GuySt

In case anyone sees this thread in a search, attached is a python script (code also below) to open a .fits file and output the RA/DEC in HMS/DMS for manual use. I still don't know of a way to get APT to use a .fits file directly (that is, get the RA/DEC from the fits file into the GoTo RA: and GoTo DEC: fields of the GEAR tab). USAGE: convertRA_DEC.py -i <inputfile> I put the script in a folder in my PATH (I'm using WSL2 in Windows 10) and then run it from the folder where the .fits file is, e.g., convertRA_DEC.py -i image.fits. It outputs: DESKTOP-JA43EBJ% convertRA_Dec.py -i ./image.fits RA: 194.696215848 DEC: 55.4703270876 Coordinates of center of image: 12:58:47.092 +55:28:13.178 RA: (12, 58, 47.09180352000203) DEC: (55, 28, 13.177515359991476, 1) If you have the astrometry.net local install so you can use solve-field on an image taken with your camera, you can have solve-field output an image.fits file (which has RA and DEC in decimal format). Run this script on that .fits file, and get the RA/DEC in a format APT can use (or other apps, if they cannot use decimal format, like APT). #!/usr/bin/python3.8 from __future__ import print_function, division import sys, getopt from astropy.io import fits from PyAstronomy import pyasl # from astropy.wcs import WCS # from __future__ import print_functon, division # from PyAstronomy import pyasl # # Coordinates of HD 1 from SIMBAD # hd1 = "00 05 08.83239 +67 50 24.0135" # print("Coordinates of HD 1 (SIMBAD): ", hd1) # # Obtain decimal representation # ra, dec = pyasl.coordsSexaToDeg(hd1) # print("Coordinates of HD 1 [deg]: %010.6f %+09.6f" % (ra, dec)) # # Convert back into sexagesimal representation # sexa = pyasl.coordsDegToSexa(ra, dec) # print("Coordinates of HD 1 [sexa]: ", sexa) # ==== # >>> from astropy.io import fits # >>> from astropy.wcs import WCS # >>> f = fits.open(<filepath>) # >>> w = WCS(f[0].header) # >>> sky = w.pixel_to_world(30, 40) # >>> print(sky) # <SkyCoord (ICRS): (ra, dec) in deg # (5.52844243, -72.05207809 # ==== def main(argv): # print (sys.argv) inputfile = '' try: opts, args = getopt.getopt(argv, "hi:", ["ifile="]) except getopt.GetoptError: print('USAGE: convertRA_DEC.py -i <inputfile>') sys.exit(2) for opt, arg in opts: if opt == '-h': print('USAGE: convertRA_DEC.py -i <inputfile>') sys.exit() elif opt in ("-i", "--ifile"): inputfile = arg hdul = fits.open(inputfile) hdr = hdul[0].header print("RA: ", hdr['CRVAL1']) print("DEC: ", hdr['CRVAL2']) sexa = pyasl.coordsDegToSexa(hdr['CRVAL1'], hdr['CRVAL2'], fmt=('%02d:%02d:%06.3f ', '%s%02d:%02d:%06.3f')) # outputs as HMS values for both RA and DEC print("Coordinates of HD 1 [sexa]: ", sexa) # or, print RA and DEC separately print("RA: ", pyasl.degToHMS(hdr['CRVAL1'])) print("DEC: ", pyasl.degToDMS(hdr['CRVAL2'])) hdul.close() if __name__ == "__main__": main(sys.argv[1:]) convertRA_DEC.py

All - I don't have a back yard, so I must plan accordingly, pack everything up, drive to an observing site, etc. Naturally, a remote site is unlikely to have online access so I'm planning and testing to do everything on my local Microsoft Surface laptop. All seems to work well in ASCOM simulations except PlateSolving. ASTAP is simply non-functional. Never solves successfully when using simulations. I'm using hnsky's Sky Simulator to download images that the APT Camera simulator is connected to (same image path on my laptop). If I upload the image.png file Sky Simulator downloads to astrometry.net it is always successfully solved even when APT PlateCraft fails (in fact, astrometry.net solves the image as PlateCraft is failing to solve it). If I get out in the woods and ASTAP won't work, I'd like to use a local copy of astrometry.net (installed in WSL2 which works quite well) that uses local files. The output of the solve-field command is an 'image.fits' file with header. My question is, Can I use this solved image.fits file in APT for GoTo and Sync? I can see the file in the APT IMG tab. I can open it in the ATP Image Preview. I can see the image Info using the APT IMG Info button. But, can I get the data in its header "visible" to APT's Gear>GoTo RA: and GoTo Dec: fields so I can GoTo and Sync? Thanks.

P.S. Here's one of those Comet NeoWise images.

vlaiv - I cannot thank you enough for such clear and direct answers to my questions. I may, perhaps, might, be understanding all this. I started down this path after taking some images with that Nikon D7500 and a regular camera tripod of comet Neowise. I was very pleased that I have images I took, but less pleased because (as a photographer of many years, albeit amateur) I knew the images could be better. And as a new retiree, I needed a hobby. Looking for how to take better images lead to a Polarie sky tracker, then I dove off the cliff toward full-scale AP with the NEQ5, Williams Optics RedCat 51, etc. (the ZWO guidescope and QHY PoleMaster are the latest two additions). I'm still learning ... but it may be I'm learning the right things. I'm a bit hampered because I live in a condominium and there is nowhere close to me I can set up the mount etc. I cannot just take things to a backyard. So I have to load it all in my truck and drive somewhere. But, that's the life I have and I'll make do. Again, MUCH THANKS. Just what I needed.

Still learning the basics of astrophotography with a GEM mount. What I have: HEQ5, PoleMaster, ZWO guide scope (<-- NOT in use as yet, next night out for this part of the gear), Williams Optics RedCat 51, Nikon D7500. Monday night was all about setting up the mount, leveling and balancing it, and polar aligning it with the PoleMaster. I think all of that was correctly done. So, though I'd not planned on taking any images, decided to since the camera was on the mount. I did NOT do the steps to get PHD2 set up. That's for next time. But, I do have some a question about the light frames nonetheless. I used APT to run a lights and darks set and Sequator to align/stack them. It's clear when scrolling the light frames that the star field is moving. The stars stay sharp and do not trail (30s exposures at 800 ISO) but the star field is shifting, left to right. Q1: Is that supposed to happen? I thought the point of an EQ mount is that it moves with the earth's rotation so, well, things don't move in the scope's FOV. Q2: Will using the ZWO guide scope prevent such star-field motion? Also, the 'black' background is VERY noisy. Horribly so. This images is processed in GIMP/G'MIC to reduce that noise and scaled down 50% (to make it much less that 115Mb in size for posting). But the Sequator output TIFF image is noissy. Q3: Is this 'normal' for astrophotographs? Recall it's made with only lights and darks (I'd not planned to take images so I didn't have the t-shirt for Flats/Dark-Flats and I forgot about biases entirely). Q4: Will these additional frame types reduce this noise? Q5: Am I foolish to think that a non-noisy background obtainable with the Nikon D7500? Regards.

All - again, much thanks for your comments and help. I'm happy to report that last night, to get more familiar with mount setup, polar aligning, etc. I took my gear out. PoleMaster worked (or so I think) for polar alignment (thank god - my old neck/back was very unhappy trying to use the HEQ5's built-in polar scope). I prepared the night by uninstalling and reinstalled the three plate solving apps that APT can use. Made sure that APT was configured correctly for my Williams Optics RedCat 51. And every time I use the PointCraft tool whichever plate solving app was used successfully solved the image I took for that purpose. Well, there was one that was VERY bad, but another plate solving run on a new image was fine. So, PointCraft worked and I can say that using the Sync button in APT **does** talk to EQMOD (and the counter in EQMOD's Alignment/Sync section increments with each use of the Sync button). So, that question is solved. Also, I did not perform an EQMOD/Stellarium Sync, so that doesn't seem to be necessary. Confess it's a bit odd (though rewarding) to have the gear see things I cannot see. Last night here in Madison, Wisconsin, was not a good night with at 97% full moon, a Class 8 Bortle sky, and high clouds. But, for fun I did an image run on M31, thinking it might work. Here's what I got with only light frames (10 @ 30s, 800 ISO) and darks (no flat or bias frames). This is post-processed in GIMP to remove noise, reduce the size by 50% and save as JPEG at 90%. M31 was not visible in last night's sky through binoculars - at all, not even a hint of fuzziness. Yet, there it is with M110 and M32 as well. Holy moly!

A shout-out and Thanks to Carole (carastro) who's mention of PoleMaster led me to research it. And buy it. And use it. Last night!! Could hardly have chosen a worse night, TBH. Very bright moon (97% full), a bit overcast, and in the midst of my city (Madison, Wisconsin) which is, according to the ClearOutside app Class 8 Bortle. But, the PolarScope could "see" more than I could see with binocs!! I ran the app and though it is different than the online video I'd reviewed I think I actually got the mount correctly polar aligned with it!! On the first go. Though I'd not intended to take any images, just work on setup, polar aligning, etc., I could not resist. Here is the result (using only lights and darks, no flats or biases used in Sequator). It's been post-processed to reduce the noise (without use of those missing flats and biases), scaled 50%, DPI reduced to 120dpi, and saved at 90% JPG in Gimp 2.10.20 I'm excited. Only one odd thing (besides the PoleMaster app being completely different from what I expected) -- it's clear when scrolling the light frames that the star field is moving. The stars stay sharp and do not trail (30s exposures at 800 ISO with my Nikon D7500) but the star field is shifting, left to right. Q1: Is that supposed to happen? I thought the point of an EQ mount is that it moves with the earth's rotation so, well, things don't move in the scope's FOV.

Paul M - so ... I read you saying that using the Sync button in APT's PointCraft communicates with BOTH EQMOD (first sentence) and Stellarium (last sentence). This was the gist of my overlong post - both Stellarium and APT have Sync options and both connect to EQMOD. At least one video shows syncing between Stellarium and EQMOD and another shows syncing between APT and Stellarium yet I could find no information anywhere that APT's Sync communicates with BOTH EQMOD and Stellarium (and I still cannot get a simulator to successfully platesolve an image to actually try it and see what happens in the EQMOD Alignment/Sync section when I do that 😡 ). I may (very iffy) get a change to try it tonight. I think I'll take the gear out and not plan on taking any real images, just futz with the mount (polar align) then get the software all talking to each other and pointing to the same place. Baby steps.

Synchronicity - If I remember rightly, the use of Aim in APT is for framing not syncing APT and EQMOD. That is, one uses PlateSolving to get an object in the center of the FOV such that it's RA/DEC is precise, these precise coordinates are synced with one's planetarium application (e.g., CdC) and mount driver (e.g, EQMOD). And thus the RA/DEC APT uses is the same as the RA/DEC CdC uses. Then when you select an object with either APT or CdC they're using the same RA/DEC. APT's PointCraft tool always center's the object, though, which may not be aesthetically pleasing. The Aim option allows you to modify the FOV (which you can then save for future imaging/viewing sessions). I was just looking at a member's images of two galaxies which this seems relevant for: they are on left/right sides of the image. PointCraft would have put one of them in the center. So the photographer has to modify the FOV to get both galaxies where they were. The video I watched that made most sense is this one:

raf2020 - yes, a proper Polar Alignment must always be done (or so I've read in multiple threads/blogs and heard in multiple videos). A leveled, balanced mount properly aligned is essential for correct, precise tracking. I distinctly remember watching a YouTube video that specifically talks about Polar Alignment when the North Celestial Pole is not visible, so I believe there are some guides for you situation (google "polar alignment without polaris").

I'm unclear on the purpose for the various align and sync options in the control chain between mount and software and, unsurprisingly, I can find no clear explanation. Thus my questions below. What I have: Sky-Watcher HEQ5 <--> EQMOD <--> Stellarium <--> APT EQMOD <--> APT It's all talking to each other. I can Connect Stellarium to EQMOD/HEQ5, select a target, select Slew, and EQMOD moves the HEQ5. I can Connect APT to EQMOD/HEQ5, select an Object, and select GoTo, and EQMOD will move the HEQ5. Now I'm trying to get a handle on making sure that EQMOD, Stellarium, and APT all look at the same thing. Off to Google, YouTube and this Forum for ideas. I discovered that EQMOD has an Alignment/Sync section and I found a YouTube vid (apparently by an EQMOD dev!) explaining how it works using Stellarium. He calls this GoTo alignment so that when Stellarium issues a Slew comment to EQMOD, EQMOD knows how much error correction it must apply in communicating with the mount. This process requires a scope with an eyepiece (to center the object using EQMOD's controls) and it uses the Stellarium Sync command. A problem here is that I do not have a scope, I have a Williams Optics RedCat 51 with a Nikon D7500 attached. Q1: I suppose I could attempt to use the D7500's Live View to do this; has anyone done this kind of Alignment/Sync either with a Nikon or Canon or Sony product using the camera's Live View? I turned my attention to APT and its PlateSolving options. I understand that the reason for use of PlateSolving is to get APT and Stellarium "synced" such that the RA/DEC for what one sees when one takes an image using the camera connected in APT is precisely the same in Stellarium. To do this, APT's PlateSolving tools also uses a Sync command. Q2: What's the difference in doing the EQMOD <--> Stellarium Alignment/Sync steps versus the APT <--> Stellarium PlateSolving steps? Q3: Are they related or do they interact? Does APT's Sync talk to BOTH Stellarium and EQMOD or just to Stellarium? Q4: Should I be doing both? Q5: If yes to doing both, which comes first? I confess I spent many hours today trying to get a simulation working to see if doing APT's PlateSolving and its use of Sync gets all the way to EQMOD, but I could never get any of the three PlateSolving apps installed in APT to successfully complete a Solving run on multiple images--not one of the three (very frustrating), and thus I turn to you. Regards.

I am ... embarrassed. I think I know what I did; I may have left the counter-weight shaft INSIDE the RA housing. Which would certainly have obscured the view through the Polar Scope. Perhaps the light I saw when I put my cell phone flashlight was light reflected by the chrome shaft? As one of you suggested I did a YouTube search for Polar Scope alignment and was going to follow the steps one of them suggested. As I was holding the mount in my lap I took off the Polar Scope caps, rotated mount so that the hole through the RA axis shaft was in place then had a look through: silver! And then the DOH! moment: the oounter-weight shaft. Pulled in out and ... oh, look, I can see things! But all is not lost. Confess that the Sky-Watcher manual about aligning things is less than clear. The YT vids are terrific (especially Martin's video) and my goal today is to get the Polar Scope aligned. Then I'll get it back outside. I think perhaps I may just take it down the street and get comfortable with setup, alignment, take-down before driving a half hour to dark skies. I thank all of you who replied. Truly. So very good advice I intend to follow.

Hello everyone - my first post. I'm 62 and newly retired. Taking up astrophotography, a long desired hobby, now I've the time to devote to it (I'm a long-time photographer so the camera/imaging end of things I know well). Gear (all brand new except the Nikon and Surface laptop): Sky-Watcher HEQ5, Williams Optics RedCat 51, ZSO 120mm mini camera and scope for guiding, Nikon D7500 camera, MS Surface Laptop with all the software to use APT/Stellarium/ASCOM (tested and all the things connect !! and I can take images with the Nikon and slew the mount). Tonight was my first time outdoors as I finally got the Battery Pack to power everything. I live in a condo in Madison WI, Bortle class 6, so I must go elsewhere to use this gear. I've done the homework while waiting for the battery and thought (?) I knew what to do to polar align the mount. But nothing doing, sad to say. Set up the tripod , N leg towards NCP and levelled it. Put mount on tripod. Latitude already set to 41-degrees at home. Plugged it into the battery and powered it up. Took off the caps for the Polar Scope, rotated DEC axis to make sure view through Polar Scope is good. Looked through the Polar Scope and saw no stars. Nada. I did see some specks, but they must be on the eyepiece/focuser as the specks rotate if I rotate the Polar Scope focuser. I turned off the mount and looked through the Polar Scope. No stars; completely black. I confirmed that there is a light path through the Polar Scope by using my cell phone flashlight to shine a light through it from the top end which I could see on my hand held near the eyepiece. Now ... I have poor eyesight. So, the issue may be the Polar Scope, or my eyes. And after all that, the reason for my post ... I want to know if it's necessary to do Polar Alignment using the built-in Polar Scope? I have read about Drift Alignment. And software using a guide scope (PHD2, etc.). If I get the HEQ5 setup with the RA axis pointing towards the NCP can these software-based tools get the HEQ5 aligned sufficient for good astrophotography? I'm thinking it may be better with my bad eyes to use a tool that uses images for alignment that I can better see than what I can see through that Polar Scope. Thoughts? Best regards - Guy S.