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About MarkS

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    Melbourne, Australia

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  1. I have an ASA 0.73 Reducer, and its dimensions are exactly as per the ASA drawing. Are you sure what you have is an ASA reducer? Mark
  2. Hi Waldemar, The USB3 signal wires are definitely heavier and better constructed than USB2, but the USB2 signal wires within the standard USB3 cable are thinner and there is only one pair, whereas the USB3 wires are paired. On Type A connectors, the USB3 do not connect to the USB2 contacts. Whether the USB2 wires are better quality in USB3 cables than they are in USB2 cables I do not know.... I have certainly had no problems using USB3 cables from mount to computer. Mark
  3. Looking at the cable specs for USB3, it is clear that a USB3 cable Type A connects to a USB2 Type A socket via a separate pair of wires from the USB3 ones. That is, Ian is right - it is probably better to spend your money on best quality USB2 cables than USB3 ones. Mark
  4. Hi Antonio, Interesting find! Lovely detail and colour - your trademark! Mark
  5. Hi Luis, Great image - detail and colour look superb. Nice to see this, as Andromeda is very low on my horizon.... Mark
  6. Hi Robert, This may not be very helpful, but after a recent extremely baffling problem with a new camera, I am prompted to ask if you have tried changing the USB cable? They are notoriously unreliable. Regarding your query about start-up sequence, I have always started the mount before turning on the computer and Autoslew. When I was learning the ASA system, I found that this sequence always worked, and I've never varied it. I'd like to know if others do the same? Mark
  7. Thomas, Great set of images. If I had to choose one it would be M100. Mark
  8. Hi Antonio, Another splendid image of a dark nebula! Mark
  9. MarkS

    LBN 258, GM 2-41

    Hi Antonio, Another splendid image! All the more interesting because it is over my horizon Thanks for showing! Mark
  10. Hi Andrew, I use the AAF3/ASA10N with ASA Sequence. The reported position can vary by 1 - 3 micron during a run, but this is totally immaterial with either f/3.6 or f/6.8 configurations. I'm not sure what these small shifts mean, but the encoders are very precise, and I suppose they may be reporting very minor flexure - which is present in all systems. Notwithstanding, the whole system is so stable that I have imaged for over 6 hours without using AF and not lost a single subframe. I could not do this with the OK3 although it did not report any shifts. Mark
  11. Hi Waldemar, I run both the DDM60 and the DDM85A. You'll really enjoy the 85 - the extra motor power makes a real difference! I hope you have better luck with the skies than I'm having here!!! Mark
  12. There appears to me to be two issues. First, there appears to be significant coma on the upper right and right of the image. Secondly, there are elongated stars on the lower parts of the image. Because the left side of the image looks basically OK, I would guess that you may have a backfocus AND a tilt problem. It is certainly worthwhile to shoot several images with small focus shifts - say 0.05mm steps for a start. This should give you some idea of what to do next. In my experience, the collimation results from CCDInspector are not always very reliable. I think careful visual
  13. You can use CCD Inspector, but I have found that the best way is to take a set of, say, 2min images of a good star field at slightly different focus settings. If there is a setting that gives good round stars all over the specified image circle, then the backfocus is correct - or very close. If there is no focus setting that gives round stars everywhere, change the backfocus distance by 1/10mm or so and repeat the process. Keep doing this until you have the best you can get. This is time consuming and tedious, but have found it very worthwhile. I did it with my Barlow when I changed ca
  14. MarkS

    Sharpless 2-73

    Hi Antonio, Very nice image of a rarely targeted object. Up to your usual high standard! Mark
  15. This looks correct. Presumably you could adjust the 3mm spacer if you need to fine tune the distance. The focus is very critical at ~f/3! Mark
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