a sample midterm in a high speed/time lapse course

[ADavidhazy-2]

If you are looking for something to maybe entertain you I just
finished preparing a midterm exam for my fall class. To amplify
this is not your usual midterm as it is not required. As part of
the "grading" process students are asked to turn in 8 illustrated
technical reports about 9 different topics covered during the
10 week period. If they earn more than a 50% on this optional
exam then they can use this exam as one of the 8 technical
reports - meaning they only have to write about 7 final reports.

The exam also serves the purpose of acquainting these students
with my "style" of questions. The final exam is also optional
and a bit more demanding but if they don't take it or get a
sufficiently high score they can't attain a grade higher than C.
Some choose to go south instead of taking the final exam! ;)

You can obtain a copy of this sample exam as a PDF from:

http://people.rit.edu/andpph/a-misc/2009-Midterm HS-TL.pdf


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*                                                               *
* andy     o o  0 0 o   o  at RIT's Imaging and Photo Tech Dept *
* davidhazy \/\/\/\/\/\/   High Speed Photo Lab  andpph@... *
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* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

[Marilyn Dalrymple]

Hi Andy,

It sounds like your Indian Summer is going to be much more colorful than
ours here in the desert.  I'm not complaining, though.  Just having it
cooler is a good start.

Thank you for adjusting my image on your end.  I appreciate it.

I hope you are feeling well.

Marilyn

[Alberto Tirado]

Just a curious note about some of the questions:

"Lucky" Q13: falling *is* an acceleration (9.8 m/s squared). There must be something I am missing?

Q16: is it possible that some students fail this? I know, in MX we use decimal system, but it seems so straightforward/intuitive to me, that I find the question quite curious.

Finally, I would most definitely fail the test! ;)

**********************
www.alberto-tirado.com


     

[David Dyer-Bennet]

On Sun, October 11, 2009 13:38, ADavidhazy wrote:
> If you are looking for something to maybe entertain you I just
> finished preparing a midterm exam for my fall class. To amplify
> this is not your usual midterm as it is not required. As part of
> the "grading" process students are asked to turn in 8 illustrated
> technical reports about 9 different topics covered during the
> 10 week period. If they earn more than a 50% on this optional
> exam then they can use this exam as one of the 8 technical
> reports - meaning they only have to write about 7 final reports.

I'm amused at the use of quotes around "grading" :-).

It was interesting to see this.  Apparently I've learned a thing or two
about photography over the years, because I believe I understood all the
questions, and was confident of my answers to most of them.

Was the Lartigue reference to his photo of car No. 6 in a race?  That's
what I think of as the most famous photo "exploiting focal-plane shutter
distortion", and it's by him, but I don't know if that's what you were
thinking of.

I'm not at all clear what's going on in #27, either.

I'm not saying I'm sure I have the right answers to all the others, mind
you, or that I wouldn't make mistakes working out the details in cases
where that's required :-).

Another question brings up a question I've had for years about sound
triggers: Where can one buy one?  I've never seen anything closer than a
kit.  I might still be able to put an electronic kit together and make it
work.  I was talking to another photographer about this yesterday on the
way back from a shoot, and we're both interested in doing something about
it.  I don't think calibrated delay is important for us -- either
un-calibrated delay, or probably the easiest is just to count on moving
the microphone to introduce any needed delay.  It wouldn't hurt to have a
unit that could also process beam interruptions to trigger equipment.  And
it would be nice to be able to trigger either cameras or flashes with it.
It would be nice to trigger continuous shooting mode and keep going until
the buffer filled up, too.  Are there commercial products, or does
everybody end up building a kit or rolling their own?  Are the commercial
products any good?  Are any of the kits any good?

--
David Dyer-Bennet, dd-b@...; http://dd-b.net/
Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/
Photos: http://dd-b.net/photography/gallery/
Dragaera: http://dragaera.info

[ADavidhazy-2]

 > I'm amused at the use of quotes around "grading" :-).

Yup ... I've "developed" this strategy for a number of reasons. Most too
obscure and without pedagogical (!!!) merit. OTOH I have been "grading"
my classes in a similar way for many years and I probably am not going to
change to a more conventional "point" system as most of my fellow
intructors use. My grading is more psychological than numerical.

 > Was the Lartigue reference to his photo of car No. 6 in a race?  That's
 > what I think of as the most famous photo "exploiting focal-plane shutter
 > distortion", and it's by him, but I don't know if that's what you were
 > thinking of.

Yes. When the "lecture" about FP shutters was given the Lartigue photogrpah
was mentioned. It was not shown though. Will there be initiative on student's
part? Who knows.

 > I'm not at all clear what's going on in #27, either.

The highlights of the bullet make a "blur" on the "wrong" side of the bullet.
"Speed lines" as drummed into our heads by illustrators should trail a moving
subject and not lead it. But as the flash falls off in output the highlights of
the bullet reflect useful light for a longer time than the shadows and as the
light level is dropping the bullet is moving forward and so one ends up with
blur on the wrong side.

 > Another question brings up a question I've had for years about sound
 > triggers: Where can one buy one?  I've never seen anything closer than a
 > kit.  I might still be able to put an electronic kit together and make it
 > work.

Well, I usually use a tape recorder that on detecting sound triggers a
sensitive gate SCR which fires the flash. I've also recently built one
based on an integrated circuit audio amplifier but when I made a second one
patterend after the first one it failed to perform - frustrating.

http://people.rit.edu/andpph/text-cheap-sync.html
http://people.rit.edu/andpph/text-audio-sync-circuit.html
http://people.rit.edu/andpph/text-PC-flash-sync-socket.html

I can sugggest two commercial sources you may want to look into.

www.quaketronics.com sells a nice unit for about $100
www.hiviz.com (associated with Lauren Winters of NC High School of Science I
believe) sells kits at quite reasonable proces.

The device cursorily described in the following article responds to light,
sound and dark activation and also can function as an intervalometer plus
it can be equipped with solid state "switches" or mechanical ones (the
latter more suitable for camera triggering - if you have a camera that
can easily be triggered from an external switch closure).

http://people.rit.edu/andpph/text-cross-beam.html

andy

[David Dyer-Bennet]

On Mon, October 12, 2009 11:46, ADavidhazy wrote:
>  > I'm amused at the use of quotes around "grading" :-).
>
> Yup ... I've "developed" this strategy for a number of reasons. Most too
> obscure and without pedagogical (!!!) merit. OTOH I have been "grading"
> my classes in a similar way for many years and I probably am not going to
> change to a more conventional "point" system as most of my fellow
> intructors use. My grading is more psychological than numerical.

Looks like I'm teaching my second course at a local community college this
spring, so "exercises" and "tests" and "grading" are on my mind even more
than usual right now.

>  > Was the Lartigue reference to his photo of car No. 6 in a race?  That's
>  > what I think of as the most famous photo "exploiting focal-plane
> shutter
>  > distortion", and it's by him, but I don't know if that's what you were
>  > thinking of.
>
> Yes. When the "lecture" about FP shutters was given the Lartigue
> photogrpah
> was mentioned. It was not shown though. Will there be initiative on
> student's part? Who knows.

I had to look it up to be sure it really was him; I remembered the photo
as being the canonical example, though, so searching on his name and
scanning for the photo I remembered worked pretty quickly.  The Internet
makes me smarter!  :-)

(I've never actually taken a course on photography; I was a math major,
and my career has been in computers, which I started 3 years before I went
to college.)

>  > I'm not at all clear what's going on in #27, either.
>
> The highlights of the bullet make a "blur" on the "wrong" side of the
> bullet.
> "Speed lines" as drummed into our heads by illustrators should trail a
> moving
> subject and not lead it. But as the flash falls off in output the
> highlights of
> the bullet reflect useful light for a longer time than the shadows and as
> the
> light level is dropping the bullet is moving forward and so one ends up
> with blur on the wrong side.

Thanks, much clearer.  Part of the problem was just that I don't have much
familiarity with high-speed photos below the "art" level of clarity, so I
was having some trouble being sure I even knew what bits were what in that
photo (though I did in fact identify the bullet correctly, as it turns
out).

No doubt having actually taken your course would have made this test
considerably easier :-).

>  > Another question brings up a question I've had for years about sound
>  > triggers: Where can one buy one?  I've never seen anything closer than
> a
>  > kit.  I might still be able to put an electronic kit together and make
> it
>  > work.
>
> Well, I usually use a tape recorder that on detecting sound triggers a
> sensitive gate SCR which fires the flash. I've also recently built one
> based on an integrated circuit audio amplifier but when I made a second
> one
> patterend after the first one it failed to perform - frustrating.
>
> http://people.rit.edu/andpph/text-cheap-sync.html
> http://people.rit.edu/andpph/text-audio-sync-circuit.html
> http://people.rit.edu/andpph/text-PC-flash-sync-socket.html

The perversity of inanimate objects continues to reign, yes!

> I can sugggest two commercial sources you may want to look into.
>
> www.quaketronics.com sells a nice unit for about $100
> www.hiviz.com (associated with Lauren Winters of NC High School of Science
> I
> believe) sells kits at quite reasonable proces.

Thanks.  Those look potentially very useful.  And the electronics are at
the level where I actually understand everything he's saying, though I
couldn't have designed them myself.  Theory is actually of some use
sometimes!

The Quaketronics  looks particularly useful, because for lots of people I
know, their hobby is photography and not electronics; especially people
who started in the digital era, lots of them just aren't into hardware
tinkering.  Being able to buy something assembled in a decent case is
highly desirable.

I'm still interested in making it trigger the shutter instead of a flash
(for slower things -- one of them is catching empty brass in flight from
guns, for example; a friend does commercial work in this area and
currently is getting his flying brass by random luck with the modestly
high frame-rates of modern cameras).  But an SCR might well be something
that could be wired into a Nikon 10-pin cable?

One of these years I'm not going to be able to resist this anymore.
Pellet guns make a lot of the classic bullet pictures doable in convenient
settings at home.
--
David Dyer-Bennet, dd-b@...; http://dd-b.net/
Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/
Photos: http://dd-b.net/photography/gallery/
Dragaera: http://dragaera.info