i have chroma green BG, sony AR7 2 on stand and 2 soft-boxes. BG is very much even. I am trying do make some fruits but i dont get any points at all. i saw some cases in the forum were ppl were getting few points but i got 0.
Is it standard for this “studio setup” to be so difficult to get results ? Because couple of test i made with walking around the objects are flawless and need almost no adjusting.
You need to zoom in on the object. It should cover most of the image if possible. Use a large f-stop to keep things in focus.
Also, you should try to match the color of the turntable and the background. So use black cloth if possible. That way the turntable becomes part of the background.
What everyone else said. :) That said, here’s what works for me.
I made an extremely cheap test setup and it’s worked so well that I haven’t bothered to change it. I built a box out of cheap, white poster board. I use a turntable ripped off the bottom of wife’s… err… ex-wife’s spice rack. On top of the turntable I have an opaque white dinner plate that I set objects on. Because the plate is glass but not very reflective it never creates any points.
I have 4 cheap lamps with led bulbs shining into the box at various points. For an average object I’ll take 100-200 photos and get 100% alignment nearly every time with very few stray points to clean up.
Like others said, zoom in to capture as much detail as possible, but balance it with a larger aperture to control DOF. For some objects I find it better to zoom out a bit rather than have blur on the far side.
Get plenty of overlap. For large features or smoother surfaces you may need less overlap/photos. For detailed objects, objects with small pits/deep cracks, you need to keep in mind that those areas may need more overlap. You need at least 3 photos of any one feature from different perspectives in order to calculate depth.
The goal is to trick the software into thinking the camera’s moving when in fact you’re only moving the object. If you can pull this off you can not only rotate the turn table but also the object on the turn table in order to capture the top and bottom of the object as well, and never have to move your camera. With a small rock for instance, I shoot a full rotation in the original orientation, then full rotations with it laying on its left and right sides. Nearly always gives 100% alignment.
When i went closer and did more cameras it is aligning very nicely !
Now i got another problem When i flip the object (scanning ginger) on the other side it is placing the point from the same level, it cannot recognize that it is flipped.
Honestly i only used agisoft before and there you could mask and it was working only with flipping.
RC has surely better engine, but this turntable workflow is more difficult to make work. And some objects are also quite difficult to capture from all the sides with big overlaps.
Getting alignment on rotation is fairly easy. Take this beautiful box for example!
Start AND end the first turn table sequence with the SAME face of the object facing the camera with a couple of shots past 0 to ensure overlap. Then, with the table at the original starting point, flip the object 90 degrees and shoot another complete 360 series.
I usually shoot 3 sequences. One original object orientation, one rotated 90, and one rotated 180. Always start the next sequence with the turn table at 0 with the original rotated object face toward the camera. I think this makes for easier alignment between rotations. Generally 50-70 photos per series (150-200 total) gives decent results I’ve done quiet a few objects like this and seldom have any alignment issues using a white featureless background and white featureless turn table cover.
Also, be careful with zoom. The more detail the better but too much zoom can cause depth of field blurring and negatively effect texture and possibly alignment. Sorry for the crappy artwork!
Something else to consider is that this will be nearly impossible for soft-body objects such as plants or stuffed animals. Rotating the object will inevitably cause some part/parts of the object to move after rotation and be in a different position relative to the object as a whole. Some of it will turn out but you’ll probably have ghosting on any parts that get moved after orientation change.