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Aramcheck

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Everything posted by Aramcheck

  1. It does, but I couldn't loosen it with the supplied tool. I should be alright now the 2 x trainer method has loosened the rings up... Thanks Ivor
  2. Thanks @david_taurus83 I didn't think we'd have any trainers, but I found an old pair of my wife's... I put some clingfilm over the heels & it worked! Many thanks! Ivor
  3. I recently bought a Baader Varilock extension tube in the hope of solving problems I've been having setting back focus with my Baader MPC III coma corrector + ZWO OAG v2 + ZWO 2600 MCPRO camera. My initial attempts to use the Varilock were hopeless, as trying to adjust everything & keep the OAG from obscuring the camera chip proved impossible. I think I've now figured that I need to have a 23.5mm extension (to get the 57.5mm required from the coma corrector (with collar ring removed), as the OAG has a width of 16.5mm and camera's sensor distance of 17.5mm)... BUT the Varilock is currently locked solid & I can't loosen any part of it. Any ideas on how to loosen it so I can set it to the required distance? Can I use WD40 or a light oil? Many thanks Ivor
  4. @bottletopburly I don't suppose you remember the dimensions for the foam fix & which bit of the packaging you used? I'm in the middle of fitting the baader to my 200pds... I thought about the adapter you listed but with shipping it worked out at 70 Euros, so I'd much rather try the foam solution! Cheers Ivor
  5. What is the length of the springs used on the 200 dps? Cheers Ivor
  6. For my CMOS OSC camera I just use darks which match the exposure time (& temperature) of the light frames & a second set which match the exposure time (& temperature) of the flats. The darks are taken with the camera by itself (not attached to the scope) with the cap on & then integrated into a Master Dark for the lights & a Master Dark Flat for the flat frames. (And as I had a coma corrector fitted at the time I used some aluminium foil over the top of the plastic coma corrector cap). The darks were also taken in a dark environment, though I doubt that made any difference. I've not had any problem with light leaks... Best of luck! Ivor
  7. I don't use WBPP but the ImageCalibration process worked fine on the single file I tried. Any reason you haven't taken Darks or Bias frames? Cheers Ivor
  8. Thanks for all the advice - much appreciated. Last night I figured out the hard way why the guide camera focus didn't appear to change... When I'd set up PHD2 it had, of course, defaulted to the 2600 MCPRO instead of the 120MM.... Took me awhile to figure out why I couldn't save any images with APT. Haven't managed to get any images yet, as cloud rolled in shortly after, but hopefully I'm on the right track now. One thing that's worrying me a bit is all the weight hanging off the focus tube. I have a compression ring fitted but even though it's tightened as much as I can, it always seems to have loosened slightly. I think I'll be saving up for a SteelTrack & Clicklock clamp next... Thanks again Ivor
  9. I'm experimenting with using a ZWO OAG (mkII) with my SW 200dps + Baader CC (mk III) & a ZWO Mini 120MM as guidescope. So far I've got it all connected & have set up PHD2 with the calibration assistant. The only way I could connect everything was with a 21mm M42 extension tube between the camera (ZWO 2600MC PRO) and OAG; & using the M48 OAG adapter to fit the Baader CC, which then inserts into the focus tube. In order for the OAG prism to be clear of the camera sensor the camera orientation is limited, so I suspect it'll be a case of keeping it one position in relation to the guidescope. The first question then is, if I want to rotate the whole assembly to either obtain better target framing, or to find a guide star, will I have to redo the guide calibration? As I've previously used a finderscope for guiding I always redo calibration each night when setting up, but with the OAG will I have to re-do it a second time if I have to rotate the assembled camera/oag/guidescope in the focus tube? Also - last night after focusing the main camera/scope, the guide camera distance didn't seem to make much difference to the view of the star in the guide camera or star profile image in PHD2. I understand that it should be set parfocal with the main camera, but how critical is the distance & how do you tell if I can't see it very well in PHD2? Many thanks! Ivor PS: I'm aware that the 120MM may not be the best, but current budget didn't extend beyond the OAG & Helical focuser.
  10. Anyone know what the 'eye' like object is in the upper left of the APOD? I searched on SImbad & found a planetary nebula at about that position (M51 29), but I'm not sure I got the right thing!
  11. I don't have the original email/details but it would have been this one:- https://kitronik.co.uk/products/polypropylene-sheet-05mm-x-1050mm-x-750mm?_pos=1&_sid=81be08b7f&_ss=r Ideally I would have picked black, but during lockdown they only had white in stock - that worked ok as it was easy to mark on the bits to cut out & black marker pen on the edges worked ok. Once you've cut the polypropylene sheet to the correct OTA length I inserted it into the OTA & then marked the overlap position at either end. That made it easy to get the correct width, so that it fits in the tube of its own accord (i.e. no tape needed) For the 200 dps the length wasn't quite enough to go to the end of the OTA, but I figured that the nearer the primary it wouldn't make much difference. In another thread on the SGL somebody recommended using hair-spray on the flocking material to help prevent it shedding fibres. I'm sure that helped, but it doesn't eliminate the problem entirely. (I'm about to give the mirrors a rinse & attempt @alacant's suggestion of replacing the primary mirror clips with blobs of neutral silicon sealant). Cheers Ivor
  12. I used 0.5mm thick Polypropylene sheet from kitronik.co.uk. Worked fine on both the 200dps and 130dps. Example of the 200dps process in the attached pdf. Cheers Ivor flocking.pdf
  13. Thanks @ONIKKINEN , now I understand why some folks have fans attached to their primary! I'll have a go with hanging a weight onto the cheshire (or my poorly collimated cheap laser) - good suggestion! Cheers Ivor
  14. Thanks for the comments/suggestions. @ONIKKINEN The scope is kept in a storage area which is near ambient & is only moved a small distance. I re-checked collimation yesterday but I don't have a collimated laser, so could only do so with a cheshire (& obviously without the coma corrector). I took a few pictures with the scope at different orientations, roughly mimicking the positions during the last imaging session, but there could be some focuser slop once the 2600 camera is attached. Why should tube currents create the elongation in one direction? @michael8554 The session 4 guiding had a four big blips in RA whilst imaging & a drift in Dec at one point. The figures reported in the PHD2 log are calculated on the whole period with these outliers & if they're removed from the calc then the RA/Dec rms is approx 0.44 / 0.41 arcsecs, respectively. Between session 4 & 5 there was only a 9 second gap, when I re-selected the main guide-star, so there shouldn't have been a big difference, aside from the 'blips'. Thanks for the tip on the RMS vs imaging scale & flexure! @alacant Thanks - I know you're a strong advocate of replacing the mirror clips with neutral silicone sealant, but I've not been able to find any video or pictures of the process (other than the completed result). The only video I've found of someone removing a SW primary:- https://youtu.be/7fIkC9GukrM?t=1073 has the cork attached to a paper disc. I think mine has the cork attached directly to the metal ring. Do you put the put the sealant onto/around the cork & at the outer edge? One old thread advocated using a coin as a spacer, but presumably if the Cork is left in situ then there is no need to do so? (Also should the sealant be Low or High modulus?) I'll have a look into the Losmandy & a second bar on the top for additional rigidity. I presume it's the longer length that helps? Also I think I need to either go down the OAG route or a top-mounted guider. The converted finderscope was all I could afford originally. Odd that only this dataset seems to have the problem though. With Pixinsight I've blinked through a few, including all the recent sessions since the last collimation, and it's only this one that is showing this particular issue. On this session I did have the camera at a different angle compared to what I usually do & I suspect that the guidescope wasn't aligned properly with the main scope. Thanks again for the help! Ivor guide.xlsx
  15. I'm a bit puzzled by the shape of the stars I've recently been getting & what to do to improve them. I'm using a SW200dps & ZWO ASI2600MC-PRO with a 50mm dia converted finder scope/ZWO120MM for guiding, which just sits in the finderscope shoe. I also have a Baader MK III coma corrector. Last Wednesday night I got 43 x 3min subs on NGC3938 & then a further 15 on the Draco Triplet. Guiding for the most part seemed ok (*), but the stars have small tails which look like tadpoles. In PHD I'm using multi-star guiding, but it's possible that the chosen guide star was outside of the main image frame. The scope has recently been collimated. The shorter 10s subs I used whilst plate-solving look like they don't have the same problem, or at least not to the same extent. Any suggestions/help much appreciated! Cheers Ivor (*) In the attached log, Section 4 + 5 was on NGC3938, with a pause while I stopped guiding & reselected the star. Section 6 was on the Draco Triplet. PHD2_GuideLog_2022-06-01_225109.txt
  16. From last Thursday/Friday night (28/29th May)... SW 200 dps + ZWO ASI2600MCPro & Bortle 8. I wanted to have another go at M101, so that I could compare with the DSLR image I took in May 2020. Forecast on Thursday looked a bit hit-n-miss & proved to be mostly cloudy with the odd clear spell. 71 x 3min Images taken between 22:54 and 03:00. Neighbours insecurity light didn't come on until 1am & then was triggered at regular intervals for the duration. Friday night I got a further 70 subs (22:54 to 02:52). Sky quality was much better, but the insecurity light was on up to 16 times an hour, although after 1am the frequency was much reduced. On the attached plot of PSF Signal Weight, you can see how the sky brightness at the start & end of both sessions degrades the images & also how the insecurity light was affecting the quality on the Friday night. (It also similarly makes the guiding accuracy worse). The good news is that my wife's had a word with the neighbours & they'll adjust the light angle & reduce the sensitivity, so hopefully things will improve! Image processed in Pixinsight... Cheers Ivor
  17. I've only tried it on one OSC (small) galaxy image so far, but it did a good job in comparison to my regular noise supression methods (MLT + ACDNR/TGVDenoise). I also tried comparing with an old copy of Topaz DeNoise & results were much better with NoiseXterminator. It is very easy to over do it though & takes some trials to avoid the over-sharpened plastic look. Cheers Ivor
  18. I wanted to have a go at this galaxy to see if the outer faint halo would be visible... 66 x 3min subs with ZWO ASI 2600-MCPRO, Skywatcher 200dps + EQ6 mount. 50mm finderscope as guider with ZWO120mini. From 11th May (22:43 - 02:46) with the Moon about 40deg away. Around 1am the neighbours floodlight came on when they let their dogs out. Afterwards they switched their external lights on, which remained on for the duration... Quite pleased with the result, as I'd found that I've not been calibrating my flats correctly (incorrect dark duration). Processed in Pixinsight. Cheers Ivor
  19. @Jerry Barnes I realised that I gave your some duff info! Recently I've been having problems with my own calibration & so the advice I gave was wrong. When integrating the Normalisation should be set to Multiplicative, not "No Normalisation" as I'd previously said. My problem turned out to be a mistake using darks taken at a longer exposure length than the flats... Glad you got your pedastal issue resolved. Cheers Ivor
  20. I've only tried it on one small galaxy image so far, but it the results were better than with my conventional Pixinsight noise reduction (MLT/ACDNR/TGVDenoise) & also better than my old copy of Topaz DeNoise. It took a bit of restraint to avoid the 'plastic' smoothness, but I'll definitely be using NoiseXterminator in future. Plugins for Affinity Photo & Photoshop are being developed too. Cheers Ivor
  21. It looks to me that the Master Flat is overcompensating. I had a similar problem with my 2600 MC Pro which arose when creating the master flat in Pixinsight. When calibrating your flats try unchecking "Enable CFA". To create the master flat under ImageIntegration try Average Combination + No Normalisation (*) & Weights set to "Don't Care (all weights = 1)". Under Pixel Rejection pick the appropriate Rejection Algorithm ("Winsorized Sigma Clippng" works well for 30 flats) & set Normalisation to "Equalize Fluxes". I'd also suggest trying shorter exposure times for the flats/flat darks, or a dimmer light source. With my cheap LED panel I have to make it pretty dim & shoot 0.155s flats. I've attached the unstretched histograms of your master flat & one of my own. Cheers Ivor (*) my problem occured because I was used to selecting "Multiplicative" normalisation here, which worked fine when I had a DSLR...
  22. Thanks @Spile. I'll no doubt get obsessive & also take up @Pixies suggestion of the steel & ptfe washers. The secondary looks like it could do with a wash in any case! I haven't checked the collimation 'in the field' yet, but the stars are now a lot better than they were. Here's a very rough process from last night (NGC3198). Thanks folks! Ivor
  23. Yesterday I spent pretty much all day going around in circles, getting good central alignment of the secondary to the focus tube, & then messing everying up at subsequent steps... This morning however I think the penny may have dropped. Here's what I did:- i) Adjusted the three primary mirror screws so that distance from the OTA base to mirror cell was approx equal (measured with digital caliper) ii) Used the Concenter to position the secondary central to the focus tube. I then took a picture through the Aline collimation cap, measured the pixel co-ordinates of the focus tube edges & used Pixelmath to draw the centre lines, and photoshop to overlay concentric circles to verify the alignment. iii) Adjusted the secondary mirror tilt in small adjustments to bring the primary into view, taking as much care as I could to avoid rotating the secondary & only loosening one screw slightly / tightening another at any one time. Once my markers on the Primary mirror ring were visible in the Aline cap, I replaced it with the Cheshire & made final adjustment to make the Primary centre dot coincide with the out of focus cheshire cross-hairs. iv) Adjusted the primary mirror tilt to bring the centre spot reflection concentric with the primary mirror dot. As a sense check I then took another picture through the Aline cap & added the focus tube centre / concentric circles to check. The result is far from perfect, but I think it will have to do for the time being. I've not had much success with the cheap laser however. I bought a Bader ClickLock Reducer to help centre it (and also the Cheshire), but haven't manged to get the laser collimated sufficiently. Best I can manage is about a 0.17 deg error & whilst the laser reflection appears close to the primary mirror spot, it's not good enough... Looks like we might be getting a bit of clear skies tonight, so I'm eager to see what difference this makes (if any!). Cheers Ivor PS: Over the last few weeks I've also adjusted the focus tube, but now I'm not convinced that was needed. In the end I used an old surveying Laser Distometer and a heath-robinson jig to hold it in position & then measured the distance fom the top of the focus tube to marks I'd made on some pvc tape stuck to the OTA, at a set distance from the focus tube base. I'm not sure of the accuracy of the distometer at these short lengths, but the measurements suggest it's aligned to the OTA to within 0.2mm in either axis.
  24. By default StarAlignment uses PSF fits. Under "Star Detection" you could try changing the 'Compute PSF fits' from "Distortion Correction only" to "Never" & ensure that the Registration Mode is "Projective Transformation" Juan Conejero suggests this where stars aren't focused in this thread: https://pixinsight.com/forum/index.php?threads/star-alignment-fails.13598/ Cheers Ivor
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