LDT File Extension

What is LDT file?

File with LDT extension contains photometric data. LDT fles are generally created and supplied by lighting products manufactures. LDT files store data for given luminaire, for example:

• light distribution curve,
• light intensity,
• size of the luminaire.

Usage

LDT files are used by specialized lighting installation design software.

How LDT files save data?

LDT is a plain text file saved in Eulumdat DIALux format.

Programs which support LDT file extension

The following listing features LDT-compatible programs. LDT files can be encountered on all system platforms, including mobile, yet there is no guarantee each will properly support such files.

Updated: 04/05/2020

How to open file with LDT extension?

Being unable to open files with LDT extension can be have various origins. Fortunately, most common problems with LDT files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. We have prepared a listing of which will help you resolve your problems with LDT files.

Step 1. Install ZEMAX software

Problems with opening and working with LDT files are most probably having to do with no proper software compatible with LDT files being present on your machine. This one is an easy one. Select ZEMAX or one of the recommended programs (for example, EulumdatTools) and download it from appropriate source and install on your system. The full list of programs grouped by operating systems can be found above. If you want to download ZEMAX installer in the most secured manner, we suggest you visit ZEMAX Development Corporation website and download from their official repositories.

Step 2. Check the version of ZEMAX and update if needed

You still cannot access LDT files although ZEMAX is installed on your system? Make sure that the software is up to date. Sometimes software developers introduce new formats in place of that already supports along with newer versions of their applications. If you have an older version of ZEMAX installed, it may not support LDT format. All of the file formats that were handled just fine by the previous versions of given program should be also possible to open using ZEMAX.

Step 3. Set the default application to open LDT files to ZEMAX

If the issue has not been solved in the previous step, you should associate LDT files with latest version of ZEMAX you have installed on your device. The process of associating file formats with default application may differ in details depending on platform, but the basic procedure is very similar.

The procedure to change the default program in Windows

• Clicking the LDT with right mouse button will bring a menu from which you should select the Open with option
• Select Choose another app → More apps
• The last step is to select Look for another app on this PC option supply the directory path to the folder where ZEMAX is installed. Now all that is left is to confirm your choice by selecting Always use this app to open LDT files and clicking OK.

The procedure to change the default program in Mac OS

• By clicking right mouse button on the selected LDT file open the file menu and choose Information
• Find the Open with option – click the title if its hidden
• Select ZEMAX and click Change for all...
• Finally, a This change will be applied to all files with LDT extension message should pop-up. Click Continue button in order to confirm your choice.

Step 4. Ensure that the LDT file is complete and free of errors

Should the problem still occur after following steps 1-3, check if the LDT file is valid. Being unable to access the file can be related to various issues.

1. Check the LDT file for viruses or malware

If the LDT is indeed infected, it is possible that the malware is blocking it from opening. Scan the LDT file as well as your computer for malware or viruses. If the LDT file is indeed infected follow the instructions below.

2. Check whether the file is corrupted or damaged

Did you receive the LDT file in question from a different person? Ask him/her to send it one more time. It is possible that the file has not been properly copied to a data storage and is incomplete and therefore cannot be opened. If the LDT file has been downloaded from the internet only partially, try to redownload it.

3. Ensure that you have appropriate access rights

Some files require elevated access rights to open them. Log in using an administrative account and see If this solves the problem.

4. Verify that your device fulfills the requirements to be able to open ZEMAX

If the system is under havy load, it may not be able to handle the program that you use to open files with LDT extension. In this case close the other applications.

5. Verify that your operating system and drivers are up to date

Up-to-date system and drivers not only makes your computer more secure, but also may solve problems with ZENAX Source EULUMDAT Format file. It may be the case that the LDT files work properly with updated software that addresses some system bugs.

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