almcl

The star in the middle is indeed Arcturus, constellation Bootes:

I hardly do any visual these days (LED street lights have made it all but impossible), but the guiding accuracy for photography is just as good as it ever was, and this is with a fairly heavy SW 190 MN and camera gear hanging off it.

I'd say go for it.

I fitted the extension tube to mine and haven't noticed any loss of stability.  

Another advantage is that I can image well beyond the meridian with no danger of collision with the tripod legs.

Getting it set up so that it didn't slip round, completely destroying the azimuth part of polar alignment, took a bit of doing but once set it was fine.:

Don't think moonlight has anything to do with it.

As others have said, the scope has moved by a noticeable amount in Dec (your image below overlaid with RA/Dec axes) and the doubling is pretty  much aligned with the long red arrow (Dec)

This should show up in the guide log for the time of the relevant sub, are you able to see a corresponding jump on the Dec trace?

If so there are several possibilities, temporary cable snag or drag being one such.

200 stars is a lot more than necessary. DSS uses up to 100, but never more.

However the main problem apears to be that your stars are not round:

as  a result DSS may be rejecting them in favour of noise pixels.

You might be able to get round this by manually selecting stars although with a 100+ images this could be tedious.  

If you can work out why your stars aren't round and fix this, you may well be able to stack next time you try but this data set may be beyond help

An unexpectedly clear night but with a very high speed jetstream right overhead was not really a sensible night to try for this small target in Monoceros, but I have been after a planetary nebula (or two) to add to a multi image project.

This is a bare 2 hours worth with a 190 MN and an ASI 2600MC

If you update to a more recent version of ASTAP, it will show the percentage tilt.  According to Han (ASTAP's author) anything below 10% is OK.

Your figures look  pretty good, but see what a later version shows?

I have had a SW 190 MN for 3 1/2 years now, so here's my experience.

I fitted the extension tube you linked to and it definitely helps avoid collisions with the tripod legs although not sure it completely eliminates them.   

I had been using an OAG before with my 200P, and with any large(ish) reflector, I now wouldn't guide any other way.  I am using the ASI OAG with an ASI 120 MM and never lack a large choice of guide stars.  Routinely we get ~0.6 " oscillation in PHD2's guide stats and on nights of exceptional stability, periods below 0.5" 

I found an Astrozap dew shield (there's one specifically for the 190 MN) to be absolutely essential: that huge chunk of glass at the front is a real dew magnet otherwise.  It also helps to keep stray light out.

I found the standard focusser to be too wobbly for my ASI 2600 and, on advice from FLO, fitted a Moonlight. Sadly I don't think these are available at the moment. 

One advantage I haven't seen much mentioned of the 190 MN over its similarly tubed brother the 200P, is that the baffles keep the tube much more rigid.  As a result it hardly ever needs collimating (after the first go on delivery) whereas my 200P needed doing every time it was lifted out of its box.

All in all, I think it's a great scope although it is markedly heavier than the equivalent straight Newtonian and lifting it up high on to the AZEQ6 plus extension, is a liitle bit of weight lifting challenge!

All with a Skywatcher  190 MN and ASI 2600 MC

NGC 2403

M16

IC434

M94

NGC 40

You don't mention flats in your calibration frames and there does appear to be some vignetting, so might be worth planning to take some of those?

Pacman is quite an Hα rich target so a modified DSLR (or an astrocam) might well pick up more.

Also, and I am not familiar with your camera, but ISO 400 and 60 seconds seems a bit short.  With my astro modded Canon (different camera, I know), I used ISO 1600 and 180 second lights on this target.

Skywatcher sell the 200P with the EQ5 mount and it's fine for visual. 

I also attached a DSLR to my 200P on its EQ5 mount and, with guiding, it usually managed about 1 arc second or just over oscillation.

You might want a coma corrector eventually but it was a good combination for the DSOs that I wanted to record.

Here are a couple of images taken with DSLR and SW200P mounted on my EQ5 (my capture and processing skills have improved since then):

Glad you got it sorted, Beka and thanks for posting back - it may help someone else in future.

Since switching to a dedicated astro cam, I can't get APT's live view to work reliably, or sometimes at all, although the capture side of things is fine. 

For initial focus and sync,  ASI Image seems a lot quicker and simpler and although a little quirky, at least it doesn't have APT's multiple irritating nag screens.  Once focussed, I then switch to APT.

It might be worth posting a question over on the APT forum (https://aptforum.com/phpbb/viewforum.php?f=4), to see if Yoddha can shed any light on the problem?

5 hours ago, beka said:

I don't have the raw files - just the FITS.

The latest version of EXIFLOG (referenced above) can read the temperature data from FITS files if your imaging ap has recorded it.

Not sure that this will answer the question, but it may be worth examining the EXIF data for the subs.  Although I've never seen quite such a dramatic a difference as your screen shot shows, I have seen  differences of up to 25°C in recorded sensor temperature between subs in a session and this might account for some of the difference.

The 700d also has a noise reduction mode which (I *think* from memory) subtracts an automatically taken dark from a sub.  If you have this mode active it might make a difference.  Mine seemed to have a mind of its own when deciding whether it was active or not.

If you don't have an EXIF data reader, there's quite a nice one available from https://www.covingtoninnovations.com/astro/astrosoft.html

EDIT:

Sorry, just noticed your image acquisition software is storing your subs as FITS rather than .CR2 files so unless you also have the raw files you may not be able to read the EXIF data.

Probably used a thread gauge from my metric tap and die set. 

In the absence of such, my usual tactic is to run a nut down the thread of the shaft (or a bolt if dealing with female) until I find one that fits. 

I bought my Alt az eq6 just over six years ago to use with an 8" SW 200p. Subsequently got a SW190mn (same size but significantly heavier).

I have never used the alt az mode, but in eq mode it usually guides about 0.6" with occasional sub 0.5 "  sessions on nights of very good seeing. 

So far, it just works. Mostly used in the back garden but has been taken out to a dark sky site on several occasions. 

Not just Cassiopea, you've caught the Andromeda nebula as well.

Well done.

Onwards and upwards! 

I started my 'Messier quest' back in January 2015.   I got to 108 in August this year.  My excuses are that at 52°½° N and living on the northwest side of a tree clad slope makes the more southerly ones quite a challenge, some don't get above 15° of elevation, even if I drive out to a windswept high moorland dark sky site.  

Also got distracted by all sorts of non-Messier things.  But, if we have a clear, windless night or two next April or early May, I might bag the last two.

7 hours ago, Cakedestroyer said:

Awesome! Thanks for the cool map, did you make it or use a tool? Seems like a cool thing to be able to use if it's like a website.

You're welcome!

Took a screen grab from  Stellarium (useful, free planetarium program, in case you don't already have it) having guessed your location as somewhere on South Island, then overlaid your image with a bit of transparency and shrunk it to fit. 

There is a Website, astrometry.net , that will do much the same thing, although it may need a slightly better signal to noise ratio image to plate solve.

1 hour ago, Cakedestroyer said:

One other thing is I am 99% sure but I would not be very happy with my self if I was taking so much time so just wanted to check, the middle "star" of those 3 is the Orion nebula right?
 

Yes, indeed it is.

Here's your image overlaid on a star map:

PHD2 does not initiate dithering, the imaging program generates a request to which PHD2 then responds.

According to your logs the last time your imaging ap requested a dither  was  21:51:21,  after that time no further requests were received. 

You need to look at the imaging software to find out why it stopped issuing dither requests.

11 hours ago, maw lod qan said:

Now is that a tall wall behind the old structure?

Don't think so.

A quick look in Google Earth suggests it's the crest of the ridge on the north side of the dale.  Seen on the upper left here:

My volume three has several indexes spanning all three volumes:

General topics
Popular names
Constellations
Messier objects 
Brightest stars  

but it is quite an old edition, purchased second hand off the 'bay. Does yours not have these?

Thank you both Wim and Paul!

Most reassuring!