NGC 4725 - closer view

[Jedi2014]

Olly and Steve recently presented their great image of the wide filed around NGC 4725 with a PN as a bonus. At the same time I was capturing the same galaxy with my newt and like to show a closer view today. Even as NGC 4725 is one of my favourite galaxies, it never made it into my collection. I gathered luminance data twice in the last 14 month, but never finished the image. So I can say here is a one year project:

More info and data: http://www.spaceimages.de/en/astrophotos/galaxies/ngc-4725

or: http://www.astrobin.com/293811/

Cheers
Jens

[Allinthehead]

Beautiful.

[Rodd]

Another winner.  I see you use a CLS filter.  Does that increase your exposure time significantly?  I have been trying to determine exactly where this filter threads into my optical path so that all filters benefit from its placement.  

Rodd

[DaveS]

Hi Rodd

I'd be inclined to put the CLS-CCD in the filter wheel and only use it for L, otherwise it takes out too much of the wanted light, especially in the blue and green.

Sorry to jump into Jens's thread.

[Rodd]

18 minutes ago, DaveS said:

Hi Rodd

I'd be inclined to put the CLS-CCD in the filter wheel and only use it for L, otherwise it takes out too much of the wanted light, especially in the blue and green.

Sorry to jump into Jens's thread.

I have issue with LP in RGB too though.  Maybe in the F4 system it works better due to the increased native speed.  I don't know.  The Astronomik CLS (the one Jens used) is suppose to have almost 100% transmission--but maybe that's advertisement hype.

Rodd

[Jedi2014]

Hi folks,

never mind to have a sub thread here :-)
I indeed use the Astronomik CLS CCD filter only for L. This increases the exposure time by 80% and delivers more contrast and a far darker background as the normal Astrodon L filter. Without the CLS filter I have distrubing reflections from the lights of my neighbours and the near city. I can not see any difference in transmission between CLS and L. Astrodons RGB filters are quite narrow, so there I don't have any problems and no need to add the CLS (which I would not recommend anyway).

See the images below: 360 sec. exposure. Guess which one is Luminance only and which one is CLS

Jens

[DaveS]

This is the transmission curve for the CLS-CCD filter from the Astronomik site

In the red it's not too bad, but pretty well a disaster for the blue and green if you stack it with a colour filter.

Sorry this is dragging the thread OT so after this I'll keep OT.

[toxic]

beaut image and nice processing

[PatrickGilliland]

Super image - like EVERYTHING about that - well done Jens

[wimvb]

Congratulations, Jens! Image of the day on Astrobin.

[Jedi2014]

Ups, thank you for the hint. It's an excellent start into the week 

[gorann]

 

7 hours ago, wimvb said:

Congratulations, Jens! Image of the day on Astrobin.

Superb image and congratulations to the IotD! Wim is really quick at spotting these

[wimvb]

They're not difficult to spot. Especially if you have latenight oil to burn. They're much more difficult to predict.