Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

etunar

Members
  • Posts

    34
  • Joined

  • Last visited

Posts posted by etunar

  1. On 26/09/2020 at 13:45, 7170 said:

    Maybe check if the other gears inside are too loose too. These two videos are worth a watch: Tuning the Backlash on a Skywatcher HEQ5 Pro Mount and HEQ5 Gear Align - Eliminating that grinding noise when you slew. If you do everything in these and then wish to still go further the next options are probably full stripdown and rebuild or Rowan belt mod, so more work.

    The suggested star-cross test in PHD2 (per the 1st video) is a good starting point to see how tuned your mount currently is.

    Thanks for the links - i did the worm adjustment by following the first video. Not sure how applicable the 2nd video is if you have the belt mod?

    I have not done the star test before - probably worth a try. After i did the worm adjustment and used the guide assistant on PHD2, it did report negligible backlash though which was a nice suprise.

  2. 23 hours ago, 7170 said:

    I would give it a go without dither in case that is the issue, or add a longer delay after dither. At worst you could eliminate that as a possible issue.

    Yea worth a try. I have readjusted the worm gear as well to see if it helps

  3. 42 minutes ago, 7170 said:

    How are you guiding the mount - via a camera and ST4 port or direct (EQDIR etc)? If using ST4 try EQDIR or vice versa.

    I have seen that effect in the past on my HEQ5 when dithering between images, every now and then one would be ruined, I had to increase the settle time slightly, but I don't believe this is your issue (unless you are dithering?). 

    direct EQDIR at the moment. I am dithering - but not every image - every 5 image if I remember correct.

  4. 12 hours ago, kens said:

    In addition to some pulse guide fails there are also a couple of capture fails on the camera. I can see you had to restart guiding but what else did you do? e.g. did you check the camera connection at those times?

    Getting intermittent pulse guide fails and capture fails is suggestive of a USB connection problem. Combined with the intermittent large jumps points to cable snags as a common cause but of course they could be independent issues.

    If not cable snags causing the jumps then another possibility is flexure in the guide scope.

    If I remember correct, the restart was due to meridian flip. On my last go, I intentionally woke up around the time on previous nights when i started to have problems (2-3am), and checked for cable snags. I couldn't see anything obvious. USB connection to the mount is via a powered usb 3 hub. Seems ok as I have not had problems with the main camera (using a 1600mm now instead of 6D).

  5. 21 minutes ago, michael8554 said:

    Probably because you didn't ask how to check for tight spots, you asked for solutions.......

    I don't have an EQ mount, but I'd guess you would reduce the worm to wormwheel mesh a tiny amount and try guiding.

    Or possibly more likely -  give them a good clean with a toothbrush, then re-grease, metal swarf from the manufacture can get in the teeth and cause those jumps.

    I'm surprised no HEQ5 owner has offered any help.

    Michael

    you have been more than helpful for someone who doesn't have an EQ mount. I am suprised too - i thought there were lots of people with heq5s..

  6. 6 hours ago, michael8554 said:

    There's probably some insight in the DebugLog, which I've never been able to decipher.

    But there was no loss of pulse guide during the lurches, all the way through them PHD2 was sending big pulses to try and drag the scope back on track.

    Michael

    I guess that's good. PHD was working fine at least. By the way, how do you tell the lurches in the debug log? When I look at it, it all looks random to me.

    So do I just re-adjust the worm gear to loosen them up a bit without introducing backlash?

  7. 3 hours ago, michael8554 said:

    Re The GuideLog for the 17th:

    Guiding is generally okay, except for sudden unexplained lurches, up to 30arcsecs in places !

    In RA - at 22:04, 02:22, 03:45, 03:53, 03:58

    And in Dec at 21:44, 04:28, 04:53

    In all cases PHD2 takes a long time to correct, minutes at times

    These events are skewing your overall guiding figures.

    These lurches could be due to cable snags, or tight spots in your worm-to-wormwheel setting and/or stiction.

    But what was you Pulse Guiding Fail message ?

    Michael

     

    Thanks. Those times line up with the trails in the subs i think.

    I checked for cable snags and I can't see anything obvious. How can I check for tight spots in the worm? as i said i couldn't hear anything obvious when slewing at high speed.

    The phd message was "PulseGuide command to mount has failedguiding is likely to be ineffective" - which seems like an occasional loss guide commands?

  8. Last week I discovered a reasonably wobble on the RA axis on my HEQ5 which ended up causing lots of double stars on my subs (i am guessing because the mount kept wobbling between the two positions.) So I did the worm gear adjustment and the wobble seems to have disappeared. I did a full slew rotation check and couldn't tell any binding/grinding (I had binding at 1st attempt but was resolved after further adjustments).

    Thanks to the clear skies last few nights, I had it running throughout the night 3 times now. My overall guiding is much better than before, averaging between 0.6 and 0.8 Total error. However, when the mount gets closer to the home position (usually after 2-3am), I seem to start having tracking issues. I have attached screenshots to show examples; sometimes it's trailing, sometimes it's double stars, and sometimes it makes a u-turn to track back to the original position.

    PHD log files from another night are here: https://openphdguiding.org/logs/dl/PHD2_logs_tych.zip

    Is this a balance issue that becomes apparent when the mount is more vertical? I'm relatively new to using this mount, so most of my previous sessions have been closer to the meridian. Or is my worm gear tightened just a bit too much and causing issues? I can't really hear anything wrong when slewing at high speed.

    Only other thing i can think of is, I sometimes get error messages on PHD but pulse command being ineffective, but these happen at other times as well without causing any issues.

    It's losing me 7-8 frames over the span of 2.5 hours, so it would be nice to get it resolved if anyone has any ideas?

    Thanks

    L_OIII_2020-09-21_03-51-12_Bin1x1_300s__-15C.png

    L_OIII_2020-09-21_04-37-17_Bin1x1_300s__-15C.png

    L_OIII_2020-09-22_01-55-58_Bin1x1_300s__-15C.png

  9. 5 hours ago, kirkster501 said:

    Me too.  I think I will wait for these cameras rather than go for the 1600 - good though that is by all accounts.  However, a little voice says to me try out the ASI 2600 or QHy268C.

    I'm thinking the same. Been going back and forth between 1600 and 2600 but if a mono 2600 is coming soon, possibly worth holding on!

  10. Thanks for sharing your data Datalord. Not having worked with proper mono stacks before I thought I'd have a go.

    - Used the base stacks and stretched in photoshop.

    - Created starless copies of both ha and O3 using starnet

    - further minor stretch on the starless copies.

    - combined the starless copies into HAOO.

    - used the copy of Ha that was stretched at the beginning as a luminiosity layer and blended with the colour image.

     

    It was interesting to work with - that blue quickly disappears under red despite looking bright in mono images. Very clean data to work with!

    Untitled-2.jpg

    • Like 4
  11. 13 hours ago, david_taurus83 said:

    I processed some data someone took with a 6D and I was pleasantly surprised with how little noise it showed compared to my old 600D. So I had a grand idea and I bought a 6D with the intention of shooting RGB and mono at the same time with a dual rig. I got a bit carried away tbh lol.

    The ASI1600 was great for narrowband. But I got a bit frustrated with LRGB as I could only ever seem to grab a few hours on one filter and then had to wait weeks for another filter. Maybe it was just bad luck with the weather. In the end I sold most of my gear and went with a small portable setup with the 6D. Built up again and just recently sold all again lol. Currently holding onto the 6D, 135mm F2 lens and a CEM25P.

    I have this awful habit of slimming gear down to acceptable levels and watch as it mysteriously grows exponentially again over 6 months..🤔

     

    Haha. I can relate to that. I love my combo of 6D, 135mm and star adventurer combo. It's a perfect travel setup i think with no laptops etc.. This is also one of the reasons why I'm more hesistant about buying an OSC - while it will definitely be an improvement over 6D, I am chuffed with what I can get from dark sky locations with it.

    • Like 1
  12. 3 minutes ago, david_taurus83 said:

    I used to shoot 900s Ha subs with my ASI1600 at unity gain so there's not much difference. I found this gave better cleaner results than say 300s subs with higher gain. Personally I prefer to shoot as long a sub as possible than say, lots of short ones. Its a pain to preprocess 1200 x 30s subs, trust me!

    oh definitely.  I dont like doing short subs at all. too many files to manage as well. How come you have gone back to a 6D after asi1600 if you don't mind me asking?

  13. 4 hours ago, MartinB said:

    In my experience, having done a fair bit of imaging with both types of camera, mono cameras gather data more effeciently (require less time to achieve a given SNR), and are more flexible than osc.  The main issue is one of expence.   

    I do get that if you have the same sensor in mono vs osc, mono will be more efficient/faster. What makes my decision difficult is how does a 4-5 year old sensor from asi1600 compare with the newer technology sensor from asi2600 with higher QE, larger well depth, 16 bit etc..  cost wise the initial outlay is roughly the same between the two (I'm ignoring astrodon/chroma filters for the time being).

     

  14. On 03/07/2020 at 13:29, RichardHurst said:

    Hi Mate, This is a question I've been trying to answer myself and to be honest I still can't decide to go Mono or OSC. I'm not sure we get enough clear nights here in the UK for me to have the patience of going Mono but I'm still deciding 

    indeed. Everytime I read about cameras I change my mind.

  15. 7 hours ago, endlessky said:

    Even if you would be slightly undersampled, you could use dithering (which also benefits to reduce noise) and then drizzle integration (if you use PixInsight) which basically doubles your resolution.

    Coming from a full frame, what would worry me is also the field of view (how much or how little of the frame the object you are trying to capture would take up).

    Lastly, I would definitely go with monochrome. I won't go into much details, as I don't want to start a war between mono and color, but from what I read the mono version of the same camera model is pretty much always better. Plus you can do narrow band more efficiently.

    Good luck with your choice and clear skies!

    I checked the field of view on astronomy tools website - I think the smaller field of view can actually be a bonus with extra reach - although until I try I will never know.

    I am definitely not afraid of monochrome, it's just the some of the common problems of the panasonic sensor on asi1600 - although it may be a case of you hear the problems more than the positive feedback. And also how does 4-5 year old 12 bit monochrome sensor compare with a newer 16 bit colour sensor.

     

    6 hours ago, MartinB said:

    There is so much to think about and some of the questions you are posing will generate conflicting views!  If you are prepared to fund the additional cost of a motorised filter wheel and filters then my personal view is that mono is a more effective and flexible way to image.  That opinion is based not just on theory but also practical experience of using both types of camera.  

    With regard to pixel size and sampling rate, my experience is that my seeing conditions rarely let me get close to the theoretical sampling rate of my ASI 1600.  Obviously seeing is site dependent but on good deep sky imaging nights, with a  transparent sky my stars are twinkling! I think the optimum sampling rates people bandy about are ideal for cloud cuckoo land!  I have been absolutely delighted with my ASI 1600 and use it with a 200mm lens and a Tak FSQ106.  Here is an example with the 200mm lens (sampling rate 3.92 arc secs/ pixel) 

    I think a ZS61 and an ASI 1600 MM Pro would be an outstanding combination.  

    I think the cost of 1600mm pro with filter wheel and filters (not astrodon/chroma) is roughly the same as asi2600, so the costs work out similar in that aspect.

    edit: oh and that's a stunning image btw. I'm always amazed what you can photograph at such a wide angle.

  16. I have been doing this for many years using  a star adventurer with a canon 6d  and different lenses upto 200mm from dark sky locations.

    I wanted to get proper scope and EQ mount for a while but I didn’t think it was worth it shooting from the cloudy UK and I didn’t realise bortle 5 skies were good enough for it. After realising I was wrong I bought a HEQ5 and WO zs61. (I wanted a relatively small scope to begin with). 
     

    next thing I want to get is a dedicated astro camera. And of course going mono makes the most sense. Coming from a landscape photography world, bigger sensor is always better. However this is where I get lost a bit. According to the ccd calculator on astronomy tools website asi183mm pro is the best match for my scope (1.38 arc sec / pixel). Next option would be asi1600mm pro with a resolution of 2.18arc sec / pixel. However I’m slightly worried about this microlensing/reflection issue. Using a relatively wide scope, I may not be able to avoid bright stars all the time. And I know it would bug me if it happened.

    i know zwo released new cameras recently but asi6200 is way out of my budget. 
     

    I can probably justify the cost of asi2600 (also 2.15 arc sec/pixel) . I know it’s an OSC and not mono, but the specs seem promising and I know few people mentioned the possibility of using this with narrowband filters. It’s still a relatively new camera so not a whole lot of information on it unfortunately but everyone who had one seems to like it. It would be interesting to compare this setup with a asi1600 for example. 
     

    - So is the asi183 really the best choice? Or slight under sampling is not an issue?

    - asi1600 vs asi2600? 
     

    - I assume it’s still a big jump to go from a full frame dslr to a set point cooled OSC with a smaller sensor? 

  17. Hi all,

    I have recently made the jump from star adventurer to a proper mount (heq5) and purchased a small refractor (WO ZS61 with Flat61R) from FLO to use with my canon 6D. I haven't had many clear nights to set up flattener properly until last night.

    I have initially fiddled with it for few hours and maybe got it 80% correct. But then after reading about it I realized using a filter changes the light path (1/3rd of the thickness of the filter). I was trying to adjust it again last night. I can't quite figure out if I have it right and this is the best this flattener will do with a full frame sensor, or am I still missing something, or do I have a faulty unit?

    Images below are quarter turn adjustments (which is roughly 0.25mm) bringing the camera closer (images 9358 to 9360)... Best one seemed to be 9359, but I moved it slightly closer to confirm which made it worse, so I tried moving it back a quarter turn again (9361) but it didn't seem as good.

    Does anyone have any experience with this flattener and a full frame sensor that can help me?

    Thanks

    Esen

    PS - in case the attached images don't work - they can also be accessed via my dropbox: https://www.dropbox.com/sh/xxe0bcxo17zwct1/AADHkN2Te1rtqVISisZmOTb5a?dl=0

     

     

    Single___MG_9358_ISO1600_60s__25C.JPG

    Single___MG_9359_ISO1600_60s__26C.JPG

    Single___MG_9360_ISO1600_60s__25C.JPG

    Single___MG_9361_ISO1600_60s__27C.JPG

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.