almcl

To interpret the guide logs there is a tool (written by one of the programmers of PHD2) here http://adgsoftware.com/phd2utils I find it very useful for analysing guiding performance. Among other things it reports that your Polar alignment error was less than 1' : There is a brief explanation of its use on that page, but if you want to dig a bit deeper, there's a pdf that can be downloaded here https://openphdguiding.org/tutorial-analyzing-phd2-guiding-results/ Looking at the 4 logs for May, I can't see any reason for the target to drift off the screen. PHD2 is making corrections, albeit of some fairly large excursions, and the guide star is coming back to position, at least as far as the guide camera is concerned. Sample of this below: That suggests that the issue may be flexure between the guide scope and the imaging scope, it doesn't take much movement at all to produce this effect and plastic tipped guidescope ring mounting screws are famous for producing this result, if you have those? That isn't to say that resolving flexure (if that's what the cause is) will completely resolve star trails, the scatter plot suggests there may some more issues to check: I'll disagree slightly with Michael here, updating to the latest version of PHD2 may improve matters slightly, with better guiding assistant analysis and improved calibration algorithms. Finally it may be worth posting guide and debug logs over on the PHD2 Google group https://groups.google.com/forum/#!forum/open-phd-guiding Andy and Bruce are pretty quick to respond and will have much greater insight.

+1 for the 700 (mine is astro modded) and have been imaging with it for just over 4 years. The 750 suffers from an (apparently) uncorrectable banding issue.

Sean If you can post a the guide log from the affected session (PHD2 stores these automatically and the default location is My Documents) it should be possible to see which axis is causing the problem, whether guide pulses are being sent and not responded to and how good the PA and calibration were. This could help show if it's a mount problem or something else.

What happens to the guide star on the PHD2 screen? Does this also move or does it stay in place? You say you took subs while 'PHD was going through its routine', is this while it's calibrating? That would produce star trails for sure, and how was the calibration? Any reported problems?

I used white Hammerite hammered finish, but as I couldn't find it in a spray can had to mix it with thinners and spray it from my air driven spray gun. The result was acceptable rather than wonderful. If you go this route your local automotive paint factor may be able to come up with a very much cheaper alternative to the unbelievably expensive Hammerite thinners. Mine did.

It looks as though you haven't got any light frames selected. You have to click on check all (or go through each sub checking the box at the left hand side). Not sure if this is the complete solution but try 'check all' and then see if it will stack?

That made me reach for my 1962 edition of the Observer's Book of Astronomy! (Yes, still got it.) I notice that while Sir Patrick condemned small refractors, he instead recommended binoculars as an alternative and having used a pair of 1960s manufacture 9 x 30 Ross binos the other night, I think that both telescopes and binoculars have come a long way in the intervening years. Both in price per millimetre of aperture and in overall performance, today's equipment seems much superior and this has surely pushed back the boundaries of what is 'useful'.

All taken with Canon 700d and either SW200P or Canon 200 mm EF 2.8 lens Whale and Fish Hook NGC 4631 & 4656 IC1396 including the Elephant's trunk Headphones nebula PK164+31.1 Spaghetti nebula Sh2-240 in Ha Lobster Claw, Bubble & M52

I'll jump in since no one else has. I didn't fit the official goto upgrade kit, just the tracking motors and handset. I found this pretty straight forward and I think the goto kit is similar but with a few extra components. I then decided to fit Tom Carpenter's AstroEQ, complete with belt mods, home made bracketry and custom pulleys. I did this to improve guiding accuracy, but found the goto ability it also provided was a real bonus. Having now got an EQ6 AltAz with the Synscan handset, I don't find the handset as convenient (and would cheerfully strangle the person responsible for fitting a coiled cable as the mount connection) but compared with failed star hops, it takes all the frustration/fun out of finding a target.

How are you taking your flats? I ask because stretching your flat frame shows a weave pattern as well as a number of very regular, circular artefacts that don't resemble traditional dust bunnies. These patterns are also present in the 'no flat' image. This raises two questions, what is causing them? and why aren't the flats helping?

IC1369A M8 M17 M20 M94

I had cataract surgery on one eye about four years ago, so now have one 'original' eye and one 'bionic' one. Being able to see distant objects clearly again was amazing. The difference in vision for stargazing is noticeable, too. The 'bionic' eye (with the replacement lens) sees things much brighter, the 'original' eye sees contrast much better. The focus points for both are quite different. Different surgeons perform the op differently and it is definitely not something I'd do again for fun, but it was over within an hour. There is a slightly increased risk of retinal tearing post surgery, and I did experience this, but this too was very quickly sorted by the NHS and full vision is back again, with a bonus of slightly reduced floaters.

Sorry to say, with failing memory, I am not quite sure. I did stop using the (rechargeable) batteries in favour of this Maplin switchable power supply, but also switched to using an Astroeq to guide, replacing the brass cogs with belt drives. The worldwide plug was a complete disaster but once this was replaced with a proper 13 amp plug, it proved OK. In its 13.5 volt mode I am still using it with my relatively newly acquired AZ EQ6.

Pacman Nebula NGC 281 Cocoon Nebula IC5146 Cone Nebula NGC2264 Iris Nebula NGC7023

Not sure if your Celestron mount is the same as my EQ5, but on mine there's a plastic plug on the under side where the bubble level sits which I think can be removed. It might be possible to shim or otherwise alter the bubble level's position and get things back on an even keel.