Hi all
Went deep last night in the very good conditions.
Firstly the Omega Nebula.
7x10 minutes, ISO 400. Idas uv/ir and Baader UHC-S filters. Hutech Modded 350D camera. 10 inch f5.6 newtonian hand off axis guided.
Then the Helix. Did some experimenting here as the fiest part of the session was 5x10 minutes same settings as above, but then I tried some very long subexposures, did 3 lots of 30 minutes each! I also did a 30 minute dark to use with that set immediately afterwards. I procedded both sets separately, adjusted levels till they appeared similar then aligned and stacked them together. The result is here, total time of 140 minutes. Im glad I did this as I found it ins indeed better to stick with 10 minute subs. the 30 minute ones are of course brighter, but noise also increases. (Houghys cooled camera would be different, I reckon in that case the longer subs would be better)
Guided as above. Guiding for 1/2 hour continiously was a bit of a challenge but not too bad All images prosessed as usual in Iris and Potoshop with resizing of jpegs by old but quick Paintshop Pro 4
I think that's the first time I've seen the Omega in the Omega neb. I find it easy to pick the swan... and haven't yet picked the lobster. Unless I'm just kidding myself, the omega is just below the swan... it's a darker shape in the nebula, a capital omega written at about 30 deg up to the right in this frame. I can see how it would stand out in a shallower exposure.
I see what you mean about the noise in the helix, but you've got some great deep detail there. It looks to me like there's some very faint detail on the verge of coming out, but I think a lot more 30 minute subs would be required to achieve a better S/N ratio... maybe some 30 minute subs on Houghy's cooled DSLR???
Definetly great set of images you have there. Helix is grand with the outer arm very visible - well done!!!
PS. Thank God we finally have some clear skies.
Both images a very clear and deep Scott. I now know how dim the Helix Neb. is. These images really show the quality of the mirror of your 10".
This is the second time in as many days that I have been tempted to build a 12" Newt Astrograph. Problem is I think it would be at the limit of my EQ6.
Thanks all.
Its the deepest ive gone with the Omega, one can see different shapes in it, and outlying nebulosity.
When taking test images I noticed how small I could get the stars, seeing was quite good, also I had the scope out from sunset to help equalize the mirror temp. Mind you the temperature plummeted as the night wore on, making it hard to get a dark the same temp as the light frames. This is where a cooled camera is good, not only less noise to start with, but taking a dark at the exact same temp as the lights makes the subtraction process far more accurate.
I estimate that 1 HOUR shot with Houghys cooled DSLR would have less noise than a 10 minute uncooled one at 15 degrees ambient. As Houghys also has an internal thermoprobe one can monitor the CMOS temp and as the night cools, can reduce the cooling to keep the temp. constant. Id get about 3 or 4 degrees CMOS temp on a night like last night, and could keep it constant when taking the darks too.
One other REALLY handy thing I do have is the Canon ACKDC20 AC Adaptor Kit. No more battery worries, I just keep going all night. Tad expensive, I got mine from http://www.cameraworld.com.au/Canon_.../canack600.htm
but at the time could not find any on Ebay but they might appear there from time to time. The adaptor has good capacitors in it as it will "store" a few seconds of power so momentary power interruptions wont shut down the camera.
I should point out that Hougys cooled camera kit includes a power adaptor that downconverts the 12volts that the peliter cooler uses and the whole thing runs off a 240v to 12v PSU so he doesnt have to worry about flat batteries either.
Scott
very nice captured scott. the faint arms really stands out in the helix. in regards to the swans bright star bottom left, what is that shadow behind the star? thats what i got from my recent horsehead shot.
Thanks Eric.
I believe it is internal reflection from the UHCS filter, I get it only on bright stars when using the UHCS. I normally shoot with the UHCS on top of the uv/ir filter, perhaps I should reverse that and see what happens.
Scott
Dang that good - my back wasnt crash hot and so I didnt get to do anything - oh for a permanent observatory!! Scott, simply stunning and I am glad you made the most of what you Have
Many thanks
I love this hobby. I see what visually is a faint smudge in the viewfinder yet can bring out all the colour and detail in a permament image. Well worth having to spend hours staring into a guider keeping a guidestar as still as I can against a red reticle, using a telescope, drive and drive corrector that is 21 years old! There was no such thing as digital imaging when it was built.
Beautiful Scott! they are both lovely images
What a guiding marathon for you..I don`t know if I could do many 1/2 hour shots these days!
But your result is defiantly worth the effort!
Many thanks
I love this hobby. I see what visually is a faint smudge in the viewfinder yet can bring out all the colour and detail in a permament image. Well worth having to spend hours staring into a guider keeping a guidestar as still as I can against a red reticle, using a telescope, drive and drive corrector that is 21 years old! There was no such thing as digital imaging when it was built.
Once again Scott I tip my hat to you (you legend!). I find your "locked in the 80's" approach to imaging very cool
These are rather good images, particularly considering your back breaking marathons.
My only critique (if I may?) would be to work on neutralising the backgrounds a little to get them more naturally dark and removing the red cast to truly delineate the nebulosity from the sky bakground. Currently the red bias looks to ba a little too strong and the stars can tend to lose there colour variations and look a little too red/pink...?
All images prosessed as usual in Iris and Potoshop with resizing of jpegs by old but quick Paintshop Pro 4
Wow! They're great Scott!
. Unless I'm just kidding myself, the omega is just below the swan... it's a darker shape in the nebula, a capital omega written at about 30 deg up to the right in this frame. I can see how it would stand out in a shallower exposure.
