leo triplet help

[seanpius]

i was wondering if there is anyone out there that could tell me what i am doing wrong with my imaging.This is an image i took of the leo triplet over two nights,it consists of 30x300s lights and 24x300s darks seeing wasnt the best as i get light pollution where i am,i used phd for guiding ,stacked in dss and just messed about with the levels in photoshop cs6.My setup is neq6 mount orion ed80t cf,tele vue 0.8x reducer/flattner,full spectrum canon 1100d with astronomik cls ccd clip filter.as you can see the stars arent the best,any advice would be much appreciated.

sean,

[Gina]

What's wrong with that Image? Looks pretty good to me You could probably reduce the background noise with more data. You don't say what ISO value you used. I would suggest 800 or 1600. If you tell me what you think is wrong with your image I may be able to help but TBH I think that's quite reasonable for an uncooled DSLR.

[Pete Presland]

agreed not much wrong at all, maybe some flats and more data to "improve" it, but certainly nothing wrong with it nicely done!

[seanpius]

Hi Gina,

i was using iso800,the problem im having is that i dont think the stars are right,i have attached a file of an example the large star seems to have a piece missing,is this to do with my setup.

regards,

sean.

030413.TIF

[Gina]

I see. Looks like you have something obstructing your field of view within the light path, as if the aperture isn't round.

[nightvision]

Could the objective be pinched in its cell?

[nytecam]

Nice image - well done The overall image seems very red so colour balance could do with a tweak

[Davey-T]

Did you take any flats ? looks like quite a few dust spots.

Dave

[Jessun]

Agree with the comments above, in that there's nothing wrong with it, but flats seem as Dave pointed out to be missing and they are very useful indeed!

I had a quick play with your jpeg, and did a few simple steps:

-Balanced the colour using curves, getting the red down a notch

-Selected the stars using a routine you'll find in the stickies, I think it's Martin_B's

-Increased saturation on the stars, and reduced lightness to make them appear a bit tighter and more interesting colour wise

-Clone stamped out the big black spot lower left

-Incresed saturation on the three galaxies

-Ran a basic noise reduction

This is by no means masterclass, but your data is on a whole very good! Nothing wrong there ! To better an image, a good tip is always to take more subs. That keeps the noise in check, and that allows more work to be done in processing before noise creeps back in.

/Jesper

The result is below,

[seanpius]

Hi all,

thank you all very much for your help and comments,advice will be taken,i will try for a lot more subs tonight and also add flats to see if i can do any better,sky is nice and clear tonight here in strabane n,ireland, hope it is where you all are.

regards,

sean.

[Gina]

I'm waiting for the clouds to go away haere as forecast but no joy so far Hope you do better

[MartinB]

Sean, I agree there is something nasty going on their with your stars. It doesn't look like a guiding problem. I'm not sure whether the burger shaped appearance is uniform across the image but I think it probably is, obviously more apparent on the brighter stars. This isn't the sort of appearance or distribution you would expect with incorrect reducer spacing. I agree that it is most likely to be something intruding on the optical path and, if this is the case, the most likely culprit is the clip filter. You need to check it is snuggly fitted and that the orientation of the window matches the chip.

[nightvision]

This might be useful, an image with bright stars taken with the same scope and reducer:

http://samsastro.com...sky/IC0434a.htm

Plenty of positive reviews for the scope:

http://www.cloudynights.com/item.php?item_id=927

[ollypenrice]

The biggest thing, once you've found what's messing with your stars, is to take flats. The vignetting is very obvious - a brighter inner circle. Flats are a hassle but they are so vital...

Pixinsight has a routine which would fix this though; Dynamic Background Extraction.

Olly