Screen Stretch Histogram

Discussion in 'Image Capture' started by JohnJ, Jun 8, 2015.

  1. JohnJ

    JohnJ Standard User

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    I am using MaximDL Pro Version 6.08.
    The histogram in Screen Stretch for a simple dark image with a short integration time shows a significant gap in the center of the histogram rather than the near Gaussian curve I would expect for a dark image. The range of pixels for the image is 179 thru 499. The histogram shows zero between 280 and 400 but if I adjust the cursers to linearize the displayed levels in the gap (280-400), it shows roughly half of the pixels with gray levels in the image indicating that they are between these levels.
    This problems is in other more complex images also.
     
  2. Tim

    Tim Staff Member

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    Can you send a copy of the FITS image dark frame for us to examine?
     
  3. JohnJ

    JohnJ Standard User

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    Thanks for responding to my request. Sorry for my delay but I have been traveling and I did not have access to my computer. I tried to upload the image fit file but is was 17.4MB and it indicated that it was too large to upload. I did upload a pdf of the Screen Stretch with the cursers at 294 and 383 where the histogram shows zero pixels but the image shows many pixels displayed between black and white. Thanks for you help. John
     

    Attached Files:

  4. Tim

    Tim Staff Member

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    We need to be able to analyze the original FITS image to get a better idea of what is happening.

    Can you upload your image to our FTP server?

    --------

    Windows XP:

    You can login to our FTP server with these credentials to avoid transfer problems and size restrictions:

    FTP Host Address: ftp.diffractionlimited.com
    User ID : anonymous@diffractionlimited.com
    Password : (NO PASSWORD)

    To login, open "Windows Explorer", (Not Internet Explorer), and paste the following address into the address bar:

    ftp://anonymous%40diffractionlimited.com:password@diffractionlimited.com

    - Please *ZIP* your images, and use your name as the file name for the zip, i.e.: "myname.zip".

    - Upload your ZIP file into the "INCOMING" folder.

    - Once you upload your image into the "Incoming" folder, *NO* file will appear...this is normal.

    - Please inform us when you have completed the upload

    -----------------------

    Windows Vista/7:

    1: Click on Start button in Windows Vista/7 and then click on "Computer".

    2: Click on “Map network drive”

    3: "Map Network Drive" window will open. Now click on the link "Connect to a Web site that you can use to store your documents and pictures."

    4: Now simply follow the step by step wizard to add a new network location. Select"Choose a custom network location" when given the choice of where to create this network connection.

    5: Type our ftp address ftp://ftp.diffractionlimited.com and click "Next"

    6: Check "Log on anonymously" then click "Next"

    7: Once the wizard is completed, if it does not open automatically, click on the Start button in Windows Vista/7 and then click on "Computer", and you should see the FTP server listed under the Network Location. You can access it the same way you access any folder on your computer.

    -----------------------

    Third party FTP Clients such as "Filezilla" can be used to upload software to our FTP server as well.

    https://filezilla-project.org/download.php

    Once the software is installed, use the following credentials to connect:

    Host: ftp.diffractionlimited.com
    User Name: anonymous@diffractionlimited.com
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    Copy or drag your files into the window panel on the right to upload your files.

    Once the files have been successfully uploaded, you will *not* see them in the Filezilla program but we will receive them.

    Let us know when the transfer is complete.

    -------
     
  5. JohnJ

    JohnJ Standard User

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    I hopefully uploaded the file John.Juvinall.zip
    I have windows 8 so I followed the general instructions for XP.
    The file did show up in "incoming" folder so I hope it went correctly.
     
  6. Tim

    Tim Staff Member

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    I opened your image on my system and the problem does not appear...there is no gap.

    After speaking with one of our developers, it may simply be a glitch as he can not explain how this could happen.

    If you have not done so already, try downloading a fresh copy of MaxIm DL and reinstall. http://www.cyanogen.com/down/MaxImDL608.exe
     
  7. JohnJ

    JohnJ Standard User

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  8. Tim

    Tim Staff Member

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    Try renaming your Settings folder to "Settings.BACKUP" and restart MaxIm DL.

    It's in "Documents\MaxIm DL 6".
     
  9. JohnJ

    JohnJ Standard User

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    I closed MaxImDL, renamed the settings folder, restarted MaxImDL and the same gap.

    I assume you were able to open my screen shot of the histogram to verify that this in fact is not proper operation. Is this correct?
     
  10. Tim

    Tim Staff Member

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    Yes, I can see your screenshot, but I am not able to replicate the problem. Have you tried opening it on a different computer?
     
  11. JohnJ

    JohnJ Standard User

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    Not yet, I will see if I can get an old computer to work to try it. I am using Lenovo Yoga 2 Pro.
     
  12. JohnJ

    JohnJ Standard User

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    Ok, it works on my old computer running XP but this computer is not very usable, it has too many problems.
    I assume MaxImDL has been tested on Windows 8. What else can I do?
    What are the chances that it would work if I bought a new computer of similar type?
     
  13. Tim

    Tim Staff Member

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    Yes it has been tested on Windows 8. Many of our users have been using it for a while now with no problems.

    The problem is somehow localized to that computer, such as corrupt OS, or system drivers are out of date. Are your graphics card drivers up to date?
     
  14. JohnJ

    JohnJ Standard User

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    It seems that my drivers should be up to date. The computer is frequently updating different software and drivers.

    It is difficult to think that it is a display problem, I have changed the resolution on the computer and the gap stays the same and the image always looks correct.

    It does seem that renaming the settings file should have eliminated any setting problem.

    Can you think of anything else that I can try? If not I can have someone that knows more about computers than I do look at it.

    I have one more day on my evaluation period, can you give me an extension?

    Thanks for your help.

    John
     
  15. JohnJ

    JohnJ Standard User

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    I was not able to get this problem resolved before my one month trial subscription ended. Is it possible to renew the trial subscription to give me more time to get Maxim DL working on my Windows 8 computer?
     
  16. Adam Robichaud

    Adam Robichaud Staff Member

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    Hi John,

    As we discussed on the phone, I'll be investigating your ticket. I'll let you know when I've got something worth sharing.

    Cheers,
    -Adam
     
  17. JohnJ

    JohnJ Standard User

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    Hi Adam,

    Is there any progress in finding the histogram problem on my Windows 8.1 computer?
    Do you think it is a problem with the software or my computer?

    Thanks,
    John
     
  18. Adam Robichaud

    Adam Robichaud Staff Member

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    I haven't. I suspect it's something to do with your PC, but without being able to reproduce it, I'm at a loss. Sorry.

    Have you tried running MaxIm DL in compatibility mode?
     
  19. JohnJ

    JohnJ Standard User

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    Adam,

    I tried compatibility mode with no success.
    Do you have any other ideas that I can try on my computer or that I could have someone try that knows more about computers than I do?

    Thanks,
    John
     

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