two telescopes on same target

[Mirrorgirl]

hi there i just wondered if someone could help me. i have started off with my William optics GT triplet refractor on the lion nebula and tonight i want to change telescopes to the 80 ed doublet refactor sky watcher is it ok to do this when imaging and stacking i was told it would be ok but i thought i would leave it to the pro's

[Lady Fraktor]

Tom (astrovetteman) uses two different sized refractors at once.
I cannot see changing the telescope to be detrimental to the image.

[SkyHiker]

It depends on the stacking program. I believe that DSS for instance will not be able to stack images of different resolutions, but you can stack them in separate groups then combine the two stacks manually in something like Photoshop or Gimp. I would think PI can do it, but I don't know for sure.

[JayTee]

@Juno16 Jim, can you answer this?

[Juno16]

@Mirrorgirl @JayTee

I really have no idea! Not ever messed around with trying that. I did play around with a few light frames shot with two different scopes and combined in Pixinsight WBPP. I will send another note soon.

[KathyNS]

I would have thought DSS could do it. Certainly PixInsight can.

[Juno16]

Not sure if this is the correct approach, but it looks like it might be close.

I had some Horsehead/Flame data from 2020 imaged with the Explore Scientific ED102 (571mm) and some Horsehead/Flame data from 2021 imaged with the Sharpstar 61 (275mm).

I simply (for test purposes) added 10 lights from the 2020 dataset and 10 lights from the 2021 dataset into the "Lights" tab of Pixinsight's WBPP. They were both 120 exposure lengths, but if the data was of different exposure times, just separate them with the keyword "EXPTIME".

I used no calibration frames.

The only issue that I had was in registration and that turned out to be that the geometry was different between the datasets. The 2020 data was shot with APT and the 2021 data was shot with N.I.N.A., and I am not sure if that is why the orientation was different. I corrected each of the ten frames from the 2020 dataset just for the test.

The frames registered and integrated fine.

These images are the stacked combination (masterlight) on the left and one light frame from each of the datasets (the middle and right image).

You can see in the combined image (left) that the image would have to be cropped to the crudely drawn arrows in the below image.

I have no idea if this is the correct way to combine this sort of data. It does look like the s/n of the area to be cropped (the combined area) is much higher.

I hope that someone with experience in this process chimes in. I would love to hear how it is correctly done!

[Mirrorgirl]

Not sure if this is the correct approach, but it looks like it might be close.

I had some Horsehead/Flame data from 2020 imaged with the Explore Scientific ED102 (571mm) and some Horsehead/Flame data from 2021 imaged with the Sharpstar 61 (275mm).

I simply (for test purposes) added 10 lights from the 2020 dataset and 10 lights from the 2021 dataset into the "Lights" tab of Pixinsight's WBPP. They were both 120 exposure lengths, but if the data was of different exposure times, just separate them with the keyword "EXPTIME".

I used no calibration frames.

The only issue that I had was in registration and that turned out to be that the geometry was different between the datasets. The 2020 data was shot with APT and the 2021 data was shot with N.I.N.A., and I am not sure if that is why the orientation was different. I corrected each of the ten frames from the 2020 dataset just for the test.

The frames registered and integrated fine.


Capture.JPG


These images are the stacked combination (masterlight) on the left and one light frame from each of the datasets (the middle and right image).

Thanks so much for that info, Jim Thank you


Capture1JPG.JPG


You can see in the combined image (left) that the image would have to be cropped to the crudely drawn arrows in the below image.




combination1.jpg


I have no idea if this is the correct way to combine this sort of data. It does look like the s/n of the area to be cropped (the combined area) is much higher.

I hope that someone with experience in this process chimes in. I would love to hear how it is correctly done!

[Juno16]

Not sure if this is the correct approach, but it looks like it might be close.

I had some Horsehead/Flame data from 2020 imaged with the Explore Scientific ED102 (571mm) and some Horsehead/Flame data from 2021 imaged with the Sharpstar 61 (275mm).

I simply (for test purposes) added 10 lights from the 2020 dataset and 10 lights from the 2021 dataset into the "Lights" tab of Pixinsight's WBPP. They were both 120 exposure lengths, but if the data was of different exposure times, just separate them with the keyword "EXPTIME".

I used no calibration frames.

The only issue that I had was in registration and that turned out to be that the geometry was different between the datasets. The 2020 data was shot with APT and the 2021 data was shot with N.I.N.A., and I am not sure if that is why the orientation was different. I corrected each of the ten frames from the 2020 dataset just for the test.

The frames registered and integrated fine.


Capture.JPG


These images are the stacked combination (masterlight) on the left and one light frame from each of the datasets (the middle and right image).

Thanks so much for that info, Jim Thank you


Capture1JPG.JPG


You can see in the combined image (left) that the image would have to be cropped to the crudely drawn arrows in the below image.




combination1.jpg


I have no idea if this is the correct way to combine this sort of data. It does look like the s/n of the area to be cropped (the combined area) is much higher.

I hope that someone with experience in this process chimes in. I would love to hear how it is correctly done!

Hi Rhoda,
Did you have a comment or question?

[Mirrorgirl]

Not sure if this is the correct approach, but it looks like it might be close.

I had some Horsehead/Flame data from 2020 imaged with the Explore Scientific ED102 (571mm) and some Horsehead/Flame data from 2021 imaged with the Sharpstar 61 (275mm).

I simply (for test purposes) added 10 lights from the 2020 dataset and 10 lights from the 2021 dataset into the "Lights" tab of Pixinsight's WBPP. They were both 120 exposure lengths, but if the data was of different exposure times, just separate them with the keyword "EXPTIME".

I used no calibration frames.

The only issue that I had was in registration and that turned out to be that the geometry was different between the datasets. The 2020 data was shot with APT and the 2021 data was shot with N.I.N.A., and I am not sure if that is why the orientation was different. I corrected each of the ten frames from the 2020 dataset just for the test.

The frames registered and integrated fine.


Capture.JPG


These images are the stacked combination (masterlight) on the left and one light frame from each of the datasets (the middle and right image).

Thanks so much for that info, Jim Thank you


Capture1JPG.JPG


You can see in the combined image (left) that the image would have to be cropped to the crudely drawn arrows in the below image.




combination1.jpg


I have no idea if this is the correct way to combine this sort of data. It does look like the s/n of the area to be cropped (the combined area) is much higher.

I hope that someone with experience in this process chimes in. I would love to hear how it is correctly done!

sorry Yes thanks for your info, Jim I'm taking all on board.


Hi Rhoda,
Did you have a comment or question?

[chartram]

Hi Rhoda,

I do this all the time with data taken through the different scopes/cameras I’ve owned over the years. Matter of fact, a buddy and i just did a collaborative image of the Lion Nebula earlier this year. Shot with completely different scope and camera setups from different locations. I see you use Pixinsight, which is the perfect tool for the job! All you do is use StarAlignment to align the calibrated subs and they should stack without issue. StarAlignmnet is pretty slick about making the geometry match the reference frame . If you need assistance, don’t hesitate to drop a line.

Mike

[Juno16]

Hi Rhoda,

I do this all the time with data taken through the different scopes/cameras I’ve owned over the years. Matter of fact, a buddy and i just did a collaborative image of the Lion Nebula earlier this year. Shot with completely different scope and camera setups from different locations. I see you use Pixinsight, which is the perfect tool for the job! All you do is use StarAlignment to align the calibrated subs and they should stack without issue. StarAlignmnet is pretty slick about making the geometry match the reference frame . If you need assistance, don’t hesitate to drop a line.

Mike

@chartram

Hey Mike,

Thanks for sharing this. I don't know if you read my post #7, but I took a shot at trying this and it looked like it worked fine. The only thing that messed me up was when I initially registered the two groups of lights (StarAlignment), it failed on the first set. I realized that these lights were captured with APT and the latter set by N.I.N.A. I don't know if that was the reason, but the orientation of the APT data was inverted compared to the N.I.N.A. data. I corrected the earlier data orientation in PI (180 degree rotation, horizontal flip) and all of the data aligned fine.
I threw all of the lights into WBPP and it took care of everything.

Not sure if I will every use this, but it sure is easy to do in PI!

[chartram]

@chartram

Hey Mike,

Thanks for sharing this. I don't know if you read my post #7, but I took a shot at trying this and it looked like it worked fine. The only thing that messed me up was when I initially registered the two groups of lights (StarAlignment), it failed on the first set. I realized that these lights were captured with APT and the latter set by N.I.N.A. I don't know if that was the reason, but the orientation of the APT data was inverted compared to the N.I.N.A. data. I corrected the earlier data orientation in PI (180 degree rotation, horizontal flip) and all of the data aligned fine.
I threw all of the lights into WBPP and it took care of everything.

Not sure if I will every use this, but it sure is easy to do in PI!

That’s weird. One would think that 180° flip would be no different than aligning subs taken after meridian flip. But I could see where a horizontal (mirror image) flip could throw it off. Wonder if there’s a difference in the FITS header info between APT & NINA.

The best way to do it (in my experience) is to register all of the light frames from all outings to one reference frame then stack them all together, if that makes sense.

The attached collaborative image was taken with different scopes, and different acquisition programs. Just aligned everything to one Ha frame, then stacked each channel’s data as if shot with one scope.

[SkyHiker]

I would have thought DSS could do it. Certainly PixInsight can.

I had DSS protesting when loading subs of different resolution a few times. I would not know how to do this with different groups. I do use different groups with RGB or other filters, and know how to align them, but that's all the same resolution.

[Juno16]

@chartram

Hey Mike,

Thanks for sharing this. I don't know if you read my post #7, but I took a shot at trying this and it looked like it worked fine. The only thing that messed me up was when I initially registered the two groups of lights (StarAlignment), it failed on the first set. I realized that these lights were captured with APT and the latter set by N.I.N.A. I don't know if that was the reason, but the orientation of the APT data was inverted compared to the N.I.N.A. data. I corrected the earlier data orientation in PI (180 degree rotation, horizontal flip) and all of the data aligned fine.
I threw all of the lights into WBPP and it took care of everything.

Not sure if I will every use this, but it sure is easy to do in PI!

That’s weird. One would think that 180° flip would be no different than aligning subs taken after meridian flip. But I could see where a horizontal (mirror image) flip could throw it off. Wonder if there’s a difference in the FITS header info between APT & NINA.

The best way to do it (in my experience) is to register all of the light frames from all outings to one reference frame then stack them all together, if that makes sense.

The attached collaborative image was taken with different scopes, and different acquisition programs. Just aligned everything to one Ha frame, then stacked each channel’s data as if shot with one scope.

@chartram
Wierd for sure. I agree that it must be something different in the fits header as they are very different.
Very good practice to register all images to create the SA reference frame.
Not a big issue for me as I don’t have plans to combine different scope data, but its a pretty cool process snd was fun to run through.
Thanks Mike.