Digital mosaics as a replacement of the large format view camera

Hi.
I have been doing large format photography for going on 2 decades.
I have also been doing wildlife photography, first with 35mm then
digital. Thus, I often carry both digital wildlife and 4x5 gear
on a hike (up to 70 pounds). That gets real tiring and limits
my range (and, obviously, I'm getting older). I want an alternative
without giving up anything ;-). I switched to a Toho field camera
(3 pounds) from heavier cameras several years ago, but it is still
too much weight doing both digital wildlife and 4x5 (I still love
the Toho though).

Mosaicking many digital image frames as intrigued me for
some time, and I have been experimenting with the methods,
from field to computer processing. Like large format view cameras
and methods, there is much to learn. But my experience so far
is that digital mosaics can equal and surpass 4x5 drum scanned
film in many applications, including large depth of field imaging
requiring tilts on a view camera. And I can get images in the
field faster and under conditions not suitable for large format
photography (like wind).

I've written up some of my experiences in this article and compare
the digital results to drum scanned 4x5 film images:

Large Digital Mosaics as a Substitute for Large Format Film
http://www.clarkvision.com/photoinfo/large_mosaics

Comments welcome.

Roger Clark
my photos at: http://www.clarkvision.com

Roger N. Clark (change username to rnclark) wrote:

Hi.

I've written up some of my experiences in this article and compare
the digital results to drum scanned 4x5 film images:

Large Digital Mosaics as a Substitute for Large Format Film
http://www.clarkvision.com/photoinfo/large_mosaics

Comments welcome.
Roger Clark


Impressive results, Roger. Thanks for the write up!

Can you elaborate on how to deal with moving clouds and the like? I
assume you 'scan' the scene moving with the clouds. Even then, you
might have several possible positions that a given cloud wind up at.

Also, I'm unclear as to how do you reconcile those clouds, or other
moving subjects like blowing grass/flowers/etc., that cross frame
boundries. With the grass, you could wind up with dozens of subjects
blowing this way and that, many out of phase with each other. I'd think
that some would wind up blurred, sheared, or distorted in the final image.

Any plans to build an automated scanning tripod head? Something that
could quickly and accurately step the camera across the scene, stopping
just long enough to trigger the shutter before slewing to the next
location. I'd think that camera data-writing lag would be the limiting
speed factor. Write lag is a serious PITA with my P/S digicam when I
take taken large numbers of panno shots to stitch. I'm sure curent
DSLRs are much better....

-Greg

Greg Campbell wrote:

Roger N. Clark (change username to rnclark) wrote:

Hi.

I've written up some of my experiences in this article and compare
the digital results to drum scanned 4x5 film images:

Large Digital Mosaics as a Substitute for Large Format Film
http://www.clarkvision.com/photoinfo/large_mosaics

Comments welcome.
Roger Clark

Impressive results, Roger. Thanks for the write up!

Thanks, Greg.

Can you elaborate on how to deal with moving clouds and the like? I
assume you 'scan' the scene moving with the clouds. Even then, you
might have several possible positions that a given cloud wind up at.

Let's look at this image as an example (a 4x5 film image):
http://www.clarkvision.com/galleries...01a2-600b.html
The foreground flowers are in a shadow from an overhead cloud.

I would generally do this image in a mosaic by first knowing my f/stop
and shutter speed, placing the camera on manual (except autofocus), and
starting image frames at the bottom and work up. At some point, the
cloud shadow edge will catch up to my framing. I'll try and frame
fast for that row, hoping the final merge can be done reasonably
(e.g. do not use mirror lock up).
Whether or not it works is dependent on the distance and speed of the
shadow edge. I had to break off several mosaics this summer when
doing wildflower images like these because the cloud shadow movement was
too fast. But the many times I've almost clicked the shutter with
4x5 film, and had to break off due to wind far exceeds a typical
field outing with 4x5. The gallery page above is a good
illustration: I spend 5 hours to get that image, waiting for the cloud
shadow, then waiting for a calm in the wind (and the final image
still has some flower movement in the distance).


Another factor I found difficult is that the light
intensity in the cloud shadow changes and that can cause difficulty
with the mosaic, although the software does pretty well with matching
levels. When it gets too extreme, the join region becomes noticeable.

For the distant clouds, they move slow enough that I haven't noticed
them as a problem.


Also, I'm unclear as to how do you reconcile those clouds, or other
moving subjects like blowing grass/flowers/etc., that cross frame
boundries. With the grass, you could wind up with dozens of subjects
blowing this way and that, many out of phase with each other. I'd think
that some would wind up blurred, sheared, or distorted in the final image.

For prominent subject blowing in the wind, I'll make a point to include extra
frames to center that one (e.g. a flower), even framing it several
times to catch the scene in several positions swaying in the wind.
I've always had enough frames and overlap to match.
In the image on the web page, there were several places
where there was misalignment due to movement. But by changing the
place where one scene merges with the next I was able to always
get a good match. I also wait for a local calm in the wind, thus
a foreground flower may be still and a wind gust is coming (and
flowers further away are moving). I'll frame until the wind gets to
my framing, then pause and wait. Once things are still again,
I'll continue. It seems that everything goes back to the same position.

Maybe I've just been lucky. ;-) But I think overlap is the key.
I generally do 50% overlap, then more when wind is a factor.

Any plans to build an automated scanning tripod head? Something that
could quickly and accurately step the camera across the scene, stopping
just long enough to trigger the shutter before slewing to the next
location. I'd think that camera data-writing lag would be the limiting
speed factor. Write lag is a serious PITA with my P/S digicam when I
take taken large numbers of panno shots to stitch. I'm sure curent
DSLRs are much better....

I don't think an automated head would be an improvement, and it
would be more weight.

If I do mirror lock-up, which takes 3 seconds, then the frame time
is about 4 or 5 seconds. My DSLR (1D mark II, which writes quite fast)
has never filled the buffer). If I don't use mirror lockup, I can
frame every second or two. I have come close to filing the buffer
when writing raw plus jpeg.

The other issue I have yet to try is working with a split density filter.
It will take careful planning for the bright/dark intensity line, then what
to do above that line? And how will the software act when it tries to
combine the scenes? Fortunately with DSLRs, the dynamic range
is huge compared to film, so it has not been an issue, yet.

Roger

In article ,
"Roger N. Clark (change username to rnclark)"
wrote:

Comments welcome.

I don't like the color balance of the ground-too green-yellow, and the
clouds look artificially flat & seem to loose detail.
--
Reality-Is finding that perfect picture
and never looking back.

www.gregblankphoto.com

Roger

Fascinating and very impressive. Makes me wonder whether the future of
LF is digital backs with an array of digital sensors, and the stitching
software in firmware.

Stewart

Roger N. Clark (change username to rnclark) wrote:
Hi.
I have been doing large format photography for going on 2 decades.
I have also been doing wildlife photography, first with 35mm then
digital. Thus, I often carry both digital wildlife and 4x5 gear
on a hike (up to 70 pounds). That gets real tiring and limits
my range (and, obviously, I'm getting older). I want an alternative
without giving up anything ;-). I switched to a Toho field camera
(3 pounds) from heavier cameras several years ago, but it is still
too much weight doing both digital wildlife and 4x5 (I still love
the Toho though).

Mosaicking many digital image frames as intrigued me for
some time, and I have been experimenting with the methods,
from field to computer processing. Like large format view cameras
and methods, there is much to learn. But my experience so far
is that digital mosaics can equal and surpass 4x5 drum scanned
film in many applications, including large depth of field imaging
requiring tilts on a view camera. And I can get images in the
field faster and under conditions not suitable for large format
photography (like wind).

I've written up some of my experiences in this article and compare
the digital results to drum scanned 4x5 film images:

Large Digital Mosaics as a Substitute for Large Format Film
http://www.clarkvision.com/photoinfo/large_mosaics

Comments welcome.

Roger Clark
my photos at: http://www.clarkvision.com

In article , says...

I've written up some of my experiences in this article and compare
the digital results to drum scanned 4x5 film images:

Large Digital Mosaics as a Substitute for Large Format Film
http://www.clarkvision.com/photoinfo/large_mosaics

Comments welcome.

Roger Clark
my photos at: http://www.clarkvision.com

Combining multiple images can be used with film cameras too.
Once the film is scanned then all the steps are the same as
with digital.
I've been doing this for years to produce panoramas where my
objective is a larger field of view (up to 360) rather than
higher resolution. The ease of digital has made panoramas
using this technique a bit of a fad these days. Some cameras
even have built in software to assist with the overlaps.

Not to get into a big philosophical debate, but I find these
super resolution image somewhat off putting. The fact that
so much fine detail is seen in objects in the distance makes
it look unnatural and makes one focus on the detail rather than
on the overall scene.
Conventional photographers who use film-based unsharp masking
give me the same funny feeling.

I am willing to accept this look as a different type of aesthetic
effect, but it requires a mental adjustment.
--
Robert D Feinman
Landscapes, Cityscapes and Panoramic Photographs
http://robertdfeinman.com
mail:

On Sun, 27 Aug 2006 08:56:09 -0400, Robert Feinman
wrote:


Combining multiple images can be used with film cameras too.
Once the film is scanned then all the steps are the same as
with digital.
I've been doing this for years to produce panoramas where my
objective is a larger field of view (up to 360) rather than
higher resolution. The ease of digital has made panoramas
using this technique a bit of a fad these days. Some cameras
even have built in software to assist with the overlaps.

Indeed, it can be done with [scanned] film, as we both know.

Although in my case I've been stitching the images
laboriously, by hand, in Photoshop -- which is slow
and never as seamless as what Scott W and Roger
routinely achieve.

Not to get into a big philosophical debate, but I find these
super resolution image somewhat off putting. The fact that
so much fine detail is seen in objects in the distance makes
it look unnatural and makes one focus on the detail rather than
on the overall scene.


Silly. Now you're claiming the *existence* of all this
detail detracts from the image.

But again, this level of detail is comparable to what
you'd get from a well-shot and well-scanned LF frame.
The "GagaPixl" project represents the bleeding edge
of that technology:

http://www.gigapxl.org/


rafe b
www.terrapinphoto.com

In article ,
Robert Feinman wrote:


Not to get into a big philosophical debate, but I find these
super resolution image somewhat off putting. The fact that
so much fine detail is seen in objects in the distance makes
it look unnatural and makes one focus on the detail rather than
on the overall scene.
Conventional photographers who use film-based unsharp masking
give me the same funny feeling.

I completely agree, does anyone remember a few years back there was a
company from Japan marketing super high resolution Laser imaged scenery
in calendars, brilliant saturated colors, and very sharp images. Problem
was after a few minutes the images lost all appeal. I find much color
imagery to be this way-the photographer only concentrating on color or
technique. And composition and a sense light rather lacking.

I am willing to accept this look as a different type of aesthetic
effect, but it requires a mental adjustment.

Like reading blue prints.
--
Reality-Is finding that perfect picture
and never looking back.

www.gregblankphoto.com

In article ,
Raphael Bustin wrote:

On Sun, 27 Aug 2006 08:56:09 -0400, Robert Feinman
wrote:


Combining multiple images can be used with film cameras too.
Once the film is scanned then all the steps are the same as
with digital.
I've been doing this for years to produce panoramas where my
objective is a larger field of view (up to 360) rather than
higher resolution. The ease of digital has made panoramas
using this technique a bit of a fad these days. Some cameras
even have built in software to assist with the overlaps.

Indeed, it can be done with [scanned] film, as we both know.

Although in my case I've been stitching the images
laboriously, by hand, in Photoshop -- which is slow
and never as seamless as what Scott W and Roger
routinely achieve.

Not to get into a big philosophical debate, but I find these
super resolution image somewhat off putting. The fact that
so much fine detail is seen in objects in the distance makes
it look unnatural and makes one focus on the detail rather than
on the overall scene.


Silly. Now you're claiming the *existence* of all this
detail detracts from the image.

But again, this level of detail is comparable to what
you'd get from a well-shot and well-scanned LF frame.
The "GagaPixl" project represents the bleeding edge
of that technology:

http://www.gigapxl.org/


rafe b
www.terrapinphoto.com

Problem is it becomes less about
--
Reality-Is finding that perfect picture
and never looking back.

www.gregblankphoto.com

Greg "_" wrote:

In article ,
"Roger N. Clark (change username to rnclark)"
wrote:


Comments welcome.


I don't like the color balance of the ground-too green-yellow, and the
clouds look artificially flat & seem to loose detail.

color balance: I use a color managed work-flow on a calibrated CRT monitor.

Some RGB values:
red green blue
The white flowers in the foreground: 28656 29555 29941
distant white flowers: 27371 27628 29812

Distant snow on mountains: 31740 31354 30069

The late season snow should be reddish as it has a lot of
dust mixed in. There is some pollution in the air from certain
west cost cities, reddening the clouds on the horizon.

The white flowers are slightly bluish, due to the blue sky
contribution. The soil is quite red, so the fields will look
green + red = yellow. That is the way it really was.


clouds look artificially flat & seem to loose detail:
Are you using a calibrated monitor? The cloud intensity values
range from ~17,000 to 32,639 in the full resolution 16-bit image.

Roger