Reply To: What practical use of connection between Image Render Output Dimensions and Camera Sensor Size?

[Wayne Dixon]

You don’t need to play with the sensor size unless you are trying to match a specific real work camera. (It will probably break your brain if you do haha)

The default sensor size is 36mm Auto.  It is mean to mimic the “Full Frame” format of shooting onto 35mm film/or digital sensor.

The sensor size has to do with the projection of the subject onto the image plane inside the camera (that’s the point where the image is formed inside the camera)

A smaller sensor size is basically cropping out a portion of what is projected, which makes it appear more zoomed (when technically it isn’t)

I hope that made sense.

As for the Resolution settings, as far as I know, Blender will always scale the frame of the camera (the orange outline) based on the ratio of the X and Y.  That is why 400×300 looks the same as 800×600 in the viewport (but the render output will be less pixilated)

You can test this out by starting with any value that is the same.  Say 1000×1000 and then grab one of them and slide it up and down. You will see it change from scaling the horizontal to scaling the vertical size.

If you wanted to print an image at say 300dpi, the best solution I have found is to calculate the print size (real world size) and then multiply by 300.  

I usually have to google this every time I do it so it’s worth double checking my calculations here but….

If you want something to be 16inches wide by 9 inches high.
Start by setting the X to 16px and then multiply by 300
then set the Y to 9px and multiply by 300.

That will be 4800 x 2700

I think I’m correct in that, but as I said, I always do a quick google before sending any image to a client (that needs stuff for printing….which isn’t too often for me)

Anyway, I hope that has been helpful.