Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

Recommended Posts

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 :-)

  • Like 2
Link to post
Share on other sites
  • Replies 982
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

Here is an unguided image made possible by the ASI1600. M31. 229 x 30 seconds at unity and 90 x 10 second binned 2x2 each RGB for under 3 hours total. TS60ED on a StarAdventurer. Amazing what can be d

Here is my latest. Narrowband 5 mins subs for all the Ha, Oiii, Sii channels. The weak signal Oiii caused problems as the amp glow at 5 mins is proving a little tricky to be honest. End result is hard

Great image - lots of data in that Here are my stacked and post-processed subs from Friday night into Saturday morning.  All subs were 30s exposure with 135mm f2.5 Asahi Super Takumar lens at ful

Posted Images

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 :)

  • Like 2
Link to post
Share on other sites

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. :icon_biggrin:

Andy

  • Like 3
Link to post
Share on other sites

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.

Link to post
Share on other sites

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.

  • Like 3
Link to post
Share on other sites
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...! :)

Link to post
Share on other sites
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

 

  • Like 1
Link to post
Share on other sites

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?

Link to post
Share on other sites
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:

Heart and Soul.jpg

Edited by Filroden
  • Like 1
Link to post
Share on other sites

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

Master RGB_HTFinal_SCNR_Take2.png

Link to post
Share on other sites

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+

Link to post
Share on other sites
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

 

Link to post
Share on other sites

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 :)

Link to post
Share on other sites
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

Link to post
Share on other sites

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 :D

Link to post
Share on other sites

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).

large.NGC281_20161004_v2.jpg

Edited by Filroden
  • Like 3
Link to post
Share on other sites
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

 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.