Anyway, I have managed to re-processed M45 in colour this time and used Iris to remove the light pollution (as per Mark's talk and advice), and used a combination of Iris and Photoshop.

I'm not sure whether this is an improvement or not, but at least I I managed to do it in colour this time.



Carole

MarkS


Carole, 

The colours look far more natural this time round.

Since you are using IRIS, you can reduce the star bloat by doing "View | Colour Stretching" and adjust the "Stretch" sliding bar to the desired effect.

Once you've done that then use "Geometry | Binning" to reduce the image size by say 3.  This has the effect of summing pixels and will help to reduce noise on the fainter nebulosity.  You'll need to adjust the "Threshold" sliders (or use Auto) to adjust the image brightness afterwards.

After that, to reduce noise further, place a rectangle around some noisy background -  right click and choose "Statistics" to obtain it's sigma (this is the same as standard deviation).  You can then choose "Processing | Adaptive Filter" and enter that value of sigma into the "Noise" entry.  The results can sometimes look a bit unnatural so I often put just half the sigma in the noise box.  However, you might find that Photoshop has some better noise reduction - I find the Noise Filter in Photoshop Elements 3.0 be be excellent - it has 3 sliders for "Strength", "Preserve Details" and "Reduce Colour Noise".  I don't know if the full  version of Photoshop has the same thing.

Mark