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Astronewb
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Reged: 09/19/11

Loc: Connecticut
ZEQ25 PE Curve
      #6154720 - 10/24/13 01:18 AM Attachment (80 downloads)

Just for info, I guess some ZEQ owners and shoppers want to know how the Z Balanced mount stacks up? For $800 bucks you could do a lot worse....

This is from PecPrep V1.84 and a PHD log file from Sept 24th, corrected for DEC. I was imaging M33, guiding with a Lodestar/Borg 50mm/250mm combo. Main scope was a Borg 125SD.

This PecPrep isn't cherry-picked, I have tons of them like this, some better, some a little worse.

Hope someone on the fence for a splendid little 10 pound mount finds this interesting, and helpful.

Clear skies,

Paul


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orlyandico
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Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6154798 - 10/24/13 03:58 AM

but that is the error while it is being actively guided - hence that's not the true PE of the mount (see the EQ8 PE thread) but rather the measure of how tight it guides.

The PE would be measured by disabling guide outputs in PHD..


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Astronewb
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Reged: 09/19/11

Loc: Connecticut
Re: ZEQ25 PE Curve new [Re: orlyandico]
      #6155283 - 10/24/13 11:02 AM

Quote:

but rather the measure of how tight it guides.




Very true Orly. If iOptron ever puts their excellent Two Star align routine back into the HC firmware, I could post a raw PE curve.

That routine reports Polar Offset, and allows you to dial out the offset to '00-00' by using the az and lat adjusters.

iOptron replaced that routine with a 'Bright Star' type routine for users that don't have a view of the pole stars (or couldn't figure out how to use the polar offset?) at the expense of users that can see the pole stars. The new routine is not even close to being accurate enough to dial out polar offset.

I have no easy way to drift align to get to that reference point, since I have no views to the West, and my view to the East has 5 streetlamps between me and the horizon, which makes selecting a suitable star frustrating, if not hopeless..:(

If I had to estimate, with my tightened mount, the resident PE is probably under 5 arc-seconds peak to peak.

But, this result is off a tripod, with just a basic polar align and a One Star go-to, and guided, which is how most of the users of this mount will be using it, so it's still relevant?

And it certainly does show how well it tracks when guided.

Clear skies,

Paul

Edited by Astronewb (10/24/13 11:06 AM)


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PGW Steve
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Reged: 10/03/06

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Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6155436 - 10/24/13 12:25 PM

It is deceiving to see "ZEQ25 PE Curve" and then come into the thread thinking that an $800 mount makes my Astro-Physics Mach1/1200/1600 look like junk. :-P


Take the mount somewhere you can drift align it properly and repeat the test, and not make any assumptions that is 5 seconds peak to peak.


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tjugo
scholastic sledgehammer


Reged: 11/06/07

Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6155457 - 10/24/13 12:34 PM

Hi Paul,

You don't need perfect polar alignment to measure PE... PECprep will remove the drift caused by polar misalignment.

Residual Error after guiding is not very meaningful cause it is tie to seeing, guiding equipment, mount operator etc.

Just be careful to compensate for DEC when reporting tracking error.

Cheers,

Jose


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core
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Re: ZEQ25 PE Curve new [Re: tjugo]
      #6155464 - 10/24/13 12:36 PM

I'm looking forward to see the raw PE curve of the ZEQ!

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Astronewb
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Reged: 09/19/11

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Re: ZEQ25 PE Curve new [Re: tjugo]
      #6155627 - 10/24/13 01:57 PM

Quote:

Hi Paul,

You don't need perfect polar alignment to measure PE... PECprep will remove the drift caused by polar misalignment.

Residual Error after guiding is not very meaningful cause it is tie to seeing, guiding equipment, mount operator etc.

Just be careful to compensate for DEC when reporting tracking error.

Cheers,

Jose




Thanks for that useful info Jose, I will give it a shot the next time I have a break in the weather.

Best...Paul


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andysea
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Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6155734 - 10/24/13 03:06 PM

0.33" RMS seems to be an excellent value. That's what I get with my Mach1 and NJP, unless the seeing is exceptional.

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ramasule
member


Reged: 04/12/12

Re: ZEQ25 PE Curve new [Re: andysea]
      #6158476 - 10/26/13 12:04 AM

http://www.cloudynights.com/ubbthreads/showflat.php?Cat=&Board=lxd55&...,,All_Forums,,&Words=&Searchpage=1&Limit=25&Main=6081789&Search=true&where=&Name=208311&daterange=&newerval=&newertype=&olderval=&oldertype=&bodyprev=#Post6082579

Mind you I haven't had a good night to get better data since.


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anat
professor emeritus


Reged: 06/03/04

Re: ZEQ25 PE Curve new [Re: ramasule]
      #6158636 - 10/26/13 04:45 AM

Could you tell me the PE in arcsec?

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ramasule
member


Reged: 04/12/12

Re: ZEQ25 PE Curve new [Re: anat]
      #6159136 - 10/26/13 12:51 PM

8 peak to peak about. Next time im out I will try for a better graph.

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Tony Finnerty
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Reged: 03/06/13

Loc: Nevada City, California
Re: ZEQ25 PE Curve new [Re: ramasule]
      #6162511 - 10/28/13 01:19 PM

No PE curve, but two nights ago I got PHD Guiding graphs for my tuned ZEQ25 (thanks for the videos, Paul!) that looked like this consistently:



This is crazy-good for the crazy system I'm developing for winter AP from my balcony with its flexible floor boards. The tripod is set on a plywood triangle and I step on separate plywood sheets to distribute weight to minimize tilting the mount when I move. The tripod is set on three 8x8x16 inch concrete blocks standing on end for 16 inches of lift, to raise the polar scope high enough to see Polaris over my roof. I stay off the balcony during exposures.


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nomosnow
sage


Reged: 03/21/11

Loc: Fort Saskatchewan,Ab ,Canada
Re: ZEQ25 PE Curve new [Re: Tony Finnerty]
      #6163190 - 10/28/13 07:21 PM

Very nice graph indeed , Tony what declination was the object that you were imaging ?
John


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orion69
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Reged: 05/09/10

Loc: Croatia
Re: ZEQ25 PE Curve new [Re: Tony Finnerty]
      #6163207 - 10/28/13 07:30 PM

Quote:

This is crazy-good ...




This was probably guided with finder scope, if so it doesn't say much.


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Astronewb
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Re: ZEQ25 PE Curve new [Re: orion69]
      #6163396 - 10/28/13 09:32 PM

Quote:

Quote:

This is crazy-good ...




This was probably guided with finder scope, if so it doesn't say much.




On the contrary, I think it says it all. That's how most imagers will use the mount?

A mount that won't guide smoothly just adds to the frustration of imaging, taking up more time with PHD than with actually taking some images.

If you don't want to use a guide scope, there are plenty of mounts in the $7~10K price range that will deliver 5 minute unguided images. But I guarantee you're not going to be carrying them out every time it's clear enough to image.

This mount takes all of ten minutes to set up, polar align and star align, and then start imaging. Tear down at the end of the night is the same.

Just my humble opinion... Paul

Edited by Astronewb (10/29/13 10:33 AM)


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Mkofski
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Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6163419 - 10/28/13 09:45 PM

Completely agree with you Paul. My take on Orion69's comment was that using a finder size guide scope wasn't very meaningful and that a longer fl guide scope is in order.

Edited by Mkofski (10/28/13 10:55 PM)


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orion69
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Reged: 05/09/10

Loc: Croatia
Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6163441 - 10/28/13 09:58 PM

Quote:


On the contrary, I think it says it all.




Most mounts will have PHD graph that smooth if guiding with finder. So, no, it does not say all at all.

Of course, that does not mean that resulting image can't be good.


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Falcon-
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Re: ZEQ25 PE Curve new [Re: orion69]
      #6163788 - 10/29/13 12:33 AM

Quote:

Quote:


On the contrary, I think it says it all.




Most mounts will have PHD graph that smooth if guiding with finder. So, no, it does not say all at all.

Of course, that does not mean that resulting image can't be good.




Actually I would say that most mounts in this price range do NOT necessarily give such good results, even with 50mm finder-guiders.

There is a reason I got my ZEQ25 to replace a CG5....


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Tony Finnerty
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Reged: 03/06/13

Loc: Nevada City, California
Re: ZEQ25 PE Curve new [Re: Falcon-]
      #6164416 - 10/29/13 11:56 AM

Hey nomosnow, I imagine you get tired of the white stuff up there in Saskatchewan, but we're looking forward to the small amount we get in winter in Nevada City, in the Sierra Nevada foothills! I was shooting M31 at the time, which was located at DEC +41 deg 20'. I'm chasing down a flexure issue, so no image to post. An early version shot with a different lens can be seen here .

Knez, I was guiding with a Lodestar on a Stellarvue 60mm finderscope. My post is a bit off topic in the sense that it doesn't measure periodic error, only what is possible when guiding the ZEQ25. I'm very pleased with what I got for $950 (mount + polar scope + 2" tripod). Until my 4" refractor arrives the mount is carrying only telephoto lenses like a 50-200mm zoom lens + mirrorless camera. Paul has shown us the ZEQ25 can perform with a ridiculous payload compared to its own weight. I bought this mount based on his early results - thank you, Paul!

Paul, you are very correct that this quality of guiding can be achieved with 10 minutes to setup, polar align and one-star align, even in the hands of a total newb in the midst of acquiring his first telescope and mount. The ZEQ25 combined with a 4" refractor will be an awesome mobile AP system.

Mike, Knez and Falcon - the bottom line is the quality of guiding. A very expensive mount can track accurately for long exposures without guiding. A less expensive mount compensates for less expensive mechanicals by way of software (guiding). The key is smooth performance so guiding can be precise. The ZEQ25 mechanicals are smooth enough so guiding is very effective. I never expected to afford performance this good.


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rmollise
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Reged: 07/06/07

Re: ZEQ25 PE Curve new [Re: Falcon-]
      #6164574 - 10/29/13 01:16 PM

Quote:

Actually I would say that most mounts in this price range do NOT necessarily give such good results, even with 50mm finder-guiders.






Which mounts are you speaking of specifically? I've found the VX and the Sirius give results pretty much identical to these.


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tjugo
scholastic sledgehammer


Reged: 11/06/07

Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6164943 - 10/29/13 04:48 PM

Quote:

Quote:

Quote:

This is crazy-good ...




This was probably guided with finder scope, if so it doesn't say much.




On the contrary, I think it says it all. That's how most imagers will use the mount?

A mount that won't guide smoothly just adds to the frustration of imaging, taking up more time with PHD than with actually taking some images.

If you don't want to use a guide scope, there are plenty of mounts in the $7~10K price range that will deliver 5 minute unguided images. But I guarantee you're not going to be carrying them out every time it's clear enough to image.

This mount takes all of ten minutes to set up, polar align and star align, and then start imaging. Tear down at the end of the night is the same.

Just my humble opinion... Paul




C'mon, don't let your love for the mount cloud your judgement. A pretty flat PHD graph not even with pixel resolution is useless.

PE profile is important because you can infer how hard/easy would be to autoguide the mount.

If you like nice flat graphs just bin the guide camera, buy a guider camera with bigger pixels or get a shorter FL guide scope.

This is a surprisnsitly good mount for the price, I had one of these mounts and it was very easy to guide, no tweaks or tuning requiere. I returned the mount because the ASCOM driver was (is?) a joke

Cheers,

Jose


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orlyandico
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Re: ZEQ25 PE Curve new [Re: tjugo]
      #6165294 - 10/29/13 08:22 PM

The new PHD2 can take your guider focal length and camera pixel size in microns as inputs, and graph the guiding profile directly in arc-seconds (and you can adjust the scale - just like in MaximDL).

Just when I had gotten used to super-flat guiding graphs (e.g. 0.01 rms) in PHD1..

Ah.. and PHD2 can store your calibration data so no need for that tortuous calibration exercise every time you start it up. It can also save the darks from your guide camera. And, the interface no longer locks up during long exposures with my Meade DSI. Some very nice and worthy improvements.


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John Miele
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Re: ZEQ25 PE Curve new [Re: orlyandico]
      #6165361 - 10/29/13 09:07 PM

I'm surprised no one is posting any raw plots here...here is my unguided Zeq25 PE curve. Guide star was at 30 deg. Dec. Scope was AT72. Total payload on the mount was maybe 10 lbs. plus 1 CW. Used PHD and a 50mm guider with Orion SSAG for a pixel scale of about 6 arc-sec/pixel. Have done no tuning of the mount. This is what I got out of the box. Is this good or is this poor...I don't really know . It does guide pretty well up to 5 minute subs so far. I have a LOT more testing planned. I want to try Paul's tuneup and repeat this test. Hope the graph here is a useful data point for someone...
John

EDIT: My first plot had the wrong gear period so I deleted it. The other following plots are corrected...John

Edited by John Miele (10/29/13 10:32 PM)


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orlyandico
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Re: ZEQ25 PE Curve new [Re: John Miele]
      #6165393 - 10/29/13 09:25 PM

I am surprised as well, people are throwing around 8" peak-to-peak. Maybe they are looking at "Av. PE+" and "Av. PE-" which IMHO is incorrect?

The above graph shows +14 / - 12 or about 26" peak-to-peak, which, if representative of ZEQ25's means it is not the wonder-worker that many think (or want) it to be, but a thoroughly middle-of-the-road Chinese offering, with the value proposition of being light.

Can you re-post the plot but with only the first two harmonics checked? (the magnitude 100 and magnitude 80 ones) - but also change the mount type to "Vixen GP" (since the ZEQ25 has the same number of worm gear teeth as the GP, which is 144 teeth).

From your graph looks like there is a fast component with a 160-second period that's even bigger than the worm fundamental. Shades of the CGEM 8/3? the 80 magnitude component is most likely the worm fundamental, since a 144-tooth worm has a 598-second period.

To measure only the worm fundamental, only check the 80 magnitude component.

However, since the 100 magnitude component is even bigger than the fundamental, it must be accounted for when measuring PE. So the best measure of PE would be the 100 and 80 magnitude components.

All of the other components are tiny and can be ignored.


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Astronewb
scholastic sledgehammer
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Reged: 09/19/11

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Re: ZEQ25 PE Curve new [Re: orlyandico]
      #6165433 - 10/29/13 09:51 PM

Quote:

Hope the graph here is a useful data point for someone...
John




A couple of minor points John. The worm period for the ZEQ is 600 seconds, so you need to set that in PecPrep. You have it set to 479.

After you load your PHD log, check 'Mag Period' and uncheck all the other boxes to see the raw PE in the mount.

Oh, once you tighten up the mount a bit, it will improve.

Good luck and thanks for the data.

Paul

Edited by Astronewb (10/29/13 09:52 PM)


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John Miele
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Re: ZEQ25 PE Curve new [Re: orlyandico]
      #6165436 - 10/29/13 09:53 PM Attachment (28 downloads)

You got it! Here is the just the first two frequencies plotted and I used the Vixen GP mount option...

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John Miele
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Re: ZEQ25 PE Curve new [Re: John Miele]
      #6165441 - 10/29/13 09:55 PM Attachment (21 downloads)

And here is the frequency data. There sure is a big spike at that other frequency...is this something to try and work on? The mount seems to guide fairly well...I'll post a single cropped 5 minute sub shortly...John

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orlyandico
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Re: ZEQ25 PE Curve new [Re: John Miele]
      #6165445 - 10/29/13 09:56 PM

well... there is no change in the peak-to-peak PE. So the first two harmonics are really the bulk of the PE..

If the 160-second harmonic is from the gearbox, it will not be removable (just like the CGEM 8/3 problem). I would really appreciate seeing an "after" graph once you've cleaned up the mount.

I'd be interested to see the results of others in the above format.. not because I'm nitpicking this mount (no point..) but because I've been thinking about getting one myself for travel. But honestly if they mostly have that much PE.. I'd probably go back to my plan B of looking for an old EM10/EM11/P2Z..


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John Miele
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Re: ZEQ25 PE Curve *DELETED* new [Re: John Miele]
      #6165451 - 10/29/13 09:59 PM

Post deleted by John Miele

Edited by John Miele (10/29/13 10:02 PM)


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John Miele
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Re: ZEQ25 PE Curve new [Re: John Miele]
      #6165483 - 10/29/13 10:15 PM Attachment (24 downloads)

I'm not really going to do any cleaning. I'm just going to adjust the worm gear mesh and RA play and make sure I have no slop in the worm bearings. I'm also going to investigate the stronger spring option. It will be several days before I can post back an "after" comparison. Here is a single 5 minute randomly picked sub @ 100% crop...John

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John Miele
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Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6165493 - 10/29/13 10:25 PM Attachment (15 downloads)

Hi Paul,

Here is the plot of just the Mag Period...


Quote:

Quote:

Hope the graph here is a useful data point for someone...
John




A couple of minor points John. The worm period for the ZEQ is 600 seconds, so you need to set that in PecPrep. You have it set to 479.

After you load your PHD log, check 'Mag Period' and uncheck all the other boxes to see the raw PE in the mount.

Oh, once you tighten up the mount a bit, it will improve.

Good luck and thanks for the data.

Paul




Edited by John Miele (10/29/13 10:29 PM)


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Astronewb
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Re: ZEQ25 PE Curve new [Re: John Miele]
      #6165498 - 10/29/13 10:31 PM

Quote:

You got it! Here is the just the first two frequencies plotted and I used the Vixen GP mount option...




You're getting there. But the Z is not a Vixen. In PecPrep, under mount types, create a type 'ZEQ25', set the worm period to 600 seconds, just '1's on the rest.

In the 'Tag' box, delete any reference there, they are for the common Synta mounts and don't apply to the Z. (I see that gear 5 entry in the drop down box..shouldn't be there)

Hit 'Save changes' and the ZEQ25 will appear in the menu.

You can enter the number of worm teeth (144) but since PEC is not permanent in the Z mount, I can't see any reason for creating a PEC curve.

If you can make those changes and post up just the 'Mag Period' results, I'd like to see it?

Oh, and here's a link to a 70 minute guided exposure taken (by mistake) off the ZEQ: http://www.flickr.com/photos/astronewb2011/8719442364/

Thanks...Paul

Edited by Astronewb (10/29/13 10:37 PM)


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orlyandico
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Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6165530 - 10/29/13 11:43 PM

For purposes of PECPrep, the Z is a Vixen, with a 598-second worm period (not 600-second). All that PECPrep cares about is the number of worm teeth. Since the Z has 144 teeth, its worm period is (86164 / 144) = 598 seconds.

You can use the corrected King rate so (86188 / 144) = still 598 seconds.


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John Miele
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Re: ZEQ25 PE Curve new [Re: orlyandico]
      #6166996 - 10/30/13 06:17 PM Attachment (10 downloads)

I made the plot Paul asked for and I think Orlandico is right. There does not seem to be any difference. One point to note: when I open PECPREP and uncheck everything but the Mag Period box, the data terms (max and min PE, etc.) all become zero. But if I move to another tab and then back to the main page, the data fills in. I do not know if this is a PECPRO glitch or if it affects the answers. But here is the plot anyway.

I think however, as Pauls images show and many others as well, that regardless of the starting raw PE plots, this mount responds to autoguiding very well and can produce some nice images. But I know we all love to deep dive into this type of thing!

John


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cloudywest
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Reged: 06/15/13

Re: ZEQ25 PE Curve new [Re: orlyandico]
      #6167229 - 10/30/13 08:25 PM

Quote:

Since the Z has 144 teeth, its worm period is (86164 / 144) = 598 seconds.
You can use the corrected King rate so (86188 / 144) = still 598 seconds.



The true peroid is 23.9344699*3600/144=598.36. Many people include me use 24*3600/144=600


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Astronewb
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Reged: 09/19/11

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Re: ZEQ25 PE Curve new [Re: cloudywest]
      #6167309 - 10/30/13 09:03 PM

Thanks John, just wanted to make sure PecPrep was behaving, and obviously it is. Orly is the guru of Pec, no doubt.

Cloudywest is the guru of mathematics, my hat's off to you.

I'll use the 24*3600/144=600 too, not because I can do the math, I just like round numbers...:)

Thanks all, for the info. I'm still waiting for a night clear enough to actually run a 50 minute raw PE exercise.

Paul


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Astronewb
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Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6171215 - 11/01/13 10:54 PM Attachment (6 downloads)

Quote:

Take the mount somewhere you can drift align it properly and repeat the test, and not make any assumptions that is 5 seconds peak to peak.




Well, I was hoping for about 5 arc-seconds, peak to peak but that's not how it turned out. Guess I'll have to settle for about 2 arc-seconds average with 7 arc-seconds peak to peak, bummer.

Guiding scope was a Borg 50/250mm and a Lodestar. Guiding was disabled after calibration and a new PHD log file created. Declination was compensated for (+42).

This is with a mount polar align and a One Star align. Life is too short to drift align. Astro Tech AT6RC in the mount with the Borg 50mm piggybacked in its normal position.

Larger res on Flickr:

ZEQ_raw__PE_110113 by Astronewb2011, on Flickr

Hope the info helps,

Paul

Edited by Astronewb (11/01/13 11:08 PM)


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orion69
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Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6171306 - 11/02/13 12:27 AM

Correct me if I'm wrong, is this actually measured using Borg 250mm FL?
Is graph compensated for FL of the main scope?

Edited by orion69 (11/02/13 12:29 AM)


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Astronewb
scholastic sledgehammer
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Reged: 09/19/11

Loc: Connecticut
Re: ZEQ25 PE Curve new [Re: orion69]
      #6171338 - 11/02/13 12:56 AM

Quote:

Correct me if I'm wrong, is this actually measured using Borg 250mm FL?
Is graph compensated for FL of the main scope?




I've asked on a few forums, and have been informed, the correct method is the focal length of the guidescope, not the imaging scope.

Makes sense to me, since PHD is gathering the data through the imaging scope.

Perhaps someone has some other information or can add some information?

Best...Paul


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orlyandico
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Reged: 08/10/09

Loc: Singapore
Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6171397 - 11/02/13 02:32 AM

1) interesting that your mount also displays the 200-second harmonic that is very strong (in John's case it was 160 seconds), in your case almost as strong as the fundamental.

2) what is the reported PE with only the 584-second component checked? and with the 584- and 200-second?

Can you post the PHD log file? (as alph would say, where's the logs..)


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freestar8n
Post Laureate
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Reged: 10/12/07

Re: ZEQ25 PE Curve new [Re: orlyandico]
      #6171422 - 11/02/13 03:20 AM

Or as Frank would say - what is the actual fwhm you are achieving in your guided images, in arc-seconds? Logs only tell you what the guider thinks is happening - and it can be far from what is actually happening in the image - especially when using a small guidescope. The image is what matters, unless your goal is to frame a plot of the guide log and put it on the wall.

Frank


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Astronewb
scholastic sledgehammer
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Reged: 09/19/11

Loc: Connecticut
Re: ZEQ25 PE Curve new [Re: freestar8n]
      #6171432 - 11/02/13 03:46 AM

Quote:

The image is what matters, unless your goal is to frame a plot of the guide log and put it on the wall.




I never thought about framing a graph, but it sounds doable..

I agree 200% Frank, the image is what matters, bottom line.

So here's a link to some images acquired with the ZEQ and various ota's:

http://www.flickr.com/photos/astronewb2011/sets/72157632878588706/

Right click the images, check the 2048 or original full res image, and let me know how many egg shaped stars you find?

All the best...Paul


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Astronewb
scholastic sledgehammer
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Reged: 09/19/11

Loc: Connecticut
Re: ZEQ25 PE Curve new [Re: orlyandico]
      #6171436 - 11/02/13 03:55 AM

@ Orly ... Really?

All I can say is, at least my PecPrep actually shows the compensated declination (unlike another graph from a really big mount) which continually shows '00'.

Harmonics may be interesting, but all I really cared about was posting a raw PE curve. Done, and done.

Regards...Paul


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jonee523
member


Reged: 10/27/12

Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6171446 - 11/02/13 04:26 AM

Paul, all I can say is thank you for the wonderful information you have shared with those of us who are looking to dive into AP with a lighter budget then some. the information you have shared with us all has helped many including myself decide on a mount for viewing and AP. I can't say I know what all these graphs are. But I can say for visual I know it will be fine. For AP I have seen a lot of pics here and I am very impressed. I look forward to "attempting" AP. If all holds to plan come tax time.

Best regards,

Jon


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Astronewb
scholastic sledgehammer
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Reged: 09/19/11

Loc: Connecticut
Re: ZEQ25 PE Curve new [Re: jonee523]
      #6171609 - 11/02/13 09:19 AM

@ Jon

Thanks for the nice comments Jon. All I can say about this mount is that, if you're in the 'astrophotography on a budget' mode, then I highly doubt if you will find a better device to get the job done in it's price range.

Your comment made me stop and think, and I can't remember ever doing any visual with the mount. I guess if it will take a 70+ minute image by mistake, with minimal trailing, it can handle an eyeball?

Good luck with tax time, keeping my fingers crossed for you!

Regards...Paul


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orion69
scholastic sledgehammer


Reged: 05/09/10

Loc: Croatia
Re: ZEQ25 PE Curve new [Re: Astronewb]
      #6171649 - 11/02/13 09:49 AM

Quote:

Quote:

Correct me if I'm wrong, is this actually measured using Borg 250mm FL?
Is graph compensated for FL of the main scope?




I've asked on a few forums, and have been informed, the correct method is the focal length of the guidescope, not the imaging scope.

Makes sense to me, since PHD is gathering the data through the imaging scope.

Perhaps someone has some other information or can add some information?

Best...Paul




I don't know where did you get that info but it can't be correct. If you want real PE plot then you'll have to use main scope and even then you have to take into account difference in pixel size between guiding camera and main camera.


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anat
professor emeritus


Reged: 06/03/04

Re: ZEQ25 PE Curve new [Re: orion69]
      #6174790 - 11/04/13 02:08 AM Attachment (24 downloads)

I got 20 arcsec (P-P) from my ZEQ25 The following image shows the raw tracking error in arcsec (Y axis) from an autoguiding software (Linguider) with no correction signal to the mount. Note that the time in the X axis was obtained from multiplying the step and 2sec (exposure time). It should have been the step x 2.x sec.

Anat


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ramasule
member


Reged: 04/12/12

Re: ZEQ25 PE Curve new [Re: anat]
      #6178304 - 11/05/13 10:08 PM

It's not even that this is a astrophotography on a budge mount. It's a legit portable astrophotography mount. This thing really is nice.

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