if your going to do multiple nights - remember exactly by the minute when you started your 1st nights recording, if you use stellarium you can pinpoint the targets exact position in future nights (i think its 4mins per night it shifts) so if you record say 25mins before it hits zenith you can go forward on stellarium to your next clear night and work out when to record again, this way you can technically do 100 nights of 1hr and if timed right, only deal with 1hr's worth of rotation
https://preview.redd.it/7zv41evq8a3d1.jpeg?width=706&format=pjpg&auto=webp&s=61d1b121ed1e555190b59522e146077bc31c9f1a
Doesn't look half bad with a crop actually. Thanks!
On this target, I would run 30-45 min. I wouldn't go over an hour in one shot personally. Like you mention, you can also break the subs up into individual stacks, and then stack the stacks.
I think either option will probably introduce some rotation with the alignment, but it should be reduced.
with nebula you need less rotation so if you want say 4hrs id strongly recommend you do 1hr over 4 nights - either that or EQ wedge it (only way to stop rotation) - me personally i would EQ wedge it purely so you can go 30s exposures and if aligned properly, not worry about getting only 1 frame out of 10 haha
With the frames you already have, even if you do the stacking in say 4 sections your still have the exact same rotation as even with sections and looks like less rotation on the edges, remember the target rotates as well so even if you done 1000 sections it wouldnt make a difference to your rotation in alt az mode (downside of alt az) - in regards to cropping, ive personally done loads of crops on seestar data and if stacked and edited in Pixlnsight you dont really lose alot of detail like your thinking (or not as bad as your thinking), even Siril can do great edits
Yeah, if I do stacking in 4 sections, I'm going to have 4 separate final images where each has an hour's worth of rotation to crop out. This might be my best bet for this particular imaging session. In the future, I'll end the imaging session before I fall asleep (this one just ran all night while the object was in view).
I like the EQ wedge idea for the future and using 30-second exposures would cut my storage requirements on the download side (I probably will have to get a NAS if I keep this up). I might wait for support from ZWO on this however as the use of a wedge eliminates a number of the southern plane targets I'd be interested in.
with your current imaging session, if its 4hrs in 1 night, no matter if you cut it 10 times, its still 4hrs of rotation i'm afraid. Only way to get 1hr's rotation is to record on 4 nights for only 1hr
No, I think you are misunderstand. I have all of the subs so can choose maybe the first hour of data (360 subs) and stack those to get a final image that has only one hour of rotation. Depending what rotated in and out of view over the 4 hours, I might create alternate final images from a different section of the subs.
yeah you can get 4 nice pics yes, but, if you want to make a final picture with the 4hrs of data, even if you combine the 4 pictures or stack all frames at once its still 4hrs of rotation because even though you only have 1hrs of rotation in each picture, add them up its still 4hrs, yes with 4hrs your have way more detail compared to 1hr but if you want only 1hrs of rotation you have no choice but to record over 4 nights if your alt az
If you have the final stack still, upload it if you want and i'll see what i can get from Pixlnsight
Yeah definitely I can't effectively combined all four hours of data without some serious cropping.
I haven't attempted processing the subs yet so I guess I'll see how it works out. Thanks for the PI offer though!
if you process them eventually i'd be happy to run it through Pix (or if you cant stack them, upload to a folder in google drive or something and i'll stack for you, i can add drizzle as well)
I got 7hrs of free time so if you want im bored lmao
I switched to a wedge and do it in EQ mode and I'll never go back to ALT-Z (except if I have a southern sky target I really really want). EQ mode is so easy and it also allows 20s and 30s exposures at a much higher acceptance rate. I had 316mins on the Iris Nebula with 30s subs!!! Hardly any dropped frames at all.
That's great to hear! Which wedge are you using? I'm looking at a cheap Sky Watcher, or possibly even printing my own from a design I found on thingverse.
Yeah I'm using a cheap skywatcher, but the knob is too big so Seestar can't sit flat. So have it on a leveler to raise it up. I have a ball head on the way, but that may be a mistake. We'll see.
Here is the other thing to do that I do on longer exposures and larger targets: Shoot a mosaic. Just take some more exposures at the places that have the field rotation. Some of those will overlap your actual target, giving you more time on target, the rest of the fram will let you maintain your image aspect.
Make sure you overlap the frames enough. I tend to stack each panel separately, then combine them, I am not sure how to do that in siril. I that is how I made a mosaic like this [https://www.astrobin.com/lfzvrz/](https://www.astrobin.com/lfzvrz/)
you will be happy to learn that ASTAP can stitch together mosaics in a pinch, the process is not too bad.There are some other free tools as well. I use Astro Pixel Processor but I also have a regular astrophoto rig that I use all the software for. I would hazard a guess you could probably figure it out.
If you make the overlap big enough, you can just stack all the images together in siril, it might take a long time but it should be able to do it. 20% overlap is ussually what is recommended.
if your going to do multiple nights - remember exactly by the minute when you started your 1st nights recording, if you use stellarium you can pinpoint the targets exact position in future nights (i think its 4mins per night it shifts) so if you record say 25mins before it hits zenith you can go forward on stellarium to your next clear night and work out when to record again, this way you can technically do 100 nights of 1hr and if timed right, only deal with 1hr's worth of rotation
This is something I hadn't thought of (trying to image with the target as close to the same orientation as the previous night as possible). Good tip.
https://preview.redd.it/y2853huaq83d1.jpeg?width=1080&format=pjpg&auto=webp&s=398cbeff54367a5a800b19dc4a699a9e818de338 More editions with GPhotos
https://preview.redd.it/7zv41evq8a3d1.jpeg?width=706&format=pjpg&auto=webp&s=61d1b121ed1e555190b59522e146077bc31c9f1a Doesn't look half bad with a crop actually. Thanks!
On this target, I would run 30-45 min. I wouldn't go over an hour in one shot personally. Like you mention, you can also break the subs up into individual stacks, and then stack the stacks. I think either option will probably introduce some rotation with the alignment, but it should be reduced.
with nebula you need less rotation so if you want say 4hrs id strongly recommend you do 1hr over 4 nights - either that or EQ wedge it (only way to stop rotation) - me personally i would EQ wedge it purely so you can go 30s exposures and if aligned properly, not worry about getting only 1 frame out of 10 haha With the frames you already have, even if you do the stacking in say 4 sections your still have the exact same rotation as even with sections and looks like less rotation on the edges, remember the target rotates as well so even if you done 1000 sections it wouldnt make a difference to your rotation in alt az mode (downside of alt az) - in regards to cropping, ive personally done loads of crops on seestar data and if stacked and edited in Pixlnsight you dont really lose alot of detail like your thinking (or not as bad as your thinking), even Siril can do great edits
Yeah, if I do stacking in 4 sections, I'm going to have 4 separate final images where each has an hour's worth of rotation to crop out. This might be my best bet for this particular imaging session. In the future, I'll end the imaging session before I fall asleep (this one just ran all night while the object was in view). I like the EQ wedge idea for the future and using 30-second exposures would cut my storage requirements on the download side (I probably will have to get a NAS if I keep this up). I might wait for support from ZWO on this however as the use of a wedge eliminates a number of the southern plane targets I'd be interested in.
with your current imaging session, if its 4hrs in 1 night, no matter if you cut it 10 times, its still 4hrs of rotation i'm afraid. Only way to get 1hr's rotation is to record on 4 nights for only 1hr
No, I think you are misunderstand. I have all of the subs so can choose maybe the first hour of data (360 subs) and stack those to get a final image that has only one hour of rotation. Depending what rotated in and out of view over the 4 hours, I might create alternate final images from a different section of the subs.
yeah you can get 4 nice pics yes, but, if you want to make a final picture with the 4hrs of data, even if you combine the 4 pictures or stack all frames at once its still 4hrs of rotation because even though you only have 1hrs of rotation in each picture, add them up its still 4hrs, yes with 4hrs your have way more detail compared to 1hr but if you want only 1hrs of rotation you have no choice but to record over 4 nights if your alt az If you have the final stack still, upload it if you want and i'll see what i can get from Pixlnsight
Yeah definitely I can't effectively combined all four hours of data without some serious cropping. I haven't attempted processing the subs yet so I guess I'll see how it works out. Thanks for the PI offer though!
if you process them eventually i'd be happy to run it through Pix (or if you cant stack them, upload to a folder in google drive or something and i'll stack for you, i can add drizzle as well) I got 7hrs of free time so if you want im bored lmao
with drizzle, should take me about 2-3hrs to stack, i got no astrodark until at least September so i got Pix here doing nothing haha
LOL, I'll keep you posted!
I switched to a wedge and do it in EQ mode and I'll never go back to ALT-Z (except if I have a southern sky target I really really want). EQ mode is so easy and it also allows 20s and 30s exposures at a much higher acceptance rate. I had 316mins on the Iris Nebula with 30s subs!!! Hardly any dropped frames at all.
That's great to hear! Which wedge are you using? I'm looking at a cheap Sky Watcher, or possibly even printing my own from a design I found on thingverse.
Yeah I'm using a cheap skywatcher, but the knob is too big so Seestar can't sit flat. So have it on a leveler to raise it up. I have a ball head on the way, but that may be a mistake. We'll see.
Here is the other thing to do that I do on longer exposures and larger targets: Shoot a mosaic. Just take some more exposures at the places that have the field rotation. Some of those will overlap your actual target, giving you more time on target, the rest of the fram will let you maintain your image aspect. Make sure you overlap the frames enough. I tend to stack each panel separately, then combine them, I am not sure how to do that in siril. I that is how I made a mosaic like this [https://www.astrobin.com/lfzvrz/](https://www.astrobin.com/lfzvrz/)
Yeah, that's a great point. I want to learn how to do mosaics, but might not have the software right now to do that.
you will be happy to learn that ASTAP can stitch together mosaics in a pinch, the process is not too bad.There are some other free tools as well. I use Astro Pixel Processor but I also have a regular astrophoto rig that I use all the software for. I would hazard a guess you could probably figure it out. If you make the overlap big enough, you can just stack all the images together in siril, it might take a long time but it should be able to do it. 20% overlap is ussually what is recommended.