Alexp

Ahhh thank you, sry, I misunderstood the guide rate as per your advice. Thank you, I will try that out. And yes, I will check the focuser and see what I'll find inside! Thanks again very much! Cheers

Thanks for your analysis and input alacant and thank you for having a look at the images. Oddly enough I usually always had a higher guide speed, between 1 and 2 seconds. But just to see the difference I once tried a lower guide speed and then I saw that overall with my AVX seemed to have performed at a lower RMS error. Sometimes I still increase the guide speed before an imaging run to see if the RMS error lowers itself, but oddly enough the RMS error always seems better at that low guide speed. I have a few upgrades planned for the scope, a new spider vane and primary mirror mask with a new secondary mirror holder, a new focuser tube (which one is best for my 150PDS I do not know yet, I'd like to budget around €300 for that), and a motor focuser. I still don't believe the mount is the issue so I'll stick to my AVX after having upgraded and regreased it. I do not know why I haven't thought about the comacorrector being the issue, guess I'll put that one on my to-buy-list as well. I do not want to go and get all of the upgrades at once so I rather thought I'd prioritise based on what item will have the most effect on reducing the egg shaped stars (and since I saw one of cuiv's recent videos about his upgrades to his new newtonian, he also talks about the low quality of the focuser, which led me to think that might be an issue with mine as well). I don't know why I haven't thought about the coma corrector itself 🤔.. I will still have a look at the inside of the focuser but I guess I will get the upgrades for the newtonion just as I feel like doing it. Thank you for your kind words and help! In general I feel quite fine with the images, but I reckon I should be able to do better with these upgrades including a new coma corrector. Cheers and kind regards

Hey guys, it's been quite a long time since anything has happened here because of all this bad weather, but I guess many of us have the same issue in Europe. Anyway, last time I was able to image an object, I went for IC 5146 and gathered around 150 minutes worth of "usable" light frames at 60 sec each. In general, I always have eccentricity issues, my stars are always egg shaped around the corners. I have, unfortunately, no experience or clue whatsoever as to what the problem could be, but I believe from looking at the images that there is a pattern to the star shapes across the images but I wouldn't know what the exact issue in the optical train is so I do not know how to solve it. My setup is a SW150PDS with an ASI533mc pro attached on a Celestron AVX. I believe that I am reaching the limits of the Celestron AVX weight wise but I doubt guiding was/is the issue. For that particular night of imaging I had a total RMS error of 0.73" according to PHD2 logviewer (I attached the guiding log here). I do have a resolution of 1,03"/pixel with the ASI533mc pro and the SW150PDS and from gathering as much information as I can I am aware that achieving half of the resolution as max RMS guiding error would be better, but I doubt that this is the main issue here? The optical train itself - beginning with the camera - is my ASI533mc pro -> filter drawer -> baader MPCC -> screw adapter for baader MPCC to the focuser tube of the SW150PDS. At some point I bought the screw adapter for the Baader MPCC because otherwise when using it with the regular focuser tube it would pinch the baader MPCC, hence the solution was to buy the screw adapter for the MPCC. To find out if the egg shaped stars are consistent over the entire imaging session I compared the stars of the image with high eccentricity (and a low fwhm) with the stars of the image that had a low eccentricity (and a high fwhm) -> the same issue is visible. According to ASTAP there is a tilt in both images, I have attached the image analysis of astap, and also, I have attached the unprocessed .fits files as well in case anyone would want to take the time and look at the two images. I do believe the telescope was collimated well enough when checking with my cheshire. Is there anyone who could be so kind and look through these images and help me find what the issues are? Is the guiding error too high for the resolution? Could it be that the lousy focuser tube has a tilt and I should get a better one or could it be bad collimation? With my current knowledge (and of that I have almost none) I am suspecting something with the focuser tube or could it have something to do with the screw adapter for the coma corrector? I hope I have added enough information for someone to look at and any help I could get would be highly appreciated! Have a nice day in the meantime, all of you!! Cheers, Alex PHD2_GuideLog_2023-09-10_205727.txt L_IC5146_12627_Bin1x1_60s__-10C.fit L_IC5146_12705_Bin1x1_60s__-10C.fit

Thanks! I'll have a look into that and see if changing some of these variables have a positive influence on guiding! Cheers

Thanks for your kind words Simon! I do think I would be able to get the details a tiny bit sharper once I solve the issues in my optical train. As opposed to buying my way out of the problems I always try to experiment, even in hopeless situations, just to see if there is a difference. Plus I am hoping that this way I will understand all the mechanical and software related issues a bit better. I always thought that it would be better to have longer exposure settings in PHD2 but trying it out differently once now really seems to have had an influence, at least for my setup and the circumstances around my setup. I was, however, not aware that it is possible to control more variables than just guiding exposure (guide exposure - correction issued - next guide exposure)? You are also using PHD2 and an AVX? I am assuming these settings are plainly visible and I am just not aware, which most often is the case for me ^^. Cheers, Alex

After many, maaaany months of not being able to image due to bad weather it has finally cleared up over the past month.. Even though there is only little astro darkness currently, I couldn't wait any longer since I really had the itch to image something in the night sky. There have been many pictures of it already, but I also wanted to have a go at M101 with the current visible supernova as I have never yet imaged an event like this. Altogether I managed around 12h of imaging time at 60s exposures in a Bortle 6/7 zone (unfortunately a lot of extra light from neighbours' windows) over the course of five nights with my SW 150pds and ASI533mc pro on my AVX (kind of pushing the weight limit on it for astrophotography). Oddly enough I found that decreasing my guide exposure setting from 2 seconds to 0.5 seconds in PHD2 gave me better guiding results on the AVX overall, which went below 0.8" RMS error. The stars are slightly egg shaped - with my half-knowledge I am assuming that this may be the result of (maybe) the cooling fan of the 533mc pro vibrating and bad collimation. Testing will be necessary to find and remedy the issue(s). After countless hours of integrating 730 frames on my laptop and post processing the final result in PI I believe I have a version now with which I am happy, though I might still try and image M101 with the ZWO duoband filter to add some Ha to this image. Comments and critique are very welcome, hope you guys like it and I wish you all clear skies! Cheers, Alex

Finally got round to image M63 in Canes Venatici, a galaxy I have been wanting to image for a long time, unfortunately we have very bad weather and true darkness is getting shorter and shorter but I guess all of us are facing this problem.. 🙈 All in all, I am surprisingly happy with the end result given the location where I shoot at (Bortle 6/7 suburban, but there are lights from apartments around me everywhere and there is not much of true darkness by now) and the usual blotchiness/red mottling of the background that I am often encountering and still figuring out (probably overcorrection of flats and/or light pollution?). The galaxy was imaged with the 150PDS and the ASI533mc pro with a UV/IR cut filter and the Baader MPCC Mark III coma corrector on my Celestron AVX. Guiding was done with the SW 9x50 scope and an ASI120mc. I really like the FOV given by the combination of the 150PDS and the ASI533mc pro for galaxies. Altogether I managed to get 454x 60sec subframes (100 gain, 13 offset at -10°C) on 15.05., 18.05., and 25.05. Dithered every 2nd shot, 50 flats and 50 darkflats per session as I still keep trying to work out proper flat settings for my image calibration. After blink and further rejections in SFS 239 subframes remained for postprocessing for this image. I used APT for imaging, PHD2 for guiding and PI for image integration and post processing. The processing steps after integration were the following: Linear Processing Phase: Dynamic Crop Channel Extraction LinearFit Channel Combination DBE Background Neutralization Photometric Color Calibration SCNR green TGVDenoise with a mask for noise reduction MMT with a mask for noise reduction Nonlinear Processing Phase: HT to stretch ACDNR with a mask for noise reduction Starnet v2 to remove stars On starless image MLT to reduce background color with range mask Curves Transformation with S-curve stretch for contrast HDRMT with range mask LHE with range mask MLT with range mask to sharpen details Extract lum and use with LRGB Combination to increase saturation Minor Color Saturation with range mask MLT for noise reduction with lum mask On starmask Curves Transformation for saturation MT to reduce star size On Final image Pixel Math to combine starless image with star mask Topaz Denoise for noise reduction, which may have introduced some artifacts but only if zoomed into the picture Thank you for looking at it, I hope you like it, comments and critique are of course very welcome! Clear skies to all, Alex

Since this challenge is about Galaxy clusters and I just finished working on Hickson 44 I thought I'd add mine as well even though all the images here are really, really amazing to look at. This was the first time I used the ASI533 on a Galaxy cluster, I have had the camera since three months now and I am really happy with it. This galaxy cluster was shot with a 150PDS sitting on an AVX and an ASI533mc pro with a ZWO IR cut filter. Guiding was done with an old ASI120mc and the SW 9x50 finderscope. I shot a total of 12h 15m, of which I used 10h 57m, all shot on 20.03., 21.03., 23.03., and 25.03. The light frames were 180s @ 100 gain, 13 offset, and -10°C, dithered every shot. All of the frames were shot in a Bortle 6/7 sky, unfortunately there are a lot of windows with lights on in the night (what are they all doing if they aren't shooting the night sky??). All of the processing was done in PI. Integrated with local normalization in Pixinsight, in the linear phase I did a dynamic crop, followed by channel extraction, linear fit to the weakest channel, DBE x2 to remove gradients, TGV denoise and MMT based on Jon Rista's tutorial. For the non linear phase I stretched the image with HT, inbetween stretching I used ACDNR for some further noise reduction, followed by starnet v2 to work on the starless image. On the galaxy cluster I used HDRMT twice with different settings, then LHE, s-curve stretch for contrast, curves on saturation and selective color boost using colorsaturation. MLT with a lum mask to sharpen details, saturation boost on stars, followed by pixelmath to combine the starless image with stars. The final step was MLT with a lum mask for noise reduction. Clear skies to all and once again, all of the images here are amazing!

I think this is one of the nicest M101 images I have seen. Looking forward to seeing the version with added L and Ha.

You're welcome. Your image is honestly really nice and has a great amount of detail. I hope to be able to produce similar images sometime in my life ;). Hopefully sooner than later. Ah yes, I barely noticed UGC 5086. For 2h worth of lightframes I'm quite happy with the result, I plan to add more data to this stack to hopefully get some more details but I was not really expecting this for 2h. Thanks for the tip concerning EZ suite, I have not yet used it and I will look into it, thanks for the link. Cheers

This is my first time finally posting an image here that I'm somewhat happy with 🙃. Managed to get 2h @60s exposures of NGC 2903 with my ASI533 and my SW 150PDS on an AVX. I tried this target already a week ago but I ran into weird issues with overcalibrating flats and walking noise. Thanks to help of @wimvb who pointed me into the right direction I was able to mitigate these issues now with this set of lightframes. The only issue that I still have remaining is the background, which seems kind of patchy blue and reddish over the picture. I'd believe that may result from a combination of the light pollution from where I'm shooting at (Bortle 6/7 suburban, lights from windows all around my setup), and a somewhat sloppy way of creating masks for noise reduction (following Jon Rista's noise reduction routine in PI)? In any case, I am glad that I was able to resolve the walking noise and flats-overcorrection issues with some help so I can continue to improve at taking and at processing deepsky images. It's certainly not as detailed as @DaveS' or @tomato's beautiful versions of this galaxy, but the galaxy itself already does a great job at looking nice 🙂. Cheers

My laptop just finished integrating M1 from the same night with the same flat frames and the same dithering settings. The image is stretched a bit more than NGC 2903 but both overcorrection from the flatframes and the walking noise is still visible. I will now try and calibrate the light frames with the new flat frames to see if this problem will be mitigated then, which also means that only walking noise should be left and that problem I can only resolve in the next imaging session. Cheers, Alex

Thanks for the tip. Currently image calibration is running on M1 that I shot the same night. If everything is as it is I should be at least able to see the same issues there as well with the same flat frames and with the same dithering settings that I had. This may be seen as unnecessary but I want to see if I have the exact same issues there. I will afterwards blink the pre registered images of M1 and NGC 2903 to see if the stars drift in any one general direction as second confirmation. Concerning your tip with the t-shirts, I did exactly as you said shortly after I wrote my last comment. With three t-shirts I at least managed to get the flat frames to 0.14s and I already shot the corrseponding darkflats at -10°C to those as well. I did not move anything in the optical train since having shot both targets so I assume the new flats should also work. After reproducing the error on M1 and after blinking the images I will try and calibrate the light frames with the new flats and darkflats to see if only the walking noise is left. I thank you for your input so far! Cheers, Alex

You may be right there. I believe it's either that or the camera may have also been completely overexposing? Either way it would be interesting to find out how the camera is connected to the scope

I am honestly not sure how well your setup will work together with a DSLR camera and how much knowledge you have already built up in astrophotography. Afaik your mount is not motorized, which means you will not be able to take long exposures as your mount can't track objects in the sky automatically to counter Earth's rotation. I guess it depends on what you want to shoot? Maybe it is possible to shoot some objects by taking many and quite short exposures (half a second --> if you are not familiar with the 500 rule, google it to find out what that is, your camera has an APS-C sensor which means you must take a crop factor into account for the 500 rule), but I am sure there are many more qualified people here that may have a better answer than I have. Apart from that, how is your camera connected to the scope? Are you using something like this 2" adapter or this 1.25" adapter? If the screen is blank does that mean black or white? It seems like you may be overexposing completely or are shooting in some other mode than manual? If you want to delve into astrophotography, you will always take pictures in manual mode. Concerning the ISO of your camera it depends I guess. With my scope and my tracking mount, when shooting objects like galaxies or star clusters I was able to take 180 seconds exposures with ISO 400 or ISO 800. If you want to take pictures of the Milky Way, you will need a much shorter focal length and shoot at a higher ISO. Also, set the focus to manual instead of automatic. Before you actually start taking any pictures, it's important to be in focus of course. Here it is quite helpful to google Bahtinov mask. Apart from that you can simply try liveview and change the focus until you believe you have the smallest stars on your screen (I'd say though this is the least effective mode on achieving focus). If you are not yet familiar with astrophotography you should also google image stacking and calibration frames, there is tons of information available and many programs (Deep Sky Stacker, for example) are free to use.

Come to think of it, since I updated APT and lost all my settings, it is highly likely the dither settings were reset and unfortunately I do not remember to what I had changed the dither settings to before updating APT.... I guess I'll research this again to work out the proper dither settings with my guiding setup resolution and my imaging resolution. Since my guiding setup image scale is 4.3 arcsec/pixel and my imaging setup image scale is, as you already mentioned, 1.03 arcsec/pixel, I left the PHD2 dither scale at 1 and set the APT dithering distance to 4. If I am not mistaken this should move the scope around 12 pixels (= (4.3/1.03)*3) when dithering, which I hope should be enough. Cheers, Alex

Thanks Wim for you input! Oddly enough this is how I have been doing everything so far and it has worked out up until now. I guess I'll try and change that somehow. I am working with a flat panel, but unfortunately with one that cannot be dimmed, hence the short exposure time. I guess I'll try to find a workaround to use the flat panel and still increase the exposure time on the flats. I guess I'll try the WBPP and check out Adam's video as well, thank you! I forgot to add that I have been dithering every third shot as well. I do not have the numbers on dithering distance in my head but I have worked with this way up until now and also not have had this problem yet. I do have to crop the sides of the pictures because of dithering so I assumed up until now that the dithering steps were fine. It seems I'll increase the dithering distance and I will also dither between each shot. Also here thanks for the input! My train of thought was to drizzle so I can increase the dimensions of the pictures in case I'd like to print them out on e.g. A1 format since I thought the 9mp resolution of the camera is rather low. But to be honest I am not really sure if my train of thought is correct here or not o_O. I still find it very odd that the way I have been shooting images has worked so far and now suddenly it doesn't anymore. I have attached a picture of M1 here to show the difference (there are other issues in this picture, but definitely not the same issues as the ones I am currently having with NGC 2903) Thank you very much for your input, I will try to somehow dim the flat panel to increase the exposure length and I will start to dither between every frame and increase the dither distance. Cheers, Alex

Hey guys, I require some help here as I unfortunately do not know what the issue is or how to resolve it :/. Recently I shot 185 frames @60 seconds, 100 gain, 13 offset and -10°C on NGC 2903. I am using a SW 150PDS with an ASI533 mc pro, a Baader MPCC Mark III with a screw on adapter to the SW150PDS to avoid the potential tilt of the MPCC. All of this is sitting on an AVX. With that I also shot 50 flat frames (I used the CCD flats aid in APT and set the target ADU to 19000) and 50 darkflat frames. In this case the flat frames and the darkflat frames had a length of 0.0062 seconds. Master dark I used from my dark library (50 darks, same length, gain, offset, and temp as lights). Since the ASI533 mc pro is very new - I am using it since two months only - the dark library should still be very fine to use. Since I have the ASI533, this is the way I have always shot targets and so far this has always worked. Due to bad weather though, i only have two other finished pictures on the Crab Nebula and the Iris Nebula but everything has worked out fine with imaging and creating calibration frames this way. For anyone interested, here is a wetransfer link to the .xisf file. Due to the filesize I have only uploaded the non drizzled master light, the issue is still the same though. After having done calibration and integration of NGC 2903 I ended up with a horrible result (I used Dynamic Background Extraction on it, then stretched it and saved as JPEG to make the issues visible) that I have attached to this post. I am highly assuming that something is not working correctly with the calibration frames as I can see remaining dust motes and a horrible lot of noise... I hope there is someone here who could maybe point me in to some direction as to what I may be doing wrong. I believe that either I have done something wrong in APT with shooting the flat frames or something in the calibration and integration process is wrong. Although the only thing that really "changed" recently is that I updated APT to the newest version and therefore lost all my settings.. If anyone could help me here and point me in the right direction I would be very thankful for any help! For image calibration and integration I usually do the following steps (part of it comes from Kayron Mercieca's excellent lightvortex astronomy site, part of it comes from Linda's Youtube video on calibrating with darkflats: integrate darkflats to make a master darkflat combination: average normalization: no normalization weights: don't care rejection algorithm: linear fit clipping normalization: no normalization uncheck evaluate noise uncheck clip low range calibrate flats with master darkflat uncheck master bias and master flat use master darkflat as master dark uncheck calibrate and optimize integrate calibrated flats to make a master flat combination: average normalization: multiplicative weights: don't care uncheck evaluate noise uncheck clip low range rejection algorithm: linear fit clipping normalization: equalize fluxes calibrate light frames with master dark and master flat uncheck master bias use master dark from dark library uncheck calibrate uncheck optimize cosmetic correction on calibrated light frames debayer light frames run through subframe selector to reject some lights and put weights on the remaining ones in this case I ended up with 164 light frames to use out of the 185 I shot run the weighted lights through star alignment (also create drizzle data, rest of settings are standard) create local normalization files, standard settings integrate light frames with drizzle data and local normalization data combination: average normalization: local normalization weights: FITS keyword leave evaluate noise checked rejection algorithm: linear fit clipping normalization: local normalization uncheck clip low range use drizzle integration afterwards on updated drizzle files with local normalization files This usually gives me an image file to work with. First thing I then do is Dynamic Crop, then Channel Extraction and LinearFit to the lowest signal channel (in this case it was the green channel), before moving over to Dynamic Background Extraction, where I am having the issues in this case. I hope that I am simply missing something as it would be sad to not being able to use these light frames at all! Cheers, Alex

Hahaha, I agree. It looks and feels more like glue 😅. I've already reassembled the RA axis and readjusted the worm gear to fit the ring gear. I left the nylon washers out between the ring gear and the tapered ball bearing, but I greased everything without using the entire tub.. I'll see how it goes and if this'll help balancing and/or if there is a negative or positive impact on the backlash of the RA axis because of the readjustment. Now only to wait for clear skies... Thanks again and cheers

Thanks you two for the input and the effort! Reading both your comments I just tried a little bit of both. First I degreased the small seam between the ball bearing and the spindle. Then I tried to carefully lift it with a plastic tool that is similar to what you suggested. That didn't work so I started looking if the ball bearing might have shifted a little bit. It didn't look that way so I carefully used a rubber hammer on the ball bearing to see if it may have been shifted. What ultimately helped was turning the spindle 180 degrees upside down and - I was not a huge fan of that - using force and knocking it on a piece of wood finally made the ball bearing come off. Now I will be curious to see how the nea tapered ball bearing will fit. Btw, I attached a picture after I have opened up the RA axis the first time. I do not know which grease they used but the amount of grease used was rather... generous 🙈. Guys, I thank both of you for taking the time and helping me remove the ball bearing from the RA axis! Cheers to you and clear skies

Hi all, I have tried to find and read as much as I could find on disassembling the AVX, adjusting the gears and cleaning and regreasing everything. In general, my AVX works fine - it used to work quite fine before opening it up, but it does work better now. Except for taking apart the worm and ring gears in the RA and DEC axis, I cleaned the gears, relubed them, and adjusted them as best I could to remove backlash. Best I could get by now is .61" total RMS error in PHD2. On average I am seeing about .85" total RMS error, which should be fine considering my imaging scale (SW150/750pds and Canon eos650d - 1.19arcsec/pixel) and as long as there aren't too many outliers in guiding corrections. From the experiences of others that I have read about I believe these numbers aren't too bad for an AVX mount. Nonetheless, bad weather doesn't currently allow for imaging and I wanted to continue working on the mount in the meantime. Besides, tinkering with the mount and getting to know it better can't hurt anyway and is actually quite "fun". I ordered a tapered roller bearing to exchange the old ball bearing in the RA axis (Timken 32007X). I disassembled the mount and took the RA axis out of its housing but I unfortunately found out that for some to me unkown reason I cannot remove the old bearing and the ring gear from the RA axis, no matter what I tried. In all the forum posts and pictures and in all the videos it was never really shown how these two parts were taken off and I assumed they could just be slipped off the RA axis, yet it wasn't possible in my case. Since these parts seem to really be stuck in their place I wouldn't think that the grease inbetween has become so sticky that I cannot remove them. Is there anyone here that has experienced something similar and how did they solve the problem? Or am I missing something or have I forgot something when trying to remove the old bearing and the ring gear from the RA axis? Any help would be greatly appreciated! Cheers and clear skies

Hi there, I hope that this odd thing will help you and if so, I hope that more people will find this as it took me quite a while to figure this out, but maybe I am just a slow learner ;). Good luck on this and do let me know! Cheers

I had the same issue while creating a dark library and bpm. When there was a video running in the background while using PHD2 and after I was done with my session I turned the video off and on a few times to see if this has an influence on PHD2. And surprisingly it did. Everytime I turned off the video lagging started up until the point where the camera got disconnected. When I turned the video back on PHD2 ran smoothly again. If you ever tried this out, I'd be curious to hear if this quick notfix with running a video in the background would help you as well but if you rarely use a pc then I guess it won't be that important :).

Hi everyone, long time lurker here, but now I thought I'd mention something here. I have not had the time to use my telescope setup in years but I am finally taking the time to catch up again on everything. Currently I am using a Celestron AVX with a SW 150/750pds and a 9x50mm finderscope with the old (untrusted it seems) ASI 120mc as guide cam. I am connecting my entire setup to a Lenovo Legion laptop with Windows 10. I am writing this here since I have encountered an issue with PHD2 and my ASI120mc and I have found some odd solution from other threads to another product here and over at cloudynights. I am quite new to all these problems and problem solving so please excuse me using a lot of laments terms as my knowledge is very limited here. Anyway, my guide cam always keeps losing connection when trying to use it in sessions and I kept receiving a message from PHD2 something like "An image has not been acquired after XX seconds so the camera has been disconnected". Sometimes it was working for a little while, but PHD2 kept "lagging" resulting in very poor guiding, but ultimately the connection to the guide cam was always lost. I have found a few topics on this in forums, most often suggesting turning off automatic USB power management to the USB ports (did that), disabling C states in BIOS (not an option in my BIOS), updating firmwares and softwares of all the relevant programs and cameras (did that), getting a powered USB hub (have that), switching to 8bit mode in PHD2 (did that), using USB 2.0 instead of 3.0 (did that), etc. etc., or simply giving up and getting a new guiding camera. Except for the last "solution" I have tried out everything I could but nothing has worked. At the same time, my QHY polemaster also kept dropping frames. When I searched for this issue I found a few topics where others have mentioned that the problem here has to do with the USB power management/savings from Windows. In these topics others have mentioned that a weird way to resolve this issue is to have a video, or a Youtube video run in the background on your laptop while using the polemaster software as this somehow stops the USB power management from changing the power supply to the USB ports. I have tried this and suddenly the polemaster software started working flawlessly again. As it seems that QHY and ASI both are using similar hardware components in some if not many of their cameras, but moreso as this seems to be an issue with the USB power management I thought I may as well give PHD2 with my ASI120mc another go while having a video run in the background. And suddenly PHD2 is also working flawlessly without losing connection to the guide cam! This is not a perfect solution but it does work. I have searched a long time for solutions to both the PHD2/ASI120mc and the QHY polemaster software problems but whereas I have found this video solution to the QHY polemaster, I have not really found this odd approach as a suggestion to the PHD2/ASI120mc problem. So I thought I'd post it here just in case there is anyone else that encounters the same problem and did not find a solution other than maybe buying a new guide camera. Has anyone else encountered this issue with the ASI120mc and resolved the problem in this same way? Cheers