he mScope viewer is limited in what it can show to the screen depending on how much memory is allocated to Java.  In typical installations (where 60-90 MB of memory is reserved for applets) some images when viewed full screen, regardless of their file size, may cause out of memory problems when scaled in the mScope Viewer.

Make sure you have the latest version of Java

Out of memory problems are solved in the latest Windows java releases. If you are a Windows user, just make sure you are running our recommended version of java (1.6.0_14, or later).  If this is not possible, an alternative solution is listed at the bottom of the page.

For Mac users, the situation is more complicated, though improving.  In all cases, check Software Update... to ensure your Mac software is up to date.

The easiest Mac solution is to use Mac Chrome, or Mac Firefox 4 (in beta as of this writing). Mac Safari users can do the workaround listed below.

Mac Safari Users

Mac Safari (all versions, all platforms) ignores java runtime parameters for applet memory, but the fix is relatively simple.

To increase the amount of memory given to java applets when they start up, you can do the steps below (with care -- misuse can break the use of java applets on your browser).

First, find Java preferences. There are two ways to get to Java Preferences:

1. Click on the spotlight icon (magnifying glass) in the upper right corner of OS X and type Java. Java Preferences should appear as the "Top Hit". Click on it.
2. Using the Finder, click on Macintosh HD. Click Applications. Click on Utilities. (Some Macs: if you see a Java folder, click on it. If you now see a J2SE 5.0 folder, click on that.) Doubleclick on Java Preferences.

Once you're there, to change the applet runtime parameters:

• If you see a Java Applet Plugin list at this point, select the top list item (which varies by OS version) and click Options...
• Under Java Applet Runtime Parameters, there is a text entry box. Click in it and add: -Xmx256m
• If there is already a parameter in this box, be sure there is a space between teh old and new parameters. Also note: 512 MB is a suggestion, and depends on your available memory. For example, 512 MB is not recommended unless you have more than 2 GB of memory on your Mac.
• Save and Close.
• Exit all browser windows and restart.

Instructions for Mac Firefox users

The easiest instruction for Mac Firefox users is to switch to Safari or Chrome, or upgrade to Firefox 4 (in beta). More details below.

Mac Firefox 3.x

Since Java 1.5 update 2, Mac Firefox 3.X does not recognize any Applet Runtime Parameters, so the Mac Safari workaround described above no longer works.

Non-Snow Leopard (OS 10.4 and 10.5) users who are comfortable modifying configuration files can use the Finder to go to their user directory and modify the Library/Caches/Java/deployment.properties file to include this line (or modify the line, if it's already present):

deployment.javapi.jre.1.5.0.args=-Xmx256m

Note: this suggestion should be used with care, as misuse can break the use of java applets on your browser.

This workaround is described in more detail in this Apple support page : http://support.apple.com/kb/HT3210

Hopefully this problem will eventually be resolved in a simpler way for Mac Firefox users.

We don't have a solution for Snow Leopard (OS 10.6) users for Firefox 3.X, as the above workaround has gone away.

Mac Firefox 4.x, Mac Chrome

Beta version of Firefox 4, and the latest version of Mac Chrome, fixes problems with runtime parameters -- you can use the mScope viewer without any problems.

Instructions for Windows Users (all browsers), earlier versions of Java

If you encounter out of memory errors and cannot run 1.6.0_14+, one option is to increase the amount of memory given to java applets when they start up.  Note: this suggestion should be used with care, as misuse can break the use of java applets in your browser

• Click on Start
• Click on Control Panel
• Double click on the Java Plug-in icon (which may be under 'Other Control Panel Options')
• Select the Java tab and click on the View button, under the Java Applet Runtime Settings section
• Find the most recent 'Version' Java runtime line and double click on the 'Java Runtime Parameters' box and add -Xmx256m (set Java maximum heap size to 256 MB). If there is already a parameter in this box, be sure there is a space between the old and new parameters
• Click 'OK' to exit all dialogs. Close the control panel window

NOTE: 256 MB is a suggestion, and depends upon your available memory.  Trying this is not recommended unless you have more then 1 GB of memory on your PC.