Realsense Camera D435 with different imaging lenses

[Wgao6]

I have Realsense D435 camera, but the View is big for us.

I changed both lenses for left and right infrared image sensor from 1.93mm to 3.8mm effective focal length.

I captured images through realsense-view and did intrinsic calibration by Matlab script, and write back the calibration result to D435

through CustomRW -w CalibrationParameters.xml command.

but when I run camera at 1280x800 resolution, it shows hardware problem, and 640x480 no problem, but almost no depth matching point.

Is there a limit in D435 processing card that limit the Focal length left and right value away from the original 1.93mm (643.3 pixels)?

[Wgao6]

I have one more question about D435 camera:

The tool I use to evaluate the D435 camera is realsense-view (librealsense/tools), I'd like to add external IR projection pattern,

I noticed that there is a button the enable external sync (PIN5 on the sync connector), but the pulse is after the current image capture is done.

How do I enable the external projector pulse so that my external IR projector is turned on the same duration as the build-in VCSEL projector in D435?

Thanks

[idata]

Hello Wenliang gao,

Regarding the use of a different lense and your camera calibration, I have sent you a private email. Regarding the external sync for the D400 cameras, this feature is under development, as soon as this is developed we will post it in the front page of the community. The ETA for this development is for Q2 of 2018. Thanks for your understanding. Best Regards, Juan N.

[Wgao6]

Hi Juan,

Thanks.

The calibration with custom lenses issue is in better situation now. what I did is as follows.

1) write a unit calibration xml file to the camera (fx=fy=633.33; pxy=640,400; all 0 for distortion, unit matrix for rotation and no translation)

2) capture 20 image pairs (left imager and right imager) at different orientation and positions in the FOV.

3) do off-line calibration (Matlab script)

4) write the xml file (with calibration result from Matlab script) to camera D435

Now it works in any resolution except 1280x800, is it because the image does not cover the whole 1280x800 after rectification?

it did not work before because I did not do step 1 above, I did not realize the the images displayed (and be saved for calibration) under the tool realsense-view is NOT raw images instead they are already RECTIFIED images.

Thanks

Wen

[idata]

Hello Wen,

The 1280x800 is only for calibration. Depth does not support 1280x800, depth only supports 1280x720 and smaller resolutions. Best Regards, Juan N.

[Wgao6]

In the realsense-view tool (librealsense/tools/realsense-view) how do I specify the depth range?

for example: I need only measure the depth range from 0.5 meter to 1 meter.

Thanks

[idata]

Hello wenliang,

See the attached imaged, in the red circle you will find how to specify the depth range. Regards, Juan N.

[Wgao6]

Hi Juan,

Thanks.

I tried that (I set min 0.6m, max 1.2m) but it still give me the whole depth.

is the setting derived from shift in pixels (so that it's focal length related, I use a focal length= 3.88mm lens for left and right)?

Thanks

Wen

[idata]

Hello WenLiang,

Can you please clarify what you are trying to achieve? The RealSense Viewer does not report depth beyond the min and max that are set. Please try the following function and let me know if this is what you are looking for: https://github.com/IntelRealSense/librealsense/tree/master/examples/alignBest Regards, Juan N.

[JYu33]

Hello, I would like to ask how to save the depth image of realsense in the format of TXT file. Each value in the TXT file represents the distance from this point to the depth camera.

[Wgao6]

Is the following signal of Realsense D435 available now?

IR project ON (or Left & Right imager exposure on ) signal output through synchronization connector.

Thanks

Wen

[idata]

Hello Wenliang,

Thank you for your interest in the Intel® RealSense™ Technology.This feature is not available yet. It requires a firmware that is not released yet.When this feature will be available there will be an announcement on the front page of the community with all the details.Best regards,GeorgeIntel Customer Support

[MartyG]

The firmware update that enables hardware sync is scheduled for the coming-soon 5.9.14 firmware version.

[Wgao6]

Hi Marty,

Thanks. Do you have estimated release date of D435 firmware version 5.9.14?

Wen

[MartyG]

I don't have a date, though it should be soon. I'll post on the forum as soon as it's available, as I check every day for updates. You can track it yourself on the link below too.

https://downloadcenter.intel.com/download/27924/Latest-Firmware-for-Intel-RealSense-D400-Product-Family?v=t Download Latest Firmware for Intel® RealSense™ D400 Product Family

[YNava]

I'm a development engineer at ANYbotics AG (Zürich, Switzerland). I'm working on the development of the perception and SLAM systems for https://www.anybotics.com/anymal/ ANYmal, our innovative and versatile quadruped robot.

We are working towards integrating the RealSense D400/D435 sensors into our sensor suite, which involves building ingress-protection housings for them. However, we have had some problems getting right the type of crystal and adhesives for our custom housings.

Would it be possible to obtain more information on the type of crystal and adhesive used in the original RealSense housing? Or get in touch with a representative concerning this. We're very interested in using your sensors on our platform.

Thank you very much.

Best regards,

Yoshua Nava

[MartyG]

The RealSense engineers and developers are located at the RealSense GitHub site. You can post a question there by going to the link below and clicking the 'New Issue' button. Thanks!

https://github.com/IntelRealSense/librealsense/issues Issues · IntelRealSense/librealsense · GitHub

[YNava]

Thank you, MartyG

[MartyG]

You can also find guidance on the casing materials at page 76 to 78 of the 400 Series data sheet document.

https://www.intel.com/content/dam/support/us/en/documents/emerging-technologies/intel-realsense-technology/Intel-RealSense-D400-Series-Datasheet.pdf https://www.intel.com/content/dam/support/us/en/documents/emerging-technologies/intel-realsense-technology/Intel-RealSen…

[MartyG]

I'll let the GitHub staff provide their own answer to the post you made there, and provide some more supporting information here that I found by looking at the data sheet of the older R200 and SR300 camera models.

********

"Glass or transparent layers covering the laser projector and infrared sensor must have a uniform thickness and no perceivable curving or bending to minimize the distortion of the transmitted and reflected patterns".

[per2012]

Helo! We have same task to change both lenses in D435 to 4.2mm focal length.

We will be very happy if you help us.

I disassembled the D435 body and see lenses rigidly glued with lens holder.

I have no idea how to dismantle them except how to break the jumpers to holder.

And lens seems as 9-10mm diameter, but all ordinaty lens is 12mm lend mount.