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which model of dlp lightcrafter evm is the most Appropriate option in high accuracy application?

Other Parts Discussed in Thread: TIDA-00361, TIDA-00254, DLP4500


I hope you be fine these days.

actually i am going to implement a 3d dental scanner which needs to be accurate(almost bellow of 50 micron). i want to ordet an evm from your products but i cant find any document which be mentioned about the minimum accuracy which be Accessible.

please inform me about this issue and also I will be happy if you have any idea about the system configuration that you think it will be useful in my application.

best regards

  • Hi Hadi,

    The accuracy of the system isn't really going to be determined by the DMD, it will mostly be determined by the camera that you choose as well as the optics that you use on the projector. When choosing the right DMD for your application, I would first look at what size device you need.

    Our DLPLIGHTCRAFTER features a 0.3" DMD and would be a good first choice. There is a TI Design which shows an example of how to do 3D scanning with this device: TIDA-00361

    Generally speaking, the quality and resolution of the scans are also going to be heavily depend on what type of 3D algorithm and methodology you use. Do you have an approach in mind?


  • hello again.
    thanks for complete answers paul.
    I think 0.45" DMD is appropriate for my application and as I'd seen in dlp lightcrafter 4500, there is a projector on it's evm. is'nt it?is it useful for gaining this amount of accuracy or i should look for another projector?
    also i want to use two cameras and as i'd seen the 4500 evm can support two camera trigger cable.I think in the video which you uploaded in your website for showing two camera usage(1.3 mega pixel) of 4500 evm, you said the accuracy in x,y directions are about 100 microns.also i have shown your training videos in site and know the accuracy and resolution are depending on such parameters like the resolution of cameras and etc. but my question is about which camera is suitable for my application(1.3 mega or higher)?can I gain below 50 microns accuracy by this configuration?
  • Hi Hadi,

    It is difficult for me to say for sure what accuracy you will be able to achieve with a particular set up because a lot depends on your algorithms and software development.

    The Lightcrafter 4500 would be a good starting point if you want to use two cameras and have a built in projector. TI does not have any example code to support two cameras however, so keep that in mind.

    We usually recommend a camera resolution that is 2 to 4 times greater than the projector resolution for best results. The LCr4500 has approximately 1.04M mirrors, so 2MP or 4MP camera would be good.

  • Hi paul,

    As i'd seen in your software, there are two types of algorithms(gray,phase shifting) in order to implement structure light algorithm.are they sufficient and suitable for gaining this amount of accuracy? or i should develop them?

    can you recommend me other projectors for my application if i dont want to use built in one?and if i use the other,Does evm 4500 compatible with the other projectors? 

    how about camera?can you recommend me 4MP camera which be suitable and comfortable with 4500 evm?

    I know TI does not have any example code to support two camera but I think it will be possible with developing codes. is'nt it?


  • Hadi,

    It is impossible for me to say what type of accuracy you'll be able to achieve. It depends too much on many system parameters which will be specific to you. You will need to develop or modify the code because we don't have any code available which supports two cameras.

    It is difficult to replace the projector on the Lightcrafter 4500. I would recommend using the system for evaluation and making sure that the ideas and your code will work in general and then develop your own system to get the final specifications you are looking for.

    For a camera, look at the TIDA-00254 user's guide to see which camera we recommend for that reference design. 



  • Hi paul
    Is it possible to inform me about the frame per second of camera?I've seen your camera which is used in dlp4500 demo is 120FPS (1.3 MPixel) and i i wana increase resolution of camera(3.2 Mega) in order to previous messages for gaining high accuracy and keep 120FPS the price will be increased to 1000&(almost twice as much). is 120 FPS necessary for my system or i can decrease it to 60FPS for instance?
  • Hi Hadi,

    You are welcome to use whatever frame rate camera you would like. The reference design allows you to change the camera and projector exposure/period. Higher frame rates are not necessary if speed isn't your top priority.

  • do you have any choice for lens of camera?i would like to choose the camera which you use in demo file(flea USB3 3.2 Mpixel 60FPS) but you didnt mention about the lens. please inform me if you have any suggestion for me.
  • Hadi,

    Your lens choice will depend on your application and what field of view you desire. Here we have generally been using the Computar 8mm f/1.4 lens.