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Posts posted by libraryman

  1. Your rms is independent of your guiding arc sec per pixel ratio if you are reporting in arc secs, so...depending  on your imaging scale..you should try to get half or less than half your imaging Arc sec per pixel scale. I.e. If your imaging scale is say..3 arc sec per pixel then a good rms might be 1.0  but really good guiding would be half an arc sec or just over I.e. 0.7 rms depending on seeing.

    some imagers do get less than this but it needs a very good mount and set up, the longer your focal length the more difficult it is to achieve.

    your Osc looks good at 0.35 but ideally you need to get your Dec guiding under control.

    The guide logs are in the PhD folder usually in c drive documents


  2. Good advice from Louise, i think she is trying to tell you that it's unlikely to be your choice of guidescope that's causing your guiding to fail, if you change to the 80mm you will no doubt have the same issue and then have the additional issue of setting up the new guidescope.

    Make sure you are focused and pointing in the general area of the scope, this will help when you polar align!  The symptoms you describe sound like a lack of good alignment.

    But it might just be the camera losing the star because of thin cloud, look down to the left bottom corner for snr.. You need about 20...make sure you have the latest version 2.6.1



  3. I'm happy with my eq8, I have used it for approaching 2 years now, I have the eq8 tripod sitting outside all year around, when I see a clear spell coming I just lump the head outside and fix it too the tripod...it mght sit there for several weeks, I only remove it if I go away from home which I do regularly!!

    I have heard some comments about water getting into the encoder area's but I don't suffer any issues to press!

    I usually stick with 20min sub's but 30 min subs are doable, its just that I live on a flight path that puts me of longer sub's, as for reliability....... Perfect, no issues at all.....I have to admit that I had some Dec backlash and it took some adjusting out but that's sorted out now.

    Guiding performance is of course dependent on various factors but half an arc second guiding is pretty much the norm on a good night!

    I run an FSQ 106 and eventually I will run two on it, weight just isn't an issue but for me, a good aspect of the eq8 is its ability to carry loads of ancillary equipment on the head with it lots of flat surfaces....and that gives me good wiring options to keep it tidy.....

    It's a heavy beast but really good with eqmod, I never use the handset.


    • Like 1
  4. I don't use a star alignment method to polar alighn, rather I prefer to use PhD..however you choose to do it; it is I feel important to understand exactly how far your mount is from being truly aligned, in that sense I prefer to be no more than 1arc min from perfect alignment!

    This level of p.a. is quite accurate but it does allow you to explore the longer sub's without rotation issues and gives you the best start for good guiding.


  5. Plus 1 for Michael's comments, sometimes it's better to set up on the bad nights just for the setup experience and practice!

    It's taken me 2 years to acquire what I want and a method to use it .....repeatability.....is my watch word.

    Having said that....recently I set up and in my attempt to get up and running I completely forgot to polar align!!! Some couple of hours later, I realised that I had forgotten. Doh.....age does that to you :) but I still wouldn't give up.


  6. Thank you for your comments all, I have to say this is my first attempt at a comet and it was purely guess work!

    I took 2 x 120 sec sub's initially then decided that might be too long so I changed it and took some 40x 30 sec sub's after reframing it.....

    When I came to process it, of course it did not like the combination of two different times and framing but I followed the Harry Page video for comet stacking and pleased I did...

    It took me a good few hours to follow it correctly but at last I had an image I am particularly happy with.....thanks Harry :)

    I will eventually run DBE on it to remove the daylight gradient top right...


    • Like 1
  7. Hi, hoping some expert will help me with a stacking question :)

    I'm trying to stack a good few subs of Catalina taken last night...I'm new to pixinsight having previously used Images Plus.

    If i use images plus to stack; i can use an align feature that allows me to use the comet head a an alignment point...this of course trails the stars...to be sorted later !!!

    Is there a similar function in Pixinsight ???


  8. I'm grabbing O111 on the jellyfish nebula, is there much to be had or is it just better to stick with HA?

    It looks farther weak, A 20 min just shows a bit on the edge!!!

    Not tried Sulphur yet but I'm at 17 x 20mins on the O111 does Sulphur add much to the nebulosity?


  9. What's your image scale? The stars look a little blocky when I zoom in, big ones o.k but the smaller ones look too blocky to my eye, perhaps a s5ar reduction routine might assist!

    Also I don't see the small nebula WeBo 1in your image but that maybe due to lack of O111.

    Looking a bit better though.


    Edit...I'm going to correct myself here, I wonder if this is a stacking issue or a registration issue! When zoom in really close, I see what appear to be some very close diffraction spikes that may indicate a stacking problem leading to the poor resolution!!

    Just shooting ideas!


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