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Showing results for tags 'guiding'.
Found 54 results
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I'm starting to worry about my mount I've got a quite significant wiggle in the RA axis when the mount is powered off in it's parked position (clutches locked of course). Before I embark on a full strip down following Atrobaby's guide I thought it would be worth asking if anyone had suggestions for a less drastic investigation / fix? I'm not sure how recently this issue has come up, I've only just become aware of it after an equipment upgrade. I've just replaced my guiding setup of a 50mm finder coupled with an SPC900 webcam, to a Celestron 70mm TravelScope with a Touptek Mono guider. When I made this change my guiding went to hell, with a crazy amount of oscillation on the RA axis, which is what led to to start looking for flexure etc. and thus I found the RA axis slop... Now I understand that my new guiding setup has a much tighter FOV, and therefore will make the guiding errors look more pronounced than I am used to with the finder guider setup, but still I'm getting graphs with massive errors and corrections, sometime 2-3 pixels worth of motion. The DEC axis looks ok, but RA is all over the place, and I wonder if it's down to this wiggle? I've tried adjusting the balance so that the mount is at least always working on one direction, but that didn't appear to help much last night. So can anyone offer me some advice? Thanks in advance
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Hello All, Been searching the inter web for info on "how to improve tracking" during solar capture (for time lapse animations). Came across this LuSol Guide. Did a search on SGL and no hits. Any one looked at this before or even tried it? http://www.oc-lab.fr/ - Nihal
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Hello all, I have had a real problem with my AZ EQ6 GT: I have found that the MOUNT guide rate in RA is 1/3 the guide rate in DEC. EQMOD is set to 0.9 in both axis?? This seems to have happened when I tried guiding with AA& instead of the normal PHD2? Is there a mount direct command to alter the RA guide rate. Bit like the mount commands to dim the polar scope and set park position. You know one of these serial commands the no one ever uses?? All the best John
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Hi - I've not posted here before as only just launched into this hobby, although I've always been massively interested in astronomy. I had first light on my rig last night, which is: Esprit 100, HEQ 5 Pro, ZWO EAF, ZWO mini filter wheel, skywatcher 50ED guidscope with ASI120, ZWO1600mm Pro, Lynx dew controller w 2 astro zap tapes A big endeavour to get that lot working from zero experience, but I love a challenge and have really enjoyed the computer side (I'm a grade A nerd)... So - what went well... I got the guide scope in focus (was stressing about this), and also the main scope. Even more awesomely, the autofocus routine in SGP is working perfectly Filter wheel also working perfectly and I'm getting lovely smooth pics from the main camera (I've already done the flats and darks while I was waiting for clouds to clear). Final good thing (well, good-ish), is that I got the platesolving working eventually, and was able to get the scope to align from Park to the Soul Nebula and centre fine. For some reason the "number of attempts" in my SGP profile hadn't applied, so it was giving up after 1 go, but I got it working in the end. So the bad... I couldn't take any data because every time it finished the platesolving and started PHD2, PHD2 would start the calibration process and then halfway through, the sidereel tracking on the EQMOD panel would turn off. Obviously, that would lead to a "lost the star" error. Is there some reason why sidereel tracking would turn off like that? I'm generally a bit confused as to whether I should be controlling the telescope from SGP (i.e. unpark) or using the park and unpark + tracking button on the EQMOD panel. Both PHD 2 and SGP are setup to use EQMOD ASCOM HEQ5/6? So at the moment I can't do anything, because there's no way of guiding without it turning tracking off Also I was cold. Very Very Cold. -
From AST Optics selling my mini guiding system that i used for my Redcat51 , i have used it also with my Esprit 100 and had excellent guiding results. There is a nice review here if someone wants to read : https://www.cloudynights.com/topic/575047-ast-mini-guide-kit-any-comments/ Lens: f=100mm F3.5 CCTV objective - made in Japan Adjustment: by ballhead - with reliable clamping Dovetail: compatible with most finder shoes True field of view: 2.9° x 3.8° Maximum guidable focal length: 1000 mm Focusing: via lens cell Connection to camera: C-Mount Lens filter thread: M30.5mm P=0.5 Weight: 79 grams Length of the objective: 44 mm PRICE : £100 (selling the mount and the CCTV lens not the camera) Paypal accepted buyer pays the fees I will cover the postage expenses Thank you, Nikolas -
I have an EQ5 telescope mount which i use for astrophotography. I have modified it with a motorised RA axis using a bipolar stepper motor - my thread for the build is here . I want to expand the mount's tracking ability by motorising the DEC axis and using a guide scope/camera. I generally use the mount in fairly remote locations so would like to use a raspberry Pi for portability. I understand that I'll need to use a Raspberry Pi Camera Module for the guide camera. The capability I want is: 1. guide the mount along RA and DEC axes using a guide star as feedback 2. track the mount using the RA axis only, and if possible continuously take 20-30 second exposures on the guide camera (this functionality is optional, but would assist in polar alignment of the mount) I don't want any GOTO capability. I am very new to RPi and need some help: - do I need to write code for this, or is there existing programming available for what I want to do? - is it possible to avoid the use of screens (in the field)? My preferred option would be to flick a switch to start and stop the guiding, with another switch for alignment mode (or something simple like this). - do I need to use any particular stepper motors/drivers for raspberry Pi? I'm using a bipolar stepper motor running quarter steps, with an A4988 stepper driver - is the RPi 3 Model B+ the unit I should buy? Thanks
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Hello stargazers! after fixing the ED80 focuser tilt and FFR spacing issues (http://stargazerslounge.com/topic/249588-sw-ed80-reducer-elongated-stars-problem/) I have some trail (i think) in all exposures i take but it takes a lot of time to really build up and manifests in the images even in the center of the field! It becomes slightly visible in 10mins, worse in 20mins and in my opinion unusable in 30mins exposures. Gear used : Heq5 Pro Modified finderscope with QHY5 bolted firmly (although on 3 screw baader rings on single shoe on one of the rings not on a plate) on top of the ED80 Pulse guiding through ascom + pec trained and applied corrections while imaging One shot of 1800secs from last night Here is the plate solve of the image if that is of any help. Image Plate Solver script version 3.5.1 =============================================================================== Referentiation Matrix (Gnomonic projection = Matrix * Coords[x,y]): +0.00059136 -3.35323e-005 -0.948749 +3.35667e-005 +0.000591379 -0.805052 +0 +0 +1 Projection origin.. [1676.147757 1266.175055]pix -> [RA:+02 54 45.62 Dec:+60 26 33.75] Resolution ........ 2.132 arcsec/pix Rotation .......... 176.752 deg Focal ............. 522.35 mm Pixel size ........ 5.40 um Field of view ..... 1d 59' 7.6" x 1d 29' 59.1" Image center ...... RA: 02 54 45.583 Dec: +60 26 33.36 Image bounds: top-left ....... RA: 02 47 15.353 Dec: +59 37 27.51 top-right ...... RA: 03 02 57.738 Dec: +59 44 03.24 bottom-left .... RA: 02 46 12.014 Dec: +61 07 05.13 bottom-right ... RA: 03 02 38.669 Dec: +61 13 59.48 =============================================================================== 200% crop of the centre of the image shows the problem clearly. And here is PhDLabs last night's analysis log. Second run does not look much different than the first one (to my untrained eyes at least). The phd graph did look at its best (flatline like) What do ladies and gents think? bad polar alignment, backlash on gears, differential flexure? If anyone has suggestions of the nature of the problem might be, I would be grateful.
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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
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Hello, I hope I'm posting this in the right section. I have a guiding query I hope people here may be able to help me with. I have just purchased a Skywatcher EQ5 mount (without GoTo) and also the Skywatcher Enhanced Dual Axis Handset For EQ5 in order to be able to guide (this has yet to arrive so I haven't been able to look at it closely). I was wondering if anyone here has worked with this setup and particularly if there is anything else I need to get in order to make it work. From what I can tell the Skywatcher Enhanced Dual Axis Handset comes with the two motors and has an ST-4 interface for an Auto-Guider. So far so good, but I can't see how it communicates with the laptop to make guiding corrections dictated by the software (I use PHD for guiding). My guiding camera is the ZWO ASI120C and the guidescope is the Orion 50mm mini guidescope. There must surely be a cable that goes from the USB port to the handset but I can't see any mention of one, or indeed if something like that is required. Looking at other setups and examining the PHD settings, I've seen mention of something called a GPUSB guide port interface adapter which plugs directly into a USB port on the computer. Using an RJ-12 cable, the adapter connects to the guide port of the telescope mount (or in this case the Enhanced Dual Axis Handset hopefully). I'm assuming I'll need something like this. On my old setup a cable goes from the USB port of my laptop and is converted to a plug that goes into the bottom of the Celestron handset and is controlled wth the ASCOM Celestron Telescope driver, while the guide camera (ZWO ASI120C) connects to the mount. While I can see how the guide camera connects to the Enhanced Dual Axis Handset on what will be the new setup, I can't see any USB cable or converter that goes into the new handset, nor can I see any mention of the need for one, which strikes me as odd. Looking at the PHD settings and also at other setups online, I saw mention of something called a GPUSB guide port interface adapter which plugs directly into a USB port on the computer. Using an RJ-12 cable, the adapter connects to the guide port of the telescope mount (or in this case the Enhanced Dual Axis Handset...hopefully). I'm assuming I must need something like this and that the Enhanced Dual Axis Handset accepts one (or an ASCOM equivalent - I didn't see Skywatcher listed in the PHD driver options). I hope this makes some sort of sense. Any advice would be greatly appreciated. Thanks
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Hi, Bit of a strange one. I have a NEQ6 which I control with EQASOM for imaging using SGP and PHD2 for guiding and have recently replaced the HC connection to the pc with an Lynx Astro FTDI EQdir cable. First time I used it it worked perfectly, it connected straight away, the guiding was good and SGP found the target without any issues. But I tried it again last night and whilst SGP worked perfectly, plate solved the image and moved directly to the target, PHD2 wouldn't connect to the scope. I selected the correct ASCOM mount from phd2 dropdown list but the EQASCOM connected briefly then disconnected with a display saying that it had failed to find the correct port. I tried adjusting the settings next to the mount selection tab and ensured it had pulse guiding selected but still no joy. As a result the phd2 software is not sending guide commands to the mount. The funny thing is that PHD2 will connect to EQASCOM if done so before SGP is connected but then the subsequent connection to SGP fails. But with PHD2 connected on its own its still not sending signals to the mount. Is this a faulty cable or is it a EQDIR driver problem or even an issue with PHD2 or EQASCOM? Any help would be appreciated as I am a loss as to how to rectify the situation. Thanks Dec
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Help with AVX troubleshooting
Ottawa Ken posted a topic in Getting Started Equipment Help and Advice
Hello, I was wondering if anyone could help with an autoguiding problem. I have a Celestron AVX mount. I cannot get it to guide at all externally. It moves fine from the handset. I have tried guiding from FireCapture, PHD2 (both auto and just manually guiding) I have tried to connect via the USB to Handset, and via the autoguide port (via my ASI290mc). I know the handset port communicates (on COM4) because I flashed the Celestron Firmware. I am beginning to think I have a tech support problem, but I want to rule out errors on my part. Thanks, Long time lurker, first time poster. -
I was wondering, is there an alternative to the ATTH3010 declination unit one could use with the Astrotrac? Counterweight is important, because I'd use a 90/600 APO.
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Would i be able to use my 10 60 Altair Astro finder & an UN-modded Toucam Pro II webcam as an auto guiding setup. I may have this wrong but i thought a guide camera would always be on or 'open' as it were to track a guide star continuously, do i need to mod the Toucam for long exposure to use it or will it work as it is ? Is PHD all i need software wise ? I have a Celestron CG-5 GT GOTO with an ST4 port. I already have a serial to RS usb converter + cable which works (i have used this connected to the hand controller then used Stellarium to control the C8) will i need either of these for guiding ? I understand the above has probably been asked before but not everyone's kit or requirements are equal, i have searched other posts as well with not much luck yet. Any advice gratefully recieved thank you. -
Hello all, So I routinely have issues with guiding. Last night, I was getting some solid sub exposures of 5 minutes on the Flaming Star Nebula. When it got to about 15-20minutes of the meridian, I began getting trails on my stars. Then after the flip, I was still getting trails despite PHD reporting all's well. I moved over to the Horsehead Nebula and tried 5 minutes there, and it behaved itself. Then I tested it on the Jellyfish Nebula and it also behaved (just about - minor trails). But it just did not want to dig it with the Flaming Star Nebula, which was practically near the zenith (about 2:30am 30/11/19). I tried recalibrating PHD (I use Pulseguide so the scope knew where it was). I then also recalibrated PHD at Alnitak so it was near the celestial equator (as the PHD best practices recommend). I even checked my Polar Alignment (done with a Polemaster), which was fine. I couldn't find anything wrong. The guide scope was slightly off alignment with the main OTA, but that wasn't making any differences before the Meridian. I did find the helical focuser of the Starwave 50mm guide scope I was using to have some movement in it again when I manipulated the guide camera. So that's something I need to look into. But before I start throwing money at this issue, I see the terms "flexure" and "differential flexure" coming up. Can anyone shed light on what this means please? I tried manipulating the OTA in its tube rings, that didn't yield any movement either. The piggyback scope is secure, the g/scope is secure in its rings as well, there's no movement in the OTA focus rack and the cameras are secure in their tubes. I do have my guide rings quite far back on the body of the telescope to assist with fitting the guide scope piggyback. Video of g/scope play: Flaming Star Nebula. 5 minute sub, post Meridian Flip, about 2:50am (30/11/19). Note the plate solve compass in the top left. Drift appears to be in S/W direction. Position of tube rings (they're now at the focus end). I think I am leaning towards needing to move my tube rings (once I remember to get the tools from work). Equipment: (brand new) Skywatcher EQ6-R Pro, SW Evostar Pro 80ED, Altair 0.8x R/F, Canon 600D, Altair Starwave 50mm Guide Scope, Altair AR130 Mono Guide Cam.
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Ok, so this is a really annoying bug / problem that I have with my setup: From time to time, in non regular intervals the image my guiding cam (ZWO ASI120) send seems to get flipped / mirrored or looks like it's from a completely different patch of sky. When I'm paying attention to the guide images I can clearly see that the image seems to be flipped in some way. It only happens for 1 frame PHD send a warning ( No star found / Star lost Mass changed) and after that everything is fine again. My gear is all connected to a single USB3 Hub which then runs via powered USB3 cable to my Pc. I'm not binning and have the noise reduction off (though PHD might got hickups while processing) but it still happens. Sometimes there are minutes between two events sometimes it happens 5 times in a row. It also seems like it's only happening during guiding, I haven't seen it happen during calibration yet... I'm completely clueless what's happening or how to get rid of it, any help / idea is greatly appreciated. -
Hi Guys, hoping someone can help me with the guiding issues Iv'e been having. First of all my setup is: Explore Scientific ED80 Triplet Skywatcher EQ5 mount with synscan Orion mini 50mm guide scope Altair GPCAM2 AR0130 Mono (as the guide camera) I did my polar alignment and 3-star alignment, which was spot on. So I set up the GPCAM2 and opened PHD2 where I selected "Altair Camera" and "On-Camera". It was all in focus, kept it on the default settings and I selected "auto select star", then it said I was guiding (I can hear the mount making small adjustments). A message popped up saying I needed to increase the max RA duration, then I needed to increase the max DEC duration, which I did gradually by 1000ms each time the message appeared. Still no progress. So I restarted the process with the max RA and DEC duration as 8000ms and it said I needed to eliminate the source of the problems. (I HAVE ATTACHED IMAGES OF THIS) I'm not sure why it not working and if I'm doing something wrong. But if someone knows where I'm going wrong, or has any advise it will be greatly appreciated! Oh and just let me know if you need any more info, because Iv'e probably missed something out. Thanks again ?
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Hi I've set my scope up on it's pier in my ROR observatory, done a few drift aligns and started to take some images. I've noticed a 'quite' regular dip in my DEC line on several nights. Would anyone be able to have a quick scan of my log and offer any insight? Could it be backlash? Could it be something with each rotation of the gears? Faulty tooth? It is quite regular, although not always, and always in the same direction. It doesn't seem to be adversely affecting imaging yet, but I've not tried anything too taxing. Thanks Joe PHD2_GuideLog_2018-09-23_200940.txt -
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Modifying a finderscope to guide with
Luna-tic posted a topic in Discussions - Scopes / Whole setups
Seems a waste to ditch a perfectly good finder scope in order to replace it with essentially the same thing, that has ability to mount a camera to. Is there a way to modify a 9x50 finder scope into a guide scope?. I'm speaking specifically about the 9x50 that comes on the Edge series SCT's. Thing is, I don't even use it for it's intended purpose, I find my Quickfinder more useful for that and don't even mount the finder scope any more when I go out. The EP of the finder is smaller than what's needed (less than 1.25"), can it be removed and an EP holder cobbled onto the body? I suppose focusing it would be part of the problem, too. -
Hi All, Apologies for what may seem like a stupid question, but if have a QSI 683 WSG which has a built in OAG which i use for guiding all the time. I want to try imaging some comets but i'm guessing this is not possible with a OAG. I do have a 60mm guide scope, but wasn't sure if differential flex would come into play as my main scope is around 1.2m F/L Any help or recommendations would be greatly appreciated. Rich.
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Perhaps DIYers will be interested in a low cost guiding setup for EQ2 mounts. I'm not sure if this approach has been tried before, but it's relatively straightforward to implement and is certainly low cost. In early 2016 I purchased a Meade Polaris 130 scope, complete with EQ2 mount and Economy RA (clockwork) motor drive with the intention of trying out astrophotography at a low entry cost. Very quickly the prime focus problem arose - so the scope was shortened by 40mm. With this mod 30 second exposures very not too difficult, with 60 seconds sometimes successful. Of course the problem was tracking. Rather than spend time taking lots of 30 second exposures and knowing that longer exposures were really the way forward, I decided to investigate the Economy RA Motor to see if it could be modified in some way for guiding. The answer soon became apparent - yes it could (with very simple mods) but I had no idea how well it would work. Next steps were to look for a way to guide the motor - an Orion mini guide scope and Microsoft Cinema webcam (modified of course) plus a Raspberry PI with Lin_guider were relatively painless to get going and the results were good. However, DEC drift could still cause star trails, so a bit of thought came up with the idea of using an Economy RA Motor as a DEC motor, again to be controlled by the Raspberry PI. This evening the setup was given its for test for dual axis guiding (5 min RA guiding had been successful previously). Not the best sky - very bright due to the moon and clouds appearing. Still, taking no time for polar alignment other than to point the scope slightly to one side of the pole star, a guide star was found, guiding started, guiding gain etc adjusted and a couple of images taken before the clouds got in the way. Results - no doubt as seasoned astrophotographers would expect, DEC guiding just needs a bit of correcting from time to time - the gain of Lin_guider had to be brought down to stop oscillation. RA guiding takes much more frequent corrections, again with a low gain for my setup. My aim with the mods was to see if such a low cost and basic setup could be made to guide - also at a low cost and with simple equipment/mods. On the face of things it is not too involved and I hope that it will be useful to those who don't want to jump into the expense of more mainstream equipment. It could also be a low cost learning curve into guided astrophotography for those who have already purchased a scope with EQ2 mount. Next steps for me is to find (hopefully!) some clear skies for a chance at decent imaging. Weight hasn't been added to the mount as yet - this should improve stability although the short 650mm focal length is a help when it comes to stability and guiding errors. Below is a 5 minute (bright) single image taken this evening with dual axis guiding (at 100 ASA due to the moon). The central star seems reasonably round, though coma affects other stars towards the edge of the image. I've also attached diagrams of the setup and another earlier 5 minute single image taken with RA only guiding.
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Hello dear guys & girls, i am guiding with a 162 mm FL guide scope (aperture 50mm), an Orion SSAG, and PHD2. (My primary scope is an 800 mm f4 Newton). It looks like the best tracking i can manage (with decent polar alignment, but suboptimal seeing) is 1.5 arcsec error (but with peaks at 3.75 arcsec, see below). What is YOUR mileage? Looking forward to many great guide graphs -
Hi all: I've just purchased an Opticstar PX125C with the aim of getting started with guiding (planning on using phd2). I'm running Linux (Ubuntu) and am struggling to get the camera connected to the PC. I'm assuming that I need to install the correct drivers, but have no idea where to start with this, as I've never used a dedicated astrophotography or guide camera before. Can anyone out there advise on potential options for getting the camera up and running? Thanks, Billy.
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Hi All, just thought i would show the results of a little project. I have been guiding with my Orion Mini Fifty with great success using a ED80 F7.5 scope to image through. recently though i wanted to get a little closer to some of the objects coming up in the summer sky. M13, M3, M33, M27, Cygnus wall, m101, wizard nebula... etc etc the list goes on. I will be trying with my 2x barlow giving a focal length of 1200. Which should be OK guiding with my mini fifty, but i wanted to try and match the pixel ratio a bit better to see if it helped, BUT i cannot get focus on the mini fifty when i use a 2x barlow on that... i can screw the barlow lens directly to the end of my QHY5ii_L mono but the focus point puts the camera about 1mm out of the back of the tube. TOO CLOSE to use a barlow as an extension tube because of the internal shoulder.... hmm dilemma. Now i am a product designer so to the drawing board i went....well to Sketchup anyway. Money is always tight so an aluminium turned part was out, but a rigid plastic 3d printed part was on the cards. And as luck would have it, my work bought a new SLA 3D printer (Form2) from form labs) capable of printing to 25 micron resolution. I thought Christmas had come early! attached are images of the final part attached to the rear part of the Mini Fifty, ready to be screwed in place. Not sure how i managed it but i got the tolerances right first time....and measuring the rear part with a ruler. fitting diameter to slide over the rear part of the min fifty = 42.25 diameter. fitting for the camera (1.25") = 32.5 diameter. as you may have noticed i will need to add 3 x M3 threaded inserts to the back end of this to clamp the QHY securely in. i can post images after this is done. if anyone wants this model i can provide it. None of the internal/external detail is needed really, but this was to see what the Form2 could do. And i can say ........it is amazing. (for everything but closed cavity printing. clear skies everyone.
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Has anyone had experience with using the Orion starshoot guider through a 900mm refractor scope for guiding? Is this an ideal focal length? Or does it make it hard to find guide stars with the smaller FoV? A friend of mine used the starshoot as a kit with a small focal length scope that fitted on a finder bracket. As he was guiding alongside his c9.25, the combination just wasn't working well due to the difference in focal lengths between scope and guide scope so now he's looking at longer focal length scopes. any advice, suggestions would be great thanks -
Hello Astrophotographers, Now that I have my CGEM on a permanent pier, I figured that I should get much better accuracy in guiding quality, especially at 2032mm (F10) focal length on my 8" SCT. I spent a bit of time getting guiding results that are at the very least acceptable and thought I’d share my experience with anyone who is looking for info on PHD autoguiding. In the pasten setting up for each astro session and using PHD I was generally getting RMS about 2.2-2.6ish and after stacking and processing, the soft effects were able to be negated to a great point, revealing detail and with results that I was quite happy with (on a good night) imaging at 2032mm using a modded Canon 40D. The stars were round and generally I was able to use most (if not ALL) of the subs generated, even when I was exposing through Halpha or SII for 30-40 minutes per sub. That in it self, I thought, was pretty good for the setup that I'm using... or... I'm just easily pleased. I use a OAG for my exposures so guiding on the same FL as imaging. That said I did spend a bit of time playing with PHD settings, as well as the backlash setting on the CGEM, along with autoguide rates to try to get better guide graph. After a spending a bit of time on both polar alignment as well as tweaking the autoguiding parameters in PHD, I was still getting a graph that showed large jumps, see pics… Nowhere near the near flat line that a few imagers were getting. Although the RMS level at 2032mm did improve, now I’m getting numbers of between 0.83-1.3, so it is definitely an improvement but still didn’t look flat. The test exposures I done at those RMS levels using the 40D at ISO100 on a 40 minute exposure showed round stars and the frame exposure looked good. I decided to investigate to try to improve the graph, and when turning off the guide commands the graph showed large bumps generated by star movement caused by the atmosphere, the graph was very similar, although slightly higher RMS, due to the star moving around obviously due to seeing. At this stage I put my larger graph RMS in comparison to other very flat graphs to perhaps me guiding at 2032mm on a 1/4” CCD and others guiding using a much smaller/shorter FL guidescope where such large seeing related star movements are not picked up at a shorter FL, I base this on the fact that when imaging and guiding while using my 80mm/500mmFL frac where I generally got a RMS of 0.3ish. Using the size of the pixels and CCD on the focal length the results are 0.548 arcsecs per pixel so multiplying that by the RMS I get the guiding is 0.45 – 0.71 arc seconds accuracy (?) which if I’m right, sub arc sec accuracy is OK for AP. I used http://www.celestialwonders.com/tools/imageScaleCalc.html for the calculation. NOTE That until I had decent backlash set on the handset I was still getting intermittent saw tooth like spikes in DEC and RA, and the guide star did spontanously jump large distances periodically. The way I adjusted the backlash on both RA and DEC was by centering a star on the laptop screen and at 1X guide speed moving forward, forward, back, forward, back, back, adjust the backlash and repeat until the star responded instantly. Also my autoguide rate is set at 40% for both DEC and RA. My PHD parameters that seem to give the best guiding at 2032mm are below: RA Aggressive: 50 RA Hyster: 10 Max RA Dur: 350 Search Reg Pix: 15 Min motion: 0.15 Calib Step: 500 Time Lapse: 0 Dec Guide Mode: Auto Dec Alg: Resist Switching Dec Slope: 4.5 Max Dec Dur: 350 Star Mass Tolerance: 1.00 Dither Scale: 0.05 Hopefully some of this helps someone. Also if I'm missing something and anyone has advice to improve that graph, please feel free to share. Clear skies.
