Training Example: Large Format Photography . Info – Review the Data, Give Your Score & Compare to the Real AI Evaluation

[H2] Large Format Photography . Info

Welcome to the primary internet resource for large format photography!

This non-commercial community of large format photographers
includes a repository of primers, how-to articles, and
user's reviews of equipment, with most the activity taking place in the
Forum.

Founded in 1995 by QT Luong,
written by many contributors.

Updated April 2015
·
Site timeline.

[H3]
How to get started in large format photography

A closer look at a
large format photograph: for some inspiration. 10/1999
Why large format ?
Pros and cons of LF photography, some references. 4/2001 (rev)
From MF to LF How large is the step from MF to LF ? 4/2015
What equipment do I need ? A discussion of
all the gear you need to get started. 1/1999 (rev)
Introduction to large format
lenses: basics, operation, lens types and manufacturers,
selection. 03/2007 (rev)
The 5x7 format in practice 11/2005
How to operate the camera ? A
detailed step-by-step guide. 6/2000
What are the common mistakes, and how to
avoid them? It is easy to ruin a picture. Lessons learned the hard
way.

[H3] Opinion

Confessions of a recovering
magic bullet chaser 12/2003

[H3]
Technical topics

[H4] Pre-exposure

Film loading

How to manage film (on a long trip)
5/2001

Dust and spotting

Diagnosing and fixing light leaks

[H4] Taking the picture

Introduction to Depth of Field (PDF)
and
Depth of Field in Depth (PDF)
(
comments
) 2/2006

How to focus the view camera 7/2000

How to select the f-stop: for maximum sharpness against
defocus and diffraction 3/2001 (rev)

bellows extension exposure
compensation 6/1998 (rev)

view camera stability

[H4] Traditional processing and printing

B&W darkroom for large format
photography: a primer. Covers basics about processing and printing
and gives additional references 6/1999
Developing 4X5 Sheet Film, an
Alternative Method 3/2003

E6 sheet film processing on a
budget with the Agitank
4x5 Unicolor Drum Development 3/2002 (includes
considerations on film washing and
comments) 10/2004 (rev)
A few ideas on using Kodak T-Max Films
Successfully. John Sexton's 1987 DT article.
7/2000
The Stoeckler Two-bath Film Developer
9/2000

James Phillips F-stop printing table (PDF) 8/2003

Ralph Lambrecht's F-stop printing table (PDF) 12/2003
Unsharp Masking 9/2003
Toning, and permanence of silver gelatin prints 6/2005

The VIDEC system: Precise Control for Superior Black and White Photography (PDF ebook) Andrew C. Eads' alternative to the Zone System 1/2013

[H4] Digital

Generating classic glass
negative look when scanning 4x5 3/2003
A collaborative scanner comparison 4/2005
Overview of color digital printing 7/2005
Scanning Black and White negative film with the Microtek Artixscan 1800F 1/2006

[H4]
Misc

Sun/Moon Calculator (description)
1/2015 (rev)

Making a DOF calculator for your camera 6/2000
(rev)

Building and using a Zone Dial (PDF) 12/2003

Slider for visualizing where tones should be placed 9/2004

Links to photographic tools
: programs, spreadsheets, calculators, tables, 2/2000 (rev)

Spreadsheets to help the
focussing process 3/2003 (rev)

Exposure Metering and Zone
system calibration (PDF) 8/2003

Restoring a 8x10 Burke and
James 3/2001

A home made 11x14 hand-held
camera (and remarks on the 8x10 Hobo) 12/2001

Reflexions on camera
construction 10/2002
Guillotine Shutters: Construction and
Speeds: simple DYI shutter for barrel lenses 11/2010

How to make a custom darkroom sink out of PVC

How to make a wonderful loupe 1/2003

Wet mounting prints 5/2003
Odds and ends. 4/2000 (rev)

Workshops

Books: for instruction and
inspiration 2/2013 (rev)

[H3] Travels

Long distance traveling with the LF
camera 2/2001
A week in the Southwest and Four
Corners 2/2001
Photographing in US National
Parks and other federal public lands 4/2001
A Backpacking trip into the Arrigetch Peaks, Gates of the Artic
National Park 7/2001
Still Photography and Permits on US
and California Public Land 2/2025 (rev)

[H3]
Equipment reviews

QT Luong's general purpose camera bag 09/2004

Daniel Geiger's camera bag 02/2007

[H4]
Cameras

Camera reviews

A 2x3 round-up:
a discussion of the 2x3 format and an extensive survey of 2x3
cameras. 9/2001

A 4x5 round-up
: an extensive survey of 4x5 cameras for the field. 03/2001 (rev)

A 5x7 round-up
: an extensive survey of 5x7 cameras for the field.
7/2000 (rev)

Cheap view cameras 08/2005

Comparisons 1/2001 (rev)

Using a monorail in the field. 9/1999

4x10 and holders 07/2004

8x10

11x14

[H4]
Lenses

Comparison charts 1/2002
Generalities, classic vs modern
lenses 5/1999 (rev)
Specific lenses: wide and normal for 4x5
5/1999 (rev)
Specific lenses : long for 4x5 5/1999 (rev)
More thoughts on selecting a long
lens for 4x5
A selection of modern lenses for 4x5 field work
A survey of modern lenses for 5x7

More on specific classic
lenses 5/1999 (rev)
Docter optik, Carl Zeiss Jena/Jenoptik, Meopta, and Russian LF lenses 7/2002 (rev)
Wisner Convertible plasmat set
10/97

Soft-focus lenses and technique 11/2003

Macro lenses, equipment, and technique 1/2004

Portrait lenses 4/2012

[H4]
Accessories

Shutters: history and use 11/2006
More on shutters: general info, packard
shutters, copals, compurs, protors. 7/2001 (rev)
Lensboard hole sizes 10/2003
Sheet Film holders: classical double
holders, grafmatics, quickloads, readyloads. 7/2004 (rev)
Shen Hao 6x17 roll-film back 2/2005
Shen Hao SH612 Multi-format roll-film back 1/2006

Enhanced focussing screens: Beattie,
fresnels... are they really useful ? 7/1998 (rev)
Filters: center, polarizers,
rectangular systems. 9/2000

The Zone VI regular tripod:
Is it the best damm tripod in the world ?
Surveyor Tripod Conversion: cheap and indestructable 09/2009
Tripod heads: Pan-Tilt heads,
Ball-heads, QR systems. 10/2004 (rev)

Backpack survey: carry all this
gear for those "unphotogenic" opportunities. 5/1999 (rev)
Black Jacket focussing cloth 7/2005

[H2] Community

Large Format Photography Forum : most active part of this site

Photographers directory Hand-maintained by Tom Westbrook

LF Groups and clubs directory Hand-maintained by Sherman
Dunnam

Links to LF photographers not currently updated

Commercial LF resources 7/2001

The following links are affiliate links.
When you click on either of those two vendors links, you are taken to
their site with an ID that identifies largeformatphotography.info as refering you.
If you purchase something during that session on either site, we get a small commission at no cost to you, so if you plan to shop there, you might as well follow those links !

B&H: the most complete stock of photographic gear, including hard-to-find professional/specialized items.

Amazon.com: for everything else.

[IMG: Home]

Forum

[H1] Large Format Photography Forum

Welcome to the Large Format Photography Forum.

[H2]
Site Forums
Threads / Posts
Last Post

[H2] LF Home Page - Articles & Reviews

A link to articles on the Large Format Photography Home Page.

[H2] Forum Guidelines

Please Read This First

[H2] News

Announcements and news about the LF Photography site, including home page articles, Forum changes and downtime.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 101
Posts: 2,939

[H4] Last Post:

[IMG: Exclamation]

Forum Upgrade Outage
[IMG: Go to last post]

by
Louis Pacilla

View Profile

View Forum Posts

Yesterday, 18:43

[H2] Feedback

Questions and answers about the LF Photography Home Page and Forum.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 760
Posts: 13,807

[H4] Last Post:

SSL Handshake issue
[IMG: Go to last post]

by
Drew Bedo

View Profile

View Forum Posts

Visit Homepage

19-May-2026, 11:05

[H2]
LF Forums
Threads / Posts
Last Post

[H2] Announcements

Non-repetitive announcements about LF related gallery openings, workshops, new books, trade shows, and other educational opportunities.Events can also be added to the forum Calendar.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 3,288
Posts: 34,483

[H4] Last Post:

August Sander at Yale
[IMG: Go to last post]

by
Oren Grad

View Profile

View Forum Posts

Visit Homepage

26-May-2026, 11:30

[H2] Business

Business aspects of LF photography, including legal, marketing and promotion.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 1,388
Posts: 29,546

[H4] Last Post:

US Supreme Court rules...
[IMG: Go to last post]

by
Oren Grad

View Profile

View Forum Posts

Visit Homepage

20-Feb-2026, 09:29

[H2] Cameras & Camera Accessories

Large format cameras of all types, 8x10 and smaller.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 16,235
Posts: 199,811

[H4] Last Post:

Kodak 4A
[IMG: Go to last post]

by
ElmoLopez

View Profile

View Forum Posts

27-May-2026, 03:57

[H2] Cameras - ULF (Ultra Large Format) and Accessories

LF cameras of all types having a diagonal of 13" or larger.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 293
Posts: 5,632

[H4] Last Post:

[IMG: Question]

Light dispersion inside the...
[IMG: Go to last post]

by
Pechoretc

View Profile

View Forum Posts

Yesterday, 00:29

[H2] Darkroom: Equipment

All about darkroom hardware: enlargers, lenses, easels, exhaust fans, etc.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 4,405
Posts: 54,102

[H4] Last Post:

Durst Mivalo manual
[IMG: Go to last post]

by
mbuonocore

View Profile

View Forum Posts

Yesterday, 11:49

[H2] Darkroom: Film, Processing & Printing

Traditional film, film processing, lab processing, chemistry, paper, traditional printing processes and conservation.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 13,900
Posts: 171,965

[H4] Last Post:

Ilford Pan F Sheet film
[IMG: Go to last post]

by
Drew Wiley

View Profile

View Forum Posts

Visit Homepage

Today, 08:56

[H2] Digital Hardware

Large format digital hardware (cameras and backs (having a capture area of nominally 4x5 or larger), scanners, printers, etc.)

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 3,354
Posts: 46,223

[H4] Last Post:

Creo iqsmart users
[IMG: Go to last post]

by
RolandR

View Profile

View Forum Posts

8-May-2026, 08:16

[H2] Digital Processing

Software, printing, workflow

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 2,422
Posts: 31,356

[H4] Last Post:

digital negative info
[IMG: Go to last post]

by
Andrew O'Neill

View Profile

View Forum Posts

Visit Homepage

15-May-2026, 07:03

[H2] Wet Plate

Large-format wet plate photography--equipment, chemistry, techniques, and examples.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 200
Posts: 2,677

[H4] Last Post:

Transporting Glass Plates on...
[IMG: Go to last post]

by
jnantz

View Profile

View Forum Posts

18-May-2026, 03:23

[H2] Gear

Questions about photographic accessories (not lens or camera body accessories) like tripods, bags, meters, etc.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 4,310
Posts: 55,561

[H4] Last Post:

Rusty Sinar back - how to fix...
[IMG: Go to last post]

by
phdgent

View Profile

View Forum Posts

16-May-2026, 22:49

[H2] Image Sharing (LF) & Discussion

Post your own large-format images (based on 4"x5" or larger format) for sharing and discussion. Critiques should only be offered if requested by the original poster.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 1,273
Posts: 132,228

[H4] Last Post:

Trains
[IMG: Go to last post]

by
Rick A

View Profile

View Forum Posts

Today, 06:32

[H2] Image Sharing (Everything Else) & Discussion

Post your own images of other formats and types here for sharing and discussion. All roll film formats and medium-format digital formats belong here, regardless of camera used. Critiques should only be offered if requested by the original poster.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 224
Posts: 42,278

[H4] Last Post:

Post yer 35mm shots!
[IMG: Go to last post]

by
Daniel Unkefer

View Profile

View Forum Posts

Today, 10:39

[H2] Lenses & Lens Accessories

Discuss Large Format Lenses & Lens Accessories (including lenses capable of being used on ULF)

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 15,185
Posts: 176,691

[H4] Last Post:

Filter Systems: trying to...
[IMG: Go to last post]

by
Drew Wiley

View Profile

View Forum Posts

Visit Homepage

Today, 10:18

[H2] LF DIY (Do It Yourself)

- discussions of how to build, restore or repair large format cameras and equipment or accessories for handling large format negatives (4x5 and larger).

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 1,833
Posts: 28,111

[H4] Last Post:

Durst Stades 1800 controller
[IMG: Go to last post]

by
Ninjaslim

View Profile

View Forum Posts

20-May-2026, 14:56

[H2] Lighting Techniques - Studio, Artificial

Discussions of artificial lighting techniques used in the studio and outside the studio.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 189
Posts: 3,630

[H4] Last Post:

Broncolor Flash Pack Bonanza
[IMG: Go to last post]

by
Mal Paso

View Profile

View Forum Posts

Yesterday, 16:15

[H2] Location & Travel

Discuss questions about places to photograph, including conditions in transit and how to travel with equipment.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 2,445
Posts: 38,008

[H4] Last Post:

Airport Film Hand Check
[IMG: Go to last post]

by
phdgent

View Profile

View Forum Posts

Today, 00:04

[H2] On Photography

Discuss aesthetics, philosophy, history,
photographers and photographs.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 3,761
Posts: 79,996

[H4] Last Post:

Colorized "Moonrise" at...
[IMG: Go to last post]

by
jnantz

View Profile

View Forum Posts

Today, 03:12

[H2] Resources

Labs, education, workshops, services, stores and places to find information on LF photography. Commercial posts are prohibited except by approval of the moderators, see the guidelines before posting.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 1,850
Posts: 21,623

[H4] Last Post:

Is The Packard Shutter...
[IMG: Go to last post]

by
John Layton

View Profile

View Forum Posts

Visit Homepage

6-May-2026, 12:18

[H2] Style & Technique

For questions about exposure, meters, Zone system, or advice on photographing specific subjects.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 2,873
Posts: 46,851

[H4] Last Post:

Depth of field fore and aft...
[IMG: Go to last post]

by
Doremus Scudder

View Profile

View Forum Posts

Visit Homepage

10-Apr-2026, 10:50

[H2]
Community
Threads / Posts
Last Post

[H2] Introductions

Introduce yourself or share your recent plunge into LF photography.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 1,993
Posts: 17,715

[H4] Last Post:

Returning after a way too...
[IMG: Go to last post]

by
6x6TLL

View Profile

View Forum Posts

28-May-2026, 23:14

[H2] Groups & Meetings

Information & questions about organized LF groups & unofficial meet-ups.Events can also be added to the froum Calendar.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 492
Posts: 7,460

[H4] Last Post:

Redwood City, CA Camera Swap
[IMG: Go to last post]

by
Dugan

View Profile

View Forum Posts

16-May-2026, 14:12

[H2] New Products and Services

A forum for announcements of a commercial nature related to large format photography. Moderator approval is required before posting promotional items.

[H4] Forum Actions:

View this forum's RSS feed

[H4] Forum Statistics:

Threads: 293
Posts: 5,349

[H4] Last Post:

Fujinon SF 420mm f/5.6 Lens -...
[IMG: Go to last post]

by
Vaughan

View Profile

View Forum Posts

18-May-2026, 20:00

[IMG: Home]

vBulletin Message

[H2] vBulletin Message

No Thread specified. If you followed a valid link, please notify the administrator

Quick Navigation

Site Areas
Settings
Private Messages
Subscriptions
Who's Online
Search Forums
Forums Home

Forums

Site Forums

LF Home Page - Articles & Reviews

Forum Guidelines

News

Feedback

LF Forums

Announcements

Business

Cameras & Camera Accessories

Cameras - ULF (Ultra Large Format) and Accessories

Darkroom: Equipment

Darkroom: Film, Processing & Printing

Digital Hardware

Digital Processing

Wet Plate

Gear

Image Sharing (LF) & Discussion

Image Sharing (Everything Else) & Discussion

Lenses & Lens Accessories

LF DIY (Do It Yourself)

Lighting Techniques - Studio, Artificial

Location & Travel

On Photography

Resources

Style & Technique

Community

Introductions

Groups & Meetings

New Products and Services

Kickstarter Announcements

All times are GMT -7. The time now is 15:19.

Powered by vBulletin® Version 4.2.5 Copyright © 2026 vBulletin Solutions Inc. All rights reserved.

Guillotine Shutters

part
2: Determining
Shutter Speeds

[H1] &copy 2010 Bill Kumpf
for largeformatphotography.info

The guillotine
shutter offers a simple device to use with a barrel mount lens. It can be
quickly constructed from many materials in minimum time. For this article, a
report cover provided the material for one while scrap 1/8-inch plywood was
used for the second. This article provides a quick method to calculate the
effective shutter speed.

The guillotine
shutter uses a slot to pass across the lens. Being powered by gravity, the drop
blade is constantly accelerating as its drops. The leading edge of the shutter
opens the lens and the trailing edge closes it. The distance the edges fall
determines the drop times.

Calculating the drop time, T =
equals the square root of (2d/g) where d = drop (in), g=32 feet/sec2

_______________________________________

Time = √  d x (
2 / ((32.17405 feet/sec2) x (12 inch / foot)))

Thus for an
initial drop of 1.75 inches and a slot with of 4.0 inches;

________________

The leading edge time,  Tl = √ (1.75 x 0.005180)

Tl = 0.0952 seconds

____________________

The trailing edge time,  Tt = √ (1.75 + 4.0)x 0.005180)

Tt =0.1726

For the exposure time T = Tt – Tli

T = 0.0774 seconds

To verify the
concept I measured the shutter time using a
photoelectric eye and an oscilloscope. The leading edge activates the switch
while the trailing edge deactivates the switch. With the oscilloscope, the
activation time was measured.

Two series of
tests were conducted. The first used the same initial drop distance with
varying slot widths and the second used the same slot width with varying drop
distances.

The first
guillotine shutter provided shutters speeds of 1/15, 1/30, and 1/60 of a
second.

The slot width was set to give an
estimated exposure time:

Slot width (in)

0.291

0.6645

1.4425

3.315

Dl=

1.7850

1.7850

1.7850

1.7850

Tl =

0.0962

0.0962

0.0962

0.0962

dt =

2.0760

2.4495

3.2275

5.1000

Tt =

0.1037

0.1126

0.1203

0.1625

Tl - Tt =

0.0075

0.0165

0.0331

0.0664

Average Measured time

0.0074

0.0168

0.0336

0.067

% Difference

1.89%

-1.91%

-1.38%

-0.93%

One
concern was vertical alignment. How far off the vertical axis could the shutter
be orientated before the friction would affect the drop rate? The drop rate was
checked at both 5° and 15°. At 5° there was no measurable affect, while at 15°
the shutter slowed approximately 5%. This will vary depending on the individual
shutter assembly and its internal friction.

Initial Drop

0.1250

5.1250

10.1250

Vertical

Time (sec)

0.0479

0.0150

0.0106

15° Angle

Time (sec)

0.0506

0.0154

0.0110

Difference

-0.0027

-0.0005

-0.0004

%

5.64%

3.01%

4.15%

The second series verified the
time distance function and to provide the bases of the following method to
determine shutter speed.

Drop

1

3

5

7

9

11

Leading edge

0.125

2.125

4.125

6.125

8.125

10.125

Tl

0.0254

0.1049

0.1462

0.1781

0.2052

0.2290

Slot Width

0.9955

0.9955

0.9955

0.9955

0.9955

0.9955

Trailing edge

1.1205

3.1205

5.1205

7.1205

9.1205

11.1205

Tt

0.0762

0.1271

0.1629

0.1921

0.2174

0.2400

Time (sec)

0.0507

0.0222

0.0167

0.0139

0.0122

0.0110

Measured

0.0479

0.02175

0.0164

0.01352

0.01176

0.0106

Difference

0.0028

0.0005

0.0003

0.0004

0.0004

0.0004

-5.60%

-2.12%

-1.76%

-2.95%

-3.65%

-3.59%

Trailing
Edge

For example, if the shutter
design has a leading edge drop of 1 1/2 inches, on the chart find the 1.5 inch
line on the vertical axis, cross over to the line and read down to the drop
time of 0.0881 seconds. For the trailing edge, add the leading edge drop
distance and the shutter slot width and repeat the process. For an opening of 3
inches, the trailing drop distance is 4.5 inches. The time from the chart is
0.1527 seconds. The leading edge time minus the trailing edge time results in a
shutter speed of 0.0646 seconds. This is approximately 1/15 second.

For reference

f stop

1/8

1/15

1/30

1/60

1/125

Time

0.1250

0.0667

0.0333

0.0167

0.0080

Difference equals the shutter speed

Trailing Edge

Leading Edge

The constant acceleration also
varies the exposure during the shutter blade drop. This above process can be
applied to the drop / velocity chart to determine the variation in exposure.
The same process applied to the “Drop / Velocity” chart will estimate the
change in velocity. A doubling of velocity would result in 1 f/stop variation
in exposure. For our example above, the Leading Edge velocity is 34.03 in/ sec
and the Trailing edge velocity is 58.95 in/ sec. This is a 73.21% decrease in
exposure.

______________________________________

Velocity= √  d
x 2 x (32.17405 feet/sec2 ) x (12 inch / foot)

Leading Edge

Hopefully this will help in
exploring the world of barrel lens.