Silver coin -first full picture

[alpal]

Hi Everyone,
This is my first attempt at a fully stacked picture with my
new 10" f4 carbon fiber Newt. with ONTC mirror.
It's over 3 times faster than my old 8" f6 Newt.
It's taken me 10 months from the time I decided to buy it
to get it fully operational.

It consists of 57 x 2 minute frames all binned 1x1.
There are 22 sub frames of Luminance - the rest in RGB -
flats, darks & bias frames applied -
from an outer suburb of Melbourne.
with a QHY9 mono camera, Astronomik 2" CLS-CCD filter in front of all 2" filters.
PHD2 guiding using dither with Lodestar & TS9 OAG,
Baader RCC1 coma corrector.
Processed with: DSS, NASA FITS Liberator, PS CS5 & Fitswork4.


The full frame & a 2.2 MByte version is available on flickr here:

https://www.flickr.com/photos/247194...in/photostream


Rotated & cropped 1 to 1 pixels:
A bit noisy - needs more integration time:
https://www.flickr.com/photos/24719437@N03/21571754433

edited to show a more blue flickr version.

There are many background galaxys just visible in the full frame.
I am pleased to be able to present something after such a long time.
I look forward to taking many more pictures & with a lot more integration time.

Any comments welcome.

cheers
Allan


The picture below is cropped from the full frame.

[Peter Ward]

Some things need working on....this is well known and predominantly blueish coloured galaxy, hence, the colour is off.

2 minute subs in not good good for the urban imager, you really want to be sky limited to supress the urban glow and maximise signal.

Try 10-15 minutes.

Image sharpness is really quite good, so stick with it

[Atmos (Colin)]

There is a nice amount of detail in the galaxy but I do agree with Peter, the colour does need some balancing. Other than that, you've got yourself a nice image to come back with

[alpal]

Originally Posted by Peter Ward

Some things need working on....this is well known and predominantly blueish coloured galaxy, hence, the colour is off.

2 minute subs in not good good for the urban imager, you really want to be sky limited to supress the urban glow and maximise signal.

Try 10-15 minutes.

Image sharpness is really quite good, so stick with it

Thanks Peter,
what about this with a bit more blue?

[astronobob (Bob)]

Thats very well detailed Al, speshly for the F/Length, Mono cams are awesome
The Blues are much better in your touch-up

[alpal]

Originally Posted by Atmos

There is a nice amount of detail in the galaxy but I do agree with Peter, the colour does need some balancing. Other than that, you've got yourself a nice image to come back with

Thanks Colin,
I'll change the image on Flickr with a bit more blue.

cheers
Allan

[Peter Ward]

Nup still way too red. I'll save you a little homework

There are lots of images on the web but , Marcus' image has pretty well nailed it.

http://www.pbase.com/gailmarc/image/157949573

[DJT (David)]

Nice to see you up and running with that rig of yours. Been an interesting drama and good to see you got it sorted.

+1 for Marcus image as a model for colour on this. Egg yolk yellow in the centre and plenty of Blue.

Detail though is very good. Enjoy the scope !

[alpal]

Originally Posted by Peter Ward

Nup still way too red. I'll save you a little homework

There are lots of images on the web but , Marcus' image has pretty well nailed it.

http://www.pbase.com/gailmarc/image/157949573

OK Peter,
I can't equal the picture from Marcus but this is
as close as I could get to his colours at this time of night.
It's showed up more noise but I like it.

cheers
Allan

[alpal]

Originally Posted by astronobob

Thats very well detailed Al, speshly for the F/Length, Mono cams are awesome
The Blues are much better in your touch-up

Thanks Bob,
Mono cams give much better results.
Still the pic could have done with 4 times the integration & maybe longer sub frames.
I also changed the picture on flickr - Peter was 100% right.

cheers
Allan

[alpal]

Originally Posted by DJT

Nice to see you up and running with that rig of yours. Been an interesting drama and good to see you got it sorted.

+1 for Marcus image as a model for colour on this. Egg yolk yellow in the centre and plenty of Blue.

Detail though is very good. Enjoy the scope !

Thanks David.
I changed the pic on flickr.

cheers
Allan

[DJScotty (Scott)]

Hi Al,
that's a really nice photo, especially shot from suburban Melbourne.
I am contemplating using a CLS filter in front of my RGB filters as you have done. Will be watching with great interest!
Again, nice image

DJ Scotty

[alpal]

Originally Posted by DJScotty

Hi Al,
that's a really nice photo, especially shot from suburban Melbourne.
I am contemplating using a CLS filter in front of my RGB filters as you have done. Will be watching with great interest!
Again, nice image

DJ Scotty

Thanks Scott,
It's been a lot of hard work to get this Newt. going.
I returned the first mirror for a more expensive ONTC type with full report.
The mirror seems to be excellent - a few subframes had stars as small as FWHM of 2.8 arc seconds.
I never changed the focus over the night.
The stars just got better as the elevation went higher.
The carbon fiber tube is great for constant focus.

The CLS-CCD filter is good as I have a whole row of sodium street lamps down the road beside me.
That filter has a sodium light blocker.


cheers
Allan

[troypiggo (Troy)]

I understand the temptation to use LP filter, but I've always had trouble getting colour balance with them because they really mess with the captured spectrum. Try testing without and see how you go.

[Shiraz (Ray)]

well, persistence paid off and you got there! congratulations on a very good first image. lots of fine tuning from here on in, but the system works .

[alpal]

Originally Posted by troypiggo

I understand the temptation to use LP filter, but I've always had trouble getting colour balance with them because they really mess with the captured spectrum. Try testing without and see how you go.

Thanks Troy,
I also think that maybe taking only RGB with no CLS-CCD filter
& much longer subframes might be better.
A clear Luminance filter picks up a lot of light pollution noise
from my location.
I have to see what will work best with this new Newt.
My picture is too noisy which I didn't expect from stacking so many shorter subframes.
22 Lum frames gives me nearly 1/5 th the noise of a single frame.
12 frames each of RGB was maybe not enough - only 1/3.5 of the noise.
Remember that I dithered all frames and also took 22 dark frames.


The idea of the 10" f4 Newt is that it keeps my system very portable.
It fits easily in the back seat of my car & the NEQ6 mount fits in the boot.
What I really want to do is get some dark site pictures.

Also remember that I am in a testing phase - this is a prototype.
It may give me better flats if I take the nose piece off the QHY9
& adjust the imaging train to suit.
That will put the camera sensor closer to the focuser.
I may also consider a better mirror cell & perhaps a different coma corrector.

cheers
Allan

[alpal]

Originally Posted by Shiraz

well, persistence paid off and you got there! congratulations on a very good first image. lots of fine tuning from here on in, but the system works .

Thanks Ray -
yes - plenty of fine tuning as per my post below.
This new scope has renewed my interest in the hobby.

cheers
Allan

[gregbradley]

Looking very good Allan.

2 minutes does seem pretty short. You have to get above the noise floor of the camera and 2 minutes is extremely short and won't do that.

Also total exposure time needs to be higher and things will improve as the hours build up.

But the main points are great, sharpness, round stars.

Adding some Ha will help as well.

Greg.

[rustigsmed (Russell)]

great to see you imaging again Al
nice and sharp first light.

Russ

[E_ri_k (Erik)]

Nice one Allan, good first light, those dust lanes stand out well
Erik