ASI 1600MMcool vs STT-8300

[Rodd]

I am considering getting the ASI 1600MMcool to use with my Televue np101is.  At present I use an SBIG SATT-8300 and it gives me a resolution of 2.06 as/p.  The ASI 1600MM will give me a resolution of 1.45 as/p WITH THE SAME FOV.  I already have a filter wheel and filters becuase I own the ASI 174MM (uncooled).  My question is, would I see a difference in a 1.45 as/p resolution instead of a 2.06 as/p resolution.  

Thanks,

 

Rodd

[Davey-T]

You can get bogged down doing the maths Rodd, theoretically you need 2 pixels across the Airy disk to satisfy the Nyquist sampling criterion in an ideal world but plenty of people manage  great images with less than mathematically perfect set ups.

Is the ASI a cmos sensor ? don't know how it compares to CCD but I know there are differences.

Dave

[Rodd]

Yes it is CMOS--very sensitive, low noise.  But the Atik 490ex is a CCD and I have the same question as I am also considering this camera for the same reason (smaller FOV though).  Would a 1.45 as/p look more detailed than a 2.06 as/p?

[Davey-T]

As usual our enemy is the seeing and other errors in the imaging setup so unless you're using the HST you are more at the mercy of the diffraction disc which may be at least three times the size of the Airy disc.

Images may be sampled at the critical point where the image is captured with just enough pixels to capture all the available detail .

Bigger pixels will undersample but not particularly detrimental allowing a bigger FOV.

Smaller pixels will oversample meaning no information is lost again not disastrous .

So none of that has really helped I guess it's just a case of suck it and see 

Dave

 

[Rodd]

3 minutes ago, Davey-T said:

As usual our enemy is the seeing and other errors in the imaging setup so unless you're using the HST you are more at the mercy of the diffraction disc which may be at least three times the size of the Airy disc.

Images may be sampled at the critical point where the image is captured with just enough pixels to capture all the available detail .

Bigger pixels will undersample but not particularly detrimental allowing a bigger FOV.

Smaller pixels will oversample meaning no information is lost again not disastrous .

So none of that has really helped I guess it's just a case of suck it and see 

Dave

 

That's the unfortunate thing about having cloudy skies---I sit around and talk myself into buying more gear.  4" refractor becomes a 5.5" refractor in an instant--cameras multiply like flies (focusers, reducers, filters, domes, extenders....etc.)  I wish skill could be added as easily. 

[Davey-T]

It can be slightly annoying when you see an image captured with a DSLR on an cheap 80mm refractor that knocks the socks off your own image just because it was taken somewhere nice and dark with good seeing.

Over the years I've lowered my expectations of what is achievable from my back yard despite spending thousands on equipment 

Dave

[Rodd]

Yeah--maybe it really is mostly seeing conditions when you get down to it.  One day soon I will try and see if this is indeed the case.  Remote sites are hard to do in the middle of a CT Winter (-20C).  But Summer it is doable.  Its on my to do list.