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AKB

ASI294 Pro – M81/82 first light

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Been unable to get out much recently due to (a) bad weather (we all suffer from this,) and (b) recovering from two rounds of middle ear surgery last year (hopefully, not too many suffer from this.)

Very excited, then, to have decided to buy a new EAA camera at AstroFest last week: ASI 294 Pro.  I went for this because it's OSC, larger and fewer pixels than the 1600, and, unlike my other cameras, USB3, so really quick downloads... just the thing!

Even more excited to see a few stars last night (Feb 11), albeit through poor transparency, some high clouds, and a bit of low-level mist.  So on to my 8" Quattro, I pointed to the clearest bit of sky (away from a rather bright moon) and decided that M81/82 was worth a try.

Here's a single 20 second sub, followed by a stack of 75 of them (for a total of 25 minutes), just because I left it running and processed them today.  I'm really hoping for better than this when conditions are improved, but also when I've played with gain settings further.  Hopefully a fair start, though... d'you think?

 

Bode20_042_220915_027_RGB_VNG_20s.thumb.jpg.9bcf88b56ba4901e41b661a0096f41de.jpg

 

20190211_M81_M82-Quattro-ASI294-75x20s.thumb.jpg.483417c50f62eae9b8594564f719e29e.jpg

 

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What stands out for me is what you can capture with a single 25 second sub - very impressive. The F4 Quattro is clearly a nice match for the camera. looking forward to seeing some more.

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Congrats on the purchase! Very nice result and glad to see it working well with the Quattro.

Is this the cooled version? Were you using a coma corrector?

I had to look up the pixel count as you say it is fewer than the 1600 but still over 11 million.... Is this the full image or were you using RoI?

Martin

 

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1 hour ago, Martin Meredith said:

Is this the cooled version?

Sorry for the dearth of information on the setup. Indeed, the Pro is the cooled version, and I was running at -12.

 

1 hour ago, Martin Meredith said:

Were you using a coma corrector?

Yes, the SkyWatcher one made for their F4 Newtonians.  It seems good to me.

 

1 hour ago, Martin Meredith said:

Is this the full image or were you using RoI?

Yes, pretty much the full image, just cropped a bit at the edges for the stacking.

I used the other settings as out of the box and subsequently discovered that the gain was set at 390 and the offset at 30.  Whilst this high gain is OK for short exposures, I think I need to set to unity gain (117?) for longer exposures and higher dynamic range. I've seen very little advice on the offset to use, although plenty of confusing comments on gain!   Perhaps the concept of post-processing EAA images is not going to yield as good a result as lower gain and longer exposures?   This may explain the rather underwhelming difference between about 20 seconds and 20 minutes worth of data!  Or perhaps it was the moon/weather.

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I revisited this target last night (Feb 13) in equally poor conditions (and more moon.)

Changed to unity gain (setting of 117, I hope), added an IDAS-P2 filter, and upped to single sub exposure to 2 minutes, eventually stacking 30 of these for an hour's worth.

Result below is better, I think, but then it should be.  My colour calibration is clearly not up to much.  Looking forward to trying in more promising weather conditions...

Single 2 minute sub (calibrated and stretched):

Bode_044_191826_007_c_d_r_clone.thumb.jpg.b893a63532fdc02449bd521ad73a321e.jpg

 

Stack of 30 for a total of 1 hour:

20190213_M81_M82-Quattro-ASI294-30x2m_B.thumb.jpg.41c68f3056b50b987b56627d9f3570a5.jpg

Edited by AKB
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Great image you have got some nice detail there your new purchase is working well with the quattro

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