Exporting from Pixinsight

[Anthonyexmouth]

New to the printing of my images and wondering if I should be saving as 16bit or 32bit Tiff. When I save as 32bit the image is super over exposed when I open in lightroom or PS but 16bit looks similar to the image in Pixinsight. Any hints on how I should be doing it?

[scitmon]

take a look at https://www.lightvortexastronomy.com/tutorial-preparing-images-for-publication.html 

[Anthonyexmouth]

Ok, hoping some lightroom or PS nerds are out there for this. I tried printing an image in lightroom but the colours printed were nothing like the screen and it was super blotchy and harsh transitions. had the correct custom ICC profile. Was getting very disillusioned with the whole thing and decided to have one more go with PS, completely identical settings but totally different print. colours on screen almost identical to print. Any ideas? I'd like to use LR as its easier to frame and border the image, at least it is for me with very very little LR or PS knowledge. 

PS left - LR Right. I highlighted the blotchy area. Really harsh blue 

 

[sharkmelley]

On 14/03/2023 at 11:12, Anthonyexmouth said:

New to the printing of my images and wondering if I should be saving as 16bit or 32bit Tiff. When I save as 32bit the image is super over exposed when I open in lightroom or PS but 16bit looks similar to the image in Pixinsight. Any hints on how I should be doing it?

32-bit data is always treated by Photoshop as linear and will be displayed with a linear profile.  It therefore displays differently to equivalent 16-bit data unless the 16-bit data has an embedded linear ICC profile.  In general, if you want your image to look the same in Photoshop as it does in PixInsight  then do not export it from PixInsight in 32-bit format.

Mark

Edited March 15, 2023 by sharkmelley

[Anthonyexmouth]

19 minutes ago, sharkmelley said:

32-bit data is always treated by Photoshop as linear and will be displayed with a linear profile.  It therefore displays differently to equivalent 16-bit data unless the 16-bit data has an embedded linear ICC profile.  In general, if you want your image to look the same in Photoshop as it does in PixInsight  then do not export it from PixInsight in 32-bit format.

Mark

Thanks, Any idea on odd LR vs PS issue? 

[sharkmelley]

3 minutes ago, Anthonyexmouth said:

Thanks, Any idea on odd LR vs PS issue? 

Sorry - I don't use LightRoom.

[ollypenrice]

18 hours ago, sharkmelley said:

Sorry - I don't use LightRoom.

What's your difficulty in cropping and sizing in Ps? Maybe we can help.

Olly

[Anthonyexmouth]

1 hour ago, ollypenrice said:

What's your difficulty in cropping and sizing in Ps? Maybe we can help.

Olly

I don't know really. It's just LR has a nice representation of the layout with borders in the print module. I've zero experience with PS and only slightly more with LR. 

If I knew how to use PS I'd probably do a little post in there too but clueless on its workings. 

[Lumos]

Often when I see results like that it means that I have screwed up the gamut, or colourspace. Usually I will be displaying and Adobe RGB image in an sRGB colourspace without having done the conversion. It looks like you have Lightroom trying to display colours that it does not have in its gamut so you are getting blotching as it groups your gradients into the dolours it has got.

[Anthonyexmouth]

17 minutes ago, Lumos said:

Often when I see results like that it means that I have screwed up the gamut, or colourspace. Usually I will be displaying and Adobe RGB image in an sRGB colourspace without having done the conversion. It looks like you have Lightroom trying to display colours that it does not have in its gamut so you are getting blotching as it groups your gradients into the dolours it has got.

I have LR set to my custom ICC profile, or is that something different?

[Lumos]

I believe that your ICC profile is to help your printer match what you see in the monitor.  I was referring to the colourspace that the image exists in. There are several places for this to get mixed up, going from Pixinsight to Lightroom and especially going to your printer, you need to make sure that your printer is going to respect your colour space and not try and help out by doing another conversion. Here is what an sRGB image reports as in the bottom left corner of Photoshop

You may have to click on the little > sign to change what it is reporting. As this is only an 8 bit colourspace if you hand it a 16 bit colour image you have way more colours than can fit into 8 bits so it clumps groups of similar colours together, and that gives your banding. It also screws up the colour balance.

[Anthonyexmouth]

2 hours ago, Lumos said:

I believe that your ICC profile is to help your printer match what you see in the monitor.  I was referring to the colourspace that the image exists in. There are several places for this to get mixed up, going from Pixinsight to Lightroom and especially going to your printer, you need to make sure that your printer is going to respect your colour space and not try and help out by doing another conversion. Here is what an sRGB image reports as in the bottom left corner of Photoshop

You may have to click on the little > sign to change what it is reporting. As this is only an 8 bit colourspace if you hand it a 16 bit colour image you have way more colours than can fit into 8 bits so it clumps groups of similar colours together, and that gives your banding. It also screws up the colour balance.

PS reports it as an RGB 16 bit image, can't find where LR reports it. 

[Lumos]

I just spent 15 minutes trying to find this in Lightroom. I think that Lightroom solely uses the Prophoto RGB colourspace, but I have no idea how it maps your original photo to Prophoto RGB. I never use Lightroom so my level of expertise is close to zero, but I still suspect that the colourspace is the problem. In photoshop if you want a border just change the canvas size to be a bit bigger than your image. For cropping the letter c is your friend. By definition a RAW file does not have a colour space, and there is an option to assign one on import into Photoshop along with the bit depth .