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Erquy

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Posts posted by Erquy

  1. Soon approaching 10 years with the Avalon M-Uno, I thought it could be of interest to share my experience for astrophotography with this mount. Before the M-Uno acquired soon 10 years ago, I had 3 years struggling with 2 different AVX mount (one still in use but I won´t compare with it).

    Before starting reporting my experience, below my typical set up and situations:

    Telescopes:

    I am typically imaging with

    • SCT C8 (with an a Star Arizona FR, so down to 1460 mm), with a large dew cover making it twice longer or
    • WO GT81 (with FR so to 380 mm) or
    • FMA 180 at 180 mm or
    • Sigma Art 50 mm (only with my canon)

    So I can cover a wide range of FL . Lately, I am now typically setting up  in “dual rig”  by attaching the DSLR (with the  FMA or with the 50 mm) on the under side of the arm as “counter weight” with a ball head/canon), while the C8 or the WOGT81 is on the main saddle (see pictures). I never tried to combine the C8 and the WO GT81 in any ways so far. 

    Imaging Camera:

    • Main imaging set up is typically with a SX694 mono with miniFW, OAG integrated, Lodestar on the C8 or the WOGT81 or the FMA
    • Canon 80D astro modified mostly used with the FMA or the Sigma art

    Guiding:

    • Lodestar with the OAG of the MiniFW starlight Xpress most of the time (with either scopes, so different guiding scales)
    • an ASI224MC and mini guidescope (ZWO miniguide scope) if I am imaging with the canon and FMA or the Sigma Art 50 mm (a matter to avoid setting up/using the WO or the C8 as “guide scope” with the SX694/min FW). So a “light” set up when working at 50-180 mm.

    Pay load: considering the different set up I am combining, the total payload varies anywhere from about 4 kg up to 15 kgs.  

    Mount set up and usage:

    • My M-Uno is among the first years it was produced and must be >10 years old model (white cover arms and chrome painted saddle/DEC and RA clutches). It is permanently set for 7 years on a brick pier.  Very robust as I never had to re-do any polar alignment for many years. I am running it with a DC adapter (adjustable 12V or 15V), not battery. No issue on powering the mount ever and stable.
    • The mount is staying 7/7, 365 days outside for 7 years, under a Telegizmo cover (also soon 10 years old, very good! and an additional cheap light grey BBQ cover, and with a blanket and a regenerative 500 gr dessicant inside, both absorbing moisture build up under the cover, and I monitor temp + moisture under it -and when moisture >85%, I typically dry the desiccant and let the mount “breath” before covering it up again (If not used, I uncover and dry the blanket/dessicant at least onceevery 4 weeks or find a time to get it dry after some high humidity nights in operations).
    • Total operating hours: Difficult to say as I never really looked at counting, but it must have some 2000-2500 hrs of usage over past 10 years. It could be more if the weather was better and I would not have to travel for work (and unfortunately, I miss many good nights)
    • The arm is set up so I don´t need to change its position when changing set up to cover all above gear set up (unfortunately I cannot remember since I set it up in the very 1st days to accommodate the C8 and the WO). I only need to add the extension for the WO GT81 or the “light” set up as compared to the SCT C8 (no extension) and final touch with eventual small counterweights on either sides depending the set up. So a quick and simple turn around when needed between the different set up. 
    • DSC_0589.thumb.JPG.1e0a4739290befcc0d498669f31ebc74.JPGDSC_0769.thumb.JPG.c4284f85cf49280bf9d90a5343785555.JPG

    Conditions South Sweden:

    • Backyard in a Bortle 7 sky city. Seeing varies quite a bit as also often jetstream passing by as well. 
      • Temp: from -25C to +30C (under the cover reaching +40C), so quite tough environment year long. Most typical winter is -10 to +5 and summer +15 to 25C. In operation, I have been imagining down to -15C, but most typically -10C to +5C in winter.
      • Humidity: vary quite a lot along the year, can be quite dry in winter, and high humidity in fall. But basically 70 to 90% RH would be typical range, so a dew heater strap is required most of time as soon as >75-85% humidity level
      • Wind : the wind is typically in 2 to 6 m/s range (gust 8-12m/s), rarely above when nights are clear.

     

    So that was all for the background, now what people are most interested to know about:

    • Maintenance: after 10 years, it is all in its original piece and one could say maintenance “free”:
      • The only “maintenance” I needed to do was a few months ago, when I noticed more difficulties to get low RMS in great conditions (I was up on 0.5-0.8” total RMS range for a while and with some spikes going up to 2-2,5” while historically I could manage lower RMS and lower spikes than that in great conditions). After checking with Avalon (always very fast supportive customer support), they recommended to check the belt tensions: the belts felt a bit under tension which I could imagine normal loosing a bit after 10 years exposed to huge condition variations constantly beside operating. I simply did about a 1/5th of a turn on the tension mechanism and it is now fully back on great  performance (see phd2 logs) from “good/ok-ish” performance. I could visually check the belts by opening the covers, and they looked problem free (like any other parts). No re-grease of any kind ever needed.
      • Durability: considering the conditions it stands (yearly outside under cover for about 7 years), I am amazed:
        • not a rust point, apart on the chromes of the original DEC/RA clutches and the original vixen type saddle (this is some years already that Avalon is not supplying with chrome on those parts, I see on commercial pictures those parts with some dark paint now, so an issue Avalon has addressed for quite sometime already).  Anyhow, this is only a cosmetic visual issue as the saddle like clutches do work as expected (and the rust seems stable for several years, it has come up within 2-4 years it was standing out). All bolts and any other parts are rust free, like brand new. Despite a number of shocks with dovetail, no scratches anywhere, very good paint job.
        • Electronics: no issues to report. Never had any issue with the Stargo hardware part (in the early days, software/firmware could have some glitches but it is now many years with stable running and keeping windows 10, ascom and other running software (Nina, phd2) up to date (and currently running last stargo firmaware/software).  
           
    • Operating performance:
      • Apart the early days of some firmware/software glitches, I would say the operating performance has always been a wonder: I don´t think I ever lost a single sub (imaging typically 10 min subs) due to a mount failure or related issue. The no-meridian flip is the main reason I chose this mount and it is just wonderful (although I guess today´s softwares and reliability makes the automatic meridian flip possibly easier and more reliable than >10 years ago). I set up the scope, plug everything on a laptop (10-15 min to set up every thing, what takes longest is manual focusing- and then launch the sequence, then I can go for a deep sleep without any concerns at all): no need to think where it is pointing and thinking how/when it will handle a meridian flip and to get this into account. Basically: no “baby sitting” required ever which is I think the best out of this mount. If something has gone wrong past 10 years has been on other things than the mount 
      • Very easy start up to operate. Start, Sync home position, then go to 1 star, do a plate solving and one is pretty much spot one in a given area of the sky just after 1 plate solving. 
      • I have not had to do the polar alignment for very long, but for what I remember, the clutches and adjustment were easy to get it precisely done (and very sturdy since I have not had to touch this again for years).  
      • I never run it with the hand control, so I cannot comment on that
      • Software and communication: no issue to report, I never had any problems for many years (again part the early days which needed some update firmware) to have it controlled via Stellarium like to talk with any other software via ascom (ATP, Nina, ASTAP, phd2, astrotortilla). It connects and I never had a connection lost from the mount to the computer and softwares. The Stargo software is easy to use once customized to it, although the plate solving and database not that great, better to use dedicated connected planetarium or other plate solvers on my point of view.  

     

    • ergonomy: I think it is very well thought mount on its ergonomy despite its unique design. It comes also with a detachable hand holder if one need to transport it. It has also a very usefull cable management "pass trough" the RA axis as well. I have a pegasus advanced set up placed under the arm and some cable guide stickers  around, I think there are many ways to get a good cable management whatsoever your set up can be.  

     

    • Guiding and image results: likely one of the most frequented question on mount performance, and in particular those type of mount as guiding is required. Nevertheless, it can be noticed I have been using it without guiding with the FMA 180 mm as well as my 50 mm lens and I could take up to 4 min long images without issues (longer may be possible I guess). Anyhow I am typically using it at lower imaging scale so guiding is needed. The guiding performance is depending of many factors, so I try to summarize here in simple conditions factors. As important as seeing conditions (incl. where you point, zenith vs horizon), the wind has definitively its importance with the Avalon (this is well commented eleswhere, and even if the guide graph may not look great, the image can still be great). Yet, as compared to general rule of reaching a guiding RMS to be half of the image scale for good results, it  does not seem to apply with the Avalon: When imaging with the C8/FR, my image scale is 0.64 “/pixel, yet I still get really good result even with 0.6-0.7” total RMS (I guess the stars may be a bit bloated or not perfectly round, but that´s looking on pixels level or measuring excentricity in PI one can effectively see). Also the RMS results I report is included the few spikes/peaks which can extend to +/- 1,5 to 2,5" but those are typically very short duration and very few (may be 1 to 5 spikes in my typical average conditions for 10 min, meaning only a few seconds in total per sub of "wild" guiding, overall you will be within short range and those few sec will not show up strongly on the images). Those spikes can be typically wind gusts related for most, possibly also some dust accumulated over the years in the mechanisms. Anyhow as a summary and data for a  full night session (and not just picking up some few 100 or 200 scales of phd2 live window), and for a typical declination in the range 30 to 70 degrees which is where I typically image:
       
      • Good seeing conditions and wind less than 4-5m/s (gust to max 6-10 m/s), whatsoever set up, guiding scale and pay load in the range I use as explained above: 0.3X“ to 0.4X“ total RMS.
      • Medium seeing and wind of 4m/s to 6m/s (gust to 8-12 m/s): 0.4X“ to 0.5X“ total RMS: when using the C8 with its long dew cover fully extended, it is definitively more sensitive to the wind with more "spikes" and it will give results on the high side of this scale at 6m/s. In such case imaging at 1460 mm (image scale of 0.64), I can get the stars not being “ideally” round, yet this is fully acceptable and those defects can be easily addressed in post processing (deconvolution methods, or simply multiscale softening on star selection, and some other methods to make them look perfectly round while pixel peeping).
      • Poor seeing (or near horizon), and wind >6m/s up to 8m/s (gust to 16m/s): I never tried in worst wind conditions than 8 m/s with the C8 I think and but in this range in such case, I avoid the C8, as it will start to clear show some star elongation or quite bloated , yet this is still fully acceptable to my taste, but it handles well the WOGt81 in such conditionsl with RMS below my image scale and I can be in such worst conditions (rare anyway) up to 0.6-1.2” range, so no issue with the WOGT81. In those windy conditions, I think the main issue is the frequencies of strong gusts and not the average itself, a very steady wind of 6-7m/s can still give very decent rms, but variable and strong frequent gusts of >15m/s may be the problematic case).  
         
      • The DEC is typically a bit better than the RA by maybe 0.05 to 0.1”
         
      • I don´t need to play around with the settings to get to above results: I simply use the recommended setting by Avalon for phd2 as per their website (lowpass2, aggressiveness to 100 , min mov of “0” and exposure time of 1s or 1.5 s depending the seeing conditions and if very windy I increase to 2 sec exposure, as too short would likely just go all around the places). Guiding rate in stargo is set according to Avalon´s recommandation depending the guiding scale use and seems to work in about all situations. For RA, I tickle the “Auto tracking Adj” and it seems to actually help. So I get from 0.3X” to 1.2” depending the set up and seeing/weather conditions as described above (all above case using the OAG with my WOGT81 or C8 so in the 380mm to 1460 mm range, so well enough to get good images). With the miniguide scope 120 mm and ASI224MC as guiding set up, I typically don´t get those low RMS, always a bit more, but I don´t really care as it is still way below image scale in such cases (imaging with the FMA 180 or wide angle FL lenses for 5-10 min subs). 
         
      • I can imagine if I would used the mount with the exact same set up all the time, there is likely room for further improvement of the guiding (in phd2 parameters, like possibly optimizing the balance, payload distribution of a given system), but I never had to bother.

     

    My learning regarding getting the best guiding performance and some tips in case of windy conditions:

      • Balance well the set up. It is quite easy to find the balance (as compared to my AVX´s), as it is very free when unclutched. As I can tell, a "perfect balance" is not always required, and some light unbalance may results in better guiding (but that´s not statistical proof, maybe a a little gain of some 0.2,0.5 RMS)
      • Cable management: I could notice it quite sensitive to hanging cables (especially with some wind) as well as cable drag. So make sure cables are well attached, not hanging around and no drag (I use cable clips sticked onto the mount and Velcro straps)
      • In case of windy conditions kind >5-6 m/s (gust >10-12 m/s): avoid the C8 or if no dew is expected, do not use the dew shield cover with the C8 (and/or avoid shooting too much towards the zenith or put the dew shield to minimum and not fully “extended”). In windy conditios and dew shield fully extended, the RMS can start getting into the imaging scale and start to get some subs with slightly elongated star (if one goes into pixel peeping). With the WOGT81 I could image without any issue with wind up to 8-10 m/s (gusts 16-18), but above that kind of wind, I have not been out. 

    Conclusions:

    • Soon 10 years and it has been just a wonderful experience. Robust and very consistant in many different set up with varying payload and situation, and durable in tough environment for many years and trully maintenance free. Great design to skip the meridian flip hurdles, no backlash (some very little can be measured by phd2, but i never used such correction) and baby sitting free. Guiding performance is great for my need, and very consistant whatsoever the set up, pay load, guiding scale.
    • The design is not without limitation (to be careful if it can handle long refractors), yet, it covers my needs with minimum adjustments between variety of set up and scopes I use
    • I don´t feel the need to find a replacement and still enjoy it every night… Would I buy a new one? Likely… but ... basically it looks like I don´t need before many more years hopefully. It is pricey as compared to many other mount, but it is definitively worth considering its longevity so far
    • It may not be best if you have long refractors or very large SCT, RC and using large dew shields if you are in a regular windy area (average winds >5-6 m/s). In such a case, I believe a dome would be more than welcome.
    I may update this in 5 years or 10 years.... Note I saw in some forum some people asking why not much is reported in forums regarding the avalon´s: yes they are not "mainstream" and premium, so there are not that many users who can report, yet I believe a simple reason is also those mounts are simply so little trouble, easy to use, that such users simply do not visit much the mount section forums looking for help or reporting problems. At least this is the case for me, since I have the avalon my presence on forums and dedicated sections about mount is very little. 

    PHD2_GuideLog_2023-09-09_184041.txt PHD2_GuideLog_2023-09-01_185832.txt

    • Like 2
  2. unfortunately I cannot check my Oiii filter IR leak topic by stacking my L IR/UV cut... it won´t fit in my FW to stack (and I have no kind of adapter to get my 2 filter stack (small one) and using same set with my SCT/FR.... a bit stuck to check up...

     

    Nervertheless, my Oiii filter is of that kind in case it would be known for IR leakage: Baader 8.5nm (claimed "IR blocked"). on normal stars of strong magnitude, i have not noticed over years halos  (note there has been a bad serie of this filter known giving extremely strong halo, but that´s not my case).

    Here is a crop of 5.65 mag star I find with strong magnitude star example, all rest is same set up image.png.9c35fbe62c6eb9f73fd66580ca18be66.png

    using same filter/camera/10 min Oiii with other scope (FMA 180) and on stronger star, no issue at all with Menkib (3.95): image.png.c31cb6b1c2e535ba1dd5498d3c1c7dc5.png

     

    And referring to the link above, I took just few weeks back the RS Cygni with my WOGT81 and no issues neither (10 min Oiii) while reported as well strong IR carbon star type if I understand the CN thread (and its overall magnitude is lower than V AM Cygn -but the latter may be then way stronger in IR as you mention)

    image.thumb.png.9df57dddbbd6facfc562be1601d5aa5c.png

     

    I looked at quite my Oiii files and cannot find any halos, but I have no image with magnitude below menkid or can think of other example than RS Cygni above

     

    DSC_0585 (1).JPG

    • Like 1
  3. just a post to add a bit better comparison of the Ha and O than my previous crop on single sub (here as the stack, unprocessed apart STF autostretch in PI) Ha left and O right.

    Also forgot to mention I think, that was taken with SCT C8 and starizona FR, so about 1430 mm FL calculated back from measured image scale by astrometry.

     

    image.thumb.png.984a036213706f2cd46ee19f90b4e20c.png

     

    • Like 1
  4. thanks. Indeed interesting and always exciting to find out some new things whstsoever 'stellar' or optical artefacts!. I will give it a try with stacking my L uv/ir cut on top of the Oiii to check up on this same star ( if weather allows...). Curious to check also on other such mira stars.

    I will give it short Ha sub to see (many strong  ha part of planetary nebula are almost totally blown up at 10 min)

    I have never seen that behavior before ( some 10 years using same equipment). Even if this is a halo effect/IR leak effect on the O filter, i am still amazed by such big difference on such star between the 2 signals (if one take away the halo on the O filter, then it has a very little tiny dot as compared to the blown big Ha star)

    • Like 1
  5. Thank you for your comments and link to cloudynight threads reporting similar. As additional comments:

    - Camera is SX694 mono and I use Ha and O baader narrowband filter. I have been using this for more than 10 years, and I never had issues of halos apart on extremely bright stars on my O filter, but not the kind anyhow I report above (the Ha is clearly "round" star like, while the O is a very little dot with a faint spread around).

    - This specific star is reported on magnitude 10 or 12 for what I have seen, so not that "bright" for giving halo from my experience. If it was a halo/filter issue, one would see similar behavior on the other 3 simialr brigthness star on the crop picture,  or? I am strucked by the huge difference in intensity of this particular one (Ha vs O) if you compare to the neighboring ones of similar magnitude.

    - the B&W cropped are from 1 single sub and without processing apart visual stretch, this is not from some processing and no AI (as reported by Cloud night thread as hypothesis for such artefacts)

  6. Hi,

    A short one as the nights are getting short up in scandinavia. 6*10 m each Ha and O, and HaOO combination. One thing that strikes me is on the upper right, it looks like a planetary nebula and not a star (or simply an artefact). Any ideas?

    On Ha, it just looks like a star, but Oiii definitively not.

    David

    Image69_ABE_ABE.jpg

    Image69_ABE_ABE_clone.jpg

    O filter:

    o_001.jpg

    Ha filter:

    h_006.jpg

    • Like 7
  7. Elp, thanks. 

    Longer is only a matter of convenience, faster overall processing and less storage space (especially from canon raw files which is my main intention for such set up/short focal). I run up to 5-10 hrs total exposure, so it matters, especially with my laptop when I am out at our summer house over several nights or somewhere on vacation and without a stationary computer (and no patience to wait going back home to process the data on stationary). I have been running out of space several time on the laptop (during processing with pixinisght, I need to delete intermediate files after the debayered, cosmetized, alignment etc... before the whole processing is completed). Alternative would be a new higher end laptop, or external disk which is of course feasible (yet still slow also to process due to very large amount of files). My current laptop is an old lenovo (U330p, i5, 8GB ram)

    example below is 8,5 hr on Iris with FMA180, Canon raw with avx 4 min exposure sub, non guided. 126 files of 30 MB to start with, so already 3,4 GB.... (which "explodes" into several 10´s GB when processing those into all intermediate files of pixinisght and  I only have some 40 GB availale unfortunately). With 2 min, I would not be able to process this on the laptop and it would take ages...

    I would prefer investing in a new mount than a new laptop (apart the space limitation and a bit slow on big job, the lenovo serves me extremly well -must be about 8 years old and spent many night down below -15 to -20 and it has never let me down!)

    iris.jpg

  8. Hi,

    I am looking for a mount for telescope/lens of focal length say below 200 mm without need of guiding and for say 3-5 min exposure if possible keeping 100% subs -so to say reliable and not just luck to have a "good copy". if this is too demanding focal leng down to 130mm, yet> 100 mm would still be interesting above 3 min (reliably again). My pixel size if 3,7 to 4,5.

    This would mean a resolution of 4.7 "/pixel or higher, so it shall accept long sub even with a periodic error which could be smooth enough over 8-10 min period and p2p of 8-10 ".

    would there be anything out there doing the job?

    Note:

    - it does not need to be a compact small mount type (Adventurer type, which I understand would not manage in most cases), as above set up with short FL would be occasional (I also have a WOGT81 and C8 which would be used guided in such cases), yet something one could transport easily

    - I believe the key is a mount with a smooth long period.

    For example: Belt driven (e.g. avalon Evo Zero? Or what about the new harmonic mount type AM5 and the like? Those are to be guided, but I wonder if really needed for FL 200 or below for few min. 

     

    The reasons behind:

    -convenience, so to avoid having to guide (no oag nor guiding scope/additional camera to handle) 

    - replacement of the AVX (very happy with it, I do manage up to  3-5 min unguided at 180 mm keeping most sub (75%), it has only  a 1-2 very steep minutes in its PE, the rest is good to give <5" over 3-4 min), but It is now getting rusty after 10 years -it stays outside- and when I use it guided, its backlash is just a pain (e.g. forget automatic meridian flip, I am running it also east heavy + slightly misspolar aligned so I guide in 1 direction -in such way I do manage RMS of 0.8-1.2 which is I think pretty good -I have not use the PPREC in phd2 yet, but I think it shall work good on RA as I have a well reproducible PE). So hopefully there are mount out there today that can do better today?

     

    Alternatively: would any have a suggestion for a compact guide scope (I have asi 224 mc I could use)?

     

    thank for some idea!

  9. Don´t have the 135, but the FMA 180 (which I understand was similar construction but I may be wrong). Regarding the comment above, I guess it depends the copy, I have no particular issue with the FMA 180 (only need to refocus on B or the O in SHO mono channel), Yet even OSC camera is good. Below Iris (with canon 80D, 9hrs) and the veil (HOO, Sx694). Anyhow if it is better than the FMA180, then cannot go wrong

     

    iris.jpg

    veil 60 40.jpg

    • Like 3
  10. Hi,

     

    I am quite happy for this little affordable lens. Below my first light, NGC7822 with SX694 mono. 2 hrs each SHO (10 min subs). Processed in pixisnght (stars have been reduced). Well corrected for this chip size, fast. One need to pay attention to get right focuse. Very well built lens. I did a quick test on RGB and it looks also good in RGB. Will try on APS-C later on. 

     

    David 

     

     

    Image182.jpg

  11. Hi,

    I tried a composite image of first quarter moon together with a full moon, 

    the bright part was taken in RGB with SX694 mono camera and it was 6 pan mosaic with a C8 with FR while the full moon (darker part here), was taken with a WOGT81. 

    David

     

    half moon dar braigt 120 80.jpg

    • Like 9
  12. Hi

    just wanted to share building a quick and cheap pier for my avx

    - 2 brake plate

    - 20 kg concrete

    - 4 M8 bolts

    - a premade concrete block for patio, deck , with 1 central top bolt about 50 kg, 70 cm height)

    - a square block

     

    for the base i used some few blocks of pavements, digged about 30 cm deep, pour concrete and add on then square block and pier, to cover about almost allup concrete.

    so we will see if it is robust enough and handles vibration. In any case

    - really quickly done, cheap (about 70 euros, brake plates being the expensive part), very little concrete to work out, it took less than 2 hours to make

    - the plates can be rotated (if polar alignment is totally off), as beingscrewed on the pier by 1 central bolt only (on the picture it shows on the right -not mounted here-

     

    cheers

    david

     

     

     

     

    FC971D1C-67CE-4A28-BB9D-E2C844B4AA11.jpeg

    • Like 3
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