Second take on M51 with ASI178MM

[michael.h.f.wilkinson]

On the night of May 8 I didn't just get some data on M13, but also on M51. I gathered about an hours worth of data using the ASI178MM behind my little APM 80mm F/6 triplet.

By accident, half the data weren't collected as FITS files, but rather as SER, but I managed to combine the lot, although the subs converted from SER to FITS by PIPP weren't flatfielded by Astro Pixel Processor. Still nice result. Combined with the data from my first take the result is clearly better.

More data are needed, but I really like the results I am getting from the ASI178MM on DSOs

[Mr niall]

Very nice - that’s surprising magnification for such a short focal length.

[michael.h.f.wilkinson]

3 minutes ago, Mr niall said:

Very nice - that’s surprising magnification for such a short focal length.

The pixels of the ASI178MM are just 2.4 micron, so compared to a more typical 5 micron of many DSLRs and CCD cameras, I am effectively working at 1000 mm

[Craney]

That's a great shot.  

It looks like a very versatile camera, I've read it performs across the spectrum, so to speak,  from small DSO's  tp planetary and solar.

 Is this the cooled version of the 178  ?    If so, do you feel it is advisable to get the cooled version to combat the 'noise'  ??

 

Sean.

[michael.h.f.wilkinson]

4 hours ago, Craney said:

That's a great shot.  

It looks like a very versatile camera, I've read it performs across the spectrum, so to speak,  from small DSO's  tp planetary and solar.

 Is this the cooled version of the 178  ?    If so, do you feel it is advisable to get the cooled version to combat the 'noise'  ??

 

Sean.

It is the non-cooled version. It seems to do well without cooling, but I might add a Peltier cooler to it. I might also just get the cooled ASI183MM, which has a similar pixel size, but much larger sensor. That would be great for wide-field too.

[Dragon_Astro]

A great result there, for an uncooled.

How long were the subs, and how many?

 

[Craney]

3 hours ago, michael.h.f.wilkinson said:

....cooled ASI183MM, which has a similar pixel size, but much larger sensor. That would be great for wide-field too.

Ah!!  ... now that is a question I need to ask.   Can you change the FOV on the 183MM  ( I think it is called the Region of Interest ROI function)  so that the 183MM effectively becomes a 178MM ??

I really am stuck in the midst of a dilemma in terms of the 'next step' from a modded DSLR.   Forgetting the mono / OSC debate,  it also comes down to the imaging targets.   I would like to image both wide field and the smaller galaxies and planetary nebulae.  I can really only afford one purchase, and would like to cover as many bases as possible in one go.    I had eyed up the 178MM / 183MM from  ZWO /QHY and the AA Hypercams...if we can talk about them on this site...   Modern platforms with excellent resolution and good first hand prices...., but then I read reports about the pixels not having enough 'well-depth', amp glow noise,   lucky imaging (whatever that is !!)  ( all my imaging is lucky  !!     etc etc etc.  

I spend a lot of time re-living the debate on-line..... without a satisfactory outcome.  I'm sure another innovation will come along to upset the accepted logic all over again.  Blimey !!

 

Sean.

 

[michael.h.f.wilkinson]

49 minutes ago, Craney said:

Ah!!  ... now that is a question I need to ask.   Can you change the FOV on the 183MM  ( I think it is called the Region of Interest ROI function)  so that the 183MM effectively becomes a 178MM ??

I really am stuck in the midst of a dilemma in terms of the 'next step' from a modded DSLR.   Forgetting the mono / OSC debate,  it also comes down to the imaging targets.   I would like to image both wide field and the smaller galaxies and planetary nebulae.  I can really only afford one purchase, and would like to cover as many bases as possible in one go.    I had eyed up the 178MM / 183MM from  ZWO /QHY and the AA Hypercams...if we can talk about them on this site...   Modern platforms with excellent resolution and good first hand prices...., but then I read reports about the pixels not having enough 'well-depth', amp glow noise,   lucky imaging (whatever that is !!)  ( all my imaging is lucky  !!     etc etc etc.  

I spend a lot of time re-living the debate on-line..... without a satisfactory outcome.  I'm sure another innovation will come along to upset the accepted logic all over again.  Blimey !!

 

Sean.

 

You can use ROI capture on all ASI cameras I have used, and the ASI183MM is no exception, I believe. They list higher frame rates for lower resolution shots on the ZWO website, after all. The 183 does have a lower dynamic range than the ASI178MM (12 bits vs 14 bits). So for solar the ASI178MM my have the edge

[Merlin66]

I went for the ASI 183MM to get the benefit of the larger chip. This allows me to do full disk imaging rather than the hassle of mosaics.

I think the 12 v’s 14 bit is not a real issue.

 

[michael.h.f.wilkinson]

4 minutes ago, Merlin66 said:

I went for the ASI 183MM to get the benefit of the larger chip. This allows me to do full disk imaging rather than the hassle of mosaics.

I think the 12 v’s 14 bit is not a real issue.

 

I didn't expect it to be much of an issue. In many cases I shoot in 8-bit mode anyway (certainly WL).

[Merlin66]

Re frame rates......

I can get >400 fps with an ROI I use on the spectroheliograph using the ASI 183MM on USB3 with an SSD drive.