File with .IES extension contains photometric data saved in ASCII text format that conforms to Illuminating Engineering Society of North America IESNA LM-63-86 standard.
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.
After converting the file to the new format, you will be able to use other programs to support it. Keep in mind, however, that the IES file after converting to LDT may differ slightly from the original. The most important information should be kept, but if you want the file after conversion from IES to LDT to be the same, you have to do this carefully and choose the proper application from the list below.
There is no guarantee, of course, that the conversion will come up to all your expectations, but it will certainly help you. If, after all, the effect of converting IES to LDT does not meet your expectations, you can simply try to find on the Internet a different version of your file in IES format, properly converted to a LDT file by someone else. If this fails, use the information provided in the further part of the website.
If after converting the file IES the desired result was not achieved, you can try to change the format of IES file to other than LDT. On our website you will find more information on the following conversion options
Unfortunately, if after performing the two previously described steps (trying to find your IES file converted by someone else, and the attempt to convert it to LDT on your own) you still have a problem with your file, then there are only a few solutions left. You can once again try to find and install an application that can open the IES file in its original format (without conversion to LDT file). Such a solution will be difficult to implement, but it certainly will give the best result.