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Subject: Imaging by screen capture - camera choice
Date: 2016-01-08 13:56:47
From: John Thurston
Having seen some of Geoffrey Waldo's efforts at screen
capture MF3D, I'm tempted to try it. Geoffrey used his TL120
for the capture, but I suspect an SLR would be a whole lot
easier to frame and control. But I don't own an SLR :(

Let's say I wanted to cover a 55x55mm piece of film with an
image of an object 335x335mm. That's a 6:1 reduction. How do
I choose a lens/camera combination for this task?

Do I just go hunt for a Hasselbad 500, an 80mm lens, and
insert extension tubes until I get the right distance? Is
there a smarter way? Is there some suitable lens noted for
its exceptional flatness?

--
John Thurston
Juneau Alaska
http://stereo.thurstons.us
Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-08 15:09:28
From: Timo Puhakka
Couldn't you use a Mamiya TLR like a c220 or c330 which has a bellows for focusing? I have such a beast and it focuses at any distance. It would be like focusing an enlarger lens to match a paper size. As to the flattest field lens, longer the better, I would guess. 

Timo
 
On 8-Jan-16, at 2:56 PM, John Thurston juneau3d@thurstons.us [MF3D-group] wrote:

 

Having seen some of Geoffrey Waldo's efforts at screen
capture MF3D, I'm tempted to try it. Geoffrey used his TL120
for the capture, but I suspect an SLR would be a whole lot
easier to frame and control. But I don't own an SLR :(

Let's say I wanted to cover a 55x55mm piece of film with an
image of an object 335x335mm. That's a 6:1 reduction. How do
I choose a lens/camera combination for this task?

Do I just go hunt for a Hasselbad 500, an 80mm lens, and
insert extension tubes until I get the right distance? Is
there a smarter way? Is there some suitable lens noted for
its exceptional flatness?

--
John Thurston
Juneau Alaska
http://stereo.thurstons.us


Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-08 15:17:43
From: John Thurston
On 1/8/2016 12:09 PM, Timo Puhakka tpuhakka@ymail.com
[MF3D-group] wrote:
> Couldn't you use a Mamiya TLR like a c220 or c330 which has
> a bellows for focusing? I have such a beast and it focuses
> at any distance.

But any TLR, unless I compose with ground glass, is going to
be a guesstimate alignment on the screen. I have a
Rolleicord, and have done the "compose through the finder
and elevate the tripod" routine for closeups. It isn't very
precise. If I have a very specific number of pixels to
capture and I don't want to miss any of them.
--
John Thurston
Juneau Alaska
http://stereo.thurstons.us
Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-08 15:27:09
From: Bob Aldridge
If I were doing this, I might try composing with the camera back open on
a ground glass and then load the film before shooting the slides.

Of course, the tripod or other camer holding arrangement woulg have to
be strong enough to resist movement when loading the camera...

Bob

On 08/01/2016 21:17, John Thurston juneau3d@thurstons.us [MF3D-group] wrote:
> On 1/8/2016 12:09 PM, Timo Puhakka tpuhakka@ymail.com
> [MF3D-group] wrote:
>> Couldn't you use a Mamiya TLR like a c220 or c330 which has
>> a bellows for focusing? I have such a beast and it focuses
>> at any distance.
> But any TLR, unless I compose with ground glass, is going to
> be a guesstimate alignment on the screen. I have a
> Rolleicord, and have done the "compose through the finder
> and elevate the tripod" routine for closeups. It isn't very
> precise. If I have a very specific number of pixels to
> capture and I don't want to miss any of them.
Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-08 16:06:58
From: Geoffrey S. Waldo
I compose on ground glass, camera on rock solid tripod. Then load film

Sent from my iPhone
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Residential Mailing Address 
(please use this as the default unless otherwise advised):

Geoffrey S. Waldo

----------
Consulting:
**Protein Solubility, Folding, Engineering, & Detection**

----------
Work Contact Information:
Geoffrey S. Waldo, PhD
Mail Stop M888
Los Alamos National Laboratory
Los Alamos, NM 87545

Tel:  505-667-8161                 email: waldo@LANL.gov
Fax: 505-665-3024
Cell: 505-204-6979


Los Alamos Fluorescent Proteins Website: http://www.lanl.gov/projects/gfp/
•Superfolder, Folding Reporter, Split Proteins
•Tools for engineering protein folding, stability, and solubility
•Protein interactions, tagging, and detection

ISFI Integrated Center for Structure and Function Innovation web site:http://techcenter.mbi.ucla.edu

On Jan 8, 2016, at 2:17 PM, John Thurston juneau3d@thurstons.us [MF3D-group] <MF3D-group@yahoogroups.com> wrote:

On 1/8/2016 12:09 PM, Timo Puhakka tpuhakka@ymail.com
[MF3D-group] wrote:
Couldn't you use a Mamiya TLR like a c220 or c330 which has
a bellows for focusing? I have such a beast and it focuses
at any distance.

But any TLR, unless I compose with ground glass, is going to
be a guesstimate alignment on the screen. I have a
Rolleicord, and have done the "compose through the finder
and elevate the tripod" routine for closeups. It isn't very
precise. If I have a very specific number of pixels to
capture and I don't want to miss any of them.
--
John Thurston
Juneau Alaska
http://stereo.thurstons.us


------------------------------------

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Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-08 17:20:12
From: JR
You need what is called a "flat field lens".  These are available in most major brands, and are designed for use in copy cameras and enlargers.  In general, the longer the focal length, the better.  It costs less to design a flat field into longer focal lengths, so short focal length flat field lenses (which have more elements due to the corrections necessary for the stronger curvature of the elements) tend to be more expensive, all else being equal.  This is the opposite of "photographic lenses" which tend to get more expensive the longer the focal length.  Some of the ones that come to mind off-the-top are the Repronar, and the Repro-Claron (note the "repro" for reproduction).  If corner-to-corner color accuracy is important, you might want to look at an apochromat process lens, although they can get quite expensive.  Using extension tubes will often mean that the lens is operating at a conjugate that it is not designed for, and can exaggerate the effect of aberrations.  However, if the lens just has a longer back focal distance, the tubes can help by extending the distance from the lens to the film plane or sensor plane, to match.  For example, if you were to use a lens that was intended for use on a 4 x 5 camera on an MF camera, the tubes would compensate for the different back focal distances.

John A. Rupkalvis
stereoscope3d@gmail.com

Picture

On Fri, Jan 8, 2016 at 11:56 AM, John Thurston juneau3d@thurstons.us [MF3D-group] <MF3D-group@yahoogroups.com> wrote:
 

Having seen some of Geoffrey Waldo's efforts at screen
capture MF3D, I'm tempted to try it. Geoffrey used his TL120
for the capture, but I suspect an SLR would be a whole lot
easier to frame and control. But I don't own an SLR :(

Let's say I wanted to cover a 55x55mm piece of film with an
image of an object 335x335mm. That's a 6:1 reduction. How do
I choose a lens/camera combination for this task?

Do I just go hunt for a Hasselbad 500, an 80mm lens, and
insert extension tubes until I get the right distance? Is
there a smarter way? Is there some suitable lens noted for
its exceptional flatness?

--
John Thurston
Juneau Alaska
http://stereo.thurstons.us


Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-08 18:24:10
From: Timo Puhakka
Good point. A "Paramender" would allow you to focus and then realign
to the shooting lens. I made a macro "mushroom cam" using drawer
slides, to make a sideways slide bar. In my case, the slide bar is
used both for stereo separation and parallax correction. The only
problem is that the camera is on it's side. Not a problem if you have
a Porro viewfinder.

Timo

On 8-Jan-16, at 4:17 PM, John Thurston juneau3d@thurstons.us [MF3D-
group] wrote:

> On 1/8/2016 12:09 PM, Timo Puhakka tpuhakka@ymail.com
> [MF3D-group] wrote:
>> Couldn't you use a Mamiya TLR like a c220 or c330 which has
>> a bellows for focusing? I have such a beast and it focuses
>> at any distance.
>
> But any TLR, unless I compose with ground glass, is going to
> be a guesstimate alignment on the screen. I have a
> Rolleicord, and have done the "compose through the finder
> and elevate the tripod" routine for closeups. It isn't very
> precise. If I have a very specific number of pixels to
> capture and I don't want to miss any of them.
> --
> John Thurston
> Juneau Alaska
> http://stereo.thurstons.us
>
>
> ------------------------------------
>
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-08 18:41:00
From: JR
While a ground glass usually suffices for conventional photography, for copy work focusing on the aerial image is usually more accurate.  For this purpose, high-end process cameras often have a special ground glass that has a clear area with a cross hair in the center.  You sight the image in this area and move your head.  If the image next to the cross hair moves, it is out of focus (even if it looks sharp on the ground glass).  It is critically sharp only when the image does not move relative to the cross hair.  

Because these special (aerial image focuser) ground glasses are quite expensive, some photographers make their own.  The take a conventional ground glass, and scribe a cross hair in the center (on the ground side) with a fine point pencil.  Then they make the ground glass clear over that by using an eye dropper to put a drop of clear paint (like clear model airplane "dope" on top of the cross line.  This renders the ground glass clear in that spot.

It is called an aerial image because what you are looking at is the image itself, as if it were just in the air, not diffused by a ground glass.

John A. Rupkalvis
stereoscope3d@gmail.com

Picture

On Fri, Jan 8, 2016 at 3:19 PM, JR <stereoscope3d@gmail.com> wrote:
You need what is called a "flat field lens".  These are available in most major brands, and are designed for use in copy cameras and enlargers.  In general, the longer the focal length, the better.  It costs less to design a flat field into longer focal lengths, so short focal length flat field lenses (which have more elements due to the corrections necessary for the stronger curvature of the elements) tend to be more expensive, all else being equal.  This is the opposite of "photographic lenses" which tend to get more expensive the longer the focal length.  Some of the ones that come to mind off-the-top are the Repronar, and the Repro-Claron (note the "repro" for reproduction).  If corner-to-corner color accuracy is important, you might want to look at an apochromat process lens, although they can get quite expensive.  Using extension tubes will often mean that the lens is operating at a conjugate that it is not designed for, and can exaggerate the effect of aberrations.  However, if the lens just has a longer back focal distance, the tubes can help by extending the distance from the lens to the film plane or sensor plane, to match.  For example, if you were to use a lens that was intended for use on a 4 x 5 camera on an MF camera, the tubes would compensate for the different back focal distances.

John A. Rupkalvis
stereoscope3d@gmail.com

Picture

On Fri, Jan 8, 2016 at 11:56 AM, John Thurston juneau3d@thurstons.us [MF3D-group] <MF3D-group@yahoogroups.com> wrote:
 

Having seen some of Geoffrey Waldo's efforts at screen
capture MF3D, I'm tempted to try it. Geoffrey used his TL120
for the capture, but I suspect an SLR would be a whole lot
easier to frame and control. But I don't own an SLR :(

Let's say I wanted to cover a 55x55mm piece of film with an
image of an object 335x335mm. That's a 6:1 reduction. How do
I choose a lens/camera combination for this task?

Do I just go hunt for a Hasselbad 500, an 80mm lens, and
insert extension tubes until I get the right distance? Is
there a smarter way? Is there some suitable lens noted for
its exceptional flatness?

--
John Thurston
Juneau Alaska
http://stereo.thurstons.us



Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-09 13:28:38
From: roderickdsage
You may consider a Miniature Speed/Century Graphic with roll film back (2x3). Roll backs come in 6x6, 6x7 and  6x9. You would have built in bellows, ground glass, and unlimited lenses. All reasonable price.

RS
Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-09 15:52:14
From: JR
That is a good idea, RS.   Even the larger, more common 4 x 5 Speed Graphics had interchangeable backs that used the Graflok system.  

For example, I used to have a 4 x 5 Speed Graphic and could interchange between sheet film, glass plate, multiple plate, multiple sheet film, and roll backs, for which I originally had a 120 back, which I later changed for a 220 back for the larger capacity (the images were the same size, 6 x 7).  The camera (used, of course) came with a half a dozen sheet film holders (each held two sheets) and one multiple sheet film holder.  I bought the roll back separately, and it easily paid for itself quickly in the much lower price per shot for the medium format.  Later, I bought a used Polaroid back, and using the 55P/N 4 x 5 Polaroid (positive/negative) film, I got a very high resolution 4 x 5 negative right away.  This may have seemed expensive, but since it did not have to be processed later, it was not that much more costly than sheet film plus processing.  And, I got an "instant" 4 x 5 print for confirmation right away.  This was great for checking the stereo when I was using my homemade image splitter in front of the lens.  The one drawback (other than cost) was that you did have to rinse off the negative right away, which meant you needed a convenient source of running water, and a dust-free place (and time) to let it dry.

I liked the camera in general, except that the focal plane shutter required that you remembered to "wind it back" between every shot, otherwise the shutter speed changed.  You could, of course, use lenses mounted in front leaf shutters, and lock the focal plane shutter "open".  

I never used it for copying, since at that time I had a separate Princeton copy camera, but if I didn't, I am sure that I would have.

For copy work, complete copy cameras usually came with a set of lights on arms extending from the base or the sides.  If you use a non-repro type camera like a Speed Graphic, you have to set up (and carefully align) your separate lights.  

In any case, the most even lighting uses four lights, each aimed such that the center of the light field of each lamp is aimed at the diagonally opposite corner of the item on the copyboard.    This tends to compensate for vignetting that results from the falloff towards the outer edge of the lens field, primarily due to the greater distance from the center, as imaged on the film or, in the case of digital, on the sensor.   That is still another reason why longer focal length lenses are preferable for flat copy work.

John A. Rupkalvis
stereoscope3d@gmail.com

Picture

On Sat, Jan 9, 2016 at 11:28 AM, rsage@earthlink.net [MF3D-group] <MF3D-group@yahoogroups.com> wrote:
 

You may consider a Miniature Speed/Century Graphic with roll film back (2x3). Roll backs come in 6x6, 6x7 and  6x9. You would have built in bellows, ground glass, and unlimited lenses. All reasonable price.


RS


Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-09 16:00:49
From: Bob Aldridge
We've been talking about flat-field lenses for this application.

I've always understood that enlarger lenses are - effectively, at least - flat field lenses. I even have a film holder for my enlarger. So, assuming that an enlarger lens can be physically grafted onto a field camera (preferably with a roll film back) this would make a good candidate for using a 4K TV for making MF slides from digital images.

Is that right?

If so, I suspect it would be easier to get set up correctly than a MF camera for my 4K film recorder...

Bob Aldridge




Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-09 17:40:50
From: Geoffrey S. Waldo
One possibility is to set up the camera of your choice. Take a picture of a calibration image. Develop and scan. Provided the scanner is calibrated, you can use the image as a control to at least calculate the correction field needed to morph the image to correct for flat field (pincushion, barrel, etc).
I found with 39" diag 4K screen and the TL120 stock (ca 80 mm lens) there was very little geometrical  distortion. 
Then, simply apply the inverse distortion to future images image prior to sending to screen.
G

Sent from my iPhone
-----------------------------------------------------------------
My personal contact information: 



Residential Mailing Address 
(please use this as the default unless otherwise advised):

Geoffrey S. Waldo

----------
Consulting:
**Protein Solubility, Folding, Engineering, & Detection**

----------
Work Contact Information:
Geoffrey S. Waldo, PhD
Mail Stop M888
Los Alamos National Laboratory
Los Alamos, NM 87545

Tel:  505-667-8161                 email: waldo@LANL.gov
Fax: 505-665-3024
Cell: 505-204-6979


Los Alamos Fluorescent Proteins Website: http://www.lanl.gov/projects/gfp/
•Superfolder, Folding Reporter, Split Proteins
•Tools for engineering protein folding, stability, and solubility
•Protein interactions, tagging, and detection

ISFI Integrated Center for Structure and Function Innovation web site:http://techcenter.mbi.ucla.edu

On Jan 8, 2016, at 2:17 PM, John Thurston juneau3d@thurstons.us [MF3D-group] <MF3D-group@yahoogroups.com> wrote:

On 1/8/2016 12:09 PM, Timo Puhakka tpuhakka@ymail.com
[MF3D-group] wrote:
Couldn't you use a Mamiya TLR like a c220 or c330 which has
a bellows for focusing? I have such a beast and it focuses
at any distance.

But any TLR, unless I compose with ground glass, is going to
be a guesstimate alignment on the screen. I have a
Rolleicord, and have done the "compose through the finder
and elevate the tripod" routine for closeups. It isn't very
precise. If I have a very specific number of pixels to
capture and I don't want to miss any of them.
--
John Thurston
Juneau Alaska
http://stereo.thurstons.us


------------------------------------

------------------------------------


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Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-09 18:11:43
From: Geoffrey S. Waldo
This assumes the depth of field is sufficient to capture the flat frame in focus 

Sent from my iPhone
-----------------------------------------------------------------
My personal contact information: 



Residential Mailing Address 
(please use this as the default unless otherwise advised):

Geoffrey S. Waldo

----------
Consulting:
**Protein Solubility, Folding, Engineering, & Detection**

----------
Work Contact Information:
Geoffrey S. Waldo, PhD
Mail Stop M888
Los Alamos National Laboratory
Los Alamos, NM 87545

Tel:  505-667-8161                 email: waldo@LANL.gov
Fax: 505-665-3024
Cell: 505-204-6979


Los Alamos Fluorescent Proteins Website: http://www.lanl.gov/projects/gfp/
•Superfolder, Folding Reporter, Split Proteins
•Tools for engineering protein folding, stability, and solubility
•Protein interactions, tagging, and detection

ISFI Integrated Center for Structure and Function Innovation web site:http://techcenter.mbi.ucla.edu

On Jan 9, 2016, at 4:33 PM, Geoffrey S. Waldo <gfpguy1@gmail.com> wrote:

One possibility is to set up the camera of your choice. Take a picture of a calibration image. Develop and scan. Provided the scanner is calibrated, you can use the image as a control to at least calculate the correction field needed to morph the image to correct for flat field (pincushion, barrel, etc).
I found with 39" diag 4K screen and the TL120 stock (ca 80 mm lens) there was very little geometrical  distortion. 
Then, simply apply the inverse distortion to future images image prior to sending to screen.
G

Sent from my iPhone
-----------------------------------------------------------------
My personal contact information: 



Residential Mailing Address 
(please use this as the default unless otherwise advised):

Geoffrey S. Waldo

----------
Consulting:
**Protein Solubility, Folding, Engineering, & Detection**

----------
Work Contact Information:
Geoffrey S. Waldo, PhD
Mail Stop M888
Los Alamos National Laboratory
Los Alamos, NM 87545

Tel:  505-667-8161                 email: waldo@LANL.gov
Fax: 505-665-3024
Cell: 505-204-6979


Los Alamos Fluorescent Proteins Website: http://www.lanl.gov/projects/gfp/
•Superfolder, Folding Reporter, Split Proteins
•Tools for engineering protein folding, stability, and solubility
•Protein interactions, tagging, and detection

ISFI Integrated Center for Structure and Function Innovation web site:http://techcenter.mbi.ucla.edu

On Jan 8, 2016, at 2:17 PM, John Thurston juneau3d@thurstons.us [MF3D-group] <MF3D-group@yahoogroups.com> wrote:

On 1/8/2016 12:09 PM, Timo Puhakka tpuhakka@ymail.com
[MF3D-group] wrote:
Couldn't you use a Mamiya TLR like a c220 or c330 which has
a bellows for focusing? I have such a beast and it focuses
at any distance.

But any TLR, unless I compose with ground glass, is going to
be a guesstimate alignment on the screen. I have a
Rolleicord, and have done the "compose through the finder
and elevate the tripod" routine for closeups. It isn't very
precise. If I have a very specific number of pixels to
capture and I don't want to miss any of them.
--
John Thurston
Juneau Alaska
http://stereo.thurstons.us


------------------------------------

------------------------------------


------------------------------------

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Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-09 19:50:12
From: JR
Good point, Geoffrey.  That reminds me of another not often considered item.  Large roll film like 120 and 220 is not perfectly flat (no film is, but sheet film, being thicker, usually is flatter).  Professional process cameras have vacuum backs to hold the film flat.  When I had an enlarger, the MF 120/220 roll film holder actually had "stretcher bars" to hold the film flat.  While a conventional ordinary MF cameras or film backs should hold the film flat enough for most practical purposes, for very critical work (like making alignment grids or registering halftone screens), a method for ensuring greater flatness might be advisable.

John A. Rupkalvis
stereoscope3d@gmail.com

Picture

On Sat, Jan 9, 2016 at 4:11 PM, 'Geoffrey S. Waldo' gfpguy1@gmail.com [MF3D-group] <MF3D-group@yahoogroups.com> wrote:
 

This assumes the depth of field is sufficient to capture the flat frame in focus 


Sent from my iPhone
-----------------------------------------------------------------
My personal contact information: 



Residential Mailing Address 
(please use this as the default unless otherwise advised):

Geoffrey S. Waldo

----------
Consulting:
**Protein Solubility, Folding, Engineering, & Detection**

----------
Work Contact Information:
Geoffrey S. Waldo, PhD
Mail Stop M888
Los Alamos National Laboratory
Los Alamos, NM 87545

Tel:  505-667-8161                 email: waldo@LANL.gov
Fax: 505-665-3024
Cell: 505-204-6979


Los Alamos Fluorescent Proteins Website: http://www.lanl.gov/projects/gfp/
•Superfolder, Folding Reporter, Split Proteins
•Tools for engineering protein folding, stability, and solubility
•Protein interactions, tagging, and detection

ISFI Integrated Center for Structure and Function Innovation web site:http://techcenter.mbi.ucla.edu

On Jan 9, 2016, at 4:33 PM, Geoffrey S. Waldo <gfpguy1@gmail.com> wrote:

One possibility is to set up the camera of your choice. Take a picture of a calibration image. Develop and scan. Provided the scanner is calibrated, you can use the image as a control to at least calculate the correction field needed to morph the image to correct for flat field (pincushion, barrel, etc).
I found with 39" diag 4K screen and the TL120 stock (ca 80 mm lens) there was very little geometrical  distortion. 
Then, simply apply the inverse distortion to future images image prior to sending to screen.
G

Sent from my iPhone
-----------------------------------------------------------------
My personal contact information: 



Residential Mailing Address 
(please use this as the default unless otherwise advised):

Geoffrey S. Waldo

----------
Consulting:
**Protein Solubility, Folding, Engineering, & Detection**

----------
Work Contact Information:
Geoffrey S. Waldo, PhD
Mail Stop M888
Los Alamos National Laboratory
Los Alamos, NM 87545

Tel:  505-667-8161                 email: waldo@LANL.gov
Fax: 505-665-3024
Cell: 505-204-6979


Los Alamos Fluorescent Proteins Website: http://www.lanl.gov/projects/gfp/
•Superfolder, Folding Reporter, Split Proteins
•Tools for engineering protein folding, stability, and solubility
•Protein interactions, tagging, and detection

ISFI Integrated Center for Structure and Function Innovation web site:http://techcenter.mbi.ucla.edu

On Jan 8, 2016, at 2:17 PM, John Thurston juneau3d@thurstons.us [MF3D-group] <MF3D-group@yahoogroups.com> wrote:

On 1/8/2016 12:09 PM, Timo Puhakka tpuhakka@ymail.com
[MF3D-group] wrote:
Couldn't you use a Mamiya TLR like a c220 or c330 which has
a bellows for focusing? I have such a beast and it focuses
at any distance.

But any TLR, unless I compose with ground glass, is going to
be a guesstimate alignment on the screen. I have a
Rolleicord, and have done the "compose through the finder
and elevate the tripod" routine for closeups. It isn't very
precise. If I have a very specific number of pixels to
capture and I don't want to miss any of them.
--
John Thurston
Juneau Alaska
http://stereo.thurstons.us


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Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-10 12:19:20
From: Brian Reynolds
Bob Aldridge wrote:
>
> We've been talking about flat-field lenses for this application.
>
> I've always understood that enlarger lenses are - effectively, at
> least - flat field lenses. I even have a film holder for my
> enlarger. So, assuming that an enlarger lens can be physically
> grafted onto a field camera (preferably with a roll film back) this
> would make a good candidate for using a 4K TV for making MF slides
> from digital images.

A few points.

One of the great things about large format cameras is that you can
pretty much use any lens on any camera. You just need the proper lens
board. For most cameras you can make a lens board with some thin
plywood (go to a hobby shop) and a bit of cutting.

A problem with enlarger lenses is that they don't have shutters. They
are "in barrel". You could use the focal plane shutter on a Speed
Graphic. In all the time I've had my Speed Graphic I've never used
the focal plane shutter to take a picture.

Besides enlarger lenses you could use a process lens. These were made
for copying flat artwork onto negatives for making printing plates.
Since process cameras aren't used anymore the lenses can be gotten
pretty cheap. Many of these process lenses have been remounted into
camera shutters for use on view cameras. Process lenses were
optimized for use around 1:1 magnification, and many were
apochromatic. In order to get a flat field you have to stop the
process lens down to its working aperture (around f/22).

There are several variables you have to look out for when getting a
Graflex roll film back. They came in different camera sizes (4x5,
3-1/4x4-1/4, and 2-1/4x3-1/4), different roll lengths (120 and 220),
and different image sizes (2-1/4 square, 2-1/4x2-3/4, 2-1/4x3-1/4).

The lever wind (as opposed to knob wind) Graflex roll film backs were
supposed to hold the film flatter.

The later backs had RH-# model numbers. The number let you know how
many exposures you got on a roll (8, 10, 12, 20 (220 film 2-3/4x3-1/4
image size), and 50 (70mm film 2-3/4x3-1/4 image size)).

You'll want a camera with a Graflok back. Some manufacturers (who I
guess didn't want to acknowledge Graflex) called these International
backs.

You do not want a Graflex back. That's an older back that does not
have as many accessories, and can not use Graflok accessories.

A Graphic back is a normal spring back. Some spring backs have enough
give that you can slide a Graflok roll film holder under them, but
that can be trouble. Calumet made slide in roll film holders for
spring backs, but they didn't hold the film as flat as a Graflex lever
wind roll film holder.

You can learn a lot about Graflex cameras at <http://graflex.org/>

> If so, I suspect it would be easier to get set up correctly than a
> MF camera for my 4K film recorder...

Depending on the MF camera it might be easier to use than a view
camera set up.

For shooting on roll film I'd probably use my Pentax 67ii before I'd
drag out my Speed Graphic or Century Graphic. Truth be told, I'd use
my Canham before I'd bother with the Speed Graphic.

The big headache would be getting the film plane parallel with the
monitor screen, and centered.

Do you have a copy stand? It may be a bit of trouble, but you could
lay the TV on the stand facing up, level the screen, mount the camera,
level the film plane, and then you would be set.

--
Brian Reynolds | "It's just like flying a spaceship.
reynolds@panix.com | You push some buttons and see
http://www.panix.com/~reynolds/ | what happens." -- Zapp Brannigan
NAR# 54438 |
Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-10 12:36:48
From: Bob Aldridge
Thanks for the reply. Yes - the missing shutter in an enlarging lens could be a problem.

As to the "centering and getting the film plane parallel" issue, I would solve that with a mirror (probably easiest with the monitor horizontal and the mirror placed on it).I would use the reflection of the lens as seen through the SLR viewfinder (I would probably use one of my Hasselblads) to achieve a pretty accurate alignment...

But, since I don't (yet?) have a 4K monitor, it's all a bit academic.

Might pursue the MF camera on the film recorder method. One day. :)

Bob Aldridge

On 10/01/2016 18:19, Brian Reynolds mf3d@reynolds.users.panix.com [MF3D-group] wrote:
 

Bob Aldridge wrote:
>
> We've been talking about flat-field lenses for this application.
>
> I've always understood that enlarger lenses are - effectively, at
> least - flat field lenses. I even have a film holder for my
> enlarger. So, assuming that an enlarger lens can be physically
> grafted onto a field camera (preferably with a roll film back) this
> would make a good candidate for using a 4K TV for making MF slides
> from digital images.

A few points.

One of the great things about large format cameras is that you can
pretty much use any lens on any camera. You just need the proper lens
board. For most cameras you can make a lens board with some thin
plywood (go to a hobby shop) and a bit of cutting.

A problem with enlarger lenses is that they don't have shutters. They
are "in barrel". You could use the focal plane shutter on a Speed
Graphic. In all the time I've had my Speed Graphic I've never used
the focal plane shutter to take a picture.

Besides enlarger lenses you could use a process lens. These were made
for copying flat artwork onto negatives for making printing plates.
Since process cameras aren't used anymore the lenses can be gotten
pretty cheap. Many of these process lenses have been remounted into
camera shutters for use on view cameras. Process lenses were
optimized for use around 1:1 magnification, and many were
apochromatic. In order to get a flat field you have to stop the
process lens down to its working aperture (around f/22).

There are several variables you have to look out for when getting a
Graflex roll film back. They came in different camera sizes (4x5,
3-1/4x4-1/4, and 2-1/4x3-1/4), different roll lengths (120 and 220),
and different image sizes (2-1/4 square, 2-1/4x2-3/4, 2-1/4x3-1/4).

The lever wind (as opposed to knob wind) Graflex roll film backs were
supposed to hold the film flatter.

The later backs had RH-# model numbers. The number let you know how
many exposures you got on a roll (8, 10, 12, 20 (220 film 2-3/4x3-1/4
image size), and 50 (70mm film 2-3/4x3-1/4 image size)).

You'll want a camera with a Graflok back. Some manufacturers (who I
guess didn't want to acknowledge Graflex) called these International
backs.

You do not want a Graflex back. That's an older back that does not
have as many accessories, and can not use Graflok accessories.

A Graphic back is a normal spring back. Some spring backs have enough
give that you can slide a Graflok roll film holder under them, but
that can be trouble. Calumet made slide in roll film holders for
spring backs, but they didn't hold the film as flat as a Graflex lever
wind roll film holder.

You can learn a lot about Graflex cameras at

> If so, I suspect it would be easier to get set up correctly than a
> MF camera for my 4K film recorder...

Depending on the MF camera it might be easier to use than a view
camera set up.

For shooting on roll film I'd probably use my Pentax 67ii before I'd
drag out my Speed Graphic or Century Graphic. Truth be told, I'd use
my Canham before I'd bother with the Speed Graphic.

The big headache would be getting the film plane parallel with the
monitor screen, and centered.

Do you have a copy stand? It may be a bit of trouble, but you could
lay the TV on the stand facing up, level the screen, mount the camera,
level the film plane, and then you would be set.

--
Brian Reynolds | "It's just like flying a spaceship.
reynolds@panix.com | You push some buttons and see
http://www.panix.com/~reynolds/ | what happens." -- Zapp Brannigan
NAR# 54438 |


Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-10 12:51:26
From: Geoffrey S. Waldo
These are great points re. the taking lenses and shuttering, film planes. 
Re film recorders...I can say from personal experience that the Polaroid 8000 film recorder gives mediocre results with MF-sized images. The phosphor screen has a 'grain' pattern that is especially distracting for stereo images. Your eyes can fuse the screen phosphor grain pattern since it's the same in both L and R. You can try the trick of rotating one image 180 so the grain pattern can't be fused. This is less of an issue with 35 mm, but still distracting in the viewer since one often ends up magnifying the 35 mm frame more than the MF to get the same apparent field of view.

A nice laser based film recorder could do better but might be more costly. 

Geoff

Sent from my iPhone
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My personal contact information: 



Residential Mailing Address 
(please use this as the default unless otherwise advised):

Geoffrey S. Waldo

On Jan 10, 2016, at 11:36 AM, Bob Aldridge Bob@Stereoscopy.net [MF3D-group] <MF3D-group@yahoogroups.com> wrote:

 

Thanks for the reply. Yes - the missing shutter in an enlarging lens could be a problem.

As to the "centering and getting the film plane parallel" issue, I would solve that with a mirror (probably easiest with the monitor horizontal and the mirror placed on it).I would use the reflection of the lens as seen through the SLR viewfinder (I would probably use one of my Hasselblads) to achieve a pretty accurate alignment...

But, since I don't (yet?) have a 4K monitor, it's all a bit academic.

Might pursue the MF camera on the film recorder method. One day. :)

Bob Aldridge

On 10/01/2016 18:19, Brian Reynolds mf3d@reynolds.users.panix.com [MF3D-group] wrote:
 

Bob Aldridge wrote:
>
> We've been talking about flat-field lenses for this application.
>
> I've always understood that enlarger lenses are - effectively, at
> least - flat field lenses. I even have a film holder for my
> enlarger. So, assuming that an enlarger lens can be physically
> grafted onto a field camera (preferably with a roll film back) this
> would make a good candidate for using a 4K TV for making MF slides
> from digital images.

A few points.

One of the great things about large format cameras is that you can
pretty much use any lens on any camera. You just need the proper lens
board. For most cameras you can make a lens board with some thin
plywood (go to a hobby shop) and a bit of cutting.

A problem with enlarger lenses is that they don't have shutters. They
are "in barrel". You could use the focal plane shutter on a Speed
Graphic. In all the time I've had my Speed Graphic I've never used
the focal plane shutter to take a picture.

Besides enlarger lenses you could use a process lens. These were made
for copying flat artwork onto negatives for making printing plates.
Since process cameras aren't used anymore the lenses can be gotten
pretty cheap. Many of these process lenses have been remounted into
camera shutters for use on view cameras. Process lenses were
optimized for use around 1:1 magnification, and many were
apochromatic. In order to get a flat field you have to stop the
process lens down to its working aperture (around f/22).

There are several variables you have to look out for when getting a
Graflex roll film back. They came in different camera sizes (4x5,
3-1/4x4-1/4, and 2-1/4x3-1/4), different roll lengths (120 and 220),
and different image sizes (2-1/4 square, 2-1/4x2-3/4, 2-1/4x3-1/4).

The lever wind (as opposed to knob wind) Graflex roll film backs were
supposed to hold the film flatter.

The later backs had RH-# model numbers. The number let you know how
many exposures you got on a roll (8, 10, 12, 20 (220 film 2-3/4x3-1/4
image size), and 50 (70mm film 2-3/4x3-1/4 image size)).

You'll want a camera with a Graflok back. Some manufacturers (who I
guess didn't want to acknowledge Graflex) called these International
backs.

You do not want a Graflex back. That's an older back that does not
have as many accessories, and can not use Graflok accessories.

A Graphic back is a normal spring back. Some spring backs have enough
give that you can slide a Graflok roll film holder under them, but
that can be trouble. Calumet made slide in roll film holders for
spring backs, but they didn't hold the film as flat as a Graflex lever
wind roll film holder.

You can learn a lot about Graflex cameras at

> If so, I suspect it would be easier to get set up correctly than a
> MF camera for my 4K film recorder...

Depending on the MF camera it might be easier to use than a view
camera set up.

For shooting on roll film I'd probably use my Pentax 67ii before I'd
drag out my Speed Graphic or Century Graphic. Truth be told, I'd use
my Canham before I'd bother with the Speed Graphic.

The big headache would be getting the film plane parallel with the
monitor screen, and centered.

Do you have a copy stand? It may be a bit of trouble, but you could
lay the TV on the stand facing up, level the screen, mount the camera,
level the film plane, and then you would be set.

--
Brian Reynolds | "It's just like flying a spaceship.
reynolds@panix.com | You push some buttons and see
http://www.panix.com/~reynolds/ | what happens." -- Zapp Brannigan
NAR# 54438 |



Subject: Re: Imaging by screen capture - camera choice
Date: 2016-01-10 13:35:36
From: Bob Aldridge
Yes. I've never been totally happy with the output from my polaroid film recorder. The Agfa PCR II + seems to yield better results. But, of course, it's only a 4K film recorder.

But the best screens these days are 4K aren't they?

Bob Aldridge

On 10/01/2016 18:51, 'Geoffrey S. Waldo' gfpguy1@gmail.com [MF3D-group] wrote:
 
These are great points re. the taking lenses and shuttering, film planes. 
Re film recorders...I can say from personal experience that the Polaroid 8000 film recorder gives mediocre results with MF-sized images. The phosphor screen has a 'grain' pattern that is especially distracting for stereo images. Your eyes can fuse the screen phosphor grain pattern since it's the same in both L and R. You can try the trick of rotating one image 180 so the grain pattern can't be fused. This is less of an issue with 35 mm, but still distracting in the viewer since one often ends up magnifying the 35 mm frame more than the MF to get the same apparent field of view.

A nice laser based film recorder could do better but might be more costly. 

Geoff