Survey camera settings

[dsandson]

Just a quick question, I've another job to do on Thursday. The first survey I've done I wasn't too happy with the survey image colours. They were very washed out.

Saw a recent comment from another poster saying that Survey Mode over-rides the current camera settings. Is this true? Or is there another way to alter the settings to produce a better exposed survey image?

 

[10-8]

Just a quick question, I've another job to do on Thursday. The first survey I've done I wasn't too happy with the survey image colours. They were very washed out.

Saw a recent comment from another poster saying that Survey Mode over-rides the current camera settings. Is this true? Or is there another way to alter the settings to produce a better exposed survey image?

Which camera are you using? I find that the E90 images are very good and stitch great.

 

[dsandson]

Sorry, Yeah the E90 was used. Stitching was great in Pix4D. Used higher quality settings and got a very low level of noise on the point cloud. The exposure and white balance were very poor though.

Pix4D Cloud link
Pix4D Cloud

 

[Graham]

In camera distortion correction became disabled during surveys at the last camera update. Whether this is important may depend on how bad your distortion is. The distortion on mine is poor and I know results are better in PIX4D with distortion correction on. Certainly there was a big improvement when distortion correction became available.
I work round this by entering survey mode, then before taking off or during flight, go through the camera settings again, making changes as necessary. This is also required at every battery change. There is a PITA notice comes up when you make the change, warning of chromatic aberration with distortion correction. I have not noticed any and would gladly take such instead of the uncorrected distortion. Surely they only need to mention the issue in the manual?
The camera also resets the colour mode to unprocessed. Quite why it does this when PIX4D uses jpegs which are processed images is unclear.
I normally use the enhanced colour mode on cloudy and neutral on sunny days.
I am happy to use auto for white balance and -0.5 for exposure if light quality is changing during the survey, otherwise I use manual.

 

[record.play.rewind]

@Graham workflow is great. Just to add to the auto exposure and EV -0.5 this is a good setup, except when it’s cloudy with partial sun, as the sun creates shadows. EV at -0.3 will gain better results in your point cloud as well as create a better mesh.

With every material that’s gathered on the field, check each exposure again manually and if the materials cannot be retaken after flight, use Lightroom to treat every material for exposure correction.

 

[dsandson]

Graham,

Thats a fanstatic response, you're a gent. That pretty much everything I need to know!

Unprocessed is probably a good description of the images I have. I knew of the distortion correction being off for surveys, and I seem to be lucky enough that it hasn't impacted the processing.

Think I understand why Yuneec deselects the distortion fix for surveys... Its probably not good for accuracy when the in camera distortion fix is followed by Pix4D's own camera calibration & correction. However I suppose that depends on the quality of the distortion correction in camera

 

[arruntus]

It is something that we already commented, it would be very interesting if they told us what parameters are changed and what parameters remain the same. The ratio of size of the image at least does not change, the resolution. Other parameters do change and it seems that with the last update things changed again.

In the end what Graham says is the right thing, check when the mission starts, you can pause and check, then resume and ready. This at least until we have clear which parameters change and which do not

 

[Graham]

@Graham workflow is great. Just to add to the auto exposure and EV -0.5 this is a good setup, except when it’s cloudy with partial sun, as the sun creates shadows. EV at -0.3 will gain better results in your point cloud as well as create a better mesh.

With every material that’s gathered on the field, check each exposure again manually and if the materials cannot be retaken after flight, use Lightroom to treat every material for exposure correction.

Thanks. The E90 exposure compensation has 0.5EV settings and not 0.3.
I use Cyberlink Photodirector to adjust images as I prefer to avoid monthly subscriptions.
I would consider using Lightroom if there was an E90 lens profile, but I understand there isn't.