Trouble with Preview boxes

[Twinkle Star]

Hello to everybody, 
I´ve just downloaded the trial version of PI, went through the video demos and consequently have tried it out on my own images. I feel a bit shaky and confused at the moment because of the immense contence and power of this tool (up to now use Photoshop).
My main problem is handling these Previews: I cannot draw boxes in the images to build these previews. ALT+N does not work and the respective icon on the top bar is not active! I spent a whole hour yesterday to sort this out - no chance.
Does anybody know what´s wrong? I use TIFF images made by my Nikon D70 mod / 7000 after having stacked them with Deep sky stacker. I know I can stack images in PI as well, but up to now I haven´t tried that out.
I appreciate any advice and help,
Angelika

[Juan Conejero]

Hi Angelika,

Welcome to PixInsight Forum.

I cannot draw boxes in the images to build these previews. ALT+N does not work and the respective icon on the top bar is not active!

That's strange. That can only happen if you don't have any image selected. The New Preview working mode is only available when you have an image open and its main view is active. Could it be that you already have a preview and it is selected as the image's current view? Nested previews are not allowed (you cannot create a preview into a preview).

Do you know Harry Page's videos? If you haven't already done so, I recommend you start with his newbie series:

http://harrysastroshed.com/pixinsighthomenewbie.html

We are working on an official series on PixInsight's interface, but our workload is huge currently so it will take some more time.

Let me know if this helps.

[Twinkle Star]

Hi Juan,
ok, I will check that - as I´m a bit confused with all the different views, I think that you´ve made a point.
Yes, I know Harries videos, that was the first thing I did, but they do not solve this problem.
I will check it in the evening,
thanks so much for your help,

Angelika

[Cleon_Wells]

Angelika, I've seen this issue on my Mac, sometimes option + N does not work, when this happens I use the PreView icons New and Delete, see attached image.
Cleon

[Thorsten Lockert]

Angelika, I've seen this issue on my Mac, sometimes option + N does not work, when this happens I use the PreView icons New and Delete, see attached image.
Cleon

I see Alt-N not working on my Mac too -- but the icon to do "New Preview Mode" does work. Once I have created a preview, it reverts, and I have to click it again to make another one. Again, Alt-N does not work.

Once in a blue moon it does work with Alt-N, but I haven't discovered a pattern to that as of yet.

Thorsten

[Twinkle Star]

thanks to you all for helping me. Juan was right, the problem was that I didn´t chose an image but a preview or something.
This time I carefully made sure I worked on a proper image - and it worked with the icon on the upper bar. Alt-N still does not work.

Another thing: I wanted to save the image in jpeg format. PI replied: .... "The generated file does not contain an accurate representation of the image".
How can I fix this. When saving out of Photoshop I had to convert the image into 8-bit format; is this problem here similar?

Thanks in advance,
Angelika

[pfile]

there's no fixing that. jpeg uses a lossy compression of the image data. if you want to display your file on the web, jpeg is fine. but if you want to save a proper, exact copy of your image you need to use something like FITS with 32-bit floating point samples. more accurately, you need to use a sample depth of whatever the image you are using has.