Basler Camera Problems

[SCB]

Greetings!

I am new to this forum, but I hope I am posting to the right place!

I am a graduate student in a research group doing HDR video. We recently purchased a Basler acA2000-50gc camera but we are having some problems.

1. Upon taking the camera out of the box, the images captured have a greenish tint to them. They look like they were taken on an old camcorder. Our application requires the images to be raw so having gamma correction or other nonlinear adjustment will cause issues.

2. There is serious vignetting of the image. Once again giving it an old 1960s camera feel. (Note: this is not a huge issue as we can offset the image in the pylon software that Basler provided, but it is still irritating)

3. A good way to capture the frames from the camera. Currently, we use the api and some sample code to extract the frames and save them directly. We initially tried to use third party software like virtualvcr and sharpcap. Although these programs detected the camera, they were unable to open video capture.

4. We are taking alternating exposures from frame to frame but we are having issues with frames being skipped and tiny black lines on the bottom and right edges of the image.

Has anyone experienced any of these issues?

Also, any suggestions for a c-mount lens? The one we have now is not robust enough for our needs.

I would appreciate any help with any of the above areas. I apologize if I am posting in the wrong place. If this is the case, please point me in the right direction.

Thanks!

[Daklu]

I'm neither a camera expert nor familiar with that camera model, and without seeing images it's hard to say for sure, but here are some ideas:

 

-The black lines could be due to a defective camera.  Over the last year I've built a dozen systems using the Basler avA series cameras and two of them had to be returned.  I'd call Basler and see about getting a replacement.

-The green tint might be correctable by changing the camera's firmware settings.  Basler has utilities for adjusting the camera firmware.  I use "Pylon" with the avA cameras.  I don't know if that's the right utility for your camera.

-Vignetting is purely a function of the lens.  Different lenses will produce different amounts of vignetting.

-We can't suggest a specific lens without knowing a lot more about your application--there are far too many tradeoffs to consider.  The best thing you can do is call a reseller and discuss your requirements with them.  They'll be able to help you select an appropriate lens.

[ShaunR]

Apart from Daklus sound advice. You might also check that you are using the High Performance Ethernet driver. Not so much for bandwidth, but more for CPU usage.

 

Missing pieces of the image (or entire images) is usually due to bandwidth saturation/collisions. Just because a camera is capable of supplying images at a frame-rate and resolution doesn't mean that it can all be squirted over a LAN interface. You generally have to play with the camera settings to get things working nicely. Whilst the "theoretical" maximum of a 1 GbE is 125MB/s, in reality I have never achieved more than about 100MB/s reliably (assuming jumbo frames are enabled) and a 100Mb interface you will be lucky to get 10MB/s (rule of thumb is about 80% of interface speed).

 

If Jumbo frames aren't being used (default is usually 1500) or are not supported by the interface, then this is usually the bandwidth restriction and you will have to go down to lower resolutions and frame-rates as the packet overhead crucifies the performance (note that if you are going through a router or switch, jumbo frames will also have to be turned on for these devices and match the packet size of the LAN interface).

[Dean Mills]

The greenish tint could be caused by whatever software you are using is not doing the bayer color decode properly.  A Google search for bayer encoding will return many results on what bayer encoding is and how to decode it.  Usually the Basler software will work properly but other software may need to be told its Bayer encoding.

 

 

[Neville D]

Are you using flourescent lighting in your lab?  The greenish tint is probably because you need to adjust white balance on the camera.  Use a white sheet of paper in front of the camera and adjust white balance.

 

In the past, I have used Fujinon and Tamron Machine vision lenses.  Great quality, high resolution, large aperture, rugged, and with locking screws on iris and focus rings.

 

http://www.fujifilmusa.com/products/optical_devices/machine-vision/

 

 

I found AudioVideoSupply out of LA to have good service and support.

 

http://www.avsupply.com/computar-lenses.php

 

The vignetting is due to the lens you are using.  Lenses are rated for the sensor size used.  Probably you have a sensor size > lens image circle.  You can use for instance a 2/3" lens with a 1/2" sensor, but not vice-versa.  Get the lens for the appropriate mount on your camera (usually C mount).  The Fujinon site had a lot of useful information for machine vision.

 

Like Shaun pointed out, make sure to enable jumbo packets for the ethernet card.  You can use either the Basler driver or the NI GigE driver, but jumbo packets should be enabled.

 

Neville.

[Jordan Kuehn]

We have used Computar lenses quite a lot to good success.  I'll typically identify what I want from Computar's website and then Surveillance Video has been a good distributor even though machine vision isn't quite their target market.

 

I agree with everything said above.  Another thing about the jumbo packets, not all ethernet cards support them especially in laptops.  Additionally not all routers support them.  Here's an expresscard that works if you need one for a laptop: http://www.amazon.com/gp/product/B000GB0N14/ref=wms_ohs_product