511A Power Transistor

Images taken in a controlled environment or with a posed subject. All subject types.

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Bob-O-Rama
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511A Power Transistor

Post by Bob-O-Rama »

Here are a few shots of a 511A power transistor - similar parts are used in almost everything.

Image

Here is more of a mug shot, with less of the geometric distortion from stacking

Image

While it acts as a single transistor, its actually composed of thousands of tiny transistors tiled together and connected in parallel. Even larger capacity power transistors used in UPS equipment or large audio amplifiers are just larger pieces of wafer with even more transistors.

Image

rjlittlefield
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Re: 511A Power Transistor

Post by rjlittlefield »

Bob-O-Rama wrote:
Mon Aug 23, 2021 12:12 pm
geometric distortion from stacking
I am interested in this aspect.

What I'm seeing in your image looks like what we sometimes call "inverted perspective", that is, farther-looks-bigger instead of the usual farther-looks-smaller that is provided by normal perspective. Certain arrangements of lenses naturally produce this perspective. A simple example can be found in the lens combo shown at viewtopic.php?p=50750#p50750 , or for industrial applications that require an extreme version you can buy special lenses such as https://www.edmundoptics.com/f/hypercen ... ses/14571/ . There's a brief article at https://en.wikipedia.org/wiki/Hypercentric_lens .

With these sorts of optics, the distortion is not really caused by the stacking, but it is certainly revealed by the stacking because extending the depth of focused detail makes the farther-looks-bigger aspect perfectly clear.

So, I am curious to know what your optics & camera setup were for this image. Can you describe and/or show those?

--Rik

Bob-O-Rama
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Re: 511A Power Transistor

Post by Bob-O-Rama »

rjlittlefield wrote:
Mon Aug 23, 2021 1:06 pm
With these sorts of optics, the distortion is not really caused by the stacking, but it is certainly revealed by the stacking because extending the depth of focused detail makes the farther-looks-bigger aspect perfectly clear.
The moment I posted that I was thinking I should have re-phrased that.

If you measure the sides of what is in truth a rectangle, you find the proper lengths of the corresponding sides. The diagonals are significantly off, which of course makes sense if you try to project a tilted rectangle in 3-D onto a 2-D plane. So I don't think its the lens either in this case. It was shot using an Infinity Photo-Optical Distamax K2 + CF-3 objective used with rack focus. So I think you nailed it with it being an optical illusion - my brain is what is distorted,

rjlittlefield
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Re: 511A Power Transistor

Post by rjlittlefield »

So I think you nailed it with it being an optical illusion - my brain is what is distorted,
Well, the distortion is not entirely in our brains.

When I carefully measure corresponding left-to-right distances at the front and back of the chip, I get that the back is definitely larger than the front, but only by about 0.5% (that is, about 5 pixels in a thousand). If the lens had normal perspective, the back would measure smaller than the front. If the lens were perfectly telecentric, or if you turned off Scale adjustment in the software while stacking, then the back should measure exactly equal to the front.

So, the perspective of the image is definitely inverted, almost certainly because the optics are slightly hypercentric and the stacking process is preserving that geometry.

However, based solely on visual appearance I would have guessed that the back-to-front discrepancy would measure a lot more than 0.5%. So there's also some optical illusion going on, probably something to do with the asymmetry of the composition, different borders on left and right, top and bottom.

I see from searching the forum that you have previously described a system as
The lens is a Infinity Photo-Optical K2 Distamax + CF-3 front lens ( so ~4x with 0.2 NA @ ~100mm wd ) I got for very, very cheap. Its an incredible versatile ( and expensive if paying retail ) system which spans the entire range from astronomy to microscopy. One one extreme, its far field objective does 1:1 to infinity focus with an focal length of about 700mm. It has a range of close focus objective that cover the 1x to 12x range with 60-250mm working distances, and you can attach any microscope objective and use it as a tube lens.

The camera is a Pentax K-1. These were shot with "pixel shift" mode which composites 4 images offset by one pixel to eliminate false color from the CFA, improves the SNR by 2 stops, and most importantly improves the chroma sampling by about 2x linearly. It also uses a fully electronic shutter in this mode ( regular single shot modes only offer EFCS on the K-1 ) so it helps with vibrations. This makes a noticeable difference for sharp lenses.
Is that the same as what you used for these shots?

--Rik

Scarodactyl
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Re: 511A Power Transistor

Post by Scarodactyl »

It's a bit hard to get a read on the Infinity systems. Not many people seem to use them, and their marketing material seems hyperbolic at best. These results do look pretty nice though!

Bob-O-Rama
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Re: 511A Power Transistor

Post by Bob-O-Rama »

rjlittlefield wrote:
Mon Aug 23, 2021 9:28 pm
Is that the same as what you used for these shots?
Yeah, that is it. Probably the CF-3 objective. Now that I am looking for it, it varies depending on the objective used and the focuser setting. There is a small difference checking those front and back measurements, sometimes tele- sometimes hyper- based on a couple quick checks. ( If you are curious, there are a number of examples here: https://bob-o-rama.smugmug.com/Infinity ... icroscope/ )

-- Bob

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Re: 511A Power Transistor

Post by Bob-O-Rama »

Scarodactyl wrote:
Mon Aug 23, 2021 10:40 pm
It's a bit hard to get a read on the Infinity systems. Not many people seem to use them, and their marketing material seems hyperbolic at best. These results do look pretty nice though!
Despite the cringe worthy marketing hype web site, they are a great company to work with. Everyone I have dealt with there have been great, especially their applications engineers. When I had issues they have really gone above and beyond. I mean to the point of replacing a 10 year old system with brand new, then refurbing the old system for basically the cost of shipping. I deal with a lot of vendors in my day job, very few go to the lengths Infinity has to fix problems - even when those problems were not theirs. But yeah, the web site. :roll: I think a lot of their products are OEM'd or resold via EO, so perhaps that is not as critical for them.

Scarodactyl
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Re: 511A Power Transistor

Post by Scarodactyl »

The founder came onto microbehunter to talk about the balplan a bit (he's worked at B&L back in the day). Definitely an interesting guy.

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