Adreneline

The periodic error quoted is much smaller and hence the tracking is far more accurate once aligned. I take care to get the best PA I can and then I follow it with a two star alignment (one of which is currently M31 - very easy to identify!). After that I find the GOTO is very accurate and the tracking excellent. Most of my imaging is with 120s or 180s exposures 135mm focal length and there is no sign of trailing. I love the fact I don't have to use a guidescope or PHD. That is not to say that my days of guiding are over - when I get the ZS71 on the mount (~320mm) or maybe the ED80 (~520mm) the increased focal length may well require me to guide. Time will tell! Adrian P.S. Have you ordered it yet?

I sold my NEQ6 and bought a CEM25-EC, so the same as the P but with the encoders. The bulid quality and ease of use is excellent compared with the NEQ6. I did not need the NEQ6 payload capacity and was finding the weight of the mount and tripod quite demanding in terms of a nightly setup. The CEM25 is easy to move around when setting up. Polar alignment is very easy using the built in polarscope with adjustment of both alt and az very much better than the NEQ6. Both axes are extremely free running so balancing is very sensitive compared with my NEQ6. So far I have only used the mount with a Samyang 135mm or Canon 200mm coupled to a ASI1600 with ZWO filter wheel, so not much of a payload. So far I have had no issues taking subs up to 300s without guiding - the extra expense of the encoders paying off for me in that respect; with sky conditions of Bortle 5 where I live there is no great advantage in pushing the 1600 beyond 180s! Although I've not tried it yet it should be quite happy with my WO-ZS71 + 1600 and I am hoping that with the addition of the 2kg counterweight I may be able to use my ED80 as well. Although I've not used it much the hand-controller seems far more intuitive than the equivalent SynScan controller. ASCOM compatibility seems fine (works well with all my other software). I did find using iOptron Commander very different to EQMOD but now I've got used to it I am finding it a much better with the simpler interface. In short - I love it! Cast caution to the wind and buy one - in fact go mad and get the EC model HTH Adrian

I like it a lot Alan - very nicely framed in amongst the surrounding star field. Adrian

Love the structure detail toward the core region. Very nice. Adrian

Thank you Alan. I like imaging these larger areas in one pass with the 135mm + 1600. I know you trade detail for wide FoV but sometimes you are not really able to appreciate just how big some of these objects are and I like to see them set in their surrounding space. Adrian

Thanks for the kind comment. I too use the ZWO adapter having tried the TS-Optics (droops) and Artesky (a complete PITA to remove the lens!); I think the ZWO is the best of the bunch. I have also expressed an interest in ordering an adapter from Astrojolo - just waiting for him to tell me they are available. I've tried various f settings but still seem to get dodgy stars especially in my top right corner of each image. All a tad frustrating! Adrian

With a 90% moon Ha is pretty much the only option available so this is 58 (out of 60) x 300s of Ha taken with a Samyang 135mm + ASI1600MM-Pro unguided. I've struggled to know what this should look like in terms of surrounding dust/nebulosity. Images of NGC7822 vary widely on the internet with anything from pristine blackness surrounding the NGC7822 to so much surrounding nebulosity it is almost difficult to distinguish the target. I've been guided by the apparent dark/near black patches towards the centre of the nebula. The image was calibrated and integrated in APP, then processed in PI (ABE and HistogramStretch) followed by a very small amount of noise reduction in PS. The image is cropped a little to remove some dodgy looking stars in the corners - an ongoing issue with my 135mm+1600 setup I am failing to solve Thanks for looking and as ever comments and criticisms are alway welcome. Adrian P.S. There is a funny little curved artefact near the very top of the image; any thoughts on what that might be? I removed two lights that contained satelite trails but this feature is only distinguisable on the stacked image.

Hi! Well maybe I could but I no longer have the MacBook; I decided it had had its day and it was time to consign it to scrap and spares. I felt it was no longer worth the effort especially as it was only 32 bit and the battery would not hold any charge; 13 years of use was not too bad. Thanks for the input and advice though.

I am still interested please Rob. Adrian

I bought the ASI1600 mount produced by ZWO specifically for the 1600. I had to space it off the vixen bar with a piece of stock aluminium bar so that I could position the lens more or less in the centre of the lens support ring (which I bought from TS Optics in Germany). I found having the toothed belt engaged with the thumb grip worked providing it was under sufficient tension but this Samyang lens is not made like a Zeiss (which is why it is about quarter of the price!) and I have noticed it is possible to distort the barrel if you put too much pressure on it from the support rings. What I really need is a felt lined ring as per the one which support the ASI1600 but so far I've not found one. If Clear Outside is to be believed I might get the chance to try the step-down ring tonight. CO even agrees with the BBC Weather app - almost unheard of! Adrian

Sounds like you've got your focus system in place but it maybe of interest of others to see what I have now done with my continually eveolving setup. I used Araldite to attach a surplus toothed belt to the lens (great care needed!) to give a more positive engagement with the mounted SW focus motor - rather than relying on friction between the focus thumb grip and the toothed belt. It has pretty well eliminated all the backlash problems I was having. Might be of interest to someone. Adrian P.S. The brass lab weights are to balance out the d.c. focus motor in the DEC axis.

Hi. Just to be clear the recommendation was to leave the lens setting at f2 but to use a step-down ring on the front of the lens - like one of these . I have a 77mm - 67mm (which allows me to fit a 67mm filter I have to my 77mm lens for regular photography) but have not used it as yet for AP. The article implied going further to like 50mm which will slow the lens down to more like f5. If I can remember where I read about it I will post again. Adrian P.S. Should have said right at the outset that star shapes aside it is a really nice image. The H&S are one of my favourite targets to image with the Samyang. I am gradually building up a huge amount of multi-session data I need to combine; hopefully it will have been worth it!

Well not sure I really know the answer to this one but I experience exactly the same problem in the extremities of my images. I've played around extensively with spacing and the results are always similar. My spacing on the current set up achieves focus just before the end-stop on the focussing ring but I still get slightly mis-shaped stars in the corners. Can't recall now where but I saw someone advising the use of step-down rings on the front of the lens to correct/ameliorate these sorts of issues. I think they had reduced the aperture right down to 50mm which slows the system down to around f5 (still keeping the aperature setting on the lens at f2) but I've not tried that approach as yet, although I do have a ring that would step mine down to 67mm. As an aside I've also tried using the 135mm/ASI1600 combination with both 1.25" and 2" filters and the result is still the same. I will be interested to see what others think/advise. Adrian

Looks to me like you came up with something very nice indeed. I like very much the rich variety and yet understated colours. I cannot believe that space is psychedelic or garish when it comes to colours. Thank you for sharing. Adrian

Hi Mick If you don't have Annie's Astro Actions I would certainly recommend them; lots of useful and helpful stuff for sorting image problems/issues and a bargain at only $15. Good lcuk. Adrian