ASI1600mm cool

[Notty]

Ok I don't think I can stand this any more. I was just about to decide between an Atik 383 or 460ex and now I find this thing which, correct me if I'm wrong, is cheaper, bigger sensor (469ex anyway) and works off ridiculously short subs, completely subverting everything I've ever learned about AP!  Why would I not get this instead of a CCD?  Can anyone vouch for this with the xagyl 8 wheel with baader lrgb/nb filters on a SWED80 DS with a .85 flattened/reducer? 

These early "test" images are killer. Really impressed- and excited :-)

[John78]

I had the same question @Notty but from what I've been reading it's lined up against a 383L but not as sensitive, so it's 'better' at brighter targets, significantly faster I guess, dim things you chance losing the photon entirely.  The 460EX is on paper in an enitrely different class sensitivity wise.

 

Given Gina has both a 460EX and a 1600MM she can hopefully pass on her insights

[Andyb90]

I've seen a few tests of the 1600 with fainter targets on CN

http://www.cloudynights.com/topic/549137-an-asi1600-high-gain-experiment-bubble-nebula/page-2

The above page shows an image of CTB-1, a stack of 35 x 120 subs. It's the 5th post down on the page. 

Here is the Ha image on astrobin with additional data.

http://www.astrobin.com/263553/B/

And a comment from the imager John Rista:

"when I got into narrow band with this camera, I figured it would be faster than most CCD cameras, but that I would still be doing multi-night projects just to get enough data on one object. Being able to acquire sufficient data to make decent narrow band images in a single night? Truly amazing, and lots of fun."

This is part of what excites me about the camera. 

Andy

[John78]

I've just seen that Altair are going to launch the "same" camera also, interested to see the pricing - doesn't take much to figure out the vendor in China these boards are all coming from... It makes it investment relatively low when you only need to package and cool it.. rather than design asics, drivers etc... that said packaged, cooled and warrantied for about £1k over the odds is steep - the vendor quoted me $450 per piece for a 1600MM USB+serial board cam and $790 for an ICX694 (Atik 460EX) that's sample pricing for development.

[Guest]

I saw Altairs cameras at Kelling - didn't get into specs but they looked alarmingly like ZWO - just purple :-)

 

David

 

[Gina]

So far I'm very impressed by this new camera   But it's really a bit soon to say that it really is better than the 460EX but it does seem that way.  You do need bias and dark frames to counteract noise which aren't needed with the 460EX.  But once taken for a given set of conditions, the stacked master dark can be used every time you use the same settings for exposure, gain and temperature.  I have a lot of testing and proper imaging runs to do yet.  I may also do some side by side comparative tests between the ZWO and Atik cameras.  But these two cameras are very different and comparative assessment is difficult.

[SkyBound]

39 minutes ago, John78 said:

I've just seen that Altair are going to launch the "same" camera also, interested to see the pricing - doesn't take much to figure out the vendor in China these boards are all coming from... It makes it investment relatively low when you only need to package and cool it.. rather than design asics, drivers etc... that said packaged, cooled and warrantied for about £1k over the odds is steep - the vendor quoted me $450 per piece for a 1600MM USB+serial board cam and $790 for an ICX694 (Atik 460EX) that's sample pricing for development.

Well I can't find the vendor...!

[Guest]

a

 

[John78]

16 minutes ago, SkyBound said:

Well I can't find the vendor...!

Download the drivers for a few of the cameras then unpackage the libraries - I'm not saying the answer will smack you in the face, but your face will be red and there will be a name on the dooooooo

 

[cosmojaydee]

Another attempt last night, seeing not great 10 subs at 2mins dirty process

[cosmojaydee]

Using an ED80 with a .85 reducer and a ZWO 1600 (see above capture) is my field of view on the small side, have I set this up right, would my FOV increase if i removed the reducing lens and keep my focal length the same?

[Andyb90]

Here's an FOV simulator for the ED80 with reducer and 1600. The FOV does look small compared with the simulator.

Andy.

[cosmojaydee]

6 minutes ago, Andyb90 said:

Here's an FOV simulator for the ED80 with reducer and 1600. The FOV does look small compared with the simulator.

Andy.

I am getting no where near that FOV , any idea's?

[Filroden]

39 minutes ago, cosmojaydee said:

I am getting no where near that FOV , any idea's?

Your FOV looks spot on. Your image appears to be centred on NGC 896 so you've clipped most of IC1805. If you moved your FOV simulator to the right then the FOV looks spot on. Likewise, I just saw your image of IC1848 and that looks a similar size.

Here's what my simulator shows:

[cosmojaydee]

Thanks, what simulator is that please?

 

[Filroden]

9 minutes ago, cosmojaydee said:

Thanks, what simulator is that please?

 

SkySafari 5

[Guest]

Here's my attempt at the Bubble Nebula - wide field

Scope: TS65; Camera: ASI1600MM; L=140x60s RGB=20x60s; Gain: 139; Offset 10; Bias/Flat/No darks; Processed in: PI

I'd really appreciate a critique of this as I'm new to LRGB processing and so not sure I'm getting it right - is this roughly what the object should look like?

Next I'm going to image it with my 115mm refractor :-)

David

[Gina]

I find a high gain works best with this camera - I use 500 which is 50dB.  Lots and lots of subs too - this camera is quite different from a CCD and lots of short exposures works best.  I used 20 or 30 minutes with the Atik 460EX mono CCD camera whereas I'm using a tenth of the exposure or less with the ZWO CMOS camera and 10x the number of subs ie. 100+

[Andyb90]

Do the shorter exposures with the 1600 give some advantage when it comes to light pollution?

Andy.

[Guest]

3 hours ago, Gina said:

I find a high gain works best with this camera - I use 500 which is 50dB.  Lots and lots of subs too - this camera is quite different from a CCD and lots of short exposures works best.  I used 20 or 30 minutes with the Atik 460EX mono CCD camera whereas I'm using a tenth of the exposure or less with the ZWO CMOS camera and 10x the number of subs ie. 100+

Hi Gina - are your comments in relation to my request for a critique on my image - if so does that mean that you think the image will be better with higher gain and more subs?

What about offset - I've seen some use 50?

Of course I get as many subs as I can but given the amount I took I was wondering if the image was going in the right direction - clear again tonight so I might get some more data.

Also interested to know if people are using darks - I haven't to date but think I will tonight

Please disregard if your post was in relation to another :-)

David

 

[Gina]

It was a general comment not connected with your image.

One thing I will ask though is why did you go for LRGB?  In general nebulae are best imaged in narrowband as they are composed of specific gases - mainly hydrogen and oxygen (and to a lesser extent, sulphur) which emit light in just a few wavelengths and are therefore shown better if just some of these wavelengths are filtered out from the background sky light and stars.

Your image look good for LRGB

[Guest]

1 minute ago, Gina said:

It was a general comment not connected with your image.

One thing I will ask though is why did you go for LRGB?  In general nebulae are best imaged in narrowband as they are composed of specific gases - mainly hydrogen and oxygen (and to a lesser extent, sulphur) which emit light in just a few wavelengths and are therefore shown better if just some of these wavelengths are filtered out from the background sky light and stars.

Your image look good for LRGB

Thanks Gina - thought that was the case - but your advice sounded good and I've taken it on board - tonight I'm going to increase the gain to 380 and offset to 50 - funny - I've got a real aversion to increasing the gain lol :-)

I don't have any ha filters yet - this initial purchase wore out my good will with my bank account :-)

Thanks for responding Gina

David

[Gina]

Increasing the gain goes with shorter exposures as you collect fewer photons with shorter exposure and each of these can put more electrons into the ADC before saturation.  I haven't tried altering the offset but my feeling is that you won't affect the image until you get up into the hundreds particularly with high gain.  I'll leave comment on this to someone who actually knows

[Filroden]

Here's my limited attempt at NGC281, Pacman Nebula. It rose above my mount's altitude limit very quickly (I'd not taken into account my cables so by 21:10 it was already too high at about 59deg). Still, I got 24 mins of L and between 11 and 12 mins each of RGB (all 30s subs at 300 gain and 50 offset, at -20C calibrated with bias and darks but no flats). To try and compensate I created a super luminous frame using data from L and RGB. It was a little better than L on its own, so I went with it. Hoping to get one more clear night before the moon rises and before it gets too high in the sky as it's far noisier than I'd like (even given such a short total integration time).

[Guest]

1 minute ago, Filroden said:

Here's my limited attempt at NGC281, Pacman Nebula. It rose above my mount's altitude limit very quickly (I'd not taken into account my cables so by 21:10 it was already too high at about 59deg). Still, I got 24 mins of L and between 11 and 12 mins each of RGB. To try and compensate I created a super luminous frame using data from L and RGB. It was a little better than L on its own, so I went with it. Hoping to get one more clear night before the moon rises and before it gets too high in the sky as it's far noisier than I'd like (even given such a short total integration time).

 

Its looking good so far :-)

I can't figure out how to keep the background black (like your image) without clipping the histogram

I've noticed many images from this camera with nice sharp black backgrounds and try as I might I can't replicate it

I'm sure it's all down to the levels/curves adjustment so I'll keep working at it but your image is a really good benchmark for me to work too :-)

David