Best Handheld Camera for Facade photogrammetry

[AndrewSJCA]

Howdy Folks.

I have been using Agisoft for a fair few years now, predominantly doing aerial surveys with a Phantom 4 with relatively good results using GCP obtained from GPS/Total station measurements (I'm a land surveyor). I've also had some good results using the Phantom 4 camera as a handheld camera (sort of) by walking along a building facade holding the drone to model building walls accurately. However, whenever i try using any phone or non-DSLR digital camera in the same fashion i can never get the same clear results like i do with the Phantom 4 camera.

I know that there is now technology like the "ViDoc" which attaches to your phone and gives you RTK accurate photos from a phone to help with camera positioning, but in using this you're still using a tiny phone sensor compared to a better focal length DSLR. There is also possibility to buy a DSLR to do facade location for our surveys but i'm not a photographer and wouldn't know where to start looking into this, i know DSLRs can get very expensive.

So my question is, does anyone have any advice on the best hand held camera for facade modelling of buildings that is reasonably priced and will give good clear photogrammetric models that i'm after. Are there any phones that are better than others for this? Will any ol' DSLR get the job done properly as long as we can get GCP on the building walls? Literally any advice would be a big help!

(I've tried a brief search online and within the forum and couldn't really find any definitive..)

(Also, it's possible that i'm just getting camera/alignment settings wrong when trying to use hand held devices, and am happy for any feedback on that topic. I know that DroneDeploy/Pix4D set the drone camera settings well when capturing, and it always helps with photo stitching when facade photos can marry up with aerial and oblique photos of half roof/half wall photos which is where i've had success using a drone for this so it's very different to just using a hand held camera)

[Bzuco]

Hello Andrew,

I am using small cheap Canon EOS M10(APSC sensor) with standard lens and I had never significant problems in terms of quality. The most important is take photos from more than just one angle when walking along a building and doing facades(picture in attachment.).

If you need more details from facade, you need to go much closer to facade or use camera with full frame sensor(good for higher ISO and less noise, when light condition are not ideal) and take higher res. photos. But the rule is still the same, take every place you want from 5-9 much different angles.
I always plan walking route before taking photos, so I don't forget on some places on facades.

Buying better lens and use higher aperture values(5.6-8) gives you sharper images.

[BetaTest]

Andrew,
Something with a large sensor, either full-frame or APS-C (cost-effective/common example: a5100) with least lens distortion (the largest POV where you get the least distortion, such as a 40mm on a full frame sensor).

Good luck!

[JJ]

Andrew,
Something with a large sensor, either full-frame or APS-C (cost-effective/common example: a5100)

i think a micro four thirds (mft) body with a small, high quality, sharp, fast prime lens such as the Lumix 20mm f1.7 (40mm equivalent) would give you clearer, sharper photos than the a5100 and kit lens

in fact you would need the best APSC/FF lenses to compete with the sharpness of the little Lumix

some other advantages of mft:

double the field of view at the same f no (so f4 on mft gives the same DOF as f8 on FF)
IBIS (in body image stabilisation) - best in the industry means you can shoot sharp images at lower shutter speeds
compact and light
high quality small bright prime lenses - cheaper than equally sharp and bright APSC/FF lenses

the main disadvantage is inferior low light capabilities but unless you're planning on doing your facade shoot after sunset, this shouldn't be a problem.  and even then the fact that you can shoot handheld at lower shutter speeds means lower ISO, so lower noise