On Friday, July 28, 2023 at 2:03:32 PM UTC-7, RichA wrote:
> If people still had a lot of large aperture scopes, there would be a lot more images of this event:
>
> https://www.cloudynights.com/topic/885223-m101-pinwheel-with-supernova-sn2023ixf/

It depends on exposure time!
I knew a guy, had a 90 mm Tak refractor, but he was taking very long exposures, no stacking.
Of course, he had a super accurate Tak mount too!
He said, he's done up to 1.5 hrs one shot images!
Longer the exposure, the more light is collected!

On Friday, July 28, 2023 at 10:02:15 PM UTC-7, StarDust wrote:
> On Friday, July 28, 2023 at 2:03:32 PM UTC-7, RichA wrote:
> > If people still had a lot of large aperture scopes, there would be a lot more images of this event:
> >
> > https://www.cloudynights.com/topic/885223-m101-pinwheel-with-supernova-sn2023ixf/

> It depends on exposure time!
> I knew a guy, had a 90 mm Tak refractor, but he was taking very long exposures, no stacking.
> Of course, he had a super accurate T of a satellite ruining that whole batch!ak mount too!
> He said, he's done up to 1.5 hrs one shot images!
> Longer the exposure, the more light is collected!

I don't know much about this subject matter, but I do believe that most astrophotographers these days take lots and lots of short exposures and just stack them up. Safety in numbers and they don't run the risk of a satellite ruining a single long exposure.

I'll wager that you will get a lot of feedback about this...

On Friday, July 28, 2023 at 10:13:39 PM UTC-7, palsing wrote:
> On Friday, July 28, 2023 at 10:02:15 PM UTC-7, StarDust wrote:
> > On Friday, July 28, 2023 at 2:03:32 PM UTC-7, RichA wrote:
> > > If people still had a lot of large aperture scopes, there would be a lot more images of this event:
> > >
> > > https://www.cloudynights.com/topic/885223-m101-pinwheel-with-supernova-sn2023ixf/
>
> > It depends on exposure time!
> > I knew a guy, had a 90 mm Tak refractor, but he was taking very long exposures, no stacking.
> > Of course, he had a super accurate T of a satellite ruining that whole batch!ak mount too!
> > He said, he's done up to 1.5 hrs one shot images!
> > Longer the exposure, the more light is collected!
> I don't know much about this subject matter, but I do believe that most astrophotographers these days take lots and lots of short exposures and just stack them up. Safety in numbers and they don't run the risk of a satellite ruining a single long exposure.
>
> I'll wager that you will get a lot of feedback about this...

That's the point, he didn't want to spend time stacking images!
Also, he wanted a very portable set up and the Tak 90 was the key!
I've seen his images, very nice!
Well, this was maybe 20 years ago!

On Fri, 28 Jul 2023 22:02:13 -0700 (PDT), StarDust <csoka01@gmail.com>
wrote:

>On Friday, July 28, 2023 at 2:03:32?PM UTC-7, RichA wrote:
>> If people still had a lot of large aperture scopes, there would be a lot more images of this event:
>>
>> https://www.cloudynights.com/topic/885223-m101-pinwheel-with-supernova-sn2023ixf/
>
>It depends on exposure time!
>I knew a guy, had a 90 mm Tak refractor, but he was taking very long exposures, no stacking.
>Of course, he had a super accurate Tak mount too!
>He said, he's done up to 1.5 hrs one shot images!

That is just stupid. There is no advantage to one exposure over a set
of them adding up to the same total time, other than a slight total
time saving because you don't lose time during image downloads (which
are typically very fast with modern cameras). But there are many
disadvantages. A single exposure will saturate many of the stars
because you reach the dynamic range limit of the sensor. Multiple
images extends your dynamic range. And, of course, a stack makes you
largely immune to the impact of planes, satellites, cosmic ray strikes
and all other things that can create artifacts on an image.

The typical exposure time that HST imagers use is 9 minutes, even
though many of its images are hours long in total.

On Fri, 28 Jul 2023 22:30:00 -0700 (PDT), StarDust <csoka01@gmail.com>
wrote:

>On Friday, July 28, 2023 at 10:13:39?PM UTC-7, palsing wrote:
>> On Friday, July 28, 2023 at 10:02:15?PM UTC-7, StarDust wrote:
>> > On Friday, July 28, 2023 at 2:03:32?PM UTC-7, RichA wrote:
>> > > If people still had a lot of large aperture scopes, there would be a lot more images of this event:
>> > >
>> > > https://www.cloudynights.com/topic/885223-m101-pinwheel-with-supernova-sn2023ixf/
>>
>> > It depends on exposure time!
>> > I knew a guy, had a 90 mm Tak refractor, but he was taking very long exposures, no stacking.
>> > Of course, he had a super accurate T of a satellite ruining that whole batch!ak mount too!
>> > He said, he's done up to 1.5 hrs one shot images!
>> > Longer the exposure, the more light is collected!
>> I don't know much about this subject matter, but I do believe that most astrophotographers these days take lots and lots of short exposures and just stack them up. Safety in numbers and they don't run the risk of a satellite ruining a single long exposure.
>>
>> I'll wager that you will get a lot of feedback about this...
>
>That's the point, he didn't want to spend time stacking images!
>Also, he wanted a very portable set up and the Tak 90 was the key!
>I've seen his images, very nice!
>Well, this was maybe 20 years ago!

Today, the process of stacking is integrated right into the other
required steps of calibration. It was a little more work 20 years ago,
but not much. And back then, cameras had higher readout noise, which
meant that optimal subexposure times were longer than today. But not
that long. Under dark skies, not using narrowband filters, 10-minute
exposures were about right.