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Mesu 200 First Light - The Pleiades


Laurin Dave

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First light on my recently acquired Mesu 200 was achieved  last Thursday evening... I've posted in Mounts about installation and setup.  I wanted something I could finish that evening so what better target for that than The Pleiades.  I got 2 hours of 30s 60s and 120s exposures on a Nikon D750 @1600 iso through my Esprit 150ED, although it was through a slight haze.  Processed in Pixinsight and Photoshop. Cropped from 6000x4000 to 5000x3500 (ie75%) because of shutter box vignetting. 

Thanks for looking

Dave

M45_Mesu_D750_Esprit_2hrs.thumb.jpg.5dcfeffa06b0bdea231d7986f3304e55.jpg

 

 

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On 17/12/2018 at 21:50, Laurin Dave said:

I did Mike...it was sub 1" rms..   

Nice image, especially with a non CCD/CMOS camera. Unguided 10 min subs? Does the new Mesu 200 have absolute encoders? Built a model? I didn't think the Mesu could do unguided. BTW we have the same scope - SW150 Esprit, its very good!

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What would be the point of not guiding? It is far more difficult and unpredictable than guiding most of the time. Even those whose mounts are intended to support unguided use find that it is is generally easier to guide.  My original Mesu has yet to drop a sub to guiding error after more than five years. What problem would I be trying to solve?

Olly

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2 minutes ago, ollypenrice said:

What would be the point of not guiding? It is far more difficult and unpredictable than guiding most of the time. Even those whose mounts are intended to support unguided use find that it is is generally easier to guide.  My original Mesu has yet to drop a sub to guiding error after more than five years. What problem would I be trying to solve?

Olly

Ooohhh Olly!! If Per was still here, he would have your guts for garters :) I've not guided for 3 years, including my visit to you when I took around 30 hours of data with my 10 micron. It really is so simple and takes another factor out of the equation ( I had a lodestar fail on me when at a star party a few years ago). We guide to correct for errors of tracking, but if these are halted at source, then isn't that better?

Adrian

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Think I’ve confused folk..  the M45 session was guided and was the first one with the new Mesu.  I was having Sitech/PHD issues, resolved with a software update, and after it was fixed I did 10 minutes unguided to get some PHD advice on guiding parameters.   Since then it’s been wall to wall cloud where I am so no chance to investigate how to create and the benefits to pointing accuracy of a sky model. 

Dave

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53 minutes ago, CCD Imager said:

Ooohhh Olly!! If Per was still here, he would have your guts for garters :) I've not guided for 3 years, including my visit to you when I took around 30 hours of data with my 10 micron. It really is so simple and takes another factor out of the equation ( I had a lodestar fail on me when at a star party a few years ago). We guide to correct for errors of tracking, but if these are halted at source, then isn't that better?

Adrian

Heh heh, greetings, Adrian. ? Per might have tried to have my guts for garters just as I might have tried to have his! We had an amicable disagreement on this matter. It would be cheap on my part to try to score points now that, to everyone's immense sorrow, he's no longer playing in this game. I won't be doing that.

However, I do get to interact with a very large number of imagers, including 10 Micron users, and the fact is that they do not, as a body, concur that unguided is best. I've no idea what the true objective statistic is regarding those who choose to guide on stars and those who choose to guide on encoders/models but I do know for certain that a good number have rejected the encoders/model solution because they found it problematic. You don't, which is fine, but I don't find star guiding problematic either.

I think that your point here is questionable: 'We guide to correct for errors of tracking, but if these are halted at source, then isn't that better?' Neither encoder/model guiding nor star guiding halts the error at source. Both systems require the mount to make an error before any corrective input can be applied. The only difference is the reference point used to decide that an error has been made.

One of the many great things about Per was that he was highly opinionated and yet had little time for arguing with people who were not, likewise, highly opinionated. I think this explained the success of our friendship. We disagreed on everything and yet, explain this if you can, we shared a profound agreement on everything... Damn, how we miss him.

Olly

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3 minutes ago, ollypenrice said:

Heh heh, greetings, Adrian. ? Per might have tried to have my guts for garters just as I might have tried to have his! We had an amicable disagreement on this matter. It would be cheap on my part to try to score points now that, to everyone's immense sorrow, he's no longer playing in this game. I won't be doing that.

However, I do get to interact with a very large number of imagers, including 10 Micron users, and the fact is that they do not, as a body, concur that unguided is best. I've no idea what the true objective statistic is regarding those who choose to guide on stars and those who choose to guide on encoders/models but I do know for certain that a good number have rejected the encoders/model solution because they found it problematic. You don't, which is fine, but I don't find star guiding problematic either.

I think that your point here is questionable: 'We guide to correct for errors of tracking, but if these are halted at source, then isn't that better?' Neither encoder/model guiding nor star guiding halts the error at source. Both systems require the mount to make an error before any corrective input can be applied. The only difference is the reference point used to decide that an error has been made.

One of the many great things about Per was that he was highly opinionated and yet had little time for arguing with people who were not, likewise, highly opinionated. I think this explained the success of our friendship. We disagreed on everything and yet, explain this if you can, we shared a profound agreement on everything... Damn, how we miss him.

Olly

Greeting Ollie, good to talk to you again and just for the record, you probably have deduced that unfortunately we won't be coming in June as per my previous inquiry, but one day, I will definitely come again, last time was very enjoyable, not only with astronomy, but those processing discussions with a brandy and burning midnight oil! Back on topic, you knew Per better than me, but he was a great contributor and person, we agree completely, a very sad loss. Per and I fully agreed about unguided imaging, its such a shame we couldn't team up against you in person in France :) Your right, I just love unguided imaging and that I have never lost a single frame in 3 years, it just works. I appreciate that others have difficulties, and my best guess is that something in the mount/scope was moving, everything needs to be locked down firmly, mirrors and all. I know that some had issues with Newtonians for example. Prior to my 10 micron mount, I was guiding for 20+ years and I did experience issues, typically, guidestar lost with cloud, low S/N, hot pixels, cosmic rays etc and as mentioned I had a guider die on me. Many more people are using automated software, so after a meridian flip, what happens if a guidestar is not visible? not often I know, but it does occur.

When autoguiding an error of star position occurs and the autoguider reacts to re-center, when tracking unguided with a model/high res encoders, a mathematical formula for correction is calculated prior to imaging and played out during the exposure, i.e. it is pre-planned and fixed. That's what I meant. And its cool to have one less item in the imaging train, with one or two less cables :) I've just purchased a Samyang 135mm F2 lens and can attach my ASI camera with filter wheel, but there is no room for a guider!

Adrian

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I really like your image Dave.

There's a balance between awe inspiring vast expanses of nebulosity and the "needle in the eye" sharpness and brightness of the stars in this object - you've really found that balance ...for me of course.

The only observation I made to myself was that I wished it was a bit more blue to bring out the glow a bit more.

...and from Berkshire as well? I'm in Oxfordshire and haven't seen a decent sky since Oct/Nov ? might have to move back to my old stomping ground near Newbury.....that's a thought actually - I wonder what the skies are like up on Greenham Common (nb of course) - should be a good view of the entire sky from there - think I'll check that out ? 

  ...guiding? 10 Microns? Mesu? ....these words are slipping from the vernacular of astrophotography with the arrival of CMOS such as the 1600MM with 1 and 2 minute subs....on a Star Adventurer no less ?, speak to me not of the need for so much disk space to accommodate either - that's what they make external drives for .......but I know nothing so please ignore all that LOL!

David

 

 

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9 hours ago, Laurin Dave said:

Think I’ve confused folk..  the M45 session was guided and was the first one with the new Mesu.  I was having Sitech/PHD issues, resolved with a software update, and after it was fixed I did 10 minutes unguided to get some PHD advice on guiding parameters.   Since then it’s been wall to wall cloud where I am so no chance to investigate how to create and the benefits to pointing accuracy of a sky model. 

Dave

Hi Dave,

I m trying to set up my new Mesu, so I  d like to hear more about your s/w issues with SiTech and PHD, I m assuming I'll come across a few when I get that far.

Did you have it in a thread here in SGL?

Thanks Tom

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10 minutes ago, David_L said:

I really like your image Dave.

There's a balance between awe inspiring vast expanses of nebulosity and the "needle in the eye" sharpness and brightness of the stars in this object - you've really found that balance ...for me of course.

The only observation I made to myself was that I wished it was a bit more blue to bring out the glow a bit more.

...and from Berkshire as well? I'm in Oxfordshire and haven't seen a decent sky since Oct/Nov ? might have to move back to my old stomping ground near Newbury.....that's a thought actually - I wonder what the skies are like up on Greenham Common (nb of course) - should be a good view of the entire sky from there - think I'll check that out ? 

  ...guiding? 10 Microns? Mesu? ....these words are slipping from the vernacular of astrophotography with the arrival of CMOS such as the 1600MM with 1 and 2 minute subs....on a Star Adventurer no less ?, speak to me not of the need for so much disk space to accommodate either - that's what they make external drives for .......but I know nothing so please ignore all that LOL!

David

 

 

I don't believe CMOS are there yet. I do think they'll get there, though.

Olly

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Great start Dave! I can even see the Ghost of Merope (aka IC 349 - Barnard's Merope Nebula) in your image. Like Tom I will be following your progress closely as I expect my Mesu to arrive in a week or two.

Happy New Year!

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27 minutes ago, Tom OD said:

Hi Dave,

I m trying to set up my new Mesu, so I  d like to hear more about your s/w issues with SiTech and PHD, I m assuming I'll come across a few when I get that far.

Did you have it in a thread here in SGL?

Thanks Tom

Hi Tom

I put a post Mesu 200 Arrives in 'mounts' a couple of weeks ago ..  the issue I had was with the version of Sitech that is on their downloads page causing an error message with PHD calibration..  changed it to version 92eg (which you need to search for ... see my post) and it was fine and the guiding was better..  been cloudy since but hope to get some more runs in soon after the new year. Using SGPro, PHD2 and Sitech, only done offset inits so far. 

Dave

 

 

 

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33 minutes ago, gorann said:

Great start Dave! I can even see the Ghost of Merope (aka IC 349 - Barnard's Merope Nebula) in your image. Like Tom I will be following your progress closely as I expect my Mesu to arrive in a week or two.

Happy New Year!

Thanks Goran..  hopefully it'll just work the next time out.  Just waiting for the filters for the SX-46 now ?

Happy New Year to all

Dave

 

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16 minutes ago, Laurin Dave said:

Hi Tom

I put a post Mesu 200 Arrives in 'mounts' a couple of weeks ago ..  the issue I had was with the version of Sitech that is on their downloads page causing an error message with PHD calibration..  changed it to version 92eg (which you need to search for ... see my post) and it was fine and the guiding was better..  been cloudy since but hope to get some more runs in soon after the new year. Using SGPro, PHD2 and Sitech, only done offset inits so far. 

Dave

 

 

 

Found it, thanks Dave,

Tom

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1 hour ago, ollypenrice said:

I don't believe CMOS are there yet. I do think they'll get there, though.

Olly

Me again Olly, why don't you think they are there yet? I bought my first one 2 years ago, just after visiting you. It has much lower noise, faster readout, smaller package, smaller pixels for high res imaging and much cheaper. Sorry to be contrary!

Adrian

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4 hours ago, CCD Imager said:

Me again Olly, why don't you think they are there yet? I bought my first one 2 years ago, just after visiting you. It has much lower noise, faster readout, smaller package, smaller pixels for high res imaging and much cheaper. Sorry to be contrary!

Adrian

Lots of issues keep popping up. Microlensing, internal reflections, amp glow...  One of our robotic team has recently posted a Horsehead, for instance, with the expensive full frame QHY OSC CMOS and has curious blue fringes around the Flame Nebula. Bright stars seem to bloat easily as well. I'm happy to be convinced but I'm not yet persuaded...

Olly

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19 minutes ago, ollypenrice said:

Lots of issues keep popping up. Microlensing, internal reflections, amp glow...  One of our robotic team has recently posted a Horsehead, for instance, with the expensive full frame QHY OSC CMOS and has curious blue fringes around the Flame Nebula. Bright stars seem to bloat easily as well. I'm happy to be convinced but I'm not yet persuaded...

Olly

If you were in the market for a Osc camera Olly, what would you go for?

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39 minutes ago, Allinthehead said:

If you were in the market for a Osc camera Olly, what would you go for?

Mono!

:icon_mrgreen: Actually I probably would consider the QHY full frame CMOS. I do have a PC which could handle the volumes of data and it would be a cheaper way to get the dual Tak running again. (Tom's reclaimed his camera to use in his new robotic shed here.) I would only ever use an OSC as half of a dual rig, though, because widefield and Ha go together like a horse and carriage. I haven't yet tried processing any data from this camera but I can easily ask to borrow some from the robotic guys. However the camera in question may have developed some dust on the chip. We're not quite sure yet. Buying a non Atik camera would be a difficult step for me to take because I like the cameras, I like Atik and I have a good working relationship with them which matters when you're a provider as I am. China's a long way away.

Olly

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