Modern Classic SLR Series :
Canon EOS-1N Series AF SLR camera
Related Reliability Issues

File size: 63K HTML Loading...

Shutter Unit

The shutter unit is an integrated component of the Canon EOS-1N Exposure Control Mechanism. The EOS-1N's shutter is a super-high-speed vertical travel type focal plane shutter with all speeds electronically controlled. The design is based on the EOS-1's shutter too but the unit is an upgraded unit that features improved durability. One of the most significant area in the upgrade is, the shutter now officially can deliver 100,000 exposure cycles without maintenance and 150,0000 cycles with maintenance - this enhancement has finally elevated Canon pro-series models at par in reliability performance with the Nikon single digit F series models. Which also means the EOS-1N has improved 1X than that of the previous Canon EOS-1. An interesting note of the shutter unit of the Canon EOS-1N was actually the SAME with the EOS-1N RS, with an exception it is a double layers formation, where the RS model shutter's rear curtain is used to provide a dual-layer light blocking function - when the camera is in standby mode. Which means to say, the shutter unit used in the EOS-1N is the same shutter unit designed for the EOS-1N RS, with the only difference being that the dual-layer light-blocking mechanism is simply not used.

Anti AIDs day Phnom Penh, Cambodia
Contact Andy Eames

Cambodia Documentary Series: March commemorating National AIDS day in Phnom Penh May 2002.

Credit: Image courtesy of Andy Eames ® who has his Portfolio at Pbase. Image copyright © 2005. All rights reserved. Please respect the visual property of the contributing photographer.

Due to the EOS-1n RS construction, light passing through the full surface of the pericle mirror constantly impinges on the shutter curtains. To maintain the same light blocking capability as the EOS-1N, therefore, the rear shutter blades are partially driven to provide two light-blocking layers in the top half of the body aperture. The light blocking mechanism adds an extra step to the shutter drive sequence compared to the EOS-1N, but both shutter unit's overall operation durability are the same. On the other hand, the sub-mirror is the EOS-1N is a spring driven type but the EOS-1N RS is low shock/noise but it is motor driven (via shcnage of assignment of Motor 2, further in RS Mode, the sub mirror is always in a retracted position).

Technical Specifications for Canon EOS-1N Super-High-Speed Shutter Unit (also refer to a chart comparing EOS-1N with EOS-1n RS side by side): -

No.   Item   Specification
1.   Type   Vertical-travel focal plane shutter
2.   Shutter blade system   Parallelogrammic link type
3.   No. of shutter blades   1st and 2nd curtains: 5 each (10 total)
4.   Shutter blade material   Blade number. 1, 2, 3: Carbon; Blade; Number.- 4, 5: Super Duralumin
5.   Travel drive source   Dedicated first and second curtain torsion springs
6.   Speed control system   All speeds electronically controlled by controlling the current supply time of dedicated electromagnets for the first and second curtains. (Magnets: Suction type, released when current supply is cut)
7.   Curtain speed   Approx. 2.7nis/24mm
8.   Speed control range   1/8000 -30 sec, bulb
9.   Max. flash sync speed   1/250 sec
10.   Signals   (a) X contact signal, (b) Second curtain travel completion signal

The shutter blades are actually being treated with water repellent lubricant coatings for any possible entry of water during film changing in wet weather. Durability was improved further by using carbon material instead of super-duralumin for the #1, #2 and #3 shutter blades, which are the most affected by inertia resulting from the large stroke when the shutter is opened and closed. Use of carbon material reduces the mass of each blade, which reduces the energy produced when the blades travel and thus improves durability. This also reduces the blade momentum when the shutter is braked, which improves durability by decreasing the load on the blades and drive mechanism.

As a result of the above design changes: The appearance of the shutter unit is shown here, and the shutter's design specifications are listed at the bottom.
Canon EOS-1N shutter Unit at the film back open postion Canon EOS-1N shutter Unit

Shutter speeds are controlled in the same way as the EOS-1. Long time exposures are also controlled in the same way as the EOS-1, with a small amount of electrical current constantly supplied to the rear curtain magnet to hold the shutter open. Battery life for continuous bulb operation under normal temperature is:-

Configuration Battery Battery life during bulb operation
EOS-1N alone 2CR5 approx. 60 hours
EOS-1N + PDB-E1 LR6 x 8 approx. 50 hours

(1) Difference between old and new model has added information for AA-type battery (BP-E1). -1. (2) Shutter Release Mechanism step switch with focusing and metering. The EOS-1N's shutter release mechanism is a two-carried out at SW- I ON and shutter release and exposure carried out at SW-2 ON. Though the EOS-1N's standard shutter button is not equipped with a built-in mechanism for adjusting the initial button height or SW-1 ON stroke amount, such adjustment is possible by having the EOS-1N's shutter button replaced with the EOS-1 shutter button at a Canon service center.

Shutter blades, Canon EOS-1N
(3) Release Time Lag The time lag from when the shutter button is completely pressed (SW-2 ON) to when camera operation starts is the same as the EOS-1, controlled by a built-in fixed 55-ms timer which is activated at SW-2 ON. The constant time lag provided by this timer absorbs aperture operation time inconsistencies caused by aperture size variations between lenses, thus stabilizing the release time lag and ensuring predictable operation.

Timing chart
(4) Overall Operation Sequence Overall operation is basically the same as the previous Canon EOS-1. For reference, an overall operation sequence flow chart as well as operation timing chart (52k Gif) for the EOS-1N combined with the PDB-E1 and a typical USM lens is shown in the illustration(s). You may check the electronic section for other related info.

<<<--- Overall operation sequence flow chart (52k Gif)

| NEXT | Electronic Circuits and Power Sources

| Back to Reliability Issues Section |

| Questions, Issues & Answers | Canon EOS-1 Series Message Board
| Canon EF lens Board | in a shared environment
| Free Trade Zone | shared environment

| Back | Index Page The Canon EOS-1N Series Professional SLR camera
| Back | Main Index Page The Canon EOS-1 Series Professional SLR camera

Background and Various Issues | The Basic Features & various Setup
Manual & Auto Focusing | Metering Systems | Exposure Control | Viewfinder Optical
Flash Photography (with Speedlite 540EZ extension & Selective info on Canon TTL Flash Models:-160E | 200E | 300EZ | 300TL | 420EZ | 430 EZ | 480EG | Macrolite | Other non-TTL Canon flash model

Reliability Issues:- Body Chassis | Shutter Unit | Electronic Circuitry | Film Transport & film handling Secondary Functions:- Custom Function Part One | Part Two | System Accessories:- Film Back Options - instruction for Command Back E1 | Macro/Close Up Part one | Part two and Part III Flash for Macro-Photography | Power Sources -BP-E1 | PDB-E1 | Focusing Screens | Remote Control with Wireless Remote Set LC-3 | System compatibility

Variants of Canon EOS-1N:- Canon EOS-1N RS | Canon/Kodak Digital DCS-1, 3 -5 & 520/560 Series | Full Technical Specification | Main Reference Map / Nomenclature | Resource Centre:- Comparative Charts between EOS-1 & EOS-1N / or with its active Competition(s) (Nikon); Quick Operational Reference Card (278k Gif File); Listings of 7-segment digital numbers/letters appeared on LCD display panel/viewfinders (HTML page); External Link:-Instruction Manual (3.3MB PDF file applicable for both Canon EOS-1N (RS). | Using EOS system for your photography | Bots & Nuts of EOS System - by Philip Chong |

The Eyes of EOS -
EF Lenses
A little OFF-TOPIC SOME Personal Thought

MIR Logo
HOME - Photography in Malaysia

Developer Link

Volunteered Maintainer(s) for the Canon EOS-1N Series Message Board: Philip Chong, Editor, Digital Camera Magazine; Vincent Thian, Photo Editor, Malaysian Bureau, Associated Press "AP", CYleow, Ex-photo Editor of local daily, The Star; Gary Rowan Higgins, Australia and other nice folks on the web.

Special Credit:- :Mr. Richard Yeow & Mr. Simon Wong from camera division of Canon Malaysia Logo Marketing Malaysia, for their continual effort in supporting development of this EOS/EF website. Others: All the nice people on earth who have contributed their photos and pictures of personal works or product shots for the creation of this site. Certain content and images appeared in this site were either scanned from official marketing leaflets, brochures published by Nikon and/or contribution from surfers who claimed originality of their own work for public publishing in this website, where majority of the extracted information are used basing on educational merits. The creator of this site will not be responsible for any discrepancies that may arise from any possible dispute except rectifying them after verification from respective source. Neither Nikon or its associates has granted any permission(s) in using their public information nor has any interest in the creation of this site. "Canon", "EOS", "EF" "RT", "EOS-1n RS", "Booster ", "Macrolite", "fluorite", "Image Stabilizer" & other applicable technical/business terms are registered trade name(s) of Canon Inc., Japan. Site made with an Apple G5 IMac.