Bowens BW-2800 Operating Instrctions

Brand: Bowens

Model: BW-2800

Type: Operating Instrctions

This manual is also suitable for

EQUIPE 1200 & 2400 PACK

OPERATING INSTRUCTIONS

Covers Models

BW-2800 BW-2810

- 2 -

SAFETY

THIS EQUIPMENT MUST BE EARTHED VIA THE PROTECTIVE

EARTH CONDUCTOR OF THE POWER CORD.

DO NOT REMOVE THE EQUIPMENT SCREWS OR COVERS.

NO USER SERVICEABLE PARTS INSIDE.

DANGEROUS VOLTAGES ARE PRESENT EVEN AFTER

SWITCHING OFF.

THE PACK SHOULD ONLY BE SERVICED BY QUALIFIED

PERSONNEL

- 3 -

EQUIPE 1200/2400 OPERATING INSTRUCTIONS

CONTENTS

FIGURE 1 EQUIPE 2400 CONTROL PANEL LAYOUT.........................................................................4

KEY TO FIGURE 1 ........................................................................................................................................5

FIGURE 2 EQUIPE 1200 CONTROL PANEL LAYOUT.........................................................................6

KEY TO FIGURE 2 ........................................................................................................................................7

IMPORTANT SAFETY NOTES - PLEASE READ BEFORE OPERATING PACK..............................8

GENERAL FEATURES .................................................................................................................................9

POWER SUPPLY CONNECTION ...............................................................................................................9

AC POWER SWITCH....................................................................................................................................9

CIRCUIT PROTECTION............................................................................................................................10

FAST/SLOW CHARGE SWITCH - EQUIPE 2400 PACK ONLY..........................................................10

FLASH HEADS.............................................................................................................................................10

FLASH POWER SELECTION/INDICATION..........................................................................................11

MODELLING LAMP OUTPUT/CONTROL ............................................................................................11

OPEN FLASH................................................................................................................................................12

EXTERNAL SYNCHRONISATION ..........................................................................................................12

PHOTOCELL................................................................................................................................................12

SOUNDER .....................................................................................................................................................12

OVERLOAD PROTECTION, COOLING FAN AND OVERHEAT.......................................................13

EQUIPE 1200 & 2400 PACK SPECIFICATIONS.....................................................................................14

ACCESSORIES.............................................................................................................................................15

QUICK REFERENCE TABLES FOR EQUIPE 2400 PACK...................................................................16

QUICK REFERENCE TABLES FOR EQUIPE 1200 PACK...................................................................17

- 4 -

Figure 1 EQUIPE 2400 Control Panel Layout

- 5 -

Key To Figure 1

1. Supply (AC) Input Socket

2. AC Power Switch and Neon Indicator

3. Charge Rate Switch - ’FAST/SLOW’ (HARE/TORTOISE)

4. Four Flash Head Sockets

5. Low Voltage ‘SYNC.’ Input Socket

6. Channel A ‘FLASH’ Variator

7. Channel B ‘FLASH’ Variator

8. ‘POWER’ Selector Switch - 600W-s, 1200W-s or 2400W-s

9. Digital ‘POWER’ Display and visible ‘READY’ Indicator

10. Channel A Modelling ‘LAMP’ Power Variator

11. Channel B Modelling ‘LAMP’ Power Variator

12. Channel A Modelling ‘LAMP’ Switch - ‘CONTINUOUS/OFF/INTERMITTENT’

13. Channel B Modelling ‘LAMP’ Switch - ‘CONTINUOUS/OFF/INTERMITTENT’

14. ‘COMBINE/ISOLATE’ Switch -

15. ‘SLAVE’ Photocell

16. Fuse - Modelling ‘LAMP’

17. Manual Reset Circuit Breaker - ‘FLASH’ Protection

18. ‘SLAVE’ Photocell On/Off Switch

19. Audible ‘READY’ Sounder On/Off Switch

20. ‘OPEN FLASH’ (Test) Button

21. Carry Handle

- 6 -

Figure 2 EQUIPE 1200 Control Panel Layout

- 7 -

Key To Figure 2

1. Supply (AC) Input Socket

2. AC Power Switch and Neon Indicator

3. Four Flash Head Sockets

4. Low Voltage ‘SYNC.’ Input Socket

5. Channel A ‘FLASH’ Variator

6. Channel B ‘FLASH’ Variator

7. ‘POWER’ Selector Switch - 300W-s, 600W-s or 1200W-s

8. Digital ‘POWER’ Display and visible ‘READY’ Indicator

9. Channel A Modelling ‘LAMP’ Power Variator

10. Channel B Modelling ‘LAMP’ Power Variator

11. Channel A Modelling ‘LAMP’ Switch - ‘CONTINUOUS/OFF/INTERMITTENT’

12. Channel B Modelling ‘LAMP’ Switch - ‘CONTINUOUS/OFF/INTERMITTENT’

13. ‘SLAVE’ Photocell

14. ‘COMBINE/ISOLATE’ Switch -

15. Fuse - Modelling ‘LAMP’

16. Manual Reset Circuit Breaker - ‘FLASH’ Protection

17. ‘SLAVE’ Photocell On/Off Switch

18. Audible ‘READY’ Sounder On/Off Switch

19. ‘OPEN FLASH’ (Test) Button

20. Carry Handle

- 8 -

Important Safety Notes - Please Read Before Operating Pack

Please read and follow these basic safety instructions:

z READ and UNDERSTAND the instructions and specifications.

z ONLY connect to an AC (Alternating Current) power supply.

z NEVER connect to a DC (Direct Current) supply.

z ALWAYS use a grounded AC outlet.

z ALWAYS use a three core cable of at least 10 or 15 Amp rating as supplied.

z WHEN practical, unplug the Pack from the electrical outlet when not in use.

z ALWAYS remove the power cord by gripping the plug, NEVER pull the cord.

z ALWAYS ensure that any extension cord used has a suitable current rating to

prevent overheating. NEVER use coiled extension cords.

z NEVER replace the fuse with one of a different type or rating. See Specification

for correct value/type of fuse.

z ALWAYS avoid placing AC power cords and Flash Head cables where they can

be tripped over.

z NEVER place heavy objects on top of the AC Power cord or Flash Head cables

and avoid running them over sharp or hot objects.

z NEVER use the equipment with damaged cables. Have them replaced as soon as

possible. NEVER attempt to repair them yourself.

z NEVER use the Pack or Flash Heads in an environment where moisture, water

vapour or inflammable liquids, vapour or materials may come into contact with the

Pack or Flash Heads. The flash output as well as the modelling lamps can cause

ignition of or damage to materials that may come into direct or close contact with

the Flash Heads.

z ALWAYS keep ALL vents in the Pack and Flash Heads clear of obstructions at all

times.

z ONLY switch the Pack ‘ON’ AFTER the Flash Head/Heads has/have been

correctly connected.

z ALWAYS ensure that the Flash Head cable locking rings at the Pack, adapters,

and Flash Heads are fully locked before use.

z ALWAYS remove the Flash Head covers before using.

z ALWAYS turn OFF the Pack, disconnect from the supply, unplug the Flash

Head/Heads and allow them to cool before:

a). Replacing the modelling lamp in Flash Head.

b). Replacing the flash tube in Flash Head.

c). Replacing the fuse in Flash Head or Pack.

z If the Pack is not used for more than a couple of months then it is advisable to just

switch the Pack on periodically for an hour or so with the FLASH variators set to

maximum - there is no need to use a Flash Head.

- 9 -

General Features

The EQUIPE 1200 & 2400 Packs have been designed to produce the most compact,

versatile and easy to use flash source available today. Features include:

z Two independent Channels, each with two Flash Head sockets, having their own

‘FLASH’ Variator, Modelling ‘LAMP’ Variator and Modelling ‘LAMP’ Control switch.

z An ‘ISOLATE’ mode which provides the two independently controlled Channels

with half the total flash capacity of the Pack available from either or both sockets in

a particular Channel.

z A ‘COMBINE’ mode which provides the total flash capacity of the Pack from ANY

single socket or combination of sockets with a single set of controls.

z Modelling ‘LAMP’ Variator and Modelling ‘LAMP’ Controls independent of Flash

controls.

z Digital ‘POWER’ display of the selected total Pack flash capacity and a visible

‘READY’ indication.

z Built in, sensitive ‘SLAVE’ Photocell with ON/OFF switch.

z AUDIBLE ‘READY’ Sounder with ON/OFF switch to give audible indication of

when the Pack is ready to fire.

z A built in fan on the EQUIPE 2400 Pack which automatically switches in to cool

the unit during periods of heavy use.

z Overheat protection which protects the unit in the event of extended periods of

continuous flashing and also in the unlikely event of failure of the cooling fan.

z EMC (Electro-Magnetic Compatibility) filters fitted.

z Special Adapters available to allow certain QUAD heads and accessories to be

used with the EQUIPE 1200 & 2400 Packs.

Power Supply Connection

z The Packs are designed to operate on an alternating current (AC) supply of 200 to

253 Volts, 50 Hz. The Packs must NEVER be connected to any direct current

(DC) supply.

z The Packs conform to current standards which require connection to a properly

grounded power supply. The 3 core power cord supplied with each Pack will be

colour coded as follows:

Live (L): Brown

Neutral (N): Blue

Earth (E): Green/Yellow

z It is essential that all 3 wires are connected to the correct plug pins in accordance

with the above colour code and that the cable is securely clamped in the supply

plug.

AC Power Switch

z The AC Power switch connects power to both the flash and modelling circuits.

The switch is illuminated green when ‘ON’.

z ALWAYS switch ‘OFF’ the unit before plugging or unplugging Flash Heads,

changing fuses or modelling lamps.

- 10 -

Circuit Protection

z Protection of the Modelling circuitry is by means of a 20mm fuse mounted on the

control panel of the Pack. The fuse is rated at 15 Amp (T) and should never be

replaced with a fuse of a different type or rating.

z Protection of the Flash circuitry is by means of a Circuit Breaker mounted on the

control panel of the Pack. This will operate under extreme conditions of use and

can be manually reset after a short period of cooling by depressing the button until

it locks down.

FAST/SLOW Charge Switch - EQUIPE 2400 Pack Only

z The ‘FAST/SLOW’ switch should be set to ‘SLOW’ if the current capacity of the AC

power supply is limited or fast recycling is not required. Switching to ‘SLOW’ will

reduce the current drawn from the supply by approximately 1/3rd.

z It should be noted that switching to ‘SLOW’ charge will also extend the charge

times at maximum power - See specifications for details.

Flash Heads

z The Packs are designed to be fitted with one to four standard EQUIPE Flash

Heads, BW-2850 with a maximum modelling lamp rating of 300W.

z The standard Flash Head has a switch to enable the modelling lamp to be turned

off independently from the Pack setting.

z The removable Flash Head cables cannot be connected incorrectly but for ease of

identification the connectors at each end are identified with colour coded dots -

WHITE for the Pack and GREEN for the head.

z To fit a Flash Head, first ensure the Pack is switched off and disconnected from

the supply. Fit the Flash Head cable to the head by aligning the GREEN dots,

inserting the cable plug into the head connector and rotating the locking ring

clockwise until it locks in place. Fit the other end of the Flash Head cable to the

Pack by aligning the WHITE dots, inserting the plug into the chosen socket and

rotating the connector locking ring clockwise until it locks in place.

z Heads from the 220/240V QUAD system may be used with the Pack in

conjunction with a special adapter, but the following limitations and warnings

should be strictly observed:-

1. Splitter boxes or QUAD extension cables SHOULD NOT

be used.

2. The maximum modelling lamp rating PER CHANNEL

must not exceed

1300W with a maximum allowable total for the Pack of 1950W.

3. QUAD heads with adapters may be used in conjunction with the

standard heads providing the modelling lamp wattage PER CHANNEL

and the Pack total above is not exceeded.

4. 1.5k QUAD heads will deteriorate rapidly if used on a EQUIPE 2400

Pack at full power.

z For detailed information on the operation of the heads, general maintenance, flash

tube and lamp replacement, and accessories available, please refer to the

appropriate Instruction Manuals supplied with the head or QUAD adapter.

- 11 -

Flash Power Selection/Indication

z By using the four Flash Head sockets and associated controls many asymmetric

and symmetric combinations of flash power are available from one Flash Head

through to four Flash Heads.

z The ‘POWER’ switch sets the TOTAL MAXIMUM flash power available from the

Pack. The power selected, 600, 1200 or 2400W-s for the EQUIPE 2400 Pack and

300, 600 or 1200W-s for the EQUIPE 1200 Pack, is shown on the digital display

and represents a coarse control range of 2 f-stops. This power can be made

available from any one socket or a combination of sockets depending upon the

setting of the ‘COMBINE/ISOLATE’ switch.

z The ‘COMBINE/ISOLATE’ switch in combination with the number of Flash Heads

fitted, gives a further f-stop adjustment. This provides the facility to have two

separate Channels, A and B, with individual sets of controls, OR to combine them

with one set of controls.

z When switched to ‘ISOLATE’ both the ‘ACTIVE’ LED’s will be lit, indicating that the

two ‘FLASH’ variators and Channels operate independently, with each providing a

continuous adjustment over a 3 f-stop range. Each Channel has a maximum

output of half that set by the ‘POWER’ switch which may be used to adjust the

overall light level without affecting the balance between channels set by the

‘FLASH’ variators.

z When switched to ‘COMBINE’, only the ‘ACTIVE’ LED for Channel A will be lit and

both A and B Channels will be controlled by the Channel A ‘FLASH’ variator which

provides a continuous adjustment over a 3 f-stop range. The maximum output set

by the ‘POWER’ switch is available from ANY socket.

z The total control range using a combination of Flash Heads, ‘FLASH’ variators,

‘POWER’ switch and ‘COMBINE/ISOLATE’ switch is 6 f-stops.

z In general the ‘POWER’ switch should be set to the lowest setting and the

‘FLASH’ variator(s) set to the highest, consistent with the flash power and the

distribution between heads required. This method provides the shortest flash

duration for a given power output. Increasing the number of heads will also

reduce the flash duration.

z Whenever the ‘POWER’ or ‘FLASH’ controls are changed, flash the Pack once

using the ‘OPEN FLASH’ button to ensure that the next flash is of the required

power.

z A study of the quick reference tables on pages 16 and 17 will explain the possible

combinations of MAXIMUM power available from the EQUIPE 1200 & 2400 Packs

to the individual Flash Heads.

Modelling Lamp Output/Control

z Refer to the Instruction Manual provided with the head for more details of the controls

and maintenance of the head.

z The Modelling Lamp or Lamps for each Channel are controlled by a ‘LAMP’ variator

and a ‘CONTINUOUS/OFF/INTERMITTENT’ switch on the control panel. Some Flash

Heads are fitted with a Modelling Lamp ‘ON/OFF’ switch which allows individual

Lamps to be turned off.

z The ‘COMBINE/ISOLATE’ switch determines which Modelling Lamp

‘CONTINUOUS/OFF/INTERMITTENT’ switch and ‘LAMP’ variator have control. With

the switch set to ‘COMBINE’ the Channel A switch and variator have control over ALL

- 12 -

Modelling Lamps. The Channel B switch and variator will have no effect and neither of

the indicator LED’s will be lit. With the switch set to ‘ISOLATE’ the Channel A and

Channel B switches and variators have independent control over the Modelling Lamps

in their respective Channel.

z Set the appropriate Modelling Lamp switch to the centre position to switch the

Modelling Lamp(s) OFF for the required channel. Neither indicator LED will be lit for

that channel.

z Set the appropriate Channel Modelling Lamp switch to ‘CONTINUOUS’ to switch the

Modelling Lamp(s) ON. The Red indicator LED will be lit and the Lamp(s) brightness

can be continuously adjusted over a 3 f-stop range using the ‘LAMP’ variator for that

Channel.

z Set the appropriate Modelling Lamp switch to ‘INTERMITTENT’ to enable the

Modelling Lamp(s) to go out when the Pack is flashed and come back on again when

‘READY’. The Green indicator LED will be lit and the Lamp(s) brightness can be

continuously adjusted over a 3 f-stop range using the ‘LAMP’ variator for that Channel.

Open Flash

z Press the ‘OPEN FLASH’ button to test the flash operation of the Pack and head(s).

When decreasing the power setting of the Pack using the ‘FLASH’ Variator(s) or

‘POWER’ switch simply flash once using this button to adjust to your new setting.

External Synchronisation

z A 6.35mm, low voltage, ‘SYNC’ jack socket is provided on the control panel for

external synchronisation. The socket accepts the supplied standard Sync. lead for

direct connection to the camera.

Photocell

z The built in Photocell may be used for remote triggering from another flash source or a

Remote IR Trigger. Set the ‘PHOTOCELL’ switch to ‘ON’ to enable the Photocell. The

Red indicator LED below the switch will be lit when the Photocell is in operation.

Sounder

z Set the ‘SOUNDER’ switch to ‘ON’ to enable the Sounder. The Red indicator LED

below the switch will be lit when the Sounder is in operation. When the Sounder is

switched ‘ON’ it will give a short beep when the Pack comes to ‘READY’.

- 13 -

Overload Protection, Cooling Fan And Overheat

z A manual reset Circuit Breaker and thermal cut-out system is provided to prevent the

Pack from overheating under heavy conditions of use.

z The operation of the thermal cut-out is highly dependent upon the conditions of use

and is typically as follows:-

• Pack working normally - Pack under moderate use at normal operating

temperature with low to moderate ‘POWER’ setting, ‘SLOW’ charge rate and/or

slow to moderate flash rate.

• Pack NOT ‘READY’, AC Power Switch neon lit, ALL other control panel

indicators off - Pack was previously under heavy use with moderate to maximum

power setting, fast recycling and warm to hot. Thermal cut-out has operated and

will be automatically reset after a cooling period.

• Pack NOT ‘READY’, AC Power Switch neon AND one or more other indicators

on the control panel are lit and the top panel Circuit Breaker has operated. Pack

previously under very heavy use with fast recycling and hot. In this condition the

Circuit Breaker button will project from the panel and may be manually reset after

allowing a short cooling period. Under certain conditions this may also be

combined with operation of the thermal cut-out.

z The EQUIPE 2400 unit is fitted with a thermostatically controlled fan which senses the

internal temperature within the Pack. Under normal conditions of use the fan is

unlikely to operate but when the Pack is used heavily the fan will cut in to lower the

internal temperature allowing many more shots to be taken. Providing that power is

applied and the Pack is switched on, the fan will operate independently of the Circuit

Breaker and thermal cut-out.

z Operation of the overload protection can be avoided by checking and modifying the

conditions of use:-

• Ensure that the cooling vents of the Pack are clear of obstructions.

• Use the ‘SLOW’ charge setting if the ‘FAST’ setting is not necessary.

• Reduce the flash rate.

- 14 -

EQUIPE 1200 & 2400 Pack Specifications

The following specifications are applicable when the Pack is fitted with EQUIPE

Flash Heads (BW-2850).

CODE NUMBER BW-2810 BW-2800

TOTAL POWER OUTPUT,

Watt-seconds

2400 1200

TOTAL FLASH OUTPUT

RANGE,

Watt-seconds

37 to 2400 19 to 1200

TOTAL FLASH OUTPUT

RANGE,

f-stops

2 with ‘POWER’ switch

3 with ‘FLASH’ variators

1 with ‘COMB/ISO’ switch

6 total

2 with ‘POWER’ switch

3 with ‘FLASH’ variators

1 with ‘COMB/ISO’ switch

6 total

TOTAL NUMBER OF FLASH

HEAD SOCKETS

4 SYMMETRIC OR

ASYMMETRIC

4 SYMMETRIC OR

ASYMMETRIC

FLASH DURATION

Full power 1 Head

Full power 4 Heads

Min. power 1 Head

Min. power 4 Head

340

second

960

second

1070

second

1660

second

570

second

1450

second

1700

second

2250

second

SUPPLY VOLTAGE 200 to 253 Volts 50Hz 200 to 253 Volts 50Hz

FLASH VOLTAGE

STABILISATION

±1% ±1%

RECYCLE

TIMES

(To 80% with

253V Supply)

FAST

SLOW

Full Power 1.7 seconds

Min. Power 0.5 seconds

Full Power 2.7 seconds

Min. Power 0.5 seconds

Full Power 0.97 seconds

Min. Power 0.3 seconds

Not Applicable

MODELLING LIGHT

(Maximum permitted

modelling lamp wattage with

230V supply)

1300W per Channel

(per pair of sockets)

1950 Watt Pack total

1300W per Channel

(per pair of sockets)

1950 Watt Pack total

MODELLING FUSE 15 Amp (T) 15 Amp (T)

SYNC VOLTAGE 15V 15V

DIMENSIONS (L x W x H)

HANDLE CLOSED

HANDLE OPEN

” x 9” x 10-

”

165mm x 229mm x 268mm

” x 9” x 11-

”

165mm x 229mm x 297mm

” x 9” x 8”

165mm x 229mm x 205mm

” x 9” x 9-

”

165mm x 229mm x 235mm

WEIGHT 18-

lb - 8.4kg 13-

lb - 6kg

- 15 -

Accessories

A number of accessories to fit this Pack and Flash Head system are available and

include a full range of Stands, Umbrellas, Reflectors and Register Wafers etc.

For details of all related products please contact your local distributor.

Due to our policy of constant product improvement Bowens International Limited

reserve the right to change equipment specifications without notice.

- 16 -

Quick Reference Tables For EQUIPE 2400 Pack

COMBINE MODE - The TOTAL flash output set by the ‘POWER’ switch and the

‘VARIATOR A’ is divided EQUALLY between the NUMBER of Flash Heads fitted to

the Pack. The MAXIMUM power available from any one head is 2400W-s divided by

the TOTAL number of heads fitted as shown below:-

NUMBER OF CHANNEL A CHANNEL B

HEADS FITTED SOCKET 1 SOCKET 2 SOCKET 3 SOCKET 4

1 2400W-s

2 1200W-s 1200W-s

3 800W-s 800W-s 800W-s

4 600W-s 600W-s 600W-s 600W-s

ISOLATE MODE - The TOTAL flash output is split asymmetrically between the two

Channels dependent upon the ‘POWER’ switch, ‘VARIATOR A’ and ‘VARIATOR B’

settings. The flash output of an individual channel is divided equally between the

NUMBER of Flash Heads fitted to that Channel. The MAXIMUM power available

from any one head is 1200W-s divided by the number of heads fitted to the same

CHANNEL as shown below:-

NUMBER OF CHANNEL A CHANNEL B

HEADS FITTED SOCKET 1 SOCKET 2 SOCKET 3 SOCKET 4

1 1200W-s

2 600W-s 600W-s

2 1200W-s 1200W-s

2 600W-s 600W-s

3 600W-s 600W-s 1200W-s

3 1200W-s 600W-s 600W-s

4 600W-s 600W-s 600W-s 600W-s

- 17 -

Quick Reference Tables For EQUIPE 1200 Pack

COMBINE MODE - The TOTAL flash output set by the ‘POWER’ switch and the

‘VARIATOR A’ is divided EQUALLY between the NUMBER of Flash Heads fitted to

the Pack. The MAXIMUM power available from any one head is 1200W-s divided by

the TOTAL number of heads fitted as shown below:-

NUMBER OF CHANNEL A CHANNEL B

HEADS FITTED SOCKET 1 SOCKET 2 SOCKET 3 SOCKET 4

1 1200W-s

2 600W-s 600W-s

3 400W-s 400W-s 400W-s

4 300W-s 300W-s 300W-s 300W-s

ISOLATE MODE - The TOTAL flash output is split asymmetrically between the two

Channels dependent upon the ‘POWER’ switch, ‘VARIATOR A’ and ‘VARIATOR B’

settings. The flash output of an individual channel is divided equally between the

NUMBER of Flash Heads fitted to that Channel. The MAXIMUM power available

from any one head is 600W-s divided by the number of heads fitted to the same

CHANNEL as shown below:-

NUMBER OF CHANNEL A CHANNEL B

HEADS FITTED SOCKET 1 SOCKET 2 SOCKET 3 SOCKET 4

1 600W-s

2 300W-s 300W-s

2 600W-s 600W-s

2 300W-s 300W-s

3 300W-s 300W-s 600W-s

3 600W-s 300W-s 300W-s

4 300W-s 300W-s 300W-s 300W-s

- 18 -

EQUIPE 1200/2400 INSTRUCTIONS BWL-0230/1 25-9-96

BOWENS INTERNATIONAL LIMITED

355 OLD ROAD

CLACTON-ON-SEA

ESSEX CO15 3RH

ENGLAND

Tel: +44(0)1255 422807

Fax: +44(0)1255 436342

Bowens BW-2800 Operating Instrctions

Brand: Bowens

Model: BW-2800

Type: Operating Instrctions

This manual is also suitable for

Download PDF

report

Bowens BW-2800 Operating Instrctions

This manual is also suitable for

Bowens BW-2800 Operating Instrctions

Related papers

Other documents