[jimster]

For my FE friends, a suggestion on a possible way to investigate FE.

A telescope pointed at a celestial object must change its angle at 15 degrees per hour to keep that object in the center of view. Bob Knodel's ring laser gyroscope turned 15 degrees per hour.

Let's assume that's not coincidence for the sake of curiosity. What might explain the exact same number, one from a spinning object on the surface of earth, the other from light rays coming from the sky.

Any ideas? Just coincidence?

[Tom Bishop]

It's not exactly 15 degrees an hour. The celestial bodies change speed throughout the day. It's just blamed on refraction.

[jimster]

When I was a kid, my father had an 8 inch Schmidt Cassegrainian telescope. It had an equatorial mount. It had a motor on it with constant speed of one rev/day. If you turned it off, whatever you looked at would move across and then out of the field of vision. One rev/day , 360 degrees, divide by 24, you get 15 degrees per hour. Worked all night while looking at various things. Works everywhere in the world. No speed control on the motor, it was always 15 degrees per hour.

Mostly we looked at night, as the only celestial body visible in daytime is usually the sun. Once the moon was visible and the equatorial mount worked to look at that, too, although you couldn't see it as well during the day.

Web sites and youtube explain this and state that is works everywhere, always 15 degrees/hour.

Refraction occurs when you look at things just above the horizon. For a couple minutes after a celestial body rises above the horizon and a few minutes before, indeed, the appearance will not be moving at 15 degrees exactly, but at 20 degrees or more above the horizon, 15 degrees, all night, every night, everywhere. The same as a ring laser gyroscope.

Do you have reason to believe that 20 degrees above the horizon, it is not 15 degrees/hr for all celestial bodies? Even if is only 75% of the sky and you don't believe refraction, seems to me like it is still a coincidence worth exploring. FE has lots of "unknown forces with unknown equations", I would think you would be eager to explore any possibility. Find the FE explanation for gyroscope 15 degrees and equatorial mount 15 degrees.

Do you think it is a coincidence, or is there a connection? Or perhaps celestial bodies are just all over the place and no one knows, much like "anomalous winds aloft" makes it impossible to know the distance across the oceans?.

[Tom Bishop]

When I was a kid, my father had an 8 inch Schmidt Cassegrainian telescope. It had an equatorial mount. It had a motor on it with constant speed of one rev/day. If you turned it off, whatever you looked at would move across and then out of the field of vision. One rev/day , 360 degrees, divide by 24, you get 15 degrees per hour. Worked all night while looking at various things. Works everywhere in the world. No speed control on the motor, it was always 15 degrees per hour.

I'm not sure why you guys like to come here and keep trying to claim this in repetition, but it is a falsity. Unguided Telescopic Equatorial Mounts only work for a few minutes before drifting off of the target star.

-----

$650 Unguided Equatorial Mount - https://www.amazon.com/gp/product/B00Z4HVOVS/?th=1

https://www.amazon.com/gp/product/B07NY44782/ref=ask_ql_qh_dp_hza

"Question: When polar aligned north, can you use a ball head mount to rotate your camera 180* to capture the southern sky without trailing?

Answer: Hi Doyle, YES! Once the head is aligned, move your camera wherever and it will track the object for up to 5 minutes when using a wide-angle the lens. A telephoto (200mm) can only go about 2 minutes."

---

In this one, on a page called "Equatorial Mount Tracking Errors" the author shows stars which drift out of shot within a short amount of time on an EQ mount.

http://www.pk3.org/Astro/index.htm?astrophoto_mount_errors.htm

Equatorial Mount Tracking Errors

~

"Capture Selected Frames capture mode was selected with period 1 second (exact period was 1.11s)."

---

Other types of advanced EQ mount packages are computerized with multiple motorized axis' and have cameras for optical guide tracking and following of a target star, and are more reliable, but this isn't what you're referring to.

Unguided telescopic equatorial mounts can only track for short amounts of time:

https://starizona.com/blogs/tutorials/exposure-times



https://web.mit.edu/wallace/instruments.html

[stack]

I think it depends on the EQ mount one uses in terms of extending the duration of a lock on stars and preventing drift using an unguided mount. As well as how accurate your polar alignment is. This guy here created a 4+ hour timelapse of Geo Satellites streaking across the sky. He used the Atlas Mach 1 Unguided EQ mount (Version available today is the Mach 2). It's like a $10,000.00 mount. Perhaps the super high precision of the mount allowed him to polar align with great accuracy and duration.



For 4+ hours he experienced little to no drift. The first half of the video here is the 4+ hour unguided EQ Mount timelapse:



Technical Details:

The video at top contains time-lapses shot on two nights: January 18 and 20, 2021. Both are made from hundreds of frames taken through a William Optics RedCat astrograph at f/5 with a 250mm focal length. The field of view is 8° by 5.5°.
Each exposure is 30 seconds long, taken at a one second interval. The camera was a Canon 6D MkII at ISO 3200 on January 18 and ISO 1600 on January 20 in the brighter moonlight that night.
In the first sequence from January 18 the equatorial mount, an Astro-Physics Mach1, is left to track on its own and is unguided. So the stars wobble back and forth slightly due to periodic error in the mount. The field also drifts north due to slight misalignment on the pole. Clouds pass through the field during the shoot.
https://amazingsky.net/2021/01/22/tracks-of-the-geosats/

He does experience some minor drift. But with a 250mm focal length the frame is pretty small. And after 4+ hours, his drift was obviously very, very minimal.

[Tom Bishop]

That's not taken through a telescope, which was claimed by the poster was possible.

And if you read the entire page it says that he took a series of 30 second exposure images and stacked them on top of each other with special time-lapse software. You don't even need an equatorial mount to do that with singular images. Just take a series of wide angle photographs over the night and align them in software.

[stack]

That's not taken through a telescope, which was claimed by the poster was possible.

How would a telescope versus a camera with an equally powerful lens be different on the same EQ mount?

And if you read the entire page it says that he took a series of 30 second exposure images and stacked them on top of each other with special time-lapse software. You don't even need an equatorial mount to do that. Just take a series of wide angle photographs over the night and align them in software.

I think you missed a bit, he used:

William Optics RedCat astrograph at f/5 with a 250mm focal length. The field of view is 8° by 5.5°. That's referred to as a "telephoto" lens, opposite of a "wide-angle lens" as you suggest, which would be 50mm or lower. And with that FOV his target would be out of frame right quick. Instead, he was able to keep the target in frame for 4+ hours, unguided.

[Tom Bishop]

How would a telescope versus a camera with an equally powerful lens be different on the same EQ mount?

I've never seen a camera with an equally powerful lens as an astronomical telescope. Who knew that telescope manufacturers were unnecessarily making their telescopes so large when they could pack it down into a small package and get equal results, as indicated by someone's claim on an internet forum.

I think you missed a bit, he used:

William Optics RedCat astrograph at f/5 with a 250mm focal length. The field of view is 8° by 5.5°. That's referred to as a "telephoto" lens, opposite of a "wide-angle lens" as you suggest, which would be 50mm or lower. And with that FOV his target would be out of frame right quick. Instead, he was able to keep the target in frame for 4+ hours, unguided.

And if you had kept reading you would have found that he used a series of images and special time-lapse stacking software to put them together.

[stack]

How would a telescope versus a camera with an equally powerful lens be different on the same EQ mount?

I've never seen a camera with an equally powerful lens as an astronomical telescope. Who knew that telescope manufacturers were unnecessarily making their telescopes so large if they could pack it down into a small package and get equal results, as indicated by someone's claim on an internet forum.

What does a telescope versus a camera and lens have to do with EQ mount functionality?

I think you missed a bit, he used:

William Optics RedCat astrograph at f/5 with a 250mm focal length. The field of view is 8° by 5.5°. That's referred to as a "telephoto" lens, opposite of a "wide-angle lens" as you suggest, which would be 50mm or lower. And with that FOV his target would be out of frame right quick. Instead, he was able to keep the target in frame for 4+ hours, unguided.

And if you had kept reading you would have found that he used a series of images and special time-lapse stacking software to put them together.

So what? No matter the stacking/timelapse software, you can't stack a star that wasn't captured in the frame of the camera.

He kept a pretty tight lock on the stars with minimal drift, unguided, for 4+ hours with 250mm telephoto lens, not a wide-angle 50mm lens. That's some super impressive manual polar alignment. Just shows it can be done.

[Kangaroony]

How would a telescope versus a camera with an equally powerful lens be different on the same EQ mount?

I've never seen a camera with an equally powerful lens as an astronomical telescope. Who knew that telescope manufacturers were unnecessarily making their telescopes so large if they could pack it down into a small package and get equal results, as indicated by someone's claim on an internet forum.

What does a telescope versus a camera and lens have to do with EQ mount functionality?

Nothing.  It's obvious that Tom has little understanding of the technicalities of astrophotography,
as he seems to think that only a massive telescope is capable of accurately tracking planets
and/or stars;  the fact that he's "never seen" something himself is a weak argument.    The fact
that he mentions "wide angle lenses" confirms this, as that sort of lens is not what's required.

A good suggestion for astrophotography would be the Canon EOS Ra, which is the first camera
modified specifically for astrophotography. The filter on the Ra's sensor has been specially modified
to transmit four times as much Ha (hydrogen alpha) light. This extended red sensitivity means
the Ra can capture the characteristic reddish color of nebulae, for example, and will reveal a larger
number of celestial objects for much richer night skies.  Mounted on a portable Star Tracker, this will
produce stunning images of, for example, nebulae.

[Tom Bishop]

Did I say that a wide angle lens was required? No, I did not. Please refrain from fibbing in these discussions. It was clearly used it as an example, and the word required was not mentioned anywhere.

It can be done with any camera. Take a picture of a set of stars a few times over the night and then you can put the images together in software. You don't even need an equatorial mount.

Obviously you must know this has nothing to do with a wide angle lens and are using a tactic of posting frivolities and delaying discussing the concept, to avoid talking about the fact that the person in the link does not actually record a video directly from the mount and goes on at length to discuss extensive use of special software editing and timelapse stacking software to make a software adjusted video from a series of images.

the fact that he's "never seen" something himself is a weak argument.

Yeah, lets all just go ahead and assume that there are cameras with equally powerful lenses to astronomical telescopes based on an internet comment on a forum.

What a disgusting miscarriage of an argument that we should assume this without having seen it because to say otherwise is a "weak argument". In fact, one person claiming this without evidence and another person following up to defend it with incredulity when challenged is one of the weakest arguments possible.

[stack]

Did I say that a wide angle lens was required? No, I did not. Please refrain from persistently lying in these discussions. It was clearly used it as an example, and the word required was not mentioned anywhere.

It can be done with any camera. Take a picture of a set of stars a few times over the night and then you can align the images in software. You don't even need an equatorial mount.

You're right, you didn't say "required". You said:

Just take a series of wide angle photographs over the night and align them in software.

The thing is, I made it clear that the guy was using a 250mm lens. Which is a telephoto lens. And by no means even near a wide-angle lens. So I'm not sure why you even brought it up.

And sure, it can be done with any camera. But not with any lens. There's no way to keep a star in frame over 4+ hours without an EQ mount. And if the star isn't in frame, it isn't captured in an image. (obvi) Therefore, that image is not a part of the stack. Simple as that.

After 15 or so seconds, without an EQ mount, you'll start to get trails and/or field rotation. This guy's exposures were 30 seconds. And with a telephoto 250mm lens, without an EQ mount, stuff would drift out of frame a lot faster than a 50mm wide-angle lens.

Bottomline, the stacking/timelapse software can't create a star that is not captured in the frame - This guy was able to keep his stars in frame, without discernable trails, for 4+ hours, with an unguided EQ mount, as evidenced by the video.

Yeah, lets all just go ahead and assume that there are cameras with equally powerful lenses to astronomical telescopes based on an internet comment on a forum.

What does a telescope lens versus a camera lens have to do with an EQ mount?

[Tom Bishop]

And sure, it can be done with any camera. But not with any lens. There's no way to keep a star in frame over 4+ hours without an EQ mount.

Incorrect. There is a distinct nebula in the frame, for example. If you were to take a series of photos of that area around the nebula at different times of the night you could put your images together in software and capture the stars around that area. No equatorial mount required.

After 15 or so seconds, without an EQ mount, you'll start to get trails and/or field rotation. This guy's exposures were 30 seconds.

Unguided equatorial mounts are capable of very short exposures, as indicated by my original sources. This falls in line with what was claimed.

The problem is that your example goes on to put the images together in software for his final product rather than recording the entire video from the mount. This is not good evidence that you can buy a mount and keep the stars static all night long through a telescope as was claimed by the poster of this thread, or even do this with only a camera on an unguided equatorial mount without all the software adjustments and stacking.

What does a telescope lens versus a camera lens have to do with an EQ mount?

Who knows? I was not the one who introduced that absurdity into the thread.

[stack]

And sure, it can be done with any camera. But not with any lens. There's no way to keep a star in frame over 4+ hours without an EQ mount.

Incorrect. There is a distinct nebula in the frame, for example. If you were to take a series of photos of that area around the nebula at different times of the night you could put your images together in software and capture the stars around that area. No equatorial mount required.

You would have to move the camera, aka, reposition the frame, throughout the night. The guy with the 4+ hour unguided timelapse said (like I cited before), "In the first sequence from January 18 the equatorial mount, an Astro-Physics Mach1, is left to track on its own and is unguided." For 4+ ours and the nebula didn't go out of frame. So obviously is can be done for long durations, especially with a $10k EQ mount.

After 15 or so seconds, without an EQ mount, you'll start to get trails and/or field rotation. This guy's exposures were 30 seconds.

Unguided equatorial mounts are capable of very short exposures, as indicated by my original sources. This falls in line with what was claimed.

The problem is that your example goes on to put the images together in software for his final product rather than recording the entire video from the mount. This is not good evidence that you can buy a mount and keep the stars static all night long through a telescope as was claimed by the poster of this thread, or even do this with only a camera on an unguided equatorial mount without all the software adjustments and stacking.

Then explain to us how software can stack a nebula that would drift out of frame and not be captured in an image and is magically stacked back into the image after 4+ hours of tracking.

What does a telescope lens versus a camera lens have to do with an EQ mount?

Who knows? I was not the one who introduced that absurdity into the thread.

If no one knows, why did you say: "That's not taken through a telescope, which was claimed by the poster was possible." What impact would a telescope versus a camera have on an EQ mount? Why bring up the distinction? Why is this even relevant? Just because the OP mentioned a telescope versus a camera? That hardly seems relevant.

[Tom Bishop]

You would have to move the camera, aka, reposition the frame, throughout the night.

Actually repositioning can be helped by software. The area just needs to be captured.

The guy with the 4+ hour unguided timelapse said (like I cited before), "In the first sequence from January 18 the equatorial mount, an Astro-Physics Mach1, is left to track on its own and is unguided." For 4+ ours and the nebula didn't go out of frame. So obviously is can be done for long durations, especially with a $10k EQ mount.

An equatorial mount might help get the camera in the general area, but doesn't guarantee that the stars will be exactly in the same place, or didn't zig zag around. This is likely why he opted for a contrived way of making the video in software rather than simply doing a single long video from the mount itself. A far simpler methodology would just be to take the video from the mount.

Again, the actual methodology used in this is completely different than what you are suggesting demonstrates is possible.

If no one knows, why did you say: "That's not taken through a telescope, which was claimed by the poster was possible." What impact would a telescope versus a camera have on an EQ mount?

The impact to the discussion is that the poster claimed that stars would be stable in telescopic equatorial mounts and we received an unrelated example which did not involve telescopes and which did not take a video from the mount and was pasted together in software.

The person is a big vague about what exactly he did in the software, but the matter is tainted by the methodology. Part of the purpose of the software was obviously to fix errors.

[stack]

You would have to move the camera, aka, reposition the frame, throughout the night. The guy with the 4+ hour unguided timelapse said (like I cited before), "In the first sequence from January 18 the equatorial mount, an Astro-Physics Mach1, is left to track on its own and is unguided." For 4+ ours and the nebula didn't go out of frame. So obviously is can be done for long durations, especially with a $10k EQ mount.

An equatorial mount might help get the camera in the general area, but doesn't guarantee that the stars will be exactly in the same place, or didn't zig zag around. This is likely why he opted for a contrived way of making the video in software rather than simply doing a single long video from the mount itself. A far simpler methodology would just be to take the video from the mount.

Again, the actual methodology used in this is completely different than what you are suggesting demonstrates is possible.

If no one knows, why did you say: "That's not taken through a telescope, which was claimed by the poster was possible." What impact would a telescope versus a camera have on an EQ mount?

The impact to the discussion is that the poster claimed that stars would be stable in telescopic equatorial mounts and we received an unrelated example which did not involve telescopes and which did not take a video from the mount and was pasted together in software.

The person is a bit vague about exactly what he did in the software programs he used, but the situation is enough to discount the issue. The matter is tainted by the methodology.

You seem to be hung up on telescopes and software. For one, it doesn’t matter whether it’s a telescope or a camera mounted on an EQ mount - neither changes the way an EQ mount tracks. Why you’re hung up on this is a mystery and is weird.

For two, software. Like I wrote, no software is going to pull a nebula, in this case, back into frame once it has drifted out of frame. If it’s outside of the frame it doesn’t show in the image. Do you not understand this? If you know of a program that can capture and stack something that wasn’t captured in an image frame, please link to it. Because that would be amazing. We wouldn’t even need cameras anymore. We could just let this magical software you have manufacture elements of anything you want without having to snap a photo of it.

Here the guy shows his frame of view for his 250mm lens 4+ hour Timelapse:



From the guy regarding the above: "This chart from SkySafari shows the belt of geosats through southern Orion with the satellites identified. The green box is the field of view of the telescope (shown below) that I used to take the time-lapses."

You see, the guy with an unguided EQ mount kept the nebula from drifting out of that FOV he shows for 4+ hours. No software could grab an uncaptured nebula that had drifted out of frame and manufactured it back into the timelapse software stack. Do you not understand this? I other words, if you don't take a picture of something, that something is not going to be magically recreated in a timelapse stacking software.
Bonus: You'll also note that he refers to his camera as a "telescope". That's because the 250mm lens he used is considered a "telescopic" lens. Making his rig a "telescope", if that makes you feel better.

[Tom Bishop]

Who said that it would have drifted out of frame? It could have wobbled around, and errors fixed by software. He could have also been monitoring the situation casually and readjusting it when it did start drifting out of frame. He mentions three different pieces of software used to manipulate the images and, quite obviously, he is using the software to fix errors. We know that he is using software to fix errors, yet you continue to insist on this farcical example.

You don't have a good example of this at all. It is not a video from a telescopic equatorial mount, and nor is it raw video from a camera mounted equatorial mount. You continuously insist on this defective and invalid example because you can't contradict the sources given to you showing that it doesn't work.

[stack]

Who said that it would have drifted out of frame? It could have wobbled around, and errors fixed by software. He could have also been monitoring the situation casually and readjusted when it did start drifting out of frame. He mentions three different pieces of software used to manipulate the images and, quite obviously, he is using the software to fix errors. We know that he is using software to fix errors, yet you continue to insist on this farcical example.

You don't have a good example of this at all. It is not a video from a telescopic equatorial mount, and nor is it raw video from a camera mounted equatorial mount. You continuously insist on this defective and invalid example because you can't contradict the sources given to you showing that it doesn't work.

You wrote as part of your argument, "In this one, on a page called "Equatorial Mount Tracking Errors" the author shows stars which drift out of shot within a short amount of time on an EQ mount." Isn't that out of shot equal to out of frame?

I already cited where he didn't manipulate the telescope, "...the equatorial mount, an Astro-Physics Mach1, is left to track on its own and is unguided."

So what's your argument? That EQ mounts can keep celestial things in a tight 250mm telescopic frame, but they may wobble? If so, that means EQ mounts do work with the rotation of the earth, just not perfectly. Unless in this guys case, you have a $10,000 EQ mount, it works infinitely better and is more precise than the ones you keep bringing up.

[Tom Bishop]

You wrote as part of your argument, "In this one, on a page called "Equatorial Mount Tracking Errors" the author shows stars which drift out of shot within a short amount of time on an EQ mount." Isn't that out of shot equal to out of frame?

That was done with a telescope, where a single star was in the frame. On the other hand this is a view of a whole swath of stars. Unlike that example, this was not done with a telescope.

The image you posted previously indicated that it was a shot of bottom part of the Orion constellation. We can see the bright star Rigel towards the lower right, and that the Orion constellation is lightly drawn in.

I already cited where he didn't manipulate the telescope, "...the equatorial mount, an Astro-Physics Mach1, is left to track on its own and is unguided."

This indicates that he didn't have a guided type mount, not that he didn't try to fix errors along the way to get a pristine result. He obviously is conscious of errors and making an artificially good scene, considering the software manipulation used.

[stack]

You wrote as part of your argument, "In this one, on a page called "Equatorial Mount Tracking Errors" the author shows stars which drift out of shot within a short amount of time on an EQ mount." Isn't that out of shot equal to out of frame?

That was done with a telescope, where a single star was in the frame. On the other hand this is a view of a whole swath of stars. Unlike that example, this was not done with a telescope.

You couldn't be more misinformed. Of course it was done with a "telescope".

Definition of a Telescope:

Tel·e·scope
/ˈteləˌskōp/
noun
an optical instrument designed to make distant objects appear nearer, containing an arrangement of lenses, or of curved mirrors and lenses, by which rays of light are collected and focused and the resulting image magnified.

In other words, a lens. How do you think astrophotographers capture an image? With a lens and some sort of capture devices, like a camera attached. Or maybe a computer. How else do you think a photograph is taken? The lens this guy used, as previously referenced, was a William Optics RedCat astrograph at f/5 with a 250mm.

Per the Williams website regarding this particular lens: “From the beginning, the goal was to create the best possible design for an affordable, small, lightweight, and fast Apochromatic refractor for astrophotography needs." I.e., a telescope.

Why you’re hung up on this telescope versus camera thing is just bizarre. Lot’s of telescopic lenses are attached to, you guessed it, a camera.

The image you posted previously indicated that it was a shot of bottom part of the Orion constellation. We can see the bright star Rigel towards the lower right, and that the Orion constellation is lightly drawn in.

And so what? It's even more proof that you can use an EQ mount, if properly polar aligned, and with a $10,000 EQ mount with hyper precision motors and gears, way more precise (and expensive) than the models you reference, you can get some 4+ hours duration - Look at Rigel in the video, stays in frame the whole time. No software is going to pull something out of frame back into frame.

I already cited where he didn't manipulate the telescope, "...the equatorial mount, an Astro-Physics Mach1, is left to track on its own and is unguided."

This indicates that he didn't have a guided type mount, not that he didn't try to fix errors along the way to get a pristine result. He obviously is conscious of errors and making an artificially good scene, considering the software manipulation used.

What part of the phrase in bold, "is left to track on its own and is unguided." do you not understand? What does, left to track on its own mean to you?

Software manipulation? How do you think any timelapse is made, whether based on video or photography?