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Author Topic: HANDHELD photogrammetry, high ISO, AI denoise... Doable/Advisable...?  (Read 1115 times)

JohnyJoe

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HANDHELD photogrammetry, high ISO, AI denoise... Doable/Advisable...?

Hello, is doing photogrammetry with Handheld Mirrorless DSLR (Cannon EOS M200), handheld, high ISO (800 lets say) and using newest AI denoise in Lightroom Classic possible...? Like will it look good? NO tripod involved (thus the need for high ISO setting in order to get at least 1/100s+ shutter speeds to hopefully NOT get blurry images) ...?
I have currently Nikon D3200 which i use at home "studio" with tripod for photogrammetry for various objects/props i bring home. I was few times (like 2x times over the span of like 7 years (!)) in the terrain/outside with the camera and tripod... Only like 2x times over 7 years (!!). I always tell myself i will go exclusively a on photoscanning "journey"/trip to the city (i live in village) with the camera and tripod to scan objects i cannot bring home, but over the 7 years (!) i just never went, never "had the time" etc...

SO... i was thinking of getting a 2nd camera (Cannon EOS M200), PURELY for the purpose of "photogrammetry on the go" - to have a camera with me whenever i leave home for the city/outside. Its a smaller camera, so i can have it always with me and if i see something worth scanning (or just shooting for texture purposes) i will pull out the camera and "handheld" scan it... No more telling myself - "Oh... this is nice... ill come later back here with my Nikon and tripod and scan it"... Guess what - i NEVER DID, and thus "lost" the model/scan opportunity... (Few times I tried using a cheap smartphone i always have on me , but the scans are just not good...)

My question is: Is it worth it...? Like will the resulting scans be any good and more or less comparable with my nikon D3200 tripod scans...? Cause with the Cannon EOS M200 i will have to shoot without tripod (and even monopod), just handheld... Can you get a good looking scan handheld with such mirrorless camera...? Depending on the lighting, i will have to probably take majority of shoots with ISO 800, F8-F11, in order to prevent blurry images due to handholding the camera... I should be able to get at least shutter speeds of 1/100 sec and higher (1/125 etc.)... This should be enough to prevent blury images right...? I will denoise the high (800) ISO in lightroom classic using the newest AI denoise feature...

So could it be done, will the final scan be "any good" and comparable/ more or less the same quality as if done with a tripod at home...?

(will use agisoft metashape probably for the photogrammetry)

EDIT:

OR... can i shoot in full sun now these days? It was adviced that you should do scanning in shadow or when the sky is cloudy to get even lighting on your model... This is what i have always done, the downside is that there is LESS light entering the camera in these conditions, so you have to use tripod or high ISO settings... OR... did the "delighting" technology got so good over the years (i started 3d scanning like in 2015 or 2017 (?)), that you can now scan in full sun and auto remove the shadows later on with specialized tech ( i know agisoft metashape has some delighiting tools (2 seperate i think), Unity has some delighting tools, and there are probably others)... Did the delighting got so good over the years, that you can now shoot in full sun?

tazzo

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Re: HANDHELD photogrammetry, high ISO, AI denoise... Doable/Advisable...?
« Reply #1 on: April 30, 2023, 07:36:22 PM »
I am always doing outdoor photogrammetry without a tripod to be much faster, for hobby purposes. I'm using a Sony A6400 with a Sigma 16mm at f/5.6, Auto ISO to scan pretty large statue / things.
When I don't have the camera with me I use my iPhone 11, less details, but better than nothing.
« Last Edit: April 30, 2023, 07:37:56 PM by tazzo »

JohnyJoe

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I am always doing outdoor photogrammetry without a tripod to be much faster, for hobby purposes. I'm using a Sony A6400 with a Sigma 16mm at f/5.6, Auto ISO to scan pretty large statue / things.
When I don't have the camera with me I use my iPhone 11, less details, but better than nothing.

well... thats nice :-), but you didnt say how the scans compare with your tripod scans (at home or outdoors)...?
are they comparable...? (you do do sometimes "proper" scans with tripod etc...?)  shooting in shadows or on a cloudy day... whats the ISO you use (most often) and the shutter speed?

thanks

tazzo

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As always.. depends.

ISO is not so important (of course don't go to crazy values), a modern camera can handle it reasonably well. The most important thing is to avoid shaked images. So a still subject is mandatory.
I am usually shooting in the range 100-800 but I can go as high as 1600 if the situation need that.

In some places is not very practical to bring a tripod.

In low-light conditions a tripod is pretty mandatory, for example have a look at this scan:
https://sketchfab.com/3d-models/fountain-of-neptune-massa-1700-39c860dd53274c88afb43fffd513ee57
Light was super difficult because of a strong directional light and dark everywhere else. I had to do many HDR.. and each one was around 1 minute :'(

https://sketchfab.com/3d-models/massa-a-g-garibaldi-1906-2a49b157a7024474bcb66d028c555945
This scan is handheld, done during sunlight, I just dropped the real texture because was not very interesting.

https://sketchfab.com/3d-models/portale-pomerio-ducale-massa-64c4deac5a554b33928a9788b5666850
This is another example of handheld scan. A drone would be probably useful to cover some high areas, but the main interest area is well covered from ground.

Zoom lenses often require a tripod, but if subject is not moving, you are very steady and using a wide angle lens, you won't have big troubles.

All my scans are hobby-scans. For topographic-level job you need many GCP, markers, a local reference system (ex. done by a total station), etc.. only in that way you can get real accuracy. A tripod alone is not enough to have a robust, consistent model.

What I do sometimes is to use the iPhone AND the Sony Camera, additional points of view can benefit the scan. I have a phone holder that I can put over the hot shoe of the camera, and a remote controller that trigger both at the same time.
« Last Edit: May 01, 2023, 01:44:44 AM by tazzo »

JohnyJoe

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thanks

so what shutter speed you usually use/get...?

tazzo

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I usually use Aperture Priority, the shutter speed is automatically set and depends from the focal lenght used.
For handheld I won´t go less than 1/100, otherwise troubles can arise. Over 50mm you need much faster speed.

cbnewham

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I shoot with a Panasonic GM-5 at ISO 3200 - plenty of noise which is tamed by denoising. All hand held - hence the high ISO for a high shutter speed and good depth of field. I take lots and lots of pictures. The results are always fantastic. Just so long as the image is sharp - that's the most important thing.