Radu Marinescu

Hi and thank you for the reply. Very interesting things you said here, however something seems wrong. Let's start with specs: - EQ6R-Pro Mount (I haven't performed mechanical adjustments for backlash yet because the nature or my issue is definitely different, backlash doesn't seem to make your DEC drop to infinity basically) - ASI120MM-Mini guide camera - SkyWatcher 250PDS (I know it's a heavy telescope but again, other people still managed to achieve <0.5" total RMS constant guiding even with this setup, the problem is somewhere else) - The mount is connected directly to my laptop (Asus) using a USB-B to USB-3 cable from the port of my mount, the power supply was recommended by the store and fits the specs of the mount. I am using NINA for slewing and plate-solving, PHD2 for guiding and Green Swamp Server as alternative for EQMOD. Now, to your points: "The mount is reporting RA and Dec position, but no mount driver" - seems to be an error because I have a mount driver. I have installed latest Ascom Platform Driver and the mount was instantly detected by both GSS and PHD2 using the new profile wizard. The guiding speed in PHD2 was automatically set to 0.9 after the mount was detected. "1. You were pointing at Az = 256.8 deg when you Calibrated. Near south is recommended Az = 180 deg. Unless you're in the southern hemisphere ?" - I am in the northern hemisphere and slewed to Betelgeuse (which was very close to the intersection of Meridian with Equator. I have absolutely no idea ehy that az value of 256.8 was logged. Unless somehow PHD2 calibrated after I slewed to Bode's Galaxy (with apparent meridian flip) :-? I am really not sure about this. "2. You don't appear to have cleared Dec backlash before Calibrating, by pulsing north until you saw the guidestar actually start to move." - This actually I have no idea how to do. The mount's backlash was never adjusted and I am reluctant to do that unless absolute necessary because stores in my country are very picky about warranty. If you are speaking of a software backlash compenstation or something similar, I am new to this and really don't know how. "3. Your Cal had a noticeable Orthogonality Error that wasn't reported, because you had "Assume orthogonal axes = yes"." - Here again I don't understand again. "4. Your Guide Rates are very low, RA Guide Speed = 4.5 a-s/s, Dec Guide Speed = 4.5 a-s/s," - Seems to be another error, PHD2 automatically selected guide speed of 0.9 and GSS has both RA Guiding Rate and Dec Guiding Rate to 90%, although I also see here some "Minimum Dec Pulse" and "Minimum Ra Pulse" both set to 20. I don't know what these are. The location settings in GSS are accurate. "5. Your exposure was 5 seconds, which is very slow. What did the Guide Assistant recommend ?" - Another possible error, PHD2 is set on 2s exposures, I have opened my guiding assistant results after calibration and confirm 2s exposures was selected. The assistant does indicate a large declination backlash and recommended me to set "RA min-move" to 0.13 and "Dec min-move" to 0.20 and recommended that I might need to guide in one dec direction. So in conclusin there are some things that I don't really understand, why the calibration position from the log is not near meridian where I phisically calibrated (using a slew and center from NINA on Betlegeuse), why the driver doens't seem to be recognised and logged guiding speeds are different than what I set up. I don't really know what to do next.

Hello. I have a pressing issue that for some reason my guiding will not work properly. It seems like the declination graph is going absolutely nuts, sometimes fades away in total 300" error RMS while the right ascention graph stays settled into values like 0.5". What is very weird is the fact that after many attemts at restarting the mount or PHD2, the guiding started acting perfectly for some time, total rms of about 0.5" on both axis. And then I started imaging in NINA and well, the first dither went well, but after the second didther the DEC went nuts again. I again reconnected everything and the issue still occurs. I have attached screenshots of my guiding working as expected then DEC suddenly running away. I know this mount has backlash issues, but I don't thing they would ever cause this infinite going drop. It's simply like the mounts stops tracking DEC altogether, the stars drift visibly inside PHD2 image looping. Can it be some power issue or lack of proper comunication between PHD2 and the mount? What can cause this issue? Thank you in advance. PHD2_GuideLog_2019-01-05_222245.txt

Thank you all for the comments!

Hello, Researching astrophotography and post-processing made me experiment with different techniques on sample images I found on the internet (I have yet to take a deep space image myself since I'm still waiting to complete my rig). As far as star size is concerned, I noticed that every photographer out there struggled with this issue at first, especially if your gear is not high-end and your photos will result in blurry objects/big stars. Even with focus off by a few microns, it becomes more and more noticeable. I've seen many people trying out different softwares for automated star size reduction, or using Photoshop and playing out with masks and levels. But I have not seen a single person online trying out the Liquify tool to manually reduce the size of the stars (doesn't mean I am the only one to ever try this out but seems nobody posts about it). I used that feature in the past for different funny edits and it struck me how well that'd work on this topic so I decided to try it out. Of course, the entire process is manual, you have to go over and shrink every star in your photo with a mouse press, but as far as I can see, it's getting far better results than any software or AI that does that for you. I uploaded a sample shot and a grid to show the amount of shrink that I manually painted over every star. Evidently, it will be a pretty hard and long-lasting work to go and shrink every single star in your image but the red grid will help know which stars you've already shrinked. I let you be the judge of these results and if you think the effort pays off. BIG DISCLAIMER: The sample image as I mentioned before is NOT MINE, I was looking for a random image on Astrobin.com to only test my little discovery and just as random, stumbled upon this extraordinary shot. The entire credit of this image goes to Bert Moyaers / https://www.astrobin.com/7pxliz/?q=EXOS-2 PMC-8 .

Hello, fellow astrophotographers. This summer I plan to finally kickstart my serious astrophotography hobby after years of shooting only wide photos of the Milky Way. I own a stock Nikon D5100 and this will be my main camera. A week ago, I had basically zero knowledge about dso astrophoto gear, being used with camera lenses I was so new into this that I didn't even understand why telescopes are described by two mm values and I couldn't find the f-stop in their titles. I spent a LOT of time this past week in learning and here is the gear I added in my wish-list so far: First things first, the camera that I mentioned earlier, the Nikon D5100 -> I was thinking about modding the battery port of the camera to allow me to keep the multiple batteries attached to a tripod leg and have wires connect them to the camera, which is an effort to prolong the shooting time and decrease the weight of the camera. William Optics ZenithStar 73/430 -> Looks like very good quality optics and sharpness, has a focal length good enough to shoot many galaxies and seems to have decent aperture. I've seen people using this one even on portable mounts like the iOptron SkyGuider Pro. As an alternative I would go for something similar from SkyWatcher. ZWO Camera ASI 120 MC-S Color & Artesky Guidescope UltraGuide MKII 32mm -> As I understand, guiding is almost as important as the mount since if offers precision for longer exposures and assures smooth tracking. These two seem like a good combination. Now my biggest concern is the mount itself and is something I don't want to spent more than 1k euro on. As I mentioned earlier, someone was using a SkyGuider Pro with a similar configuration, but to me it seems that it's reaching the upper limit of that tracker and if I'll want to invest in a bigger telescope afterwards, it will probably fail in overweight for this one. It is really important that the mount offers an ST4 port to allow the guider to send commands to it. I've read about the EQ5 from SkyWatcher but it seems an autoguider cannot be connected to it without further motors and upgrades to the mount. I am looking for something that can be used out of the box. Another topic that I'm not sure about is the GoTo function, which seems to have no effect on actual tracking or guider compatibility, it's just a little help in finding those dsos in an instant. Can anyone confirm this, because if the GoTo is not mandatory for tracking and guiding, I wouldn't spend more money just for that. All these things mentioned, what mount would you recommend for me and help me get 3-5 minute exposures withe the guider connected? Thanks!