Back into imaging at last - M16 in Ha

[multiweb (Marc)]

Hi Guys, just finished processing that one. 10x600s in Ha, dark/flat calibrated on my newly flocked 5” newtonian last night. Probably need more data but I’ve put nearly 5h on M8 so something had to give - Still processing M8 - will post later. Trying to do a HaL RGB .

Full frame is at: http://www.multiweb.com.au/astro/M16_Ha_20090703_f.jpg [2.44MB]

Enjoy - Comments/tips most welcome

[TrevorW]

Really nice image Mark tracking etc looks spot on. I like the errie look of HA images something surreal about them is this possible with a DSLR

Cheers

[Hagar (Doug)]

Very nice Marc. The detail all beit small is really good. I think I am starting to enjoy Ha as a mono image. Still not taken by false colour NB offerings.

[bokglob (Darrell)]

nice work there marc really good depth and detail,very impressed! looking forward to your m8.

[jase (Jason)]

Good to see you back imaging again Marc. The presented FOV really suits the target well. I can't help but imagine if there's more that could be extracted from the data?? - specifically in the shadows. Perhaps a two point curve would push it further while controlling the highlights relative to the mid-tones. Overall, there is good details on display. Looking forward to seeing how you'll handle the HaRGB blends either with this image or your planned M8. A great result - well done.

[peter_4059 (Peter)]

Looks good Marc. The Ha really brings out that loop. Might have to get one



Peter

[multiweb (Marc)]

Thank you all for the positive feedback guys

Originally Posted by jase

I can't help but imagine if there's more that could be extracted from the data?? - specifically in the shadows.

Yes Jase, I've always noticed I get this problem when saving greycale pics to JPEG. The TIFF 16 bits version does show a lot more nebulosity in the dark areas and better contrast in the light areas but the picture always darkens a bit when I save to JPEG for the web. Maybe the optimisation from TIFF 16 bits to JPEG 8 bits is not handled very well in PS or am I doing something wrong? The orginal is a TIFF 16bits.

[TheDecepticon]

Good shot! Ha is awesome, always great depth and detail!

[dpastern (Dave Pastern)]

That's a new re-introduction back into imaging Marc - I'd be happy with that. Sure, more data is always nice, but it's a never ending task then ;-)

Dave

[marc4darkskies (Marcus)]

Nice job Marc - some good detail there! A bit more data would consolidate it though and give you more processing latitude. Bring on the colour!

Cheers, Marcus

[Prickly]

Hi Marc,

Excellent image and a nice scale for the chip with the new 5 inch. Your hard work has surely paid off. Were you using a Meade DSI?

You might want to experiment a little with exposure times. I'm aiming at around 40 images per session to decrease the noise and working out from my imaging time how long to make the exposure. Works ok on bright objects. Dimmer ones will no doubt need longer. These chips are so sensitive its amazing how much detail comes out even at short exposures. Have seen galaxy shots posted on this website through a GSO 12 f5 with only 5sec shots - but lots of them made me think this may be a good way to go. If you are using a DSI with envisage the shorter subs will give you lots of images for drizzle to. Also less critical if some cloud drifts across etc.

Others (more knowledgable) may no doubt argue for sure stay at 10mins but I like experimenting around with things. My impressions are it does seem to work pretty well.

Cheers
David

[jase (Jason)]

Originally Posted by multiweb

Yes Jase, I've always noticed I get this problem when saving greycale pics to JPEG. The TIFF 16 bits version does show a lot more nebulosity in the dark areas and better contrast in the light areas but the picture always darkens a bit when I save to JPEG for the web. Maybe the optimisation from TIFF 16 bits to JPEG 8 bits is not handled very well in PS or am I doing something wrong? The orginal is a TIFF 16bits.

Marc,
What is your working colour space?
-Its fine to process an image in aRGB, but you'll want to convert to sRGB at some point if the goal is web reproduction. As the gamut range is different between the two, there are some tasks best done in the desired final colour space.
Did you convert the image from greyscale to RGB?
- To be in compliance with colour space it should be converted to RGB and not left in greyscale.
Are you soft proofing the image against your calibrated monitor profile?
- Soft proofing can make it easier to visualise the effect of output based on device or colour space profiles. The concept and set up of soft proofing is too much to cover conclusively here, but in short it can assist you in the validation of your work. Maybe worth investigating.

Keep at it!

[Alchemy (Clive)]

very good resolutin with a 5 inch newt, well done


clive

[lesbehrens (Les)]

nice

[Tamtarn]

Very nice Marc we look forward to seeing your M8. Has the flocking helped by the way?

[multiweb (Marc)]

Thank you all for the good feedback . Much appreciated.

Originally Posted by marc4darkskies

Nice job Marc - some good detail there! A bit more data would consolidate it though and give you more processing latitude. Bring on the colour!

Cheers, Marcus

Thanks Marcus . I'll stick more data in Ha to start with. I don't know how to blend in Ha yet. Fred's doing a talk next week at the club astro-meeting so I'll wait till then to hear it from the horse's mouth.

Originally Posted by Prickly

Hi Marc,

Excellent image and a nice scale for the chip with the new 5 inch. Your hard work has surely paid off. Were you using a Meade DSI?

Thanks David. Nope. I use a QHY8 on a newt (Celestron Nexstar 130SLT). My image scale at prime focus is approx 2.5 arc sec/pixel. Nice "widish" field but at the limit of undersampling.

Originally Posted by jase

...The concept and set up of soft proofing is too much to cover conclusively here, but in short it can assist you in the validation of your work. Maybe worth investigating. Keep at it!

Wow! Couple of things I seriously need to check ... Thanks for the offer Jase. I definitely have got more reading to do and will get back to you as not to waste your time with trivial questions. Good point. I never took notice that I'm in 16bits greyscale space.

Originally Posted by Alchemy

very good resolutin with a 5 inch newt, well done - clive

Thanks Clive - I bought an artifical star from astrozap - best thing I've ever done. I have setup my scope in the garage looking at the AS 60m away or so in a black bucket over a grassy field. It's great because you can do that anytime even during the day. I also bought Suiter's book. Still not understanding everything but I'm getting there slowly. Anyway the proof is in the pudding. Glad you've noticed. That's a $400.00 scope off the shelf .

Originally Posted by Tamtarn

Very nice Marc we look forward to seeing your M8. Has the flocking helped by the way?

Thanks guys - glad you like it. Has the flocking helped? HUGE difference. The improvement in contrast is massive. To give you an idea: shooting flats with my EL-sheet in the past, with a Ha filter I would need a minimum of 4s exposure to reach the desired level of 9000ADU. Now to reach the same level I have to do 11s exposures. Just shows how much stray light use to contribute to the final illumination pre-flocking.

[Omaroo (Chris Malikoff)]

Excellent Marc - a very pleasing image to me. I'm falling for Ha, and I really have to get a filter soon otherwise I'll go bonkers seeing takes like yours and not being able to sample some too.

It's nice to what you're getting out of the 5" newtonian. I'm keen to my new 6" to work, and on the basis of what you're achieving I can't wait.

Thanks Jase too, in reference to presenting mono web images in RGB colourspace. Good tip.

[multiweb (Marc)]

Thanks Chris. Yeah I can't wait to see what your new Tak's like on DSOs. Should be pretty cool.

[Craig_L]

Nice detail Marc. Look forward to the finished image with RGB. You've encouraged me to try my Baader Ha filter on this target with the DSLR.

Craig

[multiweb (Marc)]

Originally Posted by Craig_L

Nice detail Marc. Look forward to the finished image with RGB. You've encouraged me to try my Baader Ha filter on this target with the DSLR.Craig

Sounds good. I wasn't aware they had Ha filters for DSLR. Looking forward to your shots too.