Witch Head Nebula and Rigel wide field

[naskies]

My CCD is en-route back to SBIG for repairs, so I had to revert back to my DSLR before bad weather terminated this month's imaging effort.

Here's a wide field of the Witch Head Nebula and Rigel (1500 px version (http://dl.dropbox.com/u/13644418/iis/WitchHeadAndRigel.jpg)).

I experimented with using In-Camera Noise Reduction (sacrificing half of my shooting time) and found that it works *much* better than shooting darks separately. This needed a bit more data to really bring out the Witch Head, but alas the weather wasn't cooperative.

Details: 21x 180 sec subs (63 min total lights, 126 min including darks), 135 mm, f/4, ISO 1600, ICNR taken with a Canon 5DmkII and 135 mm f/2L lens unguided on an EQ6PRO.

[Lester]

Nice one Dave, she is faint and you have revealed her well.

[RickS]

Nice work, Dave! Hope your camera is back soon. Mine is finally fixed and about to ship back from Apogee...

[DJT]

Very nice image David. Only thing I heard about ICNR is it tends to eat stars?

[naskies]

Thanks Lester!



Thanks Rick! I hope to get my CCD on that region this season... your Halloween image was an inspiration :)

Good to hear that your camera is finally fixed! Mine's still en route to SBIG, but if they can turn it around in the 2 weeks as they suggested I should have it back in time for Feb's new moon.



Thanks David! Luckily, with wide fields I have plenty of square stars to waste :lol:

I may have confused the terminology - I'm not sure if Canon actually calls it ICNR. I've heard that it's more of an issue with Nikon DSLRs? I'll have to do a side-by-side comparison to test it out, but for the mean time I'm happy just not to see any hot pixels and colour noise in the data.

[LewisM]

I agree about in camera noise reduction - works a LOT better than dark frames etc. It is annoying needing, say, a 10 minute total exposure for one frame of 5 minutes though.

If I KNOW my night will be uninterrupted, I shot with camera dark subtraction on. I KNOW the pictures will be better.

With the newer gen cameras, I am starting to notice less and less difference between high end astro cams and GOOD DSLR's.

[LewisM]

Never found Canon's ICNR to be star eater at all.

[tilbrook@rbe.ne]

That's amazing Dave!

The witch head is such a faint bugger, it's great to see it's possible with a standard lens!

Cheers,

Justin.

[naskies]

In theory, it shouldn't though - RAW should be raw, like ADU counts from CCD cameras (but it's not (http://www.stark-labs.com/craig/resources/Articles-&-Reviews/CanonLinearity.pdf)).

I can understand that maintaining reciprocity of exposures and minimising appearance of thermal noise is preferable to 99.999% of DSLR shooters, but it's a shame that we don't get to make that choice in post!



That's why there's a market for thermally regulated DSLRs and astro CCDs :)

Good luck solving your NEQ6 woes.



Thanks Justin! In retrospect, with such faint nebulosity and limited shooting time I probably would've done better doing normal separate dark frames plus shooting at f/2.8 (sacrificing some corner sharpness). Oh well... I'll probably point the mono CCD onto this region when I get it back.

[Ross G]

Nice wide photo Dave with great detail.

Ross.

[DJT]

Cheers Ross, really enjoying the FOV with this scope.

[MrB]

Oops :lol:

I think Dave meant to reply to Ross over here: http://www.iceinspace.com.au/forum/showthread.php?t=102162 ;)

[MrB]

Oops again, I got distracted by the above.

Great shot Dave.
I've not yet tried ICNR with the 60Da, honestly never even considered it! Gonna have to try it out and see how well it works for me.

[DJT]

Blush...

[prokyon]

One of my favorite objects, nice widefield!

[Larryp]

Thats great, Dave:thumbsup:

[David Fitz-Henr]

Nice capture Dave! I would think that ICNR may work better for DSLRs (esp. on nights where the temperature is changing more) as the autodark is taken as close as possible to the light frame.

[naskies]

Thanks for the kind comments everyone! Apologies for the slow replies... classes have started at uni again for my course, which keeps me very busy!



Thanks Ross!



:rofl:



Thanks Simon!



:lol:



Thanks mate!



Thanks Larry!



Thanks David! I suspect you're right, as when I shoot a run of images with BackyardEOS I see the temperatures change dramatically as the sensor heats up (but eventually stabilises half way into the sequence).

[strongmanmike]

Hi Dave, thought I had already commented on this image, must be going crazy in my old age :nerd: Wow, this is great, such a cool field and you have handled Rigel nicely too. To me it looks like you just need more data, its already pretty good as is with lots of faint nebulosity coming through there, loads of exposure will make it really quite a fabulous image :thumbsup:. Having to do ICNR along the way will make it a bit of a marathon effort though, I know, but might be worth a try :)

Mike

[CoolhandJo]

Nice wide field. Spooky because its so prominent as a witches head. Nice one.

[multiweb]

Beautiful field and colors. Heaps of tiny stars. :thumbsup: