FAS7122

[Olympusman]

FAS7122

[Ken Ramos]

I suppose this is where the big money is, knowing what goes to where and what does what to what and why? Interesting

[Beatsy]

Another interesting set! I've been meaning to ask, do you ever stitch these chip images? I've spotted the odd discontinuity or misaligned trace in a few previous and wondered if it was in the die, or due to post processing.

[Olympusman]

Beatsy,
Yes, I do stitch some of these images.
Sometimes the jump between a 10X and 20X objective is not satisfying for the pictorial coverage result I want to obtain. I have a large selection of objectives, and I am constatly testing them to get the best results on my metallurgical microscope. None of them are rated NCG (no cover glass). However, almost all have a small degree of barrel distortion, and I have tested many of my objectives to find the least barrel distortion.
For those shooting subjects that have non-linear grid patterns, this barrel distortion is either not evident or of no concern, so many times when I do a stitch of two adjacent image areas, barrel distortion does enter into the equation.

Regards
Mike

[Beatsy]

Cheers Mike - that explains it. Actually, I was wiggling my recently-damaged glasses about at a couple of recent images. I didn't think of barrel distortion and just suspected the odd hint of distortion was "at my end" instead

You're getting very good results from objectives being used so far out of their comfort zone - assuming your using them as epi objectives! Could you rest a coverslip over the chip to give them the optimum optical path they need? Or are you doing that already?

[Olympusman]

Beatsy,
Yes, barrel distortion can drive you crazy. Even when you recalibrate weekly for changes in your eyesight, it may address astigmatism, you will never discover the slight (and annoying) barrel distortion in anything but a microcircuit, even in the best of objectives.

Mike