I apologize for the question but I have not found a univocal answer: in the setting of the camera should I use the equivalent 35mm format or the calculated one?
for example: mavic2 zoom 24mm (35 eq)> calculated with the formula found in the forum (Step 1. Before Starting a Project> 2. Configuring the Camera Settings)> Fr 4.36
should i use 24 or 4.36?
thank you
mario
Hi Mario,
It depends on how you define your other camera settings (image width and height, and sensor width).
To make it simple, I suggest you use the real values as defined by the camera manufacturer for all these elements, not the equivalent 35mm ones.
mmmm … The physical dimensions of the sensor are fixed r known, the distance of the sensor is known, the flight height is known. not so simple … there is a big difference between using one datum or the other: using the 35mm focal length eq I have a reasonable and very real flight mission (I calculated the overlap and altitude data using the classic photographic method). Using the calculated focal length I have a flight that lasts 10 times longer at unacceptable altitudes. Manufacturers usually indicate the focal length 35mm eq in all lenses. There is something wrong…
“Most lens manufacturers give the focal length (F35) that corresponds to 35 mm equivalent. To find the real focal length”. Why is it important to know the real focal length and how is it used in relation to the project? According to Pix4D Camera Model values, I calculated my Fr to be 11.813mm while the FL on the camera model is 18mm. How does this affect my results?
Hi @Fia,
have the wrong value for the focal length can influence the calibration of the project.
As you mentioned, Pix4D software optimizes initial camera parameters (18 mm in your case) for each project in order to take into account for specifics of the camera you use and the environmental conditions during the flight. The parameters that you get after the processing is done are called optimized camera parameters (11.813 mm).
Is the difference between the two values is too big then we recommend you to check what are the correct values.
The best way is to perform a camera calibration in order to calculate realistic values. Note that is it highly recommended to use GCPs in the procedure.
Once you are sure about the parameters you can save them in the camera database and use them for future project.
I hope this helps!
Best,