IC434 with ASI 120MM and Ha

[alexbb]

While waiting for the ASI1600MMC, I'm still playing with the ASI120MM.

As I don't have a clear view to the South, I can only see Orion less than 2 hours/day and I can use the mount only in AZ mode. All in all, here is the result of ~1000 7nm Ha exposures of 15s, 70/100 gain captured with FireCapture over 3 nights. Lens: CZ 135 F/3.5 wide open. I could use the smaller stars taken with the 300mm lens, but it's not a great result so I'm not sure I'll bother.

Clear skies,

Alex

[wimvb]

Lovely image, despite the limited setup. I'm eager to see your results with the 1600.

 

Cheers,

[alexbb]

Thank you! So am I! And, maybe I wrote before, patience is not exactly one of my first virtues.

[Stargazer33]

That's really nice. You've captured some nice filaments behind the Horse Head with your 7nm filter. And you've controlled Alnitak well.

[alexbb]

Thank you too!

As a matter of fact, I didn't try to control in any way the brightness of Alnitak. I didn't use any layering, not even HDR in StarTools. That's how it gets with the Ha filter. I did 1 or 2 px star shrinking though.
Maybe I'll give another shot at processing tomorrow.

[michael.h.f.wilkinson]

Very interesting result. I should have a bash with my ASI174MM or ASI178MM with the APM 80mm F/6 with reducer.

[Pete Presland]

I think it's a great looking image. Amazing to see images like this with the camera I use for planetary imaging. 

[alexbb]

Thank you!

 

Michael, I'd be very interested to see your results, especially with the 174. I ordered a manual filter wheel beside the 1600 which I plan to use later with a 174 and get a 7/8 position EFW for the 1600. I'd like to upgrade my 120mm to 174mm at some point and I'm wondering if there's any possibility to use the 174 for widefield DSO with a wide lens.

[alexbb]

OK, did my best.

I reprocessed the data above and I combined some data taken with the 300mm lens for the stars (attached as well)

BTW, forgot to mention, the data taken with the 135mm lens was binned 2x2 then 3x drizzled when stacked.

+ some colour - less than an hour in 30s exposures - taken with the DSLR@300mm

[Astrosurf]

Excellent! Just shows what this camera can do. I've always thought of it as a planetary camera!

Alexxx

[John78]

31 minutes ago, Astrosurf said:

Excellent! Just shows what this camera can do. I've always thought of it as a planetary camera!

Alexxx

When you line it up against a 414EX its better in every important spec, it just has smaller (and slightly less) pixels and no active cooling.  You can buy one with cooling from QHY...

http://www.qhyccd.com/miniCAM5S.html

[alexbb]

Thank you!

 

The ASI120MM is not suitable almost in any way for DSO imaging. Maybe just for lucky imaging with very very short exposures (~1s).

Read this further on: http://www.cloudynights.com/topic/501804-dark-noise-zwo-asi174mc-or-asi174mm-asi120mc-or-asi120mm/

The Atik 414 is a CCD with very little noise (dark current, readout).

The 414 has a 16bit ADC and ~18000 full well. You could overcome up to a certain point this inconvenience by stacking more than 256 frames (the 120mm is 8 bit) taken with the 120.

The only better part for the 120mm it's that it has a variable gain - don't know it's unity gain, but I'm pretty sure that 70/100 is above it so any captured photon should be added to the noise. You need at least 4 photons to be captured with the Atik 414 ex to be converted into signal (4x 0.28e-/ADU).

I will show you later on how a single frame looks.

[MARS1960]

Very nice indeed, i'm hoping to capture this tonight.

[alexbb]

Thanks and good luck!

As I promised, here's a single frame converted from FIT to PNG

[John78]

What settings were the camera settings?  The noise is greatly improved by cooling the back of the camera as far as i understand it - its connected to the back of the sensor PCB via a tower and a thermal pad....  I'm hoping the skies will clear here as the weather forecast to test this out.  

I've got a peltier and a heatsink ready to attach to the back for the active cooling.  If it turns out to be a bust I'll use the camera for planetary and guiding and upgrade to something more tasty (1600MM probably) when the financial controller releases the funds

[alexbb]

Well, the sensor readings were reporting about 6C at the beginning of the session and about 3 at the end. I don't think that putting a heatsink on the back of the camera's housing will drop significantly the sensor's temperature, but that's just a supposition. Other settings were bin 2x2, 15s exposures at 70/100 gain. Shot with FireCapture.

[John78]

Agree a heat sink won't do anything over the case but a thermo electric cooler will I'm sure

 

[alexbb]

Not sure we even understand the same thing after about a week of sleepless nights and work every Monday-Friday. Going to sleep at ~3AM during work days seems a bad idea after some days. Clear skies and I'm going to sleep..