Searching for better cameras

[JuKu]

I've had enough. The current cameras are adequate for the task, when they work. Easy to handle and economical enough for this price range. However, the manufacturing quality lately has been rather bad; they are not very attractive if I have to test every camera individually and end up scrapping half of every shipment. And good luck getting a refund from a Chinese store when the product kind of works anyway, even though the camera angle is skewed, the picture is out of focus or partly so or both. So, I'm looking for alternatives and suggestions.

So far, I've looked at:

- Several endoscope type cameras. Much like the current ones, but perhaps with improved specs. This seems to be the same cake with a new topping; so far, I'm not at all convinced that I (and my customers) wouldn't have these same issues after a while

- ELP modules: Somewhat expensive, various models available. Rather good image quality, but horrible barrel distortion. Unusable unless the software has correction for this and there are a means to calibrate for that. OpenPnP users often use this, but I'm not that happy about the idea.

- Various web cameras, two that are notable: Although not good for LitePlacer, but interesting find, Fujitech 720P web camera. About 10€ from a local computer store, reasonable image quality, manual focus ring, capable of focusing to close to zero distance(!). This makes it interesting to other uses, but for this application, the field of view is way too wide. My setup was crude, but I managed to focus this camera to about 3mm from the lens. Not much barrel distortion, sharp focus, about 10mm field of vision at 3mm(!) (still 8microns per pixel). Doesn't disassemble.

Best so far: Logitech C270

Pros:
-Very good image quality.
- No barrel distortion to speak of.
- Wider wield of vision that I'd like, but ok; maybe mounting it lower.
- Good resolution. It says it is 1280x720 but in reality, it seems to be 1280x960.
- Almost reasonable price.
- Screw construction

Cons:
- Manual focus, short focus range (this might be a serious issue, actually)
- Needs to be disassembled (extra work)
- Needs another mount (see below)
- Somewhat expensive

So, do you have any other viable alternatives? Please share your findings!

A note about camera mount: I don't have enough experience about the Logitech unit to comment about how directly down it is looking. Anyway, the mount might not be straight anyway, so I think I/we needs to design a camera mount that has adjustable direction and maybe also height. Most likely, 3D printing is the way to go, although I'm not that fond of 3D printing of other than prototype parts. Ideas are welcome on this, too.

[vonnieda]

- ELP modules: Somewhat expensive, various models available. Rather good image quality, but horrible barrel distortion. Unusable unless the software has correction for this and there are a means to calibrate for that. OpenPnP users often use this, but I'm not that happy about the idea.

One quick note on the ELP modules: Most of them have M12 lens mounts, which means you can use almost any lens imaginable. The barrel distortion comes from the lens. I use a 3.2mm lens on my up looking camera so that the focal distance is short. As you say, it has a lot of barrel distortion, and I map that out with software. But on my down looking camera I use an 8mm lens and it has little distortion. I don't need to run correction on that one.

Jason

[mawa]

After the original juha down camera turned out to be cross-eyed at more than 5° because the camera chip mount inside was loose and moved when you moved the cable, I replaced the camera by an other 10mm HD camera.

That also had a defect after some weeks of use. It started to blink the image and show separate displaced color images.

So I now use a third 10mm camera I bought from here

https://www.pearl.de/a-PX3714-1390.shtml

The image quality is very good and the camera chip is aligned good.

The only problem is that the cable has been reinforced by a 1mm copper wire. That makes it very or better too stiff.

But due to the fact, that I did not want to replace the cable running through the machine I just cut of both ends and just replaced the last 100mm of the camera and the USB plug side. Using shrinkable tubing for the for wires and connecting the shield weaving around the for wires the replacement was done in short time.

What I also changed was I replaced the 10mm metal holder with a 3d printed replacement which brings the camera Y position to the same Y position of the Z axis/nozzle and has a protruding circle to fix the LED ring.
That metal holder did not hold the 10mm camera tube and it was a pain to reinforce the tube with plastic tape to have it fit tight.

Using the replacement you gain the some area in Y direction. As I did not want to remeasure all locations I added a short Y + move after homing Y to bring the camera back to the optical homing circle on the table. After optical homing every Location stayed the same. I only had to recalibrate the nozzle->camera offset.

Concerning the Down camera direction I experimented with a 3d printed X at table level with a bulls eye circle approx. 15mm above. If you the bring the camera center to the X you can see the displacement of the bulls eye circle. The offset was not so critical for me as I aligned all levels (PCB board, feeders, trays) to the same z height. Lately I read the idea to use a mirror, but I did not test that approach yet.