Vela SNR in narrowband

[gregbradley]

I don't do a lot of narrowband but thought this area may be worth it.

It was handy to image it as I did it along with M78 which set "early" (2:30am) and I had a few hours left each night to image something. Vela is near its peak at 2:30am now so I imaged it again.

TEC180FL, Apogee U16M -10C (it was hot weather), Astrodon 5nm Ha O111 and S11 filters.

S11 Ha O111 90 60 45.

http://www.pbase.com/gregbradley/image/108942571

Greg.

[Quark]

Captured some extremely delicate detail there Greg.
A stunning region of the southern sky.
Very nice image, looks great, the star colours from the filter look strange but the detail in the SN Rem is exceptional.

Regards
Trevor

[Garyh]

Nice Greg! love how small those stars come out with NB stuff.
You could almost pass this off as normal RGB if you didn`t know the area!
:thumbsup:

[Ric]

Excellent capture Greg, the delicate filaments look fantastic.

[gregbradley]

Thanks for pointing that out Trevor. I worked on the stars a bit more and they look better now.
Cheers,
Greg.

[gregbradley]

Thanks Gary. They do come out tiny. Greg.



Thanks Ric. That part of the sky has a large number of these delicate filaments. I'd like to image some other areas of it. Its high in the sky at the moment so a good time to capture it. It doesn't seem to be available to image for too long.

Greg.

[renormalised]

Very good piccie....the details are exquisite in the tendrils. Stars are pinpoint. Well done:D

[AlexN]

Great shot.. some of the red looks a little strong to me? although who am I to judge :)

[gregbradley]

Quite possibly Alex. Narrowband seems quite subjective and I pushed the red a bit as the image was originally quote greenish. I value your opinion.

Greg.

[strongmanmike]

Interesting to compare this TEC shot to the BRC shot of the same region as the FOV is almost identical, actually shouldn't they be identical? Have you cropped a bit from the TEC shot?

I am sure you are able to judge better with access to the raw full frame files and I know the BRC shot had LRGB added which would fatten the stars but to me the stars look quite a bit better edge to edge, more pinpoint and I am sure under careful comparison there is higher resolution across the board in the TEC shot..?

The F5 of the BRC must help a little especially for NB compared to the F7 of the TEC.... so what is your verdict so far then...?

You are churning out really good images like a sausage machine mate, we love it!

Mike

[AlexN]

Mike is right... For all of us stuck under clouds, your steady stream of images are keeping us alive...

[gregbradley]

Hi Mike,

I just plugged both scopes data into CCDcalc from Wodaski. It shows BRC as 1.45arc seconds/pixel and the TEC180 1.47 arc seconds/pixel.

So yeah they are pretty similar. The main difference being F5 for the BRC and F7 for the TEC (which is still reasonably fast with these sensitive cameras).

The TEC of course does not have diffraction spikes which can be a bit strong with some BRC shots with the ML8300 camera and the APO should have better contrast and sharpness. Then again the BRC has about 44% more light grasp and has aperture. So pretty close I think. A bit too similar to each other.

The acid test will be when I image a galaxy soon or maybe Omega Centauri which I have already imaged with the BRC. I have some TEC shots of Omega but unfortunately high thin cloud came over and damaged some of the subs but they did look impressive.

Greg.

[gregbradley]

Thats good. I hope I am not boring everyone as I have a couple left to process!

My dark site has gone back to default of clear dark skies all night most times even if a bit windy at times (which doesn't bother my scopes).

Greg.

[Ken]

Great shot Greg plenty of detail in the filaments. Can you explain why some narrowband shots including this one have natural looking stars while others have bright magenta including the Hubble images.
Clear skies Ken

[gregbradley]

Hi Ken,

This is Ha O111 and LRGB so there is plenty of LRGB in there - about 2 hours worth and then on top of that in layers is about 45 minutes each of Ha and O111. I use a combination of layer modes in Photoshop. Lighten usually lets the colour of the stars through. It also depends where the layers are. If you move an LRGB layer up to the top of the stack you'll get your LRGB stars coming through whereas if it is at the bottom of the stack of layers it may not.

Greg.

[gregbradley]

This image is Ha O111 LRGB. So the LRGB is showing through with the natural coloured stars.

Also when doing layers if you make a duplicate layer of the LRGB (usually at the bottom of the layer stack) and have it at the top of the layers the stars come through better. Lighten mode will also let stars through better than other modes. But other modes like screen and saturate give richer colours and detail.

Greg.

[jase]

Nice one Greg. Think you need some more exposure time though. SII is probably too weak. Try normalising the masters manually using pixel math to give greater accuracy on the blend or go with clipping masks. Good to see the 180 is working well. M78 was a hallmark image, just dont think this one has the right ingredients.

[gregbradley]

You're absolutely right Jase. This wasn't really a serious attempt as I had already imaged more fully with the BRC and put in some more serious time.
This was more a fill-in to use up the last hour and a half at the end of the night. S11 is indeed low in exposure time. I am not particularly a fan of narrowband imaging although I find Ha and O111 add fullness to an LRGB image on the right object. Then its worth the time invested.

This is the one I put the effort into:

http://www.pbase.com/gregbradley/image/108130209

The other is more a comparison for myself of the TEC180 versus the Tak BRC250. They are quite similar although I find the images from the TEC more pleasing (not this particular image but overall).

Greg.

[Ken]

Thanks for the guide on layers processing
Clear skies Ken