Eta Carina in 15 seconds.

[raymo]

Single frame 15 secs @ ISO 6400.
raymo
http://www.astrobin.com/195903/

[glend]

Raymo, pretty good for only 15 seconds. That camera works well at ISO levels I can only dream of.

[Robert9]

i'm always fascinated by this area of the sky, as you may have gathered from my previous efforts posted here. This is a lovely shot Raymo, well framed and good colour. Did you take a dark frame? i feel there is quite visible noise undoubtedly due to ISO 6400 and this distracts somewhat from the overall good quality.
Which scope did you use?
Robert

[raymo]

Thanks Glen and Robert.
The 1100D was a great buy @ $297 inc 18-55 lens. It has low noise for a budget camera, has been overtaken by other cameras now.

I never take separate darks, flats, or biases Robert, just enable noise reduction. It was taken in relatively high ambient temp conditions, so
there will be some noise. These single frame shots I'm posting are not meant to be of any real quality, they're meant to show newbies that
they can produce passable images straight away, before moving on to stacking.
raymo
Oops, nearly forgot, 8" Newt Robert. I rarely use the 80mm.

[ZeroID]

Nice shot Raymo and as others have said pretty dang good for 15 secs.
You must have some decent skies where you are. At that ISO and exposure I'd have heaps of LP red sky on the SONY and that has a very low noise sensor.
Need to get a 2" LP filter I think, next purchase.

[raymo]

Hi Brent, Yes, on the rare occasions when the clouds recede I have fairly
good skies. I'm on the edge of a small town, and fortunately I mostly
have the town behind me when imaging. My only problem is having four
streetlights within 40 metres of me.
raymo

[Robert9]

You certainly achieved your aim Raymo. Any newbee would be inspired I'm sure. (and I'm not being facetious!)
I have used the NR on my Nikon also to reasonable effect. However, I have started working at ISO 400 max which means exposures of multiple minutes. After taking say 15 exposures at 4 minutes each, then one needs another hours worth of darks. I'm slowly building up of library of darks at different temperatures to try and overcome this time-waster.
I did a quick calculation and 15 secs. at ISO 6400 is equivalent to 4 minutes at ISO 400.
OK on the Newt.
Robert

[raymo]

Why are you limiting yourself to 400? At this time of year you could surely work at 800, or as many people do, 1600.
raymo

[cometcatcher]

That's a quick one Ray! Good example of 15 seconds. Anyone for 10 seconds? ;)



For daylight photos, yes but not for astronomy. With my Pentax for instance, 15 seconds at ISO 6400 is equal to (after stretching) 15 seconds at ISO 400. The noise increases at virtually the same rate as gain.

[Robert9]

Higher ISO equates to higher noise. Noise reduction methods are good but none are perfect. Why add noise unnecessarily? Probably ISO 800 is still reasonable, but I prefer not to make more work for myself than I have too.:cool2:
Robert

[Robert9]

Once you start "stretching" the whole ball-game changes. Lets keep the playing field even. :argue: Just compare exposures.
Robert

[raymo]

My point was that at this time of year with much lower ambient temps you can move up an ISO step without incurring extra noise.
raymo

[Robert9]

Sorry Raymo, didn't grasp your intended meaning. Possibly true, especially in Melbourne of late.
Robert