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Displaying stars in daytime Finder Chart
#1
I have a Finder Chart on screen (which I opened from the Mount Alignment Tool / Display Celestial Pole chart). How can I display stars for that chart during daylight? All star settings that I can see are turned on. When I move to twilight times then the stars appear, which leads me to think that this chart is taking into account the time of day. Fair enough. However, I do have an open cluster displayed in said daylight chart which contradicts my original thinking.

Have I missed a setting somewhere?

Thanks
Bob
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#2
Hello Bob,

The finder charts are primarily meant for finding, so they accurately present what you will see to the eye, in your finding device and in your eyepiece. That includes the brightness of the sky, so you must have turned that off or you would see a bright sky. If so, I urge you to turn it back on. You do that via the Chart Preferences, Basic Style tab, set the background to Simple or Natural complex sky.

The polar finder uses these same finder charts. This feature is meant to be used at the scope in real time, so normally it would be dark and lots of stars will show. There normally isn't any point to using it during the day because you can't see enough stars to recognize the field. Can you even see Polaris during the day?
Clear skies,
Greg
Head Dude at Skyhound
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#3
(2021-07-09, 11:48 PM)theskyhound Wrote: Hello Bob,

The finder charts are primarily meant for finding, so they accurately present what you will see to the eye, in your finding device and in your eyepiece. That includes the brightness of the sky, so you must have turned that off or you would see a bright sky. If so, I urge you to turn it back on. You do that via the Chart Preferences, Basic Style tab, set the background to Simple or Natural complex sky.

Sure, I do understand. However, as I initially explained, even with a bright daylight sky, I still see an open cluster being displayed as well. No stars, but an open cluster. In fact, zooming out, it appears all DSOs are visible. I presume this is just a bug then, albeit insignificant.

(2021-07-09, 11:48 PM)theskyhound Wrote: The polar finder uses these same finder charts. This feature is meant to be used at the scope in real time, so normally it would be dark and lots of stars will show. There normally isn't any point to using it during the day because you can't see enough stars to recognize the field. Can you even see Polaris during the day?

Since I am south of the equator, no chance!  Smile
While I understand you have designed things like the polar finder with a specific purpose in mind, that doesn't mean to say that we users cannot find additional uses for things. For this specific example it would be great if you could implement a "ignore daylight" switch at some point in the future.

Thanks
Bob
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#4
Hi Bob,

I think what you're seeing as the open cluster is just the chart icon for the object. Those aren't affected by sky brightness while the stars are. If you want to see the stars in the daytime, try setting the background color to black in Preferences. Well bugger! I just tried it & the stars disappear as the twilight occurs.

The stars will show in the IA, but the scope finder charts (including the pole finder charts, apparently) have sky brightness affecting the star's visibility. Since the pole finder chart is part of the Real Time functionality, you can't just change the time to nighttime to fool the program, either. I'm not sure changing the system time is something you'd want to try either. Seems like a lot of effort to go to.

Sorry I couldn't offer a solution,

Phil S.
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#5
(2021-07-10, 08:17 AM)Bobbo Wrote:
(2021-07-09, 11:48 PM)theskyhound Wrote: Hello Bob,

The finder charts are primarily meant for finding, so they accurately present what you will see to the eye, in your finding device and in your eyepiece. That includes the brightness of the sky, so you must have turned that off or you would see a bright sky. If so, I urge you to turn it back on. You do that via the Chart Preferences, Basic Style tab, set the background to Simple or Natural complex sky.

Sure, I do understand. However, as I initially explained, even with a bright daylight sky, I still see an open cluster being displayed as well. No stars, but an open cluster. In fact, zooming out, it appears all DSOs are visible. I presume this is just a bug then, albeit insignificant.

(2021-07-09, 11:48 PM)theskyhound Wrote: The polar finder uses these same finder charts. This feature is meant to be used at the scope in real time, so normally it would be dark and lots of stars will show. There normally isn't any point to using it during the day because you can't see enough stars to recognize the field. Can you even see Polaris during the day?

Since I am south of the equator, no chance!  Smile
While I understand you have designed things like the polar finder with a specific purpose in mind, that doesn't mean to say that we users cannot find additional uses for things. For this specific example it would be great if you could implement a "ignore daylight" switch at some point in the future.

Thanks
Bob

Hello Bob,

I'm sorry, but I'm just not following you. I don't understand what you are trying to do. It would really help if you would explain it. You say that people may want to use a tool in a different way, but when someone tells me that, 99 times out of 100, there is already a different and better way to do it. So please explain why you are trying to use a polar alignment chart in daylight so I can better help you out.

Phil, no, you are quite wrong about the clusters. SkyTools does a full simulation in the charts based on what is visible. That includes everything, not just stars. But every simulation is limited by the data available and although I am not aware of such a problem, it is possible that a cluster could have a very bright, unrealistic, integrated magnitude associated with it. This could, under the right conditions, result in a cluster that was incorrectly calculated to be visible.

Bob, please advise me which cluster this is so I can have a look at it.

But then... on the other hand, Bob, you also said that all DSOs are visible? That just isn't right, not most of the time. Maybe you have something set incorrectly? Maybe in your location, light pollution, etc? If you have the sky background turned off then how do you know its really daylight? There are some special situations where you can force objects to be visible, but these require enabling settings that are turned off by default. At this point it would be best to send a screen capture.

Lastly, you appear to believe the polar finder chart won't work for the southern hemisphere, but in fact it does. That's why this feature starts with a choice of hemispheres...

Again, I think its time to tell me what you are trying to do so I can help you do it.
Clear skies,
Greg
Head Dude at Skyhound
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#6
Thanks for the help so far.

But I would like to state that at no time previously have I stated or even implied that I believe the polar finder will not work in the S.Hem. I'm not sure what gave you that impression. It is, in fact, precisely because it works exactly how I would like it to work that I was hoping to show the stars during daylight. This is because I have found it a great educational tool, and was hoping to demonstrate the rotation of the stars around the scp over a 24 hr period. If that isn't possible to do currently, that is perfectly fine.

The query I then had was to why non stellar objects were still visible during daylight, when the stars were not. Screenshot attached for 2pm.

Thanks

   
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#7
Here is how to do what you want to do. Use the Interactive Atlas. Target the North (or South) Celestial pole. Click the Eyepiece View button to open the Eyepiece Viewer. Select your telescope and eyepiece. This will place an appropriate eyepiece circle on the atlas, centered on the pole. Dismiss the Eyepiece View window. At the top of the Atlas, under where it says Coordinate System and Projection, select "Horizon" as the coordinate system. Leave the projection at Auto. Set the Time Step to something appropriate, perhaps 10 minutes. Click the time step arrows to see the view rotate.

I have to admit that one of my secret wishes is that people would start out by simply telling me what they want to do. It would save so much time and trouble. The magnitude limits and other aspects of this chart are highly customizable so you should be able to achieve the result you want. Let me know if you have any questions.

It is more difficult to answer your question about some things being visible in the eyepiece view during the day, but I but believe this is a feature of the Pro version that is designation to force some objects to be visible in the eyepiece view that have no magnitude or size associated with them, and thus the algorithm can't determine if they are visible. Otherwise, there would be no way to find these objects on a chart.
Clear skies,
Greg
Head Dude at Skyhound
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#8
Hi Greg,

I think this is what Bob is referring to when he says that OCs & DSOs are visible on the Finder Charts in daytime: [attachment=1898]

Bob, is this what you're talking about? No stars, just the outlines of some objects.

Phil S.
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#9
Phil,

I already addressed this in my last post. Bottom line: don't use the eyepiece view zoomed all the way out during daylight. I suggested a much better way to do what he wants. This is NOT A BUG.
Clear skies,
Greg
Head Dude at Skyhound
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#10
Greg,

My point was that the scope Finder Chart's eyepiece view shows the NGC objects 1975, 1976 & 1977 in daylight despite there being no stars displayed. I think that's what's confusing Bob. Maybe not, though.

Also NGC 1976's mag is listed as 24.8 in the OI. That doesn't seem correct.

I didn't say anything about a bug.

Hope this is clear,

Phil S.
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