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Everything posted by Oddsocks

  1. Do you have Photoshop Sara? It’s fairly simple to create .gifs in PS and I have made a few NEO and Lunar gifs over the years in PS 5 & 6. https://blog.hubspot.com/marketing/how-to-create-animated-gif-quick-tip-ht Never tried in PixInsight and there doesn’t seem to be a tutorial on their resources pages but I’ll have a look later this morning when we get back home after swimming.... William.
  2. Unfortunately you can’t tell when buying power supplies from non-electrical specialists such as astronomy retailers etc. The Nevada unit is a mass market general purpose power supply used primarily to power devices in the home or workshop that would otherwise be used in a car or truck, such as a CB radio or portable short wave receiver, coolbox, air jack or tyre inflator etc. I’m always going to be biased after a working life in medical engineering where we have some of the toughest regulations regarding power supplies, particularly in operating theatre environments where as little as 6 microamps of leakage via an intravenous catheter will stop a beating heart. Of course, the power supplies we used in that environment, roughly equivalent in output to the Nevada, cost in the region of €2,000 each and though they still fail occasionally they never fail in a way that is dangerous to the equipment they are powering or the patient. It’s really a question of risk and how much you may be prepared to lose in the event of a failure. I’m currently running three QSI cameras and at nearly £5,000 each plus nearly as much again for the Atlas digital focusers, I would not risk powering them with the Nevada, or an equivalent. I don’t even use the switch mode power supplies that were provided by the manufacturer but I bought ITE & Medical grade rated, 12V 12.5A switch mode PSU’s from Farnell Element14 that cost close to £80 each and for me that was the minimum level of risk I was prepared to take. With a full specification and data sheet provided plus all the relevant UK and EU safety markings I am as sure as I can be that the power supplies I am using offer the best chance of avoiding catastrophic failure and effectively the end of astronomy for me as now I am retired I could not afford to replace any of my cameras or other equipment should the worst happen. When you look at the Nevada unit, for example, you have to ask where is the specification sheet for it and what UK/EU standard markings does it carry? As you say, without opening it up yourself how do you know how well it is built? and the answer is that you can’t and therefore you have to look at where you are buying from, the data sheets provided and the national-international markings it carries. For something that is really quite critical, even though rather boring, I would only be looking at specialist suppliers with full accountability, such as RS or Farnell Element 14 and I would expect to see a full data sheet/product specification. If your observatory is going to be housing something in the region of ~£10,000 - £15,000 worth of equipment all linked to a single £40 power supply, well, do you really feel that is worth the risk or maybe spend up-to four times that for something that is fully compliant with current standards and the higher level of protection that is implied by those standards? As they say, “You pays your money and you takes your chances” (sic).
  3. I remember that Alan. I think part of the composition was CC14, Carbon Tetrachloride, and the propellent was Freon, both banned substances now. If you used the spray for too long the can froze to your fingers. I don't think I would try to repair James's PSU myself, too many bad joints, bad practice and failure points. Not worth the risk, and expense of a mains leakage to the output side destroying everything downstream. At the very least there should be big varistors and/or crowbar diodes on the output but I see none in the pictures. William.
  4. I don't even think it was the apprentice Gina, probably one of the warehouse operatives filling in while the apprentice was on day-release.
  5. It's perplexing how often I see this recommended across the web and even written in published manuals. On the REME sponsored courses I did in Germany back in the late 70's early 80's we were told never to use any type of contact cleaner or solvent on skeleton carbon presets as it softens the carbon bonding agent on the track and within a very short while the preset would fail completely. The general recommendation was to replace a defective preset if possible but if desperate we were instructed to gently lift the wiper from the track and slide a piece of typewriter paper under the wiper, release the wiper back on to the paper and wiggle the preset back and forth a few times to clean the wiper contact, then slide the paper away. We were told that contact cleaner is only for metals, never for carbon or carbon composites, at least, that was the instruction then and I've not seen any changes to the construction of skeleton presets that would suggest it is now acceptable to squirt solvents on to them.
  6. The banding was apparent in mine at an ambient of around +5c and a sensor temperature of -15c. If it is there you will see the banding most clearly in calibrated darks so make a master bias as you have done, you won't easily see the banding in the bias, and use that to calibrate a master dark of at least 50 frames. The banding will then show clearly, if it exists, with your camera. ( my master dark image in the forum post showing the banding was 100 frames @ 300 seconds )
  7. If that is correct Ade it might indicate that keeping the diagonal in the Lunt case as being a possible issue as many foam rubbers outgas Sulphur naturally as they age and Sulphur reacts readily with Silver.
  8. I had the same issue Dave, my filter became completely obscured in a matter of months. I did wonder if the problem was from something in the case outgassing, possibly vapour from the glues used in the case construction or foam lining, possibly even the paint on the OTA. Bresser sent me a replacement filter very quickly, arriving just two days after requesting it, and I now keep the diagonal in a sealed food container with desiccant bags, completely away from the Lunt case and scope. William.
  9. Don't worry Gav, PM sent to Jonk with link to Dropbox files. William Jon. Have sent you a Dropbox link via PM William.
  10. Depends on the design of the regulator James, some older design use series following power transistors and feedback resistors to effect regulation and these 'leak' a very small forward current continually, this will show as a high voltage, above the stated regulation voltage, when no load is applied, your multimeter will have too high an impedance to pull the leakage voltage down but connect a load and the voltage should drop down to the stated level. Try connecting a small, unimportant, device to the output to load the regulator while monitoring with the multimeter. Just a simple 1W resistor of around 220 ohm should load it enough to pull the voltage down for testing. William.
  11. ******* Item sold, listing to be moved to completed section ******* William Optics GT81 Triplet APO. £520. Payment by direct bank transfer, cleared cheque or cash on collection from Christchurch, Dorset. Price includes DPD Local, next-day courier delivery, shipping to UK addresses only. Will reduce price by shipping cost if collecting in person. Thanks for looking... Anniversary edition with back-pack carry case and tube rings. fl = 478mm 81mm diameter fpl53 triplet objective. f/5.9 3.7kg 2"/1-1/4" adaptors Crayford focuser with reduction gear, digital mm incremental movement display and thermometer. Perfect condition. William.
  12. As an additional point that has not yet been discussed...... I too have an HEQ5 PRO, used now just for daytime solar but originally was my mobile setup. The description of mount continuing to move / creep for a few seconds after the drive button is released is one that I experienced with my mount after the first few months of use and was just due to backlash in the worms, more in Dec than in Ra, but present in both, and was completely cured by carrying out the worm mesh adjustment as described in the manual at that time. I remember that this “creep” after the drive button is released was most noticeable with a three star alignment as the mount balance point tended to swing for the final star of the three star alignment and the mount would continue to move on under gravity and mass momentum for a short distance after the drive button was released. From your description of the problem so far it seems you are most likely seeing the normal “running in” of a new mount with softening and redistribution of the worm gear grease and bedding together of the various components, plus the general movement and disturbance to the drives caused by normal setup and tear down for each session. Before sending the mount back I would at least take the motor covers off, check and adjust if necessary the transfer gear mesh tolerances and adjust the worm-gear mesh pressure, this after all, is something that is a normal part of the standard HEQ5 PRO routine maintenance protocol, and used to be documented in the manual, at least the worm-gear adjustment was. The drive motors on the HEQ5 PRO are stepper motors so they can not “creep” with a direct “leakage” voltage applied, they can only rotate when “pulsed” and if one of the buttons were sticking, or the electronics failed and constantly sending drive signals, you would continue to hear the pulses after the drive button was released. If you are seeing continual un-commanded creeping, so that the object will slowly drift out of the frame and never stop and you are sure that polar alignment is good then the last thing to check, or perhaps the first thing to check is, does the mount “creep” with the ST4 guide cable disconnected? It is not unusual for the rather fragile ST4 cables to go faulty, or for a guide camera to fail in such a way that it is continually, or intermittently, sending guide corrections to the mount when not commanded to do so, if you are using “on-camera” relays and the mount’s ST4 port for guiding (rather than EQMOD/pulse guiding) then disconnect the ST4 cable at the mount and check to see if the mount continues to “creep” during star alignment and after slewing, if not then check the ST4 cable for damage and the guide camera for malfunction. HTH. William.
  13. From your description of the problem it seems that the contact area and limited compression range of a standard Viton or Nitrile rubber ‘O’ ring is just too small to accommodate the flex range of your casing when it is bolted together. How about a wide flat gasket cut from closed cell expanded neoprene rubber, with a large compression range and increased contact area it should cope easily with distortion of the casing when bolted together. As long as it is not over exposed to UV it should have a good few years of life. Fairly easy to cut from a flat sheet with a sharp craft knife or scalpel using a printed paper template as a guide. Might be a solution? I have a few offcuts of low density 6mm thick, self adhesive, expanded neoprene sheet here, left over from when I insulated my observatory’s glass fibre dome roof last year, I can put a couple of bits approx’ 300mmx300mm in a postal tube and mail them off to you .f.o.c. Just send me a pm with a suitable delivery address if wanted. Otherwise, here is a link to a set of closed cell neoprene foam sheet gasket material on eBay: https://www.ebay.co.uk/itm/Neoprene-Rubber-Sponge-Rubber-Nitrile-Cork-Sheet-GASKET-Material-Foam/191593795500?hash=item2c9be14fac:g:U1IAAMXQvTlRgzTV William.
  14. Because the edges of the dust artefacts are rather fuzzy then the tiny amount of focus change between filters can be ignored for the flats, as long as the focuser is in roughly the same place when taking the flats as it was for the images then the flats will be fine, the vignetted field too will hardly change, camera rotation is the thing that must be avoided. Problems sometime creep in if you have a mix of non-parfocal filters, i.e. some filters that are 3mm thick and some that are 0.6mm thick and combined with very fast ratio telescopes, then the change in focuser position may be quite substantial and when applying the flats they may just leave very faint ring outlines of the donuts behind. For your current telescope there is no need to worry. The best position to set the focuser for flats is the one you had for luminance as that filter passes all wavelengths and will provide the best 'average' focus position across the rest of your RGB filters. For taking flats in the field consider an A3 or A4 USB tracing panel, search on Amazon or eBay, you'll find several. Lots of folk here on SGL use them, no need for extra power supplies as they are lit by the USB port of your laptop, just add a little extra absorption (paper) to reduce the light output. If using a flats panel then you need to extend the distance of the tracing panel from the opening of the OTA by at least the diameter of the OTA to avoid light from the panel directly entering the focuser port (see below) and if you have a dew shield already that would be sufficient, if you don't yet have a dew shield then quite a few folk here use inexpensive yoga mats from Aldi or Lidl etc for dew shields, wrapped around the OTA and held in place with a bungee strap, then you can place the tracing panel directly on the dew shield with the OTA pointing upwards and take flats right in the field before dismantling the telescope and risk moving the camera substantially. HTH.
  15. Yes, you would normally have a set of flats for each filter as the dust that causes the donuts will be dispersed randomly across all the filters in your system. With a reflector telescope the principle wavelengths for colour should all be bought to the same focal plane so provided you are using par-focal filters then focus should be close when changing between them however if you have any glass in the instrument such as a flattener or reducer then there will be some shift of focal plane between the colour wavelengths and you will need to re-focus for each filter to achieve tight stars in all four channels (LRGB). The telescope will cool gradually during an imaging session anyway requiring you to re-focus periodically so it's easier logistically to just shoot say half an hour of one colour, change to the next filter, refocus, and shoot another half an hour then repeat for the next filter etc until the session is over. Eventually you may decide to add an electronically controlled focuser to your system and that makes things much easier as focus can be automatically carried out at regular intervals and any required focus shift between filters can be programmed into the system enabling you to quickly run through repeating cycles of LRGB filters without the need to manually refocus with each change of filter, handy with our fickle climate and limited opportunities to collect data. I like your new image but perhaps you have set the background level a little too dark and lost just a tiny hint of the galaxy outer 'glow', at least that is how it appears on my Mac, though the forum does mess with the uploaded images and so too does the web browser I'm using so perhaps the image on your local computer is fine in which case you can disregard this comment. Glad the flats worked out for you, look forward to seeing the 'full colour' version... William.
  16. What type of bearings are used on the worm shaft and worm block carriers Huw, plain ball or tapered roller with pre-load? In the original thread you had some engineers blue paste to check that worm-gear mesh was on the valley sides of the gear and not the valley floor, did you ever confirm with the blue paste that the worm-gear mesh was ok and not bottoming? My money would be on combined end and side float on the worm carrier and worm shaft bearings as a minuscule amount of both end and side float on both bearing sets working together with a worm gear translates to a large combined end play, or backlash under load so with a worm-gear lift, twist and end float in any of the worm carrier or worm shaft bearings will contribute to backlash. Having begun using a new mini-lathe earlier this year I found a surprising amount of end-play at the chuck with the standard plain ball bearings in the head stock, even with a large pre-load applied, and changing those to quality tapered rollers eliminated that. Of course, the magnitude of the loads involved between a lathe and a telescope mount are somewhat different but the principle is sound and if you are currently using plain ball bearings on the worm block carriers and worm shafts I think that would be my first place for a change to quality tapered rollers with a good bit of pre-load applied and see if that made a difference. Can’t think of anything else ATM but will come back to this if I do. William.
  17. @PhotoGav , @Davey-T , @continuum, @Mathieu80, @Whirlwind, @ollypenrice Just a quick thanks to all who posted in this thread. I had this banding problem with my QSI683-8-WSG since new, can't believe that was back in 2012, but as it mostly calibrated out I wasn't that bothered until recently begun using scaled darks for asteroid and NEO studies with limited data in PixInsight, where it became more apparent. Also a big thanks to Andrew Kirby at QSI support who emailed me the new FPGA and version 7.1.1. firmware within an hour of requesting it, installed in a few minutes and problem fixed....? The banding in the bias master with the old FPGA and firmware is very subtle but can be seen, it is much more apparent in the darks and totally absent with the new FPGA and firmware. For reference below are four QSI master frames, bias and calibrated darks, showing the problem before and after upgrading the firmware. Unfortunately I did not make a note of the original FPGA version, only the original firmware which was v6.3.1, the new FPGA version is 0212 and firmware version 7.1.1. If Gav hadn't started the thread I would have been non-the-wiser so thanks again... William. Old firmware v6.3.1 and original FPGA, master bias, 999 frames bin 1x1, -15c, high image quality download mode: New firmware v7.1.1 and FPGA v0212, master bias, 1998 frames bin 1x1, -15c, high image quality download mode: Old firmware v6.3.1 and original FPGA, calibrated master dark, 100 frames bin 1x1, -15c, high image quality download mode: New firmware v7.1.1 and FPGA v0212, calibrated master dark, 100 frames bin 1x1, -15c, high image quality download mode:
  18. Rob. One other thought occurred after posting the above reply, are you using a I.R. blocker filter with the camera? The Meade series 4000 f3.3 reducer was not well corrected for I.R. and produced quite a large bloat if a blocking filter was not used. If not using an appropriate blocker I wonder if part of what you experience with variability in coma correction might lie with variability of the stars I.R. content with atmospherics? William.
  19. Hi Rob. I used to use the Meade series 4000 f3.3 reducer many years ago with an LX200 and Canon 35mm SLR film camera. The problem you are having is almost certainly due to spacing between the rear lens element of the reducer and the camera. With the ultra aggressive beam shaping and very acute beam angle of the ray paths leaving the reducer the camera sensor has to be placed at just the right distance from the reducer and the tolerance is very tight, +/- 0.1mm will show a change in coma at the edges of the frame. My experience with the 35mm format SLR was that coma was impossible to eliminate and only the central area, around 5x5mm was free of coma, and that was with perfect spacing, an imperceptibly small change in distance between reducer and film plane would see coma creeping in further. I quickly gave up with the f3.3 reducer, particularly because with film you never knew if it was going to be any good until many hours of darkroom processing time had been wasted. For the remainder of the time I had the LX200 i just used the more forgiving Meade f6.3 reducer. It probably comes down to how you are attaching the camera to the reducer, even a rigid screwed-together assembly will be subject to variations in optical path length due to temperature variations from one session to the next. If you are able to finely tune the distance between the reducer and sensor “live” then that may offer a solution for you but it won’t be simple as the distances to move are so small. The above is all that comes to mind given my experience with the f3.3 reducer all of nearly thirty years ago.... William.
  20. Before you waste too much time, be aware that flats will only work if the optical chain is undisturbed between taking the “lights” image and taking the flats. If you have disassembled the telescope and camera since taking the galaxy image then putting the optical components back together again later to take the flats will most likely be unsuccessful because the exact geometric relationship between the dust causing the donuts and the image path will have changed. Certainly good experience, and might work for you, but don’t be disappointed if you still have odd artefacts left behind. Normal working procedure for an imaging system that has to be assembled-disassembled each session is to take the flats at the end of the night while the focuser is still set as it was for the imaging run, or, at the beginning of the run if you have marked the focuser position on previous runs and know where it should be set prior to taking the flats, and the camera’s spatial angles with respect to the optical components is unchanged throughout. For a permanently set-up system that is never disturbed, such as in an observatory, or under a cover in the garden etc, then you can take the flats anytime with the caveat that in an open tube telescope additional dust may accumulate , or move about, on the camera window and filters after the imaging session ended and these will contaminate the flats producing bright donuts instead of dark donuts in the calibrated image. The other calibration frames, darks and bias, can be taken anytime since they are recorded in total darkness and record nothing of the optical chain, purely the camera electronics. Lastly, remember to set camera cooling on for all calibration frames, these all need to be taken at the same temperature as the “lights”. William.
  21. Should be bright if they were internal reflections, not dark, most likely just very large dust specks on the filter or back of the flattener if you are using one, and perfectly normal. Very difficult to keep an open tube telescope free of dust, the donuts should be removed if you take and apply calibration frames. The image shows vignetting (darkening) around the edges of the frame so it is apparent that no calibration frames have been used, particularly 'flat' frames, which will remove the donuts and flatten out the background so that the dark corners disappear and the image has the same background brightness across the full frame. HTH William.
  22. Hi John A new dark frame library is not required since darks only record “dark”, there is no light entering the camera to record and therefore what the camera is connected to is irrelevant. Only important thing is that when you make the dark library that the surrounding environment truly is dark. If your camera does not have an internal mechanical shutter then there is always the chance that some stray light may leak into the optical path via the gap around the focuser draw tube, or screw holes for guide scope attachments etc, so make your dark library in a dark room at night, or in a blacked-out room during daylight. Don’t be tempted to cover the scope and camera with a cloth to take the darks in a lit room as this may overheat the camera and damage it. William.
  23. Hi Tom Not having a MESU or Sitech here to play with I can’t help that much with the setup, the only thing that consistently appears in web discussions is the need to configure the Sitech, Encoders Config, set encoders to “Polite” mode, plus a fairly large tolerance of 10:00:00 degrees in the supervisory threshold window, otherwise the MESU’s motor encoders and shaft encoders may consistently argue with each other after a slew causing the mount to continually re-slew to the requested coordinates. ( I think this info originated in Steve Richards quick-start guide but has been referenced several times in other web pages ) William.
  24. Hi Amajed Your image shows the result of tilt somewhere in the image train. Check the connections between the camera, OAG and visual back. Ideally all the parts will be screwed together with threaded adaptors. If you have to use push-fit connectors make sure they are not a sloppy fit, as illustrated in the exaggerated picture below. A slight 'droop' or sag, in the assembled components of the image chain will result in smeared stars that have the appearance of coma that increases in magnitude across the full frame. If your SCT has a mirror lock make sure the mirror lock is applied after focusing because mirror sag, or droop, will cause the same effect and will vary with changing angles of AZ and ALT (or RA and DEC if using a wedge). If using push fit components to attach the camera and OAG to the visual back and they are loose you can wrap a thin sheet of hard-plastic packaging film around the push fit connector to take up some of the slop but beware that the camera may slide out of the push fit connector when doing this and it requires a safety lanyard to attach the camera to the telescope so that it can not accidentally fall to the floor. The usual culprit for a sloppy connection is the safety undercut in the barrel of camera nosepieces as they often allow the nosepiece to deflect out-of-line when the clamping screw is tightened. HTH
  25. Hi David. POTH (Plain Old Telescope Handset) is more of a developer tool, think of it as a mail sorting office with the added benefit that you can read and rifle through the incoming and outgoing messages and only choose to deliver the messages you think fit. With logging enabled it is a great resource to help with ASCOM driver development etc. There is no reason for you not to use POTH it is just more difficult to set up when presented with all the capabilities that POTH has. You will find a help document for POTH under All Programs > ASCOM Platform 6 > Scope-Dome-Hubs > POTH Help. To use it for your purposes you make no changes to the options in the POTH control window, all settings should be left at default but rather, in the client program(s) APT, Stellarium etc you have to choose in setup POTH as the Telescope, and optionally, POTH as the Focuser, & Dome. Each time you make a selection of POTH in the client program as the device being connected to, the POTH setup window will open where you choose the actual telescope driver, EQMOD in your case, and optionally focuser and dome drivers if used. You only need to set up the actual device hardware drivers in POTH once, so if you open APT and choose POTH, set up POTH for the EQMOD driver, focuser driver and dome driver, if applicable, then in Stellarium Scope just set POTH as the "Telescope" there is no need to repeat the actual device driver selection again as once selected in POTH it will be the same for all client software connecting to it. To use POTH you do nothing other than connect to the "Telescope" plus "Focuser" & "Dome" if used, in the client software which will then connect to POTH and POTH will relay the messages back and forth between hardware device and client software. Do not try to manually connect to the Telescope, Focuser or Dome from within POTH unless you want to actively test the ASCOM drivers etc. When used for actual mount control, when you connect to the "Telescope" (POTH) from inside APT and Stellarium Scope the POTH window will launch, you need to minimise this to the bottom tool bar on the desktop, or hide it out of the way on the desktop and do not interact with it at all, however the program, must remain "open" otherwise POTH will not work and your client programs will have nothing to connect to. As an alternative, the ASCOM "Generic Hub" does all the above but without the developer tools and log tracing that are included with POTH. Setup and use of the "Generic Hub" is exactly the same as it was for POTH and you will probably find it does everything you need with less user "options" to get in the way. HTH William.
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