orion photo

kamayok3 · Post by **kamayok3** » Fri Feb 02, 2007 1:06 pm

yes..stacking problem.

Tommy

kingkong · Post by **kingkong** » Fri Feb 02, 2007 1:07 pm

sifu uni24, are you referring to the elongated or seeming double stars..?
i'm not sure if it is a problem with the stack/alignment or mount/drift/pec/vibration (i.e. bad frames were used).
all the frames were taken without reframing so why would it give alignment problem.. unless it's rotation... but...
anyway, what alignment method do you recommend to use in iris? there's no manual adjustment to alignment right? one just choose one-star or something and hope the software will get it right...

Post by **perseid** » Fri Feb 02, 2007 2:02 pm

When you mentioned "center and the edge nebulosity is way too high"
U mean your images were suffered from vignetting? If not too bad, can still save.

What universe24 says is correct. There are some alignment problem possible with one of your frame. (At first, I thought it was supernova!!!. New stars popping here and there...just joking)

At 3.15 position of any stars, especially, bright ones, you will noticed the "shadow" of the bright star. IF done in registax, I can understand that the software have problem aligning the first and the last frames, where the alignment stars may drift a lot. The software can get confused if there are too many stars in the field of view.

Try processing the image again. I'm sure the result would be better.

universe24 · Post by **universe24** » Fri Feb 02, 2007 2:27 pm

To align & stack star field photo using Registax, we can choose manual aligment to align manually. This will avoid from miss alignment.
I am sorry that I still not touch IRIS as my prime processing software...cannot help...if possible, choose 2 stars for automatic alignment.

chrisyeo · Post by **chrisyeo** » Fri Feb 02, 2007 2:37 pm

I thought there was something odd with the image at first, and looking now it is obvious that one of the frames has been misaligned.

Just recheck the images (you can load and 'blink' them) and restack them.

For those who are curious to try out IRIS, it is very simple and more powerful than registax. The alignment can be done on full auto with global matching. It can even do transformations to correct for lens distortions.

Try using 'stellar registration' and 3 star align or global matching. Show us your new result, kingkong!

clear skies,
Chris

kingkong · Post by **kingkong** » Fri Feb 02, 2007 4:06 pm

thanks Chris. i'll try global matching on the orion. i tried global_match on some m42 images and the result was much better than one-star. but it took a loong time to churn, i guess that's another reason to upgrade my pc...

kingkong · Post by **kingkong** » Tue Feb 06, 2007 2:55 am

and...

what's wrong with this image of M42?

single frame, lxd55 unguided, 56sec, iso1600, unmod eos350d, wo zs66 petzval prime facus. Neat noise reduced, ps processed and cropped.

all comments and advices would be highly appreciated. except - please don't tell me i need an apo... :oops:

cataclysm · Post by **cataclysm** » Tue Feb 06, 2007 9:32 am

what's wrong with this image of M42

Hi Kong, I see nothing wrong in this image. In fact I was amazed at what this little scope can do. Lots of nebulosity with just even with just a single frame. A stacked image should look great!

chrisyeo · Post by **chrisyeo** » Tue Feb 06, 2007 11:12 am

Great image! Stars are overblown but you can deselect them and leave them out of the stretching used in the nebula.

TG Tan has a rough guide to the process:
http://www.angelfire.com/space2/tgtan/p ... _part3.htm

You can then further use Remus' method of 'star shaping' to improve the look of the stars.

kingkong · Post by **kingkong** » Tue Feb 06, 2007 12:22 pm

Chris, thanks for the tip on overstretched stars and the reminder to TG's guide.

could you please kindly point me to Remus star-shaping method? my search skill not too good... thanks.