Another Chip Image

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

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mawyatt
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Another Chip Image

Post by mawyatt »

Bare chip image of a banged up chip (defective) from our lab. This is a Frequency Generation Unit, thus FGU nomenclature. All these chip images are very low resolution. The balls are solder that is used to mount the chip upside down, called flip-chip.

Image

Chris S.
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Post by Chris S. »

Mawyatt, welcome to the forum! And nice work--this and your other post.

Between this and your images, I'm especially drawn to this one. Shiny spheres being a classic challenge to photograph, and I like your treatment them.

One small thing about this image leaves me slightly unsettled, though. There is--to my eye at least--the illusion that this chip is warped. Not that it is, but something leads me to perceive it as such.

Best,

--Chris

rjlittlefield
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Post by rjlittlefield »

Chris S. wrote:but something leads me to perceive it as such.
I have a similar perception. Objectively I notice that there seems to be a bit of "inverse perspective", where the rear of the chip is a few pixels wider than the front. I'm not sure this is causing the whole effect, but surely it's a contributor.

This sort of perspective can creep in with certain lenses & lens combinations that put the entrance pupil way out in front of the lens, on the back side of the subject.

So I'm curious: what optics was this shot with?

--Rik

mawyatt
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Post by mawyatt »

Chris, Rik,

Yes the perspective of the chip is warped. I did not try and correct this in PS, believe this is due to the different distance between the effective lens and subject as you move the lens to image across the chip. The chip distance is much larger than the DOF which I believe changes the perspective.

If I was good with PS I might be able to correct this. Maybe a task over the holidays.

rjlittlefield
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Post by rjlittlefield »

With this subject you can definitely fix most of the distortion in Photoshop, using one or another of the Edit > Transform tools. But these tools affect the whole frame, so often they introduce other problems around the edges of the frame.

I think it is better to attack this sort of problem when the images are being shot or processed.

In truth, my question about the optics was not just curiosity.

Sometimes issues like this can be solved by simple changes such as altering the aperture. See HERE for a particularly clear example.

In other cases a simple change in processing is sufficient. In Zerene Stacker you can go to Options > Preferences > Alignment and remove the checkmark on Scale. With this change, the output image will be forced to have orthographic perspective, so that all parallel lines on the subject remain parallel in the image. In order for this to produce a clean output image, the optics must have only a very little change in scale within each in-focus slice. But this is often the case with high magnification high resolution stacks, such as shot through a microscope objective.

If necessary, there is a special configuration of lenses called "telecentric" that naturally gives orthographic perspective. See for example the discussions here:

1. "Telecentric optics, third round" http://www.photomacrography.net/forum/v ... php?t=1472 (Be sure to look at both pages of this one -- there's much good stuff on the second page.)

2. "Telecentric combo at 0.8X to 1.69X" (using Raynox DCR-250 in front of a Canon 100mm f2.8L): http://www.photomacrography.net/forum/v ... hp?t=18323

I hope this helps.

--Rik

mawyatt
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Post by mawyatt »

Rik,

Thanks, you give me some things to think about. Just got back from Burbank on a business/vacation trip, so I'll need a couple days to digest this.

Cheers,

mawyatt
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Post by mawyatt »

Here's another chip image (same FGU chip) with maybe a somewhat better perspective. This is sitting on a dime. All these images are downsized from the original TIFF files.

Image

ChrisR
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Post by ChrisR »

Fascinating pics mawyatt!
The second one still looks a bit bent, from where I'm sitting :?
A quick trip to Photoshop's "perspective" tool makes then look OK, but seems to need a rather strong correction, which is probably just overwhelming the effect.
The "Warp " tool (also in the Edit menu) does things in a non-linear way. It doesn't keep straight lines straight. Pushing the top edge - both corners and middle, of the picture downwards, gives a more natural appearance, but getting the lines in the right places as well as acceptably straight, is a challenge.

I wonder if the solder balls are made in a miniaturised analogue of the way they used to make lead bullets - dripping them off a tall tower so they froze in mid air :)
Last edited by ChrisR on Fri Dec 13, 2013 1:03 am, edited 1 time in total.

iPhoto
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Post by iPhoto »

Mawyatt,

Sorry but to my eye this second image repeats the distortion seen in the first, if anything more so.

It's an otherwise very good image and for me working at trying to resolve the source of the distortion be it in shooting of PP would make it a fun project to spend a few winter evening resolving :-)

Mark
There is nothing worse than a brilliant image of a fuzzy concept. - Ansel Adams

Twitter @iPhotoUK - flickr MASPhotographyUK

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Post by rjlittlefield »

The dime certainly gives a nice impression of just how small this thing is. But I don't think it does anything about the perceived warping that Chris mentioned. As with the previous image, I see here that the back of the chip is quite a bit longer then the front -- 716 vs 705 pixels according to the measurement I took just now.

Matching this up against an actual dime, it looks to me like frame width is about 6 mm on subject. I also see what looks like some vignetting in the corners.

So again I'm wondering about the optics.

Is this perchance a 10X objective used on a zoom tube lens set shorter than 200 mm?

If it is, then I definitely suggest reprocessing with Scale turned off to force orthographic projection. What happens with high mag wide aperture objectives is that the computational alignment process is very likely to make things worse instead of better, because of the way things appear to "bloom" as they go out of focus. With a typical 10X NA 0.25-0.28 objective, DOF is so shallow that there is usually no problem just turning scale off to avoid that problem.

--Rik

mawyatt
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Post by mawyatt »

Rik, Chris, Mark,

Thanks for the notes. This as the earlier image were shot a few months ago, so this wasn't a new attempt. Thought maybe the perspective was better. I'll try with the Scale off when I get some "free" time, also try PS.

Just got home from a 3 week bus/vac trip and the pool pump is burned out, house AC is down, car battery is dead, Nikon D800 is dead and 24-70F2.8 is split in half (dropped camera/lens!!).

Back in the office I have a trip report, DARPA report and host of other tasks due...and they are cleaning the AC today because the mold is so bad (I have really bad allergies, so I can hardly breath & see now...and constant sneezing).

Wait this is Friday the 13th, I am suprised my plane didn't crash late last night!!

iPhoto
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Post by iPhoto »

mawyatt wrote:Rik, Chris, Mark,

Thanks for the notes. This as the earlier image were shot a few months ago, so this wasn't a new attempt. Thought maybe the perspective was better. I'll try with the Scale off when I get some "free" time, also try PS.

Just got home from a 3 week bus/vac trip and the pool pump is burned out, house AC is down, car battery is dead, Nikon D800 is dead and 24-70F2.8 is split in half (dropped camera/lens!!).

Back in the office I have a trip report, DARPA report and host of other tasks due...and they are cleaning the AC today because the mold is so bad (I have really bad allergies, so I can hardly breath & see now...and constant sneezing).

Wait this is Friday the 13th, I am suprised my plane didn't crash late last night!!
Is your middle name "Lucky" by any chance :wink:
There is nothing worse than a brilliant image of a fuzzy concept. - Ansel Adams

Twitter @iPhotoUK - flickr MASPhotographyUK

mawyatt
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Post by mawyatt »

iPhoto wrote:
mawyatt wrote:Rik, Chris, Mark,

Thanks for the notes. This as the earlier image were shot a few months ago, so this wasn't a new attempt. Thought maybe the perspective was better. I'll try with the Scale off when I get some "free" time, also try PS.

Just got home from a 3 week bus/vac trip and the pool pump is burned out, house AC is down, car battery is dead, Nikon D800 is dead and 24-70F2.8 is split in half (dropped camera/lens!!).

Back in the office I have a trip report, DARPA report and host of other tasks due...and they are cleaning the AC today because the mold is so bad (I have really bad allergies, so I can hardly breath & see now...and constant sneezing).

Wait this is Friday the 13th, I am suprised my plane didn't crash late last night!!
Is your middle name "Lucky" by any chance :wink:
Yeah, maybe "Lucky" in Wayne's World context!!

mawyatt
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Post by mawyatt »

Rik,

Here's an image stacked with Scales turned off. Seems like a little better hold on the perspective to me.

Image

g4lab
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Post by g4lab »

Eye Candy!! Thank you.
In addition to the great imaging, extremely interesting subject matter.

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