Sketchfab Forum

Share Gear / Software or Hardware Comparisons / Scan Experiments

(Nebulousflynn) #1

With so many options and workflows out there for museums / digitizers it could be useful to start a thread for people to share their findings, set up, gear and best practice for 3D scanning in the Cultural Heritage sector.

To start things off, here's a pic of my homemade portable set up in action:

Full dislcosure: I had to reshoot the porcelain figure with a black background (shooting white on white was a bad idea!)

(Nebulousflynn) #2

Hardware reviews by Nick Lievendag

Nick Lievendag has been building collections around his comparative test reviews i.e. Recap360, Structure Sensor, etc.

(Nebulousflynn) #3

Scan Comparisons by Samantha Porter

PhD candidate Samantha Porter has shared some nice examples of her experiments with scanning shiny obsidian objects.

CAA Conference 2016 by Samantha Porter on Sketchfab

(Nebulousflynn) #4

Scanner tests by Aukland Museum

Aukland Museum has collated results of some of their tests with David SLS1 and Creaform Go!Scan 20 scanning setups:

Scanner Tests by Auckland Museum on Sketchfab

(Abby Crawford) #5

Here are some model experiments made using different types of cameras - iPhone and DSLR. It's a small collection at the moment, but should get larger and more methodologically rigorous soon.

iPhone vs DSLR by Abby Crawford on Sketchfab

(Nebulousflynn) #6

Software Comparison on Wikipedia

Loads of software I've never even heard of in here!

(Nestor F. Marques) #7

Some time ago I experimented with scanning qualities. I made 3 versions of the same object. It was scanned with my usual gear: Canon 5Ds mounting a 40 mm lens and processed with a 16 Gb RAM Macbook Pro in Photoscan.

The experiment was to make the model as light as possible without loosing geometrical definition and to look for the limit. I learned that each case has its own complications but here is the example.

The first model is a decimated untouched model from the 3M poly mesh.

Legio original decimada by Néstor F. Marqués on Sketchfab

The second model is the one that was finally published (manually optimized).

Ara votiva de Legio by Néstor F. Marqués on Sketchfab

And the last one is the experimental model contaning only 337 faces. It looses a lot of geometrical detail but its still decent for some applications.

Pedestal Low Poly by Néstor F. Marqués on Sketchfab

(Nestor F. Marques) #8

Also I wanted to share something about my gear and scanning results. I originally posted it here, but I wanted it to be also in this post (which I think will serve as a common share spot)

I can tell you something about my own experience. I've learned that the most important part of a photogrammetric capture is the photo taking (not entirely the gear, but instead your experience with photography). Here you have two examples: one is made two years ago with a low profile gear and the other one is made with my current setup.

Boxeador (The Boxer) by Néstor F. Marqués on Sketchfab

This was taken with a 18-55 mm lens on a Canon 450D, processed with Photoscan version 0.9 or 1.0 (aprox.) and edited in Blender in my 2011 8Gb RAM Macbook Pro. Despite having a low end camera, the results were pretty great, also thanks to Sketchfab's tweaking capabilities, as @nebulousflynn already told you (awesome tutorial, btw)

Bronce ibérico con cabeza de lobo by Néstor F. Marqués on Sketchfab

On the other hand, the second model was made only a few months ago with my new Canon 5Ds mounting a 40 mm lens and processed with my current 16 Gb RAM Macbook Pro. Also Blender and Sketchfab retouching.

Between this two models there is a significant several thousand euros difference in the camera equipment, but if you see them, both of them have good quality and visual appeal. What I mean with all of this, is that it doesn't matter what camera you have as long as the capture planing and method are good. Thus you'll always have great results.

(Banalesmuseovirtual) #9

Hi! Thanks for good advice here.
I would like to contribute with a gadget I built myself. I have already used several times to get captures from a high point of view, specially monuments, and it works! I am quite proud of it... :wink:
This is a simple diagram on the pole. It's all in Spanish... I think it's easy to see the idea, but I can translate it if anyone is interested.

An here is an example of how to use it: I can control my Nikon camera from my table for just a few euros.

You can read a more complete description on my little blog. Again in Spanish; if interested, please tell me so I can translate.!Inventos-del-TBO/colb/56e99a970cf282fc9b00cda6

For instance, I used it for this model:

Acotado funerario de los Atilios (siglo I d.C.) by Los Bañales - Museo Virtual on Sketchfab

Unfortunately, the monument was taller than the pole, so I had to complete the top of it in Blender. But it was very useful to capture correctly the parts that were facing upwards.

Hope it is useful for someone! :wink:

(Nebulousflynn) #10

Thank you @abbyec, @NestorMarques and @banalesmuseovirtual - these are all useful and very interesting contributions!

These are just the kind of things I was hoping people would share - I think all this information will be really useful to people/institutions taking their fist steps with photogrammetry.

Specific details like camera make and model, photography techniques and software and hardware specs are invaluable in helping 'de-mystify' the process and democratize knowledge of these techniques.

@banalesmuseovirtual - I for one would love to read a translation of your awesome design, is it a painter's pole?

(Banalesmuseovirtual) #11

Hi, Nebulous! No, it is even more grotesque :blush: : it's a telescopic pole to clean swimmingpools! (I can't imagine if that thing has a name itself...) It's cheaper, longer and more resistant than painters` poles.
I will prepare a brief in English this afternoon. Thanks for the appreciation!

(Nebulousflynn) #12

Scan Comparisons by dtmcnamara

Collection with examples of same object processed with PhotoScan, 3D Zephyr, ReCap360 and Reality Capture:

Scan Comparisons by dtmcnamara by Thomas Flynn on Sketchfab

(Nebulousflynn) #13

Flash Photography Experiments by Nordnorsk Fartøyvernsenter og Båtmuseum

Going against conventional wisdom and advice, @gunnar has been getting some pretty convincing results using a ring-flash during photography:

Flash Photography Experiments by @gunnar by Thomas Flynn on Sketchfab

(Gunnar) #14

Thank you for sharing! I put som comments to the model to share what gear I'm using.

(Nebulousflynn) #15

Great - I think this will be really useful for people new to photogrammetry.

(Banalesmuseovirtual) #16

Here is the translation (shortened):

Photogrammetric scans of Heritage elements are not always placed at an accessible high level. Photos of the upper sides are annoying and complicated, and it’s frustrating when the model is unfinished. You can find solutions to raise the camera position, but commercial poles for photography are expensive and I did not find any over 3.5 m. Drones, cranes and mobile platforms are even more expensive, and you need licence, permits, planning…

So this is can be an easy and cheap solution.

All the components can be found at a reasonable price, and you only need a drill for the upper hole. The total budget is 45 € (plus 45 € for the WiFi connection, that has other utilities.

But most important: does it work? It provides a maximum height of 4.5 m. I have used it several times, getting good results for the faces that are facing up. So this “top advanced mega-future sofisticated technology device” can be useful for anyone in this situation.

Sorry for my English! :wink:

(Banalesmuseovirtual) #17

By the way: another Sketchfab mate from Spain told me yesterday about a solution with a fishing rod and action camera that allows him to scan up to 10 m. height. I might test it this summer...

(Banalesmuseovirtual) #18

I just remembered this montage I did some time ago about my capturing kit:

I have added some more gadgets since then, but this can be a good start point that covers all kind of pieces to scan.
Hope it is useful!

Edit: I just realised of an error: the camera is obviously DSLR, not SLR.

(Misterdevious) #19

Just a noob photography tip for those that may not know:

Good depth of field (DoF) is imperative for scanning small objects. Good DoF will mean less artifacts in your final mesh, much less to clean up in post and the highest quality texture/image maps. Using a 50mm lens on my Canon 6D, I usually set the f-stop to f11 or greater to achieve 6" - 12" range of focus on the object (see the Simon scan for an example). This will usually mean that your exposure time will be 1/4 of a second or longer to get the best image possible. There was almost no cleanup of the original model (however, with this one I played with retopology) and the textures were sharp and crisp over the entire mesh. (I can post the original scan mesh for comparison if you like)

Anyway, that's my little tip... :smile:

Simon (Doll Head) by misterdevious on Sketchfab

(Nebulousflynn) #20

good advice @misterdevious - specifics like this are really useful. How big was the doll's head IRL?

would be great to see the original scan to compare if you get time to upload...