Thanks for the report JP.
Just browsing the Point Grey catalog and came across their BlackFly version of the 1280x960 e2v mono camera for $395
http://www.ptgreystore.com/blackfly-13- ... e-ev76c560
I wonder if the less expensive cameras have poorer coatings on the protective glass chip covers that cause these Newton Rings.
In my experience (which is limited to discussing the problem with customers, I have no hands on experience at all with Newton Rings) we've come to the conclusion that the major source of NR is the sensor cover glass, not the camera optical window (see below). Since camera manufacturers use the same sensors, if the cover glass is the issue, then the NR are out of the camera manufacturers control and for the same sensor, any camera vendors' model could/should have the same issues. This is not definitively proven, but I am always concerned when anyone says "Manufacturer X cameras don't get NR as much as Manufacturer Y" because all the info I've heard about this is annecdotal and a small sample size of cameras (usually 1).
(I guess the one thing that is in the manufacturer's control is the accuracy at which the flange of the camera is parallel to the sensor - however, from what I understand, better placement in this respect may actually make NR worse! Maybe NR is a sign of quality construction?
I guess what I'm saying is that if you want an e2v camera - you can buy it from us, or from someone else, and my prediction is that there is no way to see if you'll have NR problems until you get the camera, and your odds of a good one are equal across vendors. (However, I am always interested to hear evidence against this - this is just the conclusion I've come to so far).
For Point Grey cameras, the optical path components, which are really just the sensor and the optical window, are identical quality across models. The sensor is obviously the same, and the optical window is a very low cost component compared to the rest of the camera. The differences are really due to the electronic components. The more expensive cameras will sometimes have the potential to run faster, and also to have more on-camera processing and more I/O capabilities (strobe and trigger signals, etc).
BTW, to clarify what I mean by optical window, the optical path on our cameras goes
- optical window
- about 0.5mm to 1cm space (depending on model)
- sensor cover glass (attached to sensor)
- 0.1mm or so air space
The optical window is there to hold dust off the sensor so it will be less visible in the image.
I hope this helps.
Don (the Point Grey Don).