Are there any PMX PE measurements yet?

[cventer]

When tripod Arives I will take pics

[cfranks (Charles)]

My MX seems all over the place but I assume it is me somehow. - I did an auto claibration run of 50 points and got a error circle of 15.6 arc sec. Did another of 93 points and the error increased to 44 a.s. I thought I would try a PEC but how do I get the Log it wants? I seem to have missed that part of the docs.

Charles

[cfranks (Charles)]

I think I found the instructions but it's now completely clouded out. Try again tomorrow.

Charles

[frolinmod]

Originally Posted by cfranks

....how do I get the Log it wants?

I use CCDsoft as per Tom's Corner here: http://www.bisque.com/tom/PrecisionPEC/mypec.asp

Note that Tom writes about doing this for an ME using PrecisionPEC, but PrecisionPEC is fact now built into TheSkyX's Tools->Bisque TCS->Periodic Error Correction->Compute PEC Curve, so PrecisionPEC is no longer needed. The procedure is the same for the MX.

If you guys haven't already been all over Tom's corner, you should! It's geared to the TheSky6 and the ME, but still very much applies to TheSkyX and the MX with a little "translation." Tom accumulated many years worth of experience in his little corner there. It should not be lost.

Tom's Corner: http://www.bisque.com/tom/tom.asp

Tom's Corner Paramount ME: http://www.bisque.com/tom/Paramount/paramount.asp

[cfranks (Charles)]

Thanks Frolinmod, I had seen that article but didn't think it applied since I don't have an ME, Sky6 nor PrecisionPEC. I'll have another look tonight.

Charles

[cventer]

The one thing in instructions I am not sure about is using very short exposures when capturing the PE log in ccdsoft.

Surley this means you are capturing the variabililty in the seeing ?

Would it not be better to take 2 or 3 sec exposures to average it out ?

I read a few posts on Paramount yahoo group where 3 - 5 sec exposures are being used.

What do you guys think ?

[gregbradley]

My PMX arrived today. I am off to set it up.

You never know it may even be clearish tonight.

Greg.

[Bassnut (Fred)]

Originally Posted by cventer

The one thing in instructions I am not sure about is using very short exposures when capturing the PE log in ccdsoft.

Surley this means you are capturing the variabililty in the seeing ?

Would it not be better to take 2 or 3 sec exposures to average it out ?

I read a few posts on Paramount yahoo group where 3 - 5 sec exposures are being used.

What do you guys think ?

Yes, chasing seeing would make PEC a mess. 5secs or more would Be the go, depending on seeing. Although there is some smoothIng effect with a few runs, and PE tends to change over 10s Of seconds.

[cventer]

Is it normal with Bisque TCS software that when you capture pec data pointed east of meridean you need to tick the box in PEC within The Sky X to indicate data was captured on the west ?

I found that even though I captured data on east. ie scope was pointing east of mediean if I did not tick the box saying it was west my PE got worse.

I am not that happy with the impact turning PEC on has had. It has slightly reduced the PE but not by very much. probably only 2 arc sec total. be interested in any other southen hemisphere users if they have used PEC yet on MX and your experience.

[cfranks (Charles)]

Originally Posted by cventer

Is it normal with Bisque TCS software that when you capture pec data pointed east of meridean you need to tick the box in PEC within The Sky X to indicate data was captured on the west ?

I found that even though I captured data on east. ie scope was pointing east of mediean if I did not tick the box saying it was west my PE got worse.

I am not that happy with the impact turning PEC on has had. It has slightly reduced the PE but not by very much. probably only 2 arc sec total. be interested in any other southen hemisphere users if they have used PEC yet on MX and your experience.

There is a very confusing staement about this, by Tom Bisque. AFAICS, the telescope is West if it is pointing East and the box has to be ticked. I haven't got anywhere near this as I am still getting '655' errors. The MX is a brilliantly made item but the software leads something to be desired. That and the Plurry clouds.

Charles

[cventer]

Thanks Charles. I have found software to be realy good so far other that few issues that daily build adds every so often.

What's a 655 ? What are you doing when you get this error ?

[nickbtx (Nick)]

Originally Posted by cventer

Is it normal with Bisque TCS software that when you capture pec data pointed east of meridean you need to tick the box in PEC within The Sky X to indicate data was captured on the west ?

Chris,
From my experience, not only does the software require that RA has to be the "X" axis (horizontal), but it expects west to be to the left and east to the right (north up). If my camera is upside down, I have to check the box indicating it was recorded in the opposite side of the sky. I'm in the northern hemisphere so what I'm seeing may not apply to the southern hemisphere. You may have to determine what is "normal."
Nick

[gregbradley]

I haven't used PEC with the Sky X although I am about to. But with Precision PEC there is a button about east and west and an auto button for the software to check it.

This is the one I had back to front that caused my PEC to worsen guiding.

With it running it does improve tracking and took me the rest of the way to round stars. My PEC curve is a very minor curve with only small corrections.

I can take a screen save of it if you like.

But I will know more about the PMX one shortly. I got the idea Pempro was a bit more accurate than Precision PEC. You can always use that instead.

Greg.

[frolinmod]

Originally Posted by cventer

Is it normal with Bisque TCS software that when you capture pec data pointed east of meridean you need to tick the box in PEC within The Sky X to indicate data was captured on the west ?

I found that even though I captured data on east. ie scope was pointing east of mediean if I did not tick the box saying it was west my PE got worse.

The exact same thing happened to me with an ME. I reported it, but they acted like I was nuts. I didn't really know if it was me or them that was nuts. I'm still not sure! In any case, if it comes out twice as bad, you just reverse the check box and reprogram. No big deal.

By the way, I don't know if PEMpro knows about the MX yet. I understand the mount fundamentals and the PEC table are different than the ME.

[cventer]

Thanks. I have my camera ra on x. But not sure about east and west. I tried clicking the "data caputred on west button on and off". With clicking the west my PE reduced a little. with it not clicked it got worse. problem is it did not reduce nearly enough. ie it did not take out the PE properly and in fact made things worse than no PE it all.

Last night there were a few breaks in clouds. I did a 30 sec shot with PE on. Looked like sideways logs. turned PE off. and round stars.

Something is just not right. I posted on Bisque forums so will see. I have worked out though that without PEC my mount is actualy within spec. Its about plus or minus 3 right now. When I did first check I thought my image scale was 1.83 but turns out it was .87. So at least i know its within spec. I just cant seem to reduce the PE very much with PEC. I can increase it or reduce it by about .5 or an arc sec but I am expecting it to go go less than 1 peak to peak with PEC and its no where near that

Originally Posted by nickbtx

Chris,
From my experience, not only does the software require that RA has to be the "X" axis (horizontal), but it expects west to be to the left and east to the right (north up). If my camera is upside down, I have to check the box indicating it was recorded in the opposite side of the sky. I'm in the northern hemisphere so what I'm seeing may not apply to the southern hemisphere. You may have to determine what is "normal."
Nick

[frolinmod]

I hope after properly programming the PEC you'll eventually get your MX down below one arcsecond PE. My ME came with about 3 arcseconds peak to peak of PE that reduced to sub-arcsecond when programmed. I can't think of any reason why the MX should be any worse.

[gregbradley]

There is no auto check button like in Precision PEC? I am not up to that point yet. But Precision PEC has an auto east/west button.

Back to front your mount is reversing the PEC curve making things worse not better.

Greg.

[Bassnut (Fred)]

but what seeing whilst PECing, I've never quite wirked it out, but if seeing was 2-3 arcsecs how can you hope to get a curve down to 0.5?

Originally Posted by cventer

Thanks. I have my camera ra on x. But not sure about east and west. I tried clicking the "data caputred on west button on and off". With clicking the west my PE reduced a little. with it not clicked it got worse. problem is it did not reduce nearly enough. ie it did not take out the PE properly and in fact made things worse than no PE it all.

Last night there were a few breaks in clouds. I did a 30 sec shot with PE on. Looked like sideways logs. turned PE off. and round stars.

Something is just not right. I posted on Bisque forums so will see. I have worked out though that without PEC my mount is actualy within spec. Its about plus or minus 3 right now. When I did first check I thought my image scale was 1.83 but turns out it was .87. So at least i know its within spec. I just cant seem to reduce the PE very much with PEC. I can increase it or reduce it by about .5 or an arc sec but I am expecting it to go go less than 1 peak to peak with PEC and its no where near that

[gregbradley]

The PEC software promotes that fact it can work out PEC and get past the seeing.

I guess the way it does that may be mathematical in that seeing would be irregular and erratic and smoothing would remove that influence. Much like median combine gets rid of artifacts.

Having said that I would have to think that PEC data done on a stable night would give you a better chance than on a bad night. Bad seeing in my CDK17 really shows up horrendously. Fortunately it is not that shocking very often.

Greg.