Intensity grading

[mdkendall]

I recently bought a Rigol DS1104Z. In general I have been very impressed by the capabilities at the price.

While playing around I noticed one interesting thing with the intensity grading. At the outer edge of the trace, where the signal probability is less, the trace fades to black rather than to transparent as it would do on a real analog scope. If traces don't overlap each other on the screen this is an academic distinction, but when traces are overlapping you can easily see the difference.

The attached screenshot from the Rigol shows three traces, each of which was a low-amplitude, fairly noisy sinewave. Where the traces overlap you can see an odd black shadowing effect, which is due to the trace "on top" fading to black and being composited over the underlying traces rather than blended with them.

As it happens the local Agilent rep was in a few days ago and left a DSO-X 3054A scope with us for evaluation. I thought I would compare the Rigol with it and see how much better the Agilent was. (Second attached picture shows them side-by-side for comparison). To my surprise it appears to overlay the traces in exactly the same way, and it looked no better.

So I guess my question is, is this common to the Agilent 2000 and 4000 series as well (I guess it would be since they all use the same MegaZoom ASIC). And has anyone had a chance to see how this looks on the new Tek MDO3000 series?

[mikeselectricstuff]

I think it makes more sense to have the black edges to distinguish traces - probably also avoids unwanted colour mixing to produce false colours at the overlap.
One thing the older Agilent 5/6/7000's do is that when you use the Y shift control for a channel, it pulls that channel's trace to the front.