johneta

I'll try PEC with EQMOD next 😬

Yeah AstroEQ seems great. I converted my SW EQ5 mainly to try and tame backlash and get better RA accuracy. Backlash improved alot (still bad because of worm gear though) and RA figures in PHD are OK now, and more importantly more stable overall, so I did my first 2 nights of imaging with the new kit and only had 1 bad shot. (5min subs) I certainly recommend it, although there is a heck of alot of little hurdles to overcome to get it running. Thats Astro I guess though.

Agreed I thought the same. Good to be on the learning curve. Makes it more fun, if a little taxing.

Thanks again everyone for the great advice. I've got it sorted now. Yay! As I mentioned I am just newly running AstroEQ with EQMOD and Stellarium. And I have used it successfully with PHD. The problem was my motor direction was the wrong way 🙄. So the AstroEQ is brand new, (originally inspired by almcl in another post) I have built and installed the electronics and the stepper motors etc. I had the guiding working well with PHD. Next step was to get GOTO working. In the AstroEQ Config settings you can choose the directions of the 2 motors (forward or backward) as of course initially the software doesn't know which direction they are rotating the mount. I took a stab at the direction that seemed right. When I came to testing out the GOTO - because of my lack of understanding about RA/DEC coordinates and the initial slew movements away from the polar position, -that initial movement away from the SCP seemed like odd movement to me and really threw me. It looked like it was going the opposite direction toward the star that it should. So I updated the Config a few times, reversing the direction of the motors, both together and individually. But I couldn't see a movement that seemed sensible to me. So I chased my tail for a bit until your explanations of the initial 6hr difference and the mount slewing 90degs in RA if aiming at an object on the Meridian etc. I found I needed the RA motor Forward and the DEC motor Backwards and all came right. I synced 4 or 5 stars easily and GOTO was very accurate. So thanks again, your help is much appreciated. When you're going round and round in circles it can seem impossible at times. I hope some of this can be of use to others too. Regards John D

Im at work so cant give it to much thought at the moment, but I was doing that GOTO last night and was always way off. Will try again

Thanks Merlin 66 -- when you say RA of EQMOD and cdc always match - what does the RA match to? The meridian hr line from the CP to the ground? symmetal-- I partially understand what your saying. I will read again later. - So if I choose my first star to sync with and its 6hrs wrong and I correct it in eyepiece, and then sync it, will this big 6hr error be a problem? I assume the second star I choose will be substantially more accurate, and the third more so etc? Note my PA is very good as I have a permanent setup.

I had a thought. I seem to be out about 5hrs. I was only taking rough readings to speed up the process. if its more like 6hrs out then 6hrs is 1/4 of 24hrs. And 1/4 of 360degs is 90 degs. Is home position - counterweight bar horizontal - 90 degs difference. I will check out.

OK that makes sense. I just dont understand how the mount knows what hr line its pointing at because as almcl said- all the RA lines combine at the SCP. Heres an example of what I was playing with (without success) tonight: Im at S 45 52' odd and E 170 35' time was 10 30pm local time. So when I look at Stellarium, the meridian running from SCP to the ground (South) is about 8hr The line going up North towards North Pole is around 20hr. Stellarium tells me the star Fomalhaut is at 22h 58m. -29degs 31' So I start manually slewing to those coordinates in EQMOD watching the eqmod readout and watching the mount is going the right direction. Home position says -Dec 90 degs and RA 2hrs odd ( but as above this RA figure is meaningless at the SCP?? ) I slew some way toward Fomalhaut in DEC then I slew a bit in RA, in the direction of the star. As soon as I start slewing the RA in the direction toward Fomalhaut, the RA figure in EQMOD jumps to 14Hr odd. It makes sense that it could jump as it is now on a RA line away from SCP. BUT I dont quite get how it knows what that should be. --from LST I guess. Any way, I slew to DEC -29deg 31' - looks close. Then I slew in RA but I get to around RA 18hr and the star is lined up. Stellarium is telling me it should be 22hr 58' about 5hr difference. BUT DEC seems to be bang on. Also the EQMOD readout is telling me that the scope is east side pointing west I think?-(gear is packed away now)--but Im actually the reverse In my mind there needs to be some sort of calibration to tell the mount where to start the RA hours and also what side of the mount the scope is on. Sorry for all the detail -its hard to explain all this in words.

Thanks almcl -"Yes to the first bit (Dec 90) but at Dec 90 all the RA lines meet (see image below - northern hemisphere but the principle is the same) so any RA is correct if you are pointing directly at the pole:" So essentially the RA reading given by EQMOD at park (pointing at Pole) is random. I should ignore it and just give it a try - GOTO an object?

Hi Ive just started using EQMOD with AstroEQ, PHD2 and stellarium. Everything seems to be talking OK but I dont understand the home position. Im new to using DEC and RA coordinates also. -I think home position is facing South (Im in southern Hemisphere) along Meridian line, and with weights bar straight up and down. -Polar Aligning position So thats DEC 90degs and RA is the Hrs that are currently at my location for the date and time of day. I can get this off stellarium. But when I look at the Current RA in EQMod it differs from Stellarium. (I have checked and both are set to the same Lat/Long and date/time) For example, When I just checked, stellarium said it was around 1 Hr 50 mins But EQmod (after just parking it) says mount is at around 19 Hr 50mins--this RA line goes through about East at this time on Stellarium. Am I missing something or is there somewhere you can recommend I go to read up on this in order to learn me good Thanks very much John D

Thanks for the suggestion of pics Blue Straggler. I have now spent an embarrassing number of hours on stacking these images and trying different options. To cut a long story short.. My original problem of not being able to take Autosave straight to PS doesn't seem to be too much of an issue now. I found that once I started to really stretch and add saturation to the image that some bad posturizing started appearing and I could not get rid of it so any further editing of image was pointless But I stumbled across a weird issue in my PS. At a certain zoom level (Wider View) while I was editing the posturizing was visible BUT then when I zoomed in just one more click the posturizing dissapeared. This made me think of saving the image as a 16 bit tiff file at this stage and see what happened. When I saved the image it had NO posturizing and was clean and smooth. So the Weird artifact is added by PS just at certain zoom positions but is never visible in the saved image. A workaround would be to save the image early on in the editing phase and reopening it (16bit Tif). Then it edits as if its a normal image. It may be a bug/quirk of PS when you convert the image from 32bit (from DSS) to 16 bit when you first bring it into PS ?? So anyway now I find that editing an Autosave and an adjusted DSS image with settings embedded, give about the same outcome when adjusting in PS. Bringing a AutosaveFits DSS image into Fits Liberator and then bring the R,G,B images into PS and combining them into an RGB image is similar but for me slightly worse (I did struggle getting good contrast in Fits Liberator when I stretched mages though) So all in all I can now not see much difference in the 3 different methods. Although I would pick this one --Do very basic adjustments in DSS, save as a 16bit tif with adjustments embedded and used, and then edit in PS. It can be very hard to do comparisons sometimes due to the time it takes to stack and edit. You can get pretty lost in the middle of it all. Thanks for the suggestions. Here's the images I was talking about. Its of a Dark nebula close to the southern cross pointers (I'm in New Zealand). I found it a pretty hard subject as its quite dim and hard to pluck out detail in amongst the sky glow. I use an Orion 8" F4 Newt but I haven't got a coma corrector yet so please excuse the nasty stretched stars away from center. Camera is Canon 1200d(Rebel T5) unmodded. Image is about 1hr 40mins of lights total (Dithered). No darks, No Flats, No Bias Image 1. 1 x light image unaltered (of the 24 or so). Image 2. Stacked in DSS, Basic adjustments made and embedded and used in saved image, then edited in PS (1st FAVORITE) Image 3. Stacked in DSS, Autosave saved in Fits format, Autosave brought to FitsLiberator, FL opens it as 3 separate R,G,B greyscale images then you stretch them there and save each one as a 16bit tiff,then bring into RGB channels of a PS image and combine them to create an RGB image. Then just normal PS editing. (3RD FAVORITE AS I HAD ISSUES GETTING GOOD CONTRAST ON SEPARATE RGB IMAGES-I COULD PROBABLY DONE BETTER WITH MORE PRACTICE ON THIS ONE) Image 4. Stacked in DSS, Autosave saved in 32bitTif format, Brought into PS, converted to 16bit with Gamma and exposure setting, then edited in PS as usual. (2ND FAVORITE - THIS SEEMED ESSENTIALLY THE SAME AS IMAGE 1 BUT I DIDN'T FINISH IT OFF VERY WELL AS I WAS GETTING SICK OF IT AT THAT STAGE. IF I WAS FRESH I THINK IT WOULD HAVE NETTED THE SAME RESULT AS IMAGE 2) Image 5. This is a screenshot of image 4 showing the posturizing I mentioned. As I said this weirdly dissapeared when I either zoomed in a bit or saved it as a jpg or tiff

OK I will do a couple and post in next couple of days

Hey thanks alot. That really is a missing piece of information. I haven't seen anyone else mention that. Makes a lot of sense. I had a play and did it a similar way that you described and yes it works well !! Yes it is horrible to use but you only have to do a few things on it and your done I guess. I've got the methodology sorted now so I will practice it and it looks like it will give good results. It really surprises me that so many others don't seem to know about this, but it seems like a crucial step. Thanks Again

MM interesting. 'save as three RGB 16bit files for PS' -- are you doing RGB seperate captures?? I use DSLR at the moment, could I do the same but save as a single 16bit file for PS.

Thanks Bright Giant I did catch a setting or 2 in DSS that was helpful, so thanks for that. Most important was dont tick "set the black point to zero" in 'RAW/FITS DDP settings' or you can get a very dark image that no amount of stretching will fix. I restacked an image over and over again with different DSS settings and bringing over to PS with or without settings embedded in the 16bit tiff, but the best image is always with basic settings done in DSS and embedded in the image. Im disagreeing with the majority on the net (hence my frustration) but its the only way I can get the better image. Thanks again

Thanks Blue Straggler I have tried this again. I restacked an image over and over again with all sorts of settings in DSS and brought them over to PS, with or without settings, and I still think its better to do basic adjustments in DSS and embed the settings in the 16bit Tiff image. I know Im disagreeing with most suggestions on the net (hence my frustration) but its the only way I can get the better image. Thanks again

Another update Alan. I found a "set the black point to zero" tick box in DSS 'RAW/FITS DDP settings' was ticked. If you have this ticked and dont take care adjusting histogram in DSS it can create a very dark image that no amount of stretching will fix. I think it should always be unticked. I also went back and re stacked an image over and over with different settings and taking it to Photoshop with or without embedded adjustments, and I agree with you it is always better to embed the adjustments -- being careful to do them subtely in DSS first. Thanks again

Thanks. When you say 'save a 16bit tif with embedded settings, it should be dark' Do you mean do some adjustments and then save or just save with no adjustments

This is an old post I know, but I disagree with the 'dont adjust in DSS but rather bring across to PS and do the stretching etc there'. ---I cant get this to work. I have to stretch it so much that the image gets very noisy and ugly. Also when I try to add saturation to the monochrome looking image, I just get an overall hue to the image-- no individual colors. I'd love to hear a possible thing Im doing wrong as I can only get it to work if I stretch/saturate in DSS but then DSS is noisy and adds artifacts. Note: I have recently tried trial versions of APP and Pixinsight and easily got noise free bright images with plenty of color. Help Please. Thanks JD

Hi stonedunicorn I have the same issue as you (although I have around 2-5 min exposures). When I bring the DSS stacked image to Photoshop it is dark and monochrome looking. I have to stretch it a huge amount and it gets very noisy and ugly. I try to add saturation, but as it looks monochrome all I get is an overall increased hue to the whole image--no individual colors. I have seen many people on the net say to not adjust curves/saturation in DSS which makes sense, but it never works for me. The only way I can get it to work is to adjust curves/Saturation in DSS and then bring over to Photoshop. But DSS is not great for that and introduces noise and artifacts to the image. So I cant understand how many people make it sound so easy. If you have got an answer to this issue please post it here as I would love to know. Also note I have recently tried trial versions of APP and Pixinsight and was able to easily get good brightness without noise, and good color in my images. Thanks JD

Thanks Alan. Same for me, but I still feel results aren't that good and I was hoping for better the other way. I also recently tried Trial versions of APP and Pixinsight and was able to get significantly better results quite quickly (not withstanding steep learning curve) Cant afford that at the moment though. Also note, I can get better results by stacking manually in Photoshop. I get very smooth noise free background with virtually no noise and no odd artifacts. John

I have been using DSS for a couple of years now and have never really been happy with it. I do the stack and end up with the mostly monochrome image that seems normal for DSS. Also the auto brightness settings on the stacked image are usually way over stretched. Both these issues are easily fixed with the controls in DSS. (for the preview image) I have been saving the image with these settings embedded, and opening it in photoshop. I can get OK-ish results but DSS seems to have lots of artifacts and is quite noisy. People on the net say not to use the saturation or level controls in DSS but to do all that editing in Photshop (or similar). Just save the the unstretched, un-saturated image, and use that. Sounds like a good idea, but I have never been able to get that to work. The image is very dark, and any amount of stretching required is huge, and gets very noisy and horrible looking. Also the image looks monochrome to me, and when I try to saturate the image all I really get is an overall colour hue to the image. No individual colours in different parts of the nebula as are actually there in the original subs. People who recommend taking the unstretched/un-saturated DSS image into photoshop seem to have no problems getting good results. Am I missing something very simple? Sorry for long winded question. Thanks for any help. I am shooting with a Canon DSLR 1200D(Rebel T5)