IC1396 Elephant Trunk in Cepheus 250512

[Fay]

I have been using a 7nm ha filter, but individual subs from the last 3 images I have done have not shown much detail, so I deleted them along with the christmas tree that I had taken at Kielder.

when I compared an IC1396 taken in 2010,  with the Atik and 12nm ha, the difference was really noticeable. I had forgotton to take the 12nm to DSC, this weekend, so John P offered to pick mine up from my home & bring it down to me on his day visit to camp.
So this is 20x600, QSI534ws, 12nm ha filter, 0.85 fr. ED80.

[Tony G]

Fay,

That's two great images this weekend, this one and the one that confronted JohnP when picking up the filter. 

Great image Fay and you were worried that you didn't get anything?

Tony G

[Fay]

 

well I could not see properly, but next time have picked up a tip from Carole. Process sitting in the portaloo in the field!!!!! I thought she was in there a long time

[mickw]

Cracking image John.

Typical of Fay to try and take credit for it 

[MarkS]

Vey nice Fay.

The contrast is good and there lots of faint stuff and detail.

Mark

[JohnP]

Well I really like that Fay - came out great - you must be chuffed. I think the 7nm Ha comes into its own when imaging from Bromley/ light pollution etc...

Great result - John.

[Fay]

thanks a lot John & Mark. So do you think that the 12nm is best from dark sites, John, and the 7nm locally?

[Carole]

Very nice image Fay.

Carole

[RobertM]

That's an excellent result Fay.

What john has said about the 7nm coming into it's own in Bromley is completely true, I would also add it also goes for DSC.  The 7nm will almost always beat the 12nm as it lets in less stray light and makes the back ground stars tighter (and fainter).  If you compare the background counts of both filters in the same conditions then you will see what I mean.  The Lyman Ha emission happens at exactly one frequency and not over a band so it will not make any difference how wide the filter is as it'll capture exactly the same amount of Ha light.  A filter will capture a band of other frequencies depending on how wide it is and therefore the background count from other light sources will increase thereby reducing contrast.  An analogy is - do you prefer more or less light pollution ?

Robert

[Fay]

thanks for that info Robert

Fay