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Found 12 results

  1. Hi The longest frames i seem to be able to capture using my Atik 414ex and PHD2 are about 2 minutes. Any longer than that and i start to get egg shaped stars. PHD is making corrections, but i can't understand why i can't get to subs of at least 5 minutes. I'm not sure if its a limitation of the scope (6SE, with f/6.3 FR), limitation of the guide camera (orion magnificent mini, 50mm scope), poor polar alignment or poor worm gear. Would PEC training help improve my sub length? Or is it settings in PHD to experiment with? I look at the logs, but it's all just numbers to me. I can provide logs if that would help? Any suggestions appreciated. Thanks Joe
  2. The struggles of a beginner learning how to use the equipment. :-) Pointed mount North and Levelled EQ6 pro mount 8:30 pm Attached wireless release, 2" nose and UHC filter to Nikon DSLR Attached scope and camera, balanced scope for camera use Collimated the telescope -took 40 minutes of messing around Waited until dark. Took the dogs for a walk around the field to pass the time Polar aligned using the mobile app and sighting against Ursa major. Rebalanced DEC for eyepiece rather than camera 3 star alignment. 1st star was way off and took ages to get it in the eyepiece Restarted 3 star alignment. - Selected a star behind a house. Restarted 3 star alignment -complete. Checked collimation using a bright star - perfect (should bloody be after 40 minutes!) Tried to fine adjust polar alignment using a method discovered online (not drift- I don't think I have the patience.) Didn't work. Restarted 3 star alignment then used the polar alignment on SynScan Took a look at Jupiter was great to look at but not what I set out to do, I want DS images... Attached camera Used live view (LV) to try to focus stars Pointed the scope at M3 and took a 2 minute exposure Tried again with a 4 minute exposure SD card failed. Lost some family pics, grrr Now I have to explain to my partner that it wasn't because of Astronomy, these things just happen. Replaced SD card Took some cautious 1 minute exposures of M90 expecting the camera to explode Pictures were faint so moved to 4 minute with a little more confidence telling myself SD card failures can just happen. Noticed star trails Located a bright star Decided to give PEC training a try. Couldn't do it with an eyepiece. Tried with the camera in LV but noticed some gradual movement in the DEC axis. Hoped PEC training would sort this. Moved onto the Spiral Galaxy Took some 2 minute exposures of the whirlpool galaxy. Wireless timer worked flawlessly. Still a little faint so up'd the ISO and took some more. More detail but more noise. Took some darks with the same settings. Packed away while the camera did its thing. Viewed the pics briefly on laptop. There was star trails (DEC axis again and blurring) Went to bed 1:30 am Summary: So what have I learned? Well DEC error was probably due to the balance of the scope being off. I never did re-balance for the camera. I've also learnt today that I should bias the balance slightly East so the gears engage better. PEC training is a waste of time without an illuminated reticule which I don't have the desire to buy. I'd rather save for a guide scope and guide camera. I've learned I can refine the polar alignment after the 3 start alignment process. I've also read on forums that perhaps I should manually move the scope to the first alignment start then continue with the usual process. I've also seen that two star may be the way forward for EQ6. So perhaps next time I'll start with a 2 star, polar align using the SynScan handset then back to 3 star with the first manual adjustment. I should also purchase a few SD cards that are dedicated for Astrophotography and upload them ASAP after the session. The Astronomik UHC Deep Sky Filter worked wonders with the images for where I live. I can now take longer exposures. Assuming I sort out DEC errors and invest in guiding rig.
  3. If you are using an auto-guiding scope and ccd with PHD, do you need to worry about drift alignment and/or periodic error correction of the mount?
  4. Hey Guys. I was just wondering if it is possible for me, to do PEC training using my Nikon DSLR and the cables that I got? I don't have a guiding setup yet, and I want to wait until the money is there and also getting more used to imaging. I tend to have a very good polar alignment, as the image doesn't drift through each frame, but rather there is a "jerk" or drift every other frame, when doing 2-3 minute subs. I guess that is periodic error, as it happens even on windless nights. So, I have both my Nikon DSLR and my mount hooked up to my pc (the mount through port in the Celestron Advanced VX Controller), from which I can send slew commands. I have the periodic error correction tool too, but as of right now it seems that I have to monitor and correct any PE myself, which I honestly don't want to do as doing that 8 minutes straight with precision doesn't sound easy. So can I hook up the DSLR through say PHD2 and let it correct for me, and do the PEC training, or do I need the actual cable that goes into the Guider port of the mount? Any thoughts on if this is possible would be well received! And if not, I guess I'll either just need to get used to shorter subs (or throwing 1/2 of them away), or trying to do the training manually with the zoomed image of Backyard Nikon.. Cheers -Mathias
  5. Hi all! Yesterday I was out taking a few pics of M56 and M71 (no nebulas or galaxies, because the moon is still quite full). This was the first time I tried my new coma corrector, which I think works fine. One RAW sub: A few problems, though. As you can see from the above RAW example, there is no coma anymore, but all stars are kind of triangular in shape. Is this due to collimation error, ie warping the primary by tightening too much? I tracked (unguided) using also PEC... Second problem. On RAW sub that wasn't so good...: These subs are frequent, one in every 4, on average... I'm guessing my HEQ5 is old and not too precise anymore... Or could it be something else still? Here is the stack of the good subs (no post production), to show the beneficial effect of the coma corrector again: Ideas? Gerhard.
  6. Guys and Gals - Really hoping for some help from the imaging gurus and mount doctors here. Lucas has been helping me with my Mesu 200, which arrived with what I believe was an out of spec RA servo/encoder. It's one of the latest versions with magnetic motor encoders rather than optical. Historically, mag encoders have never been as accurate as optical (although they are normally more reliable), and typically they're not well suited to being on the end of an electromagnetic servomotor, but he re-assured me that no-one else had reported problems. My initial tracking graphs (PHD into PECPrep, 400mm ST80 into QHY5) revealed a 'fast' periodic error, going from around +2 to -2 arcsecs every 21 seconds (this is twice the fundamental motor rotation period). Not what I hoped for. Here it is again with a little Low Pass filtering: Now Lucas sent me one of the original optical encoders, which I have fitted and I believe it has resolved this fault. Here is the new raw tracking plot: I do still see a repeating PE, but it now has a 42s period, which makes more sense. It is also pretty small, in the region of 0.7 arc seconds pk-pk, but it is definitely a repetitive mechanical product. Here it is again with the same Low Pass filtering: Most of you will probably say, "Well, the seeing will be worse than that, so why worry". And I agree to a point, but I would sooner just suffer the seeing, if possible, than the seeing combined with a PE which repeats every 42s. I will be guiding anyway of course. Also, everyone who reviews the Mesu mentions that it only has a very small and very slow tracking error, with it going gently from -2 to +2 in around 300+ seconds. Even the tracking curve on the Mesu website shows this: If my mount is the 'norm', why doesn't the Mesu PE plot show a 0.7 arc second ripple superimposed on the curve? When Bisque and AP quote PE's of 7 arcsec or 3 arcsec, do they also have this faster ripple superimposed on top (I mean faster PE components - I know any real world test using star to track will show random seeing noise too)? Does anyone's Mesu 200 produce a PE curve which, without massive low pass filtering, looks like their graph on the website? If Olly or Yves see this - does your mount do this? Does it produce those fantastic images anyway? Can anyone tell me if I'm going mad? Not many folk seem to post raw PE curves, some have a huge amount of filtering applied, which makes it hard to know what to expect. Or tolerate. I know Lucas will replace my mount if I ask him - he has been great throughout, but he gives me the impression that they will all have some level of this 42-second Periodic Error. On a mechanical level, this makes sense, but I did a huge amount of research before I bought this mount, and no-one mentioned a 42s PE. If you made it this far - thanks for reading! Any advice appreciated. Jack
  7. Hello everybody, I am going to apply Permanent PEC correction to my AZ-EQ6 GT SkyWatcher mount in an attempt to eliminate most minor negative contributions to my so-and-so autoguide. I will do that by following instructions on the SynScan manual. Does anyone have some advice? I also started using Guide Assistant of PHD2 and applying the calculated min-move and backlash changes suggested by the system. More, I tweaked the worm and gear bugs of the DEC axis to reduce the backlash, and after a few attempts I found the right position between screeching and jerky movements of the mount at one extreme, and shaky setup at the other. I hope getting some improvements to my awkward setup because I am afraid that the heavy (14-16 kg) and long (1600 mm focal length) Meade 7" refracting scope plus guide scope is close to this mount's limiting payload, and difficult to be correctly balanced. In addition to seeing, its length also makes it strongly sensitive to wind gusts making PHD2 log graphs look not so good. I cannot minimize these effects without changing my scope, which I don't want to do because of crisp images it yields under (rare) favourable conditions, so I started a search to minimize everything else that can be addressed. Thank you for useful suggestions!
  8. Here's one for y'all: what's a fellow stargazer to do to receive an answer, or any useful feedback, on a subject where are literally dozens of skilled and knowledgeable users? I just returned from another failed attempt -fourth, and probably my last one - at PECing my AVX mount. This time i tried the inverted curve provided initially by Metaguide and PECprep, thinking that maybe last time it was wrong since the PEC graph and the PE graph looked pretty much identical; PECtool managed to load it snd upload it to the controller, but none of the curves tried so far seems to work. Nothing works!!..... HOW EXACTLY DO YOU, PEOPLE, EVEN PEC TRAIN YOUR AVX MOUNTS?? Seriously, i'm pretty desperate here, and horribly frustrated by this lame failure. Please, PLEASE, anyone (preferably knowledgeable), tell me what to do! I see older topics where people flex their astro-muscles, with success stories. I find it hard to believe that absolutely everyone switched to guiding lately, or got into a mass amnezia.. Unless, of course, no one gives a rat's @$s about a fellow stargazer's trouble. In which case i might as well sell my mount, sell everything i have and quit astro for good, because i see no point in struggling like a mad man, with no help. I also tried private messages - got totally ignored. What more can i say....
  9. This is more of a story about last nights efforts than a cry for help. I went out at ten to focus the OAG on the scope fitted with a lodestar and align the guiding axis to the telescope. The ultimate aim was to calibrate the PEC on the SS2K to start to take decent pictures with the mount. It was a glorious night. But my lodestar seems to have grown duff bright pixels by the dozen over summer. Even using full autocalibration in Maxim didn't seem to remove them. So I created a bad pixel map and applied it to my auto calibration groups but still with no effect. Meanwhile I soldiered on, using a brighter star in the OAG to focus and align axiis on. That done, I discovered there seemed to be a reflection from the bright star that Maxim insisted trying to guide on. It turned up on the row of the first bright star image and even after subsequent images when the star clearly moved according to movement calibration requests, the false star remained fixed and caused maxim to fail the tracking calibration. An hour and a half of this I tried, with various combinations of bin ratios, exposure times, star in different quadrants of the CCD and all with no success until I put the star in the top left quadrant and then calibration success! You might think that was it, I was motoring, since Maxim was now seeing the star. But no. Maxim could calibrate on the star but reported 'star faded' when trying to use it a guide star, consistently and persistently. Apparently it needs a different type of star to guide on. There were no others. So half an hour later I gave up with that and went to PhD2. It had support for the Lodestar and for the ZWI so I persevered with the Lodestar. It could even see the star Maxim refused to guide on and I could use it to calibrate the movement of the scope for Phd to guide with. I did get a 'ratio difference alert since my motion was very assymetric 'L' shaped but it did calibrate so on I went. Now I could calibrate my PEC!. Several times I achieved this, repeating it starting at different times on the worm since the ss2K will even out the measured with the already recorded. And then Puff! the star had gone - nothing to guide on and the duff pixels were there polluting the image as before. Where did it go ? The sky was still clear and the dome slot was right there where the scope needed it to be. Now I tried a few exposures at 3mins just to get a feel on what quality had resulted from all my efforts. Its an 8" 1800mm so its was optimistic but the evening conspired further - the camera intervalometer battery was flat. Not to be deterred I dug out the spare. That'll teach it. But that one has a duff lead that causes the camera to turn off occasionally and it wanted to play. It was now 1.30, I was freezing and not thinking about swapping batteries so it was time to hit the sack. Only up at 6 for work. I love these succesful evenings. Gotta have more of them. Better luck to every one else, and if you have a solution to the Maxim problem I'm interested. Mike
  10. Hi all, Just another update on my progress thus far... I had some good nights recently, with rather variable results, so wanted to share, and hope to receive some feedback on my musings as to the causes of the differences. First I went high up (1600 m) on a quite clear night, with also good seeing, and I was able to take this: Then, last week, I went less high (1000 m), good clear night, but with some more light pollution, but (IMHO) with better setup: The latter image was done doing drift alignment, AND PEC on my HEQ5 SynScan. The former only with drift alignment. I also tried the M31 on the second occasion, but it was much lower than the NGC6960 (which was close to zenith) and it has terrible traces and other anomalies: I had to dump a lot of subs... :-( So, as you might see, the stars in the second image are much better, but the light was better on the first image... I am obviously still also on a steep learning curve, so that might also have contributed... Question: how much of the quality of the stars in the second image do you think is due to the mount being better balanced pointing to zenith? If this is a significant amount, that would mean that for now I should limit myself to zenith objects, to obtain quality subs..... :-/ Second question: do you think making flats would help with the obvious lighting problems on the second image? Friday maybe I'm going out again, and will have another try at the NGC6960, or maybe its sister NGC6992... There's a full moon, though.... :-/ Thanks!! Gerhard.
  11. hi all, been a while since i was on here (thanks to renos and moving to new home). Getting excited to start getting into observing and imaging again but prior to that been looking into PEC. Does anyone have detailed steps on how to properly do PEC (especially using PEC Tool) for a CGEM? Also does PEC have to be done before every object you image or is it a once off things that once you upload to the CGEM its permanently sorted? I am reading celestron blogs, documents and experiments people have undertaken that PEC should only be done before you image an object and it would only apply for that imaging session. Thanks in advance
  12. Hi Astronomers... I decided that after modding my 40D, in the last few years taking a few long exposure images successfully with the modded DSLR even up to 45min (30 mins usually) subs at 2000mm with all subs usable unless clouds ruined the exposure. Lately I thought I'd tackle a new challenge, that challenge being PEC training on the CGEM to see if I can improve the tracking quality (RMS in PHD) and in turn tighten the star bloat a bit and improve the detail, particularly imaging at F10. Currently my attempts failed miserably. Initially I learned the hard way that you can not train PE on the CGEM using the GPUSB autoguider port, can't even have the cable plugged it since the CGEM starts to make a tapping noise and the whole alignment gets confused or theres is a conflict between the autoguider and the handcontroller, the mount becomes unusable until it is power cycled. The second attempt was to connect the NexRemote via COM8 (on my laptop) and generate a Virtual COM32 for PHD to connect to the NexRemote. PECTools connected to NexRemote directly, so had all three bits of software talking to each other. I have installed ASCOM version 6 and the Celestron ASCOM drivers. I connected PHD using ASCOM via these drivers. I aligned the scope via nothing but NexRemote on the laptop, the NexRemote read the GPS and aligned successfully. I located a guide star, calibrated PHD and commenced guiding, which it was guiding with no problems. Till this point everything was smooth and as expected but here's where the problem started... I had PECTools connected and seemingly everything was OK, it found the index, which came up with a dialog box warning that the scope will move up to 2 degrees, which it did when I hit "OK", returning the guide star to nearly the same spot, which I thought was quite good for such a small FOV since I was using the IS21au618 CCD as a guide camera with a 1/4" CCD. I resumed guiding in PHD, hit "Train PEC" to start the training procedure and nothing... where the sine curve is, there is meant to be a yellow line showing the start point and a grey line moving as the scope goes through its 479 second worm cycle. I waited for more than 10 minutes than left it for a half hour to see what will happen and nothing. When I hit stop training nothing changed on the graph. Same thing was with batch training, I left it for 90 minutes and still nothing, no files generated nor was there any difference in the software after I stopped training. I decided to do a PEC training procedure using the hand controller (after starting from the beginning, aligning the scope using the hand controller) on the scope, which it seemed to be OK, PHD was guiding and the mount was recording, after 8 odd minutes it stopped. When I initiated playback, it seemed to improve the guiding scale a bit, but not so much as to be worth while.. but a improvement nonetheless. I tried running everything with administrator privileges with no change. I'm under the impression that the CGEM has a 3 cycle worm period before truly being periodic, so the way to get the best result is to average over 6, 9 or 12 cycles and upload the result. Has anyone tried this and had a similar outcome, or does anyone have any advise... the laptop I'm using is a Sony VAIO running Windows Vista Basic... but all of the controls are working so I'm reluctant to think that the OS is incompatible with the software. The second thing I tried was using "PERecorder" which worked OK with the calibration and verification until I hit "Record" to record the PE... all it did was display a error message, a crossed out rectangle was all that was shown where the PE graph was supposed to be generated and the tracking was stopped of course losing the guide star. When checking the hand control Tracking setup, it changed from EQ-South to "Zone-5"... Normally there is no "Zone-5" option, just OFF, EQ-North and EQ-South. Sorry for the novel but currently I'm out of ideas, if anyone has any ideas, help would be appreciated. Mariusz
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