Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-31 Thread Gregory Parkinson

At 6:41 AM -0800 10/30/01, TSHACK wrote:

[...]

 you can also get it with a Lomo LC1 - it's a 35mm, with
 a lens with pinhole-like falloff, and it has an exposure meter
 that will keep the shutter open until it thinks it's received


I just ordered a couple of fully manual Lomos from Free Style Camera.  I'll
see what it takes to convert those.  $12 each, so not a huge investment.  I
did a search for the LC-1 online, but kept getting the LC-A.  Is that the
same?  Looks like the one Free Style sells for $149.


Sorry, it is the LC-A


 > enough light - I've had it stay open 5 minutes.  I have photos

 from halloween in Greenwich Village a few years ago that
 look very much like this one.


I would suspect there is not much variability between photos taken while
driving in traffic at night. ;-)


I have a series that I took by holding the camera against the front
window of the PATH train that went from New Jersey to the WTC.
Exposures of a minute or more, and lots of variation depending on
the lights in the tunnel.  I suspect for driving on flat roads without
a lot of buildings you are probably right.

I used to use Agfa Ultra 50 film.  I think it's been discontinued,
but it combined long exposure times with over-the-top color.
I have a bunch of it frozen

Greg
--



Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-30 Thread Philip Arny


Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-30 Thread Philip Arny


Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-30 Thread TSHACK
> Just as a point of reference, if you're going for this look

Well, this is my first time attempting something like this.  I suspect they
will all look the same pretty quickly and get boring.  I can't see this one
hanging on the wall very long.  But, I'm usually heavy into composition, so
its nice to have something that took off on its own.  I'm trying to figure
out how to incorporate a mirror into the image plane to get the image into a
mirror-image Rorschach sort of format.

> you can also get it with a Lomo LC1 - it's a 35mm, with
> a lens with pinhole-like falloff, and it has an exposure meter
> that will keep the shutter open until it thinks it's received

I just ordered a couple of fully manual Lomos from Free Style Camera.  I'll
see what it takes to convert those.  $12 each, so not a huge investment.  I
did a search for the LC-1 online, but kept getting the LC-A.  Is that the
same?  Looks like the one Free Style sells for $149.

> enough light - I've had it stay open 5 minutes.  I have photos
> from halloween in Greenwich Village a few years ago that
> look very much like this one.

I would suspect there is not much variability between photos taken while
driving in traffic at night. ;-)

Thanks for the info.

Dwight




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-30 Thread Gregory Parkinson

Just as a point of reference, if you're going for this look
you can also get it with a Lomo LC1 - it's a 35mm, with
a lens with pinhole-like falloff, and it has an exposure meter
that will keep the shutter open until it thinks it's received
enough light - I've had it stay open 5 minutes.  I have photos
from halloween in Greenwich Village a few years ago that
look very much like this one.

At 4:52 PM -0800 10/29/01, TSHACK wrote:

- Original Message -
From: Chris Peregoy 
To: 
Sent: Monday, October 29, 2001 4:19 PM
Subject: Re: [pinhole-discussion] Zone Plate Focus stringency

[...]





OK, I just got back a test roll from my hacked TLR zone plate camera.

This is the only one worth reporting on.  Its taken in traffic at night, but
I flipped the image because it works better like that.  Unfortunately, this
doesn't really showcase the zoneplate qualities, unless its to give the
lights a softer glow.  But it certainly has a lot more life than the other
shots on the roll.

http://groups.yahoo.com/group/pinholegallery/files/DSZP/zpdashboard.jpg

Focal length, 90mm, ASA 100, exposure 4 blocks at 25mph.

I'm about to build a rig to use as a mount for the cameras that will fit in
my moonroof opening and allow me to also reach up and trigger the shutter
open and closed.


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Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread TSHACK
- Original Message -
From: Chris Peregoy 
To: 
Sent: Monday, October 29, 2001 4:19 PM
Subject: Re: [pinhole-discussion] Zone Plate Focus stringency


> TSHACK wrote:
>
> >very good.  thanks.
> >
> That was going to be my reply

Mom, Chris is making fun of me.

OK, I just got back a test roll from my hacked TLR zone plate camera.

This is the only one worth reporting on.  Its taken in traffic at night, but
I flipped the image because it works better like that.  Unfortunately, this
doesn't really showcase the zoneplate qualities, unless its to give the
lights a softer glow.  But it certainly has a lot more life than the other
shots on the roll.

http://groups.yahoo.com/group/pinholegallery/files/DSZP/zpdashboard.jpg

Focal length, 90mm, ASA 100, exposure 4 blocks at 25mph.

I'm about to build a rig to use as a mount for the cameras that will fit in
my moonroof opening and allow me to also reach up and trigger the shutter
open and closed.




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread Chris Peregoy

TSHACK wrote:


very good.  thanks.


That was going to be my reply






--







Chris Peregoy | http://www.gl.umbc.edu/~peregoy | http://imda.umbc.edu/ 










Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread TSHACK
very good.  thanks.



- Original Message -
From: Guillermo 
To: 
Sent: Monday, October 29, 2001 2:34 PM
Subject: Re: [pinhole-discussion] Zone Plate Focus stringency


>
> - Original Message -
> From: "TSHACK" 
>
> > That was going to be my question.
>
> When you focus a lens using a ground glass, you are just making coincide
> the -ideally- flat image the lens is projecting with the surface of the
> ground glass, if you remove the ground glass, your eyes can't see the
image,
> but the image is still there focused "in the air".  If you take a loupe
and
> make its base coincide with that image "in the air", in other words, with
> the "Aerial Image", you will then see the the exact same image your film
> will see.  This is best seen in axis with the lens.  If your camera has
GG,
> remove it an install a piece of clear glass, this will allow you to rest
the
> loupe steady, otherwise, you will have to rely on your steady hand.
>
> Again, you will probably be surpriced of what you see.
>
> Guillermo
>
>
> ___
> Pinhole-Discussion mailing list
> Pinhole-Discussion@p at ???
> unsubscribe or change your account at
> http://www.???/discussion/
>




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread Guillermo
- Original Message -
From: "TSHACK" 

> That was going to be my question.

When you focus a lens using a ground glass, you are just making coincide
the -ideally- flat image the lens is projecting with the surface of the
ground glass, if you remove the ground glass, your eyes can't see the image,
but the image is still there focused "in the air".  If you take a loupe and
make its base coincide with that image "in the air", in other words, with
the "Aerial Image", you will then see the the exact same image your film
will see.  This is best seen in axis with the lens.  If your camera has GG,
remove it an install a piece of clear glass, this will allow you to rest the
loupe steady, otherwise, you will have to rely on your steady hand.

Again, you will probably be surpriced of what you see.

Guillermo




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread TSHACK
- Original Message -
From: Chris Peregoy 
To: 
Sent: Monday, October 29, 2001 12:14 PM
Subject: Re: [pinhole-discussion] Zone Plate Focus stringency


> Guillermo wrote:
>
> >Although I do not recommend focusing of the zoneplate every time you make
an
> >exposure, I do recommend you focus it ONCE so you find out (if you wish)
the
> >actual focal length of it.  To do it, aim your camera to a light source
> >(light bulb for instance) or well illuminated object and focus on the
aerial
> >image, rather than on the ground glass.  You will be surprised how "good"
is
> >the image a ZP produces.  And yes, use a loupe.
> >
> >Guillermo
> >
> >
> >
>
> What do you mean by "aerial image"

That was going to be my question.




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread Chris Peregoy

Guillermo wrote:


Although I do not recommend focusing of the zoneplate every time you make an
exposure, I do recommend you focus it ONCE so you find out (if you wish) the
actual focal length of it.  To do it, aim your camera to a light source
(light bulb for instance) or well illuminated object and focus on the aerial
image, rather than on the ground glass.  You will be surprised how "good" is
the image a ZP produces.  And yes, use a loupe.

Guillermo





What do you mean by "aerial image"

--
Chris Peregoy | http://www.gl.umbc.edu/~peregoy | http://imda.umbc.edu/ 







Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread Guillermo
- Original Message -
From: "TSHACK" 

> I congratulate you folks who can focus one of these things through the
> viewfinder.  I pulled out my Crown Graphic, slapped on the reflex viewer,
> tried focusing on a light source, tried focusing on a subject outside, and
I
> really couldn't tell any difference except at the extremes.
>
> Maybe if I use a loupe.   Maybe not.

Although I do not recommend focusing of the zoneplate every time you make an
exposure, I do recommend you focus it ONCE so you find out (if you wish) the
actual focal length of it.  To do it, aim your camera to a light source
(light bulb for instance) or well illuminated object and focus on the aerial
image, rather than on the ground glass.  You will be surprised how "good" is
the image a ZP produces.  And yes, use a loupe.

Guillermo




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread TSHACK
>
> A zone plate focusses like a lens so you should adjust the focus for
> objects at different distances.  On the other hand, they tend to have
> large f numbers (like f/32) so they have large depth of field.  They
are
> also hard to focus because they are so dim.

I congratulate you folks who can focus one of these things through the
viewfinder.  I pulled out my Crown Graphic, slapped on the reflex viewer,
tried focusing on a light source, tried focusing on a subject outside, and I
really couldn't tell any difference except at the extremes.

Maybe if I use a loupe.   Maybe not.




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread Guillermo
- Original Message -
From: "Richard M. Koolish" 

> A zone plate focusses like a lens so you should adjust the focus for
> objects at different distances.  On the other hand, they tend to have
> large f numbers (like f/32) so they have large depth of field.  They
are
> also hard to focus because they are so dim.

Right.

And if you ever decide to focus them, it is best to do it on the aerial
image. My suggestion: don't bother focusing, mount it at a distance from the
fillm plane equal or as close to the focal length it was made for and that
should be sufficient to get good results.

BTW, I don't think making ZP faster than f/64 is a good thing.  A f/32 ZP
would require a large number of rings/zones and that augments the
noise/signal ratio considerably.  For instance, a 90mm ZP f/32 would need 79
rings/zones (total), f/64 would just need 19.

Guillermo






Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread Richard M. Koolish
> I think technically they should be refocused (anyone, please correct me if 
> I'm wrong).but in practical terms my experience is, they needn't be. Try 
> simply setting it to it's designed focal length and shootingIMHO little 
> out of focus softness is often a plus.
> 
> Mike
> 
> 
> In a message dated 10/28/01 5:02:21 PM, tsh...@silver-bayou.com writes:
> 
> << Once you have the zone plate focused for one object, will it be focused for
> any other objects closer or further away, or do I need to refocus according
> to the distance of my subject?
> dwight >>




A zone plate focusses like a lens so you should adjust the focus for
objects at different distances.  On the other hand, they tend to have
large f numbers (like f/32) so they have large depth of field.  They are
also hard to focus because they are so dim.



Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-29 Thread TSHACK
If it needs to refocused, my hacked TLR job is not going to work.  I'll
either need an SLR, or my Crown Graphic.  I hope not.

We'll see what happens.

Tonight I took my Zero Image 6x9, gripped it in place on the top of my car
by closing the moonroof on it, then drove around in traffic.  I'll see what
comes out of it.  I've come up with a new exposure measurement system:
f/90, 100 asa, exposed 4 blocks @25mph.

I took the ZP TLR out and took some shots of neon lights reflected into the
bay water, so I had the long, wide streaks extending down into the water.  I
sort of half-assed guessed at the exposure of 5 minutes.  It might have
needed to be more, but I can always go back.


- Original Message -
From: 
To: 
Sent: Sunday, October 28, 2001 5:13 PM
Subject: Re: [pinhole-discussion] Zone Plate Focus stringency


> I think technically they should be refocused (anyone, please correct me if
> I'm wrong).but in practical terms my experience is, they needn't be.
Try
> simply setting it to it's designed focal length and shootingIMHO
little
> out of focus softness is often a plus.
>





Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-28 Thread NeuhausPhoto
I think technically they should be refocused (anyone, please correct me if 
I'm wrong).but in practical terms my experience is, they needn't be. Try 
simply setting it to it's designed focal length and shootingIMHO little 
out of focus softness is often a plus.

Mike


In a message dated 10/28/01 5:02:21 PM, tsh...@silver-bayou.com writes:

<< Once you have the zone plate focused for one object, will it be focused for

any other objects closer or further away, or do I need to refocus according

to the distance of my subject?


dwight >>




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-28 Thread TSHACK
> Here's my zone plate argus
>
> http://members.aol.com/neuhausphoto/arguszpcam.jpg";>arguszpcam.jpg
>  or   http://members.aol.com/neuhausphoto/arguszpcam.jpg
>
> I discarded the lens cells but used the barrel as a hood for added
protection
> to the mechanism. I adapted  prontor II shutter to the camera too...this
> shutter has many more speeds than the original argus item. Good luck

That looks good.  I may try that.  I went to a local antique camera store
this week, but they had nothing really functioning.  Actually, I was looking
for an SLR body with removable lens, focal plane shutter.  They did have
some cameras like you show here.  I may go back.

Let me ask a clarifying question on zone plate focus.

Once you have the zone plate focused for one object, will it be focused for
any other objects closer or further away, or do I need to refocus according
to the distance of my subject?

dwight




Re: [pinhole-discussion] Zone Plate Focus stringency

2001-10-26 Thread NeuhausPhoto
In a message dated 10/26/01 0:45:31 PM, tsh...@silver-bayou.com writes:

<< Anyone know of some cheap SLR's that I can remove the lens but keep a

functioning shutter?  Like toy level prices

Dwight >>

Dwight,
Try ebay for an old argus model aor check flea markets for old folding 
cameras with small shuttered lenses...some model shutters have lots of timed 
speeds, some don't so you'll have to look. When you find a good one remove 
the lens/shutter assembly, remove the lens cells, set the diaphram to a 
medium aperture and tape your zone plate directly to the diaphram. If you 
tape the zone plate very well, the diaphram blades are quite secure, but it 
does help to pin the diaphram adjustment lever in some way.

Here's my zone plate argus

http://members.aol.com/neuhausphoto/arguszpcam.jpg";>arguszpcam.jpg
 or   http://members.aol.com/neuhausphoto/arguszpcam.jpg 

I discarded the lens cells but used the barrel as a hood for added protection 
to the mechanism. I adapted  prontor II shutter to the camera too...this 
shutter has many more speeds than the original argus item. Good luck

Mike