NINA preview images are great but saved images are greyscale and dim

[Peter Reader]

Hi all,

Had my first imaging session with PhD2 for guiding and NINA for imaging last night. I was watching the images come in on NINA and they looked to be full of detail and certainly colour (my session included M42).

Went to bed feeling very happy with myself but this morning upon reviewing the saved image files I cannot even see stars in the .tif files without a huge histogram stretch in photoshop and the images are greyscale. DSS doesn't detect stars until 2% threshold (the lowest available).

What might I be doing wrong? Screenshot and raw image attached from last night.

A separate question is how do I get NINA to save meta data with the image files? DSS can't identify ISO or exposure time of the saved image files which is annoying for stacking.

19-42-53_LIGHT_180.00_0010.tif

[Anne S]

I've only played with NINA inside but I have used SGPro and Maxim DL.

A couple of things:

Is there any reason why you're capturing in Tiff, I suspect that won't support metadata. You should be using fits file type which does.

Subs are usually shown in the capture software with a visual stretch applied so you can see what you've got. They will be saved without this stretch. My subs will only show a few bright stars. You then need to stretch the stacks in your processing software.

Hope that helps.

[scotty38]

As above save in fits and then use another application to stack and process them accordingly. Yes it's a faff compared to files being produced "ready to go" but it's how it's done most of the time (unfortunately or fortunately depending on your view). Also as above NINA will apply a stretch (that can be turned off and/or configured too) but if you also click on a captured file (in the Imaging tab) rather than the latest one shown you'll also see it displayed with colours too.

It's a great tool and worth persevering with.

[scitmon]

Are you are using the Canon DSLR you bought off me?  Images should be saved as CR2 files if so... not tiffs or fits. 

 

CR2 files are also compatible with DSS.  Each image will require a stretch to see all but the brightest stars, and will also need debayering to see colour, but you need not worry about doing this with individual subs.  A DSS stack should debayer them for you.

Edited January 5, 2022 by scitmon

[Peter Reader]

Thanks for all the replies guys, tonight I had a better session after collimation, new LPS from Scitmon and SW 0.9x coma corrector.

14 hours ago, scitmon said:

Are you are using the Canon DSLR you bought off me?  Images should be saved as CR2 files if so... not tiffs or fits. 

 

CR2 files are also compatible with DSS.  Each image will require a stretch to see all but the brightest stars, and will also need debayering to see colour, but you need not worry about doing this with individual subs.  A DSS stack should debayer them for you.

Scott, I don't have the option to save in CR2 in NINA for some reason... FITS seems to be workin - is there any reason to try and make CR2 work?

[The Lazy Astronomer]

Just looking at the screenshot you posted above, it looks to me like the stars everywhere but the centre are affected by coma (I had a similar issue when I tried imaging with my (non EdgeHD) SCT) - DSS won't identify them as stars, so stacking might be difficult or even (as in my case) impossible.

[ONIKKINEN]

The linked sub is very out of focus, this is easy to see if you zoom in and see that stars are hollow donuts with dark spots in the center. The screenshotted frame also looks like it might be a bit out of focus, but maybe not that much. The aberrations and elongation of stars everywhere except the center of the image is coma, which all fast newtonians suffer from. Looks like you already know about this since you have a coma corrector in your signature so i assume you just didn't use the corrector for this night?

That is what my NINA settings window looks like, and it is true that this setting is ignored. My 550D files are always saved as .CR2 format RAW files and i cant save them as .TIFFs even if i try.

As i open your .TIFF in Siril it seems i cannot debayer the frame as it has no bayer matrix pixel order information in the header (as it does not have a header because its a .TIFF and not a raw file). This is why it is monochrome when you open it. I can split the color channels into individual frames and maybe re-composite them later but maybe not worth the time and effort, something is wrong with capture. I found this thread on CN: https://www.cloudynights.com/topic/745264-nina-saving-canon-files-as-fits/

Where someone had a similar issue as you, but instead their frames were saved as .FITS files. Question is, what driver do you use to connect to the camera? Native Canon driver should be used instead of the ASCOM one is what i gather from that thread.

17 hours ago, Peter Reader said:

I cannot even see stars in the .tif files without a huge histogram stretch in photoshop and the images are greyscale. DSS doesn't detect stars until 2% threshold (the lowest available).

This by itself is not that strange if you took short exposures. Or longer exposures but with a slow scope. I cant see anything but the cores of the brightest stars in all of my images, and its not an issue at all. The reason why DSS doesn't detect the stars in your case is because it doesn't recognize them as stars, due to their large size and coma from being out of focus. Nothing to do about the focus issue now except reshoot and pay attention to focus drift during the next night. If the temperature changes, so will your focus. Also focusers can slip and cause focus to drift during the night.

From your screenshot it looks like you have the image statistics completely off-screen and star/HFR measurements are not in use at all. Click the star icon to use the star analysis and use this to focus the scope. The more stars NINA finds per shot the better, the lower you can get your HFR the better. Looking at HFR values in NINA is a very easy and quick way to reach very good focus, and you'll immediately see if focus has drifted when the HFR value increases.

[Peter Reader]

Had a much better session yesterday evening after re-collimating and spending more time focusing with bahtinov mask: 

18 hours ago, The Lazy Astronomer said:

Just looking at the screenshot you posted above, it looks to me like the stars everywhere but the centre are affected by coma (I had a similar issue when I tried imaging with my (non EdgeHD) SCT) - DSS won't identify them as stars, so stacking might be difficult or even (as in my case) impossible.

Yes I definitely had coma but I think it's pretty much sorted now with the corrector. Do you see any issues with my images linked above? Images came out pretty well, although some questions remain...

16 hours ago, ONIKKINEN said:

Question is, what driver do you use to connect to the camera? Native Canon driver should be used instead of the ASCOM one is what i gather from that thread.

Thanks for your detailed response. Is the Native Canon driver something I need to download from Canon's website? I don't see the option to connect to anything other than ASCOM DSLR in NINA. And is there any reason to switch from fits to the canon CR2?

16 hours ago, ONIKKINEN said:

From your screenshot it looks like you have the image statistics completely off-screen and star/HFR measurements are not in use at all. Click the star icon to use the star analysis and use this to focus the scope. The more stars NINA finds per shot the better, the lower you can get your HFR the better. Looking at HFR values in NINA is a very easy and quick way to reach very good focus, and you'll immediately see if focus has drifted when the HFR value increases.

Thanks I will try this next time for sure.

Edited January 6, 2022 by Peter Reader

[ONIKKINEN]

4 minutes ago, Peter Reader said:

Had a much better session yesterday evening after re-collimating and spending more time focusing with bahtinov mask: 

Yes I definitely had coma but I think it's pretty much sorted now with the corrector. Do you see any issues with my images linked above? Images came out pretty well, although some questions remain...

Thanks for your detailed response. Is the Native Canon driver something I need to download from Canon's website? I don't see the option to connect to anything other than ASCOM DSLR in NINA. And is there any reason to switch from fits to the canon CR2?

Thanks I will try this next time for sure.

They might still be a bit out of focus, hard to tell if its processing or just slightly big stars due to focus, but coma is gone.

I just see a Canon driver option in NINA. Have not downloaded anything from Canon, thats for sure. I think this is just on NINAs end to deal with the driver? I dont see this option straight away by the way. I must plug in the camera and then click the refresh button for this option to appear. Also, the camera must be set to manual shooting mode first.

Can you use the FITS files as you would raw files, as in they are debayerable and have usable header information (ISO or gain/exposure time)? If you can, then im not sure there is a benefit to having the files be in .CR2 format. One benefit might be that .CR2 format files are easy to open and browse through in windows where as .FITS files really are not.

[Peter Reader]

4 minutes ago, ONIKKINEN said:

Can you use the FITS files as you would raw files, as in they are debayerable and have usable header information (ISO or gain/exposure time)? If you can, then im not sure there is a benefit to having the files be in .CR2 format. One benefit might be that .CR2 format files are easy to open and browse through in windows where as .FITS files really are not.

The FITS open in DSS and from memory the meta data for ISO and exposure time was available to the software. Also true that I cannot view the fits files in windows photo viewer so canon CR2 would be better for that...

[ONIKKINEN]

1 minute ago, Peter Reader said:

The FITS open in DSS and from memory the meta data for ISO and exposure time was available to the software. Also true that I cannot view the fits files in windows photo viewer so canon CR2 would be better for that...

Then they would probably work just fine. But one more tip i will give about the.FITS files not being viewable easily: They dont have to be viewed!

In NINA you can set various parameters to be written on the file name itself and so can inspect all the useful information of the sub without opening it. You'll find this in the options-Imaging tab.  Example below:

In this image you can see a screenshot of the folder i have saved my subs. The file name consist of the time and date it was taken on, then the exposure time, then the number in the sequence it was taken on. The next number, for example on the top one 1.15 is the guiding error in RMS arcseconds from the duration of the sub, not the total error of the session mind you. Next line is the name of the sequence that i had created. The final 2 numbers are HFR being 3.77 in the top example and the number of stars NINA detected and used for this HFR measurement. If these values are clear outliers from the average sub, then probably a good idea to just throw it away.

Just by glancing at this list i can immediately tell that there are some clear outliers that should not be used for stacking because either the guide error or HFR was too high (for example the HFR 4+ subs are not good). This way i dont need to inspect the sub itself and can just remove it from the list without much worry on losing data. I find this to be an essential method when there can be hundreds of subs after a night to inspect.

[scitmon]

On 05/01/2022 at 23:28, Peter Reader said:

Thanks for all the replies guys, tonight I had a better session after collimation, new LPS from Scitmon and SW 0.9x coma corrector.

Scott, I don't have the option to save in CR2 in NINA for some reason... FITS seems to be workin - is there any reason to try and make CR2 work?

As has been said, if the FITS files have the metadata needed then it should be fine.  I wasn't aware that NINA saved Canon images as FITS.  Looks like your process is working pretty well now.

[jjosefsen]

5 minutes ago, scitmon said:

As has been said, if the FITS files have the metadata needed then it should be fine.  I wasn't aware that NINA saved Canon images as FITS.  Looks like your process is working pretty well now.

I believe Nina only saves dslr images as fits/xisf/tiff if you are using the dslr accom driver. I that case the image data is passed as a byte array if am not mistaken. When using the native canon/nikon driver it is saved without modification straight from the camera.