FunkyKoval35

10 minutes ago, saac said:

If the object was accelerating through then as we take the red shift measurement we would see it progressively change reflecting the change in velocity. 

Yes, but still the Doppler Effect is a function of velocity. You will see progressive change in velocity but you have to do at least two mesurments of Doppler Effect. For each of them you will get diffrent velocities.

12 hours ago, saac said:

In truth stars will have an acceleration component to their motion for a number of reasons; for example the rotational motion around their galaxy's centre of mass. That change in direction by definition means the velocity is changing (even if there was a constant speed), in turn by definition acceleration. This is what we measure when we detect a star's radial doppler shift as it rotates in its orbit around the centre of mass.  So at some point we will detect a red shift and at others a blue shift, and inbetween a changing red and blue shift.

It doesn't matter whether the mass is accelerating or not. The Doppler Effect is a function of velocity, not acceleration. When you measure a spectral shift, you do it at a specific point in time at which the mass has a specific velocity - even if it is accelerating.

Well, total explosure time will be the same in both cases, but you are absolutely right about noise. Stack of shorter single explosures will be much noiser - faint regions, if they will be visible at all, they will be much noinser.

Example:

1 hour ago, Lee_P said:

Ok, so here's an update and all the things I've tried to stop the camera and EAF dropping out.

* New USB cables
* New power cables
* Wiggling all cables
* Different ports on the ASIAIR
* Different ports on my cigarette splitter
* Removing dew heaters from the rig
* An electrician friend used a multimeter to test my Nevada regulated power supply, cigarette splitter, and all cables. Clean bill of health.
* Entirely new ASIAIR and power cables! 

Yet the problem persists. Options remaining:

* Dodgy EAF. But would that cause the camera to conk out? 
* Dodgy regulated power supply or splitter. Possible but the electrician friend doesn't think so; and surely an issue there would affect more than just the camera and EAF. Still, possible.
* Dodgy camera.

I think dodgy camera because last night I was testing and the camera / EAF dropped out, again. I could reconnect the EAF, but the ASIAIR wouldn't display the camera in its list. Like it didn't exist. I did a full power cycle but still the same. I removed the USB B cable from the camera, and hey presto, it sparked back into life. For a while at least. It disconnected a while later, but again I could get it back by removing and reinserting the camera's USB B cable; this time at the ASIAIR end.

So I think this points to it being an issue with my camera. Which I guess would necessitate being sent to ZWO for repairs.

Thoughts welcome! 

Hi.

Are you using USB 3 cables? In my setup I had a similar problem. When ZWO EAF was in use(autofocusing) my guiding camera(ASI120MM mini) was constantly disconnected - not enough voltage to operate both(?) .  After changing ALL cables to USB 3 ones problem dissapeared.

Disappearing camera from the list after disconneting is normal. After disappearing, the camera may receive a new address (COM port) and that's why you need to reinstall the camera`s USB cable to allow ASIAIR to see it.

8 minutes ago, Rodd said:

Wow-you really removed it well.  Who knows.  I use Astrodon filters.  I am not going to start trying new filter wheels or filters.  If the fuilters are too far or too close, that is a byproduct of crappy design of the camera or filter wheel--same manufactuerer.Maybe its sky conditions, which always such.  But the sensor does have diffraction patterns around bvright stars when I shoot at a longer focal length.

The simplest way to check where is the problem is to take a few shots without any filter. If halos will disappear then you will know that it is not problem with your camera. Also, you can check if protective glass in your camera is clean.

BTW. Nice picture

Are you sure it is camera issue? It looks like typical reflection from filter - too close to the sensor or foulty.

A couple years ago I had similar problem with Baader OIII filter:

5 x 1200s, Sbig ST2000XM

I was able to remove halo from the star in PS, but it was annoying:

Do you have halos when you are not using any filter, or only on particular filter/filters?

1 hour ago, rl said:

Very nice shot taken with basic kit used properly. Resolved to the core and you got the little galaxy as well.

Thanks. Yes, I am happy that setup, especially SA GTI is working nice Now, time to save money for astro dedicated CCD camera and filters...

Hi.

The first image taken using my new setup: William Optics Zenihstar Z73 III + Canon 1100D(full spectrum) + OAG(ASI120MM) + SW SA GTI.

I am suprised how well SW SA GTI can guide - around 0.5" tot error. For comparision, on my previous mount HEQ5 PRO I was able to guide with tot error of 1.0" - 1.2".

Total explosure time is 40 min - 20 x 120s. Bortle 7 sky and no filters used. Flats and darks applied. Converted to b/w. Processed in Siril + PS.

Crop on M13:

Yours stars are not cut off. If you look closely you will see that yours stars are elongated at the edge of entire picture. It looks like your sensor is to close to flatener.

https://optcorp.com/blogs/deep-sky-imaging/how-to-set-the-correct-back-focus

Hi Don.

I have the same mount. Check to what COM port number your mount is assigned(Control panel -> Hardware and Sound -> Device Manager) and make sure that in synscan pro app connecting settings you have the same COM port selected.

Also, I do not know what is your setup, but if your mount will be powered by batteries, and you will connect it by USB, then I suggest to turn off wfi on your mount to lower power consumption. You can do it in synscan pro app wfi connectin settings - will be accessible when you connect your mount by wfi(!).

You do not need hand controller at all... I am controlling my mount in NINA together with Stellarium using USB 3 ports and cables with no any issues

10 minutes ago, Mr Spock said:

Kids are taught at school, which is the acquisition of knowledge. Knowledge and intelligence aren't the same thing 

Yes, but kids are also lerned how to solve the problems/tasks - reading, calculating, etc..

49 minutes ago, billhinge said:

I think the whole AI debate is semantics, it is a back propagation convolution  which I have no issue calling AI, the architecture is here

Agree. Most of the people thinks that inteligence = self-consciousness. Well, mabey in the future, but self-consciousness is not needed for inteligence.

1 hour ago, Mr Spock said:

Looks to me like a misuse (again) of the term AI. What they have there is a computer model which has been programmed, it's not AI. AI is something which can adapt and improve without human input.

With your definition humans are not inteligent because kids are learned at school and by parents - other human input . Inteligence is, first of all, ability to solve problems/tasks. The process of acquiring this ability is irrelevant.

3 hours ago, imakebeer said:

I think there's a danger (and it's by no means restricted to you, this thread of even this forum) in discouraging newcomers by telling them that they must have this gear or that gear - the inference is that there's no point even trying unless you have some mega-expensive setup, which is a real shame as it's demonstrably not true and there's still a lot of fun to be had even with basic equipment.

First of all.. I never mentioned that people MUST have this gear or that gear... Of course, everyone has equipment they can afford or want to have. I only claimed in my comment that you are givin wrong assumption/information that it does not really matter if we do multiple short exposures or one long exposure.

3 hours ago, imakebeer said:

This doesn't make sense. Firstly the definition of a long or short exposure is totally arbitrary. Secondly the greater the total integration time (however you do it) the more photons can hit the sensor hence total signal must also be increased, no?

It is not about signal itself... When you do shorter exposures you have lower SNR - Signal to Noise Ratio.

http://dslr-astrophotography.com/long-exposures-multiple-shorter-exposures/

18 hours ago, imakebeer said:

To a first approximation at least, and as far as I've understood it, whether you do 1 x 600s exposure or 600 x 1s exposures it doesn't really matter. Longer exposures save disk space, but it's 2023 not 1993 and storage is cheap. I do have a tracking mount now but so far I'm still only using 60s exposures.

I disagree. There is a reason why companies are making tracking mounts for astrophotography, and peoples are buying them   10x30s image will be much noiser and will have much less detiails than 1x300s image.

On 05/05/2023 at 20:57, happy-kat said:

Rechargeable batteries don't quite give enough power as they are 1.2 each not 1.5 as none rechargeable batteries

https://www.ebay.co.uk/itm/354237766527

5 minutes ago, Elp said:

As a general rule you shouldn't use any filter other than maybe a UV/ir cut or luminence filter (on cameras sensitive to or with windows that pass UV and IR) for galaxy OSC imaging. They block out too much signal. Its not impossible, but when I had a similar filter I felt it blocked too much signal within the target. Your image above will benefit from flats and also green noise removal, maybe the latter may bring back some colour to boost. The other issue is total imaging time, it needs to be much longer.

I agree. A lot of light pollution, not enough exposure time - M81 is much fainter than M82. I created arificial flat and subscrat it from image in PS to confirm that.

Good site, but.. I do not see any seeing data...?