Incentive is to choose bad focus

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gregson
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Incentive is to choose bad focus

Post by gregson »

I've just been through a series where there were three events at the limit of the focal plane. The first was a calibration movie where my response was correct. The second was a calibration movie where my response was incorrect. And the third was a real movie. In retrospect, there was not much difference between the three. So, I can only conclude that to not be penalized because of capricious calibration movies, I should select bad focus when I see an event at this limit. Is that the intent of the Stardust team?
John

bmendez
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Re: Incentive is to choose bad focus

Post by bmendez »

gregson wrote:I've just been through a series where there were three events at the limit of the focal plane. The first was a calibration movie where my response was correct. The second was a calibration movie where my response was incorrect. And the third was a real movie. In retrospect, there was not much difference between the three. So, I can only conclude that to not be penalized because of capricious calibration movies, I should select bad focus when I see an event at this limit. Is that the intent of the Stardust team?
Calibration movies are not capricious, they were selected with great care and thought (that is the opposite of capricious). They are more difficult to be sure. But that is because the interesting features that were brought to light in phase 1 were very subtle. Our intent is for you to be as careful as you can in your search.

We truly appreciate your efforts.
-Bryan
"I am made from the dust of the stars, and the oceans flow in my veins"
- RUSH

cretinbob
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Post by cretinbob »

There is still a lot of bad focus out there.

gregson
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Why is this a CM?

Post by gregson »

Why, in this movie, 5177604V1, is the in focus spot a CM and the other out of focus spots not?

John
John

bmendez
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Re: Why is this a CM?

Post by bmendez »

gregson wrote:Why, in this movie, 5177604V1, is the in focus spot a CM and the other out of focus spots not?

John
Things that are only on the surface will only be in focus on the surface. What you see in that movie is a feature which comes into focus below the surface. It's practically invisible above the surface. Then the features near it come into focus, then as you movie beneath the surface it comes into focus.

Hope that helps,
-Bryan
"I am made from the dust of the stars, and the oceans flow in my veins"
- RUSH

bmendez
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Post by bmendez »

cretinbob wrote:There is still a lot of bad focus out there.
Sure, but that has to do with the very uneven surface of the aerogel and the technical difficulties with adjusting the microscope to the varying surface. This has been one of the greatest challenges of the project so far.

-Bryan
"I am made from the dust of the stars, and the oceans flow in my veins"
- RUSH

marymouse
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Regarding bad focus

Post by marymouse »

In Phase 1, I remember discussions about where we should see the surface - and if it were below the last quarter of the blue bars, we should consider it bad focus.

Does this still apply?

Thanks.

Also, is it possible to show an old movie next to a new one of the same place so we could get an idea of how it appears changed?

fjgiie
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Same movie in different scales, 50 and 100 micron

Post by fjgiie »

marymouse wrote:Also, is it possible to show an old movie next to a new one of the same place so we could get an idea of how it appears changed?
There are 100 micron scale movies at the VM and most are 50 micron scale movies. You can see the better magnification in the new movies.
For a picture of the same movie in 100 micron and 50 micron scale, SEE HERE.

marymouse
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Post by marymouse »

Thanks, figgie.

But I was hoping to compare a track from an old movie to the same track in the new movie so I could better understand what to look for.

And my other question is still about how low down on the focus you should go before deciding "bad focus."

Thanks.

bmendez
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Post by bmendez »

marymouse wrote:Thanks, figgie.

But I was hoping to compare a track from an old movie to the same track in the new movie so I could better understand what to look for.

And my other question is still about how low down on the focus you should go before deciding "bad focus."

Thanks.
Mary,

There are no hard and fast rules about when to chose "Bad Focus." We created a FAQ about this question (http://stardustathome.ssl.berkeley.edu/ ... .php?t=645).

The basic idea is that if the focus is not good enough to enable you to make a fair determination, then you should chose "Bad Focus."

Thanks,
-Bryan
"I am made from the dust of the stars, and the oceans flow in my veins"
- RUSH

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