introduction
image crop factor
using SQ lenses on digital cameras
Using digital backs:
Brief history:
Viewfinders:
PS Lenses:
Older S Lenses:
Film backs:
Accessories:
Troubleshooting the SQAi

Bronica SQ 6x6 medium format film system

see also:
- photography and camping main index page
- SQ Ai Instruction manual (pdf)
- tips on use of SQ series
- medium format film camera systems
- repairs & servicing in Victoria, Australia:
  - http://www.hotfrog.com.au/Companies/Bronica 389 Lonsdale St, Melbourne 9670 4786
- S vs PS lenses:
  - http://www.buonaluce.com/S2PS.pdf
- https://petapixel.com/bronica-history/

NB. $US prices quoted are the list prices on Tamron's website (2005), but retail at 25-50% off as out of production. I don't sell camera equipment - I just write about it!

2007 Ebay sell prices in Australia for 2nd hand Bronica SQ are:

SQAi bodies with 80mm lens, back, viewfinder ~$A400-600
most lenses $A200-400 ea instead of the $2000-3000 prices when as new in the 1990's.

introduction

the Bronica SQ system is a 6×6 modular film system designed for the professional photographer in the 1980's and 1990's.
allows TTL flash using Metz flash units with the Bronica SQ adapter if using the SQ Ai camera
the lenses have an electronic leaf shutter with flash sync to 1/500th sec
unfortunately, the system is now rather redundant as it is quite clunky to use with digital backs, if you can buy a $1000 adapter to achieve this, and whilst the lenses can be used on Canon or Nikon dSLRs via an adapter, there is little if any reason to do so
the 6×6 film format uses 120/220 medium format film giving square images (2¼“ × 2¼” or 6cm x 6cm nominally or 56mm x 56mm actual image area)
one can buy 645 backs which will allow more photos per roll and give a rectangular 6×4.5cm aspect ratio with the same 120/220 film
NOTE that each back is designed for EITHER 120 film or 220 film

image crop factor

this 56x56mm film area is 3.6x that of 35mm film and gives a diagonal of 79.2mm which gives a crop factor compared to 35mm film (24mm x 36mm and a diagonal of 43.2mm) of 0.55x
thus the popular 150mm f/4 portrait lens on this basis equates to an 83mm f/2.2 lens on a 35mm full frame camera although the aspect ratios will of course differ

using SQ lenses on digital cameras

these lenses can be used on other cameras in manual focus and manual stop down aperture mode:
- if you buy a SQ-Nikon F adapter, you can then get a Nikon-SonyNEX or Nikon-MFT tilt shift adapter and convert it into a tilt shift lens
- if you are using it on Canon EOS, get an adapter with a Dandelion AF confirm chip to allow manual focus confirmation in the camera
- to stop the aperture down you have 2 choices:
  - hold the lens DOF preview button down with velcro, or,
  - use T mode on the lens (via Jeff Livacich):
    - Make sure the lens is cocked
    - Pull out on the lock on the the T/A switch on the underside of the lens and move the switch to T (time exposure). To pull the switch out on PS lenses, hook a fingernail under it and pull outward; with the older lenses unscrew it, then pull it out.
    - Look around the edge of the mount from the side of the lens until you see the small metal lock lever projecting from a slot.
    - Push that in, and while holding it in, rotate the two cock/release pins on the back of the lens to the uncocked position. The shutter will close then reopen as you move the pins to the uncocked position.
    - The shutter will stay open until the T/A switch is moved back to A, and the diaphragm will open and close in response to the aperture ring so long as the pins on the back of the lens are in the uncocked position.

Using digital backs:

see http://luminous-landscape.com/forum/index.php?showtopic=24863&st=0&p=191211&#entry191211
unfortunately few if any digital back manufacturers make a digital back designed for the Bronica system
- perhaps Leaf Valeo, Leaf Aptus and Leaf Aptus S may be available in Bronica SQ mount
- perhaps Sinar via Sinarback FW/Bronica SQ-A Adapter Kit (552.65.048)
however, you can use many of the digital backs designed for Hasselblad V system as follows:
- purchase a Bronica SQ to V adapter plate (~$US900)
  - Kapture Group
  - Silvestri
- mount the adapter plate via the supplied pin accessory
- mount a compatible V-type digital back
  - be aware that sensor size will generally be smaller than 6×6 which will limit wide angle capability
  - you may need to test focus accuracy and add a shim to correct any issues
  - generally, you will need a cable from the PC sync to the digital back
  - you will lose exposure metering as the Bronica meter normally gets ISO information from the film back
  - you will not get lens, camera, shutter or aperture in the image EXIF data
given the expense and practical difficulties, lack of digital correction and metering, you may be better off getting a Hasselblad instead.

Brief history:

1980: Bronica SQ camera and system introduced with flash sync at all speeds (1/500th sec is fastest speed)
- it was the 1st 6×6 camera to use a mechanical/electronic leaf shutter lens.
- it was based on the ETR operating system with a single electronic timer in the body controlling the Seiko #0 shutter in each lens. This provides for maximum accuracy, and consistency of exposures between each lens.
1982: SQ-A camera introduced with refinements including:
- viewfinder contacts increased from 6 to 10 to allow auto-metering & the new AE finder S.
- mirror lock up lever added
- instruction manual
1983: SQ-Am camera introduced with a built-in motor drive at 2 frames per 3 secs, running on 6xAA batteries
1986: S series lenses gradually replaced by higher quality ones called PS made from the new Bronica factory with world-class facilities which since 1983 had been making the 6×7 camera, the GS-1 and its PG series of lenses.
1990: SQ-Ai camera ($US1661 body only) introduced with refinements including:
- TTL-OTF flash metering with Metz SCA 386 adapter:
  - used with a Metz SCA flash set on TTL, with camera AE prism meter set to manual (else in low light it will select a long shutter speed)
  - to achieve fill-in flash, increase the ISO setting on the SCA adapter to give under-exposure
  - different films may require compensation to allow for the physical reflectivity of the film surface
- add-on motor drive (SQ-i)
- battery changed to 4×1.5V LR44
- multi-exposure warning in viewfinder
- 16 sec calibrated shutter speed & Bulb setting but no longer able to use the mechanical 1/500th shutter speed without batteries.
- ISO dial on film back relocated to back rather than top where hard to see with prism, & ISO range extended to 6400.
- new Ai-only winder crank
- 2005: some retailers new price reductions to clear stock: body only - was $A2130 now $A1650; instant back was $A748 now $A440;
- kit with 80mm lens, back was $A3545 (2005);
- user manual here: http://www.butkus.org/chinon/bronica_sq-ai/bronica_sq-ai.htm
- see:
  - http://www.photo.net/equipment/bronica/sq-ai
1996: SQ-i AE viewfinder added (for SQA/SQAm/SQAi) which added spot metering, LCD display, diopter, 4 stops more sensitivity, exposure lock, blind for long exposures.
1996: “budget” SQ-B camera introduced which was similar to the SQ-A but lacked metering
2004: production of SQ system discontinued

Viewfinders:

see http://www.tamron.com/bronica/prod/sq_vfind.asp
waist level Finder S with magnifier glass $US249
prism finder S $US967
45deg prism finder w/variable diopter $US1020, $A974
MF finder S with match LED TTL manual metering & adjustable magnifier from -3 to +2 $US1005
ME prism finder S with match LED TTL manual metering $US1322
AE prism finder S $US1494, $A1980 - aperture priority auto or manual
AE prism finder SQ-i LCD prism finder with spot metering or avg. & AE lock, variable diopter $US1736
- diopter correction - the +/- closest to eyepiece
- exposure compensation - the +/- dial at the top giving +/- 2EV
- dial on right side settings are:
  - A = aperture priority automatic exposure - sets shutter speed according to metering
  - Off = turns light meter off
  - M = manual light metering - user must manually set shutter speed as well as aperture
- M/C buttons on right:
  - M = memory - holds exposure for 15-30sec - presumably this also allows for mirror lock up capability
  - C = clears previously locked exposure measurement
- Sp/Av switch on top:
  - Sp = spot metering
  - Av = averaged metering
- on the under-surface when removed there is a switch with 3 settings:
  - O,1,2 are just meter calibration setting (for if you use an off brand focusing screen for example that's brighter than Bronica's, I suppose). 0 is neutral. 1 is 0.3, 2 is 0.7 - but I forget if it's plus or minus. Just leave it at 0.
- all that's needed to activate meter properly is having it set to A or M on the side dial, darkslide out, film advanced to frame 1 (or advanced to a stop w/ double exposure lever engaged).
- LCD in bottom of view should become activated and backlit by green light by half-pressing shutter, this displays:
  - AE or ME for auto vs manual
  - shutter speed (or ERR if light to low or too bright)
  - spot or [] to indicate metering mode
- the film ASA information is provided by the ASA dial on the film back which acts as a variable resistor:
  - the ASA setting is adjusted by slightly lifting the bottom part of the inner dial & rotating it so the value corresponds with the small arrow marker which at 0EV compensation should be at the 9 o'clock position. If the markers are rubbed off, then the two textured finger areas should be symmetrically placed at 4.30 & 7.30 o'clock position for 0EV.
  - the 12 o'clock mark is the EV compensation & this is changed by holding the lever down while rotating the outer dial
  - the resistance at the two contacts at the top of each film back at 0EV compensation setting should be:
    - 100ASA = 400 ohms
    - 200ASA = 600 ohms
    - 400ASA = 800 ohms
    - 800 ASA = 1000 ohms
    - 1600 ASA = 1200 ohms, etc
- errors displayed on the LCD screen:
  - flashing 500 usually means you need to close the aperture down, but may be a viewfinder connection problem
  - flashing ERR may occur because the viewfinder's contacts are not sitting properly - adjust the viewfinder.
manual finders have 6 contacts, whereas the automatic finders have 10 contacts.
SQ auto finders cannot be attached to an SQ body
ETR camera finders can be attached to SQ bodies via an adapter plate #1309 but only provide 6×4.5 view.

PS Lenses:

introduced starting in 1986 to replace the S series with improvements including:
- better optics, Multicoated lenses in different groups, elements.
- better mechanics, Half stop detents, back and front assemblies
- redesign of the system transmitting the cocking stroke from camera to the shutter, takes care of the “Sloppy Lens Syndrome”
- redesign of the front assembly eliminated the barrel side screws.
- addressed light leakages in some lenses
- removed the vignetting with the 50mm by increasing filter size to 77mm
35mm f/3.5 fisheye with 32.5mm filter $US4440
40mm f/4 95mm filter, $US2718 (equiv. to 23mm f/2.2 in 35mm)
50mm f/3.5 77mm filter, $US2372, $A2310 (equiv. to 28mm f/1.9 in 35mm)
65mm f/4 67mm filter, $US2168 (equiv. to 35mm f/2.2 in 35mm)
80mm f/2.8 67mm filter, $US1660 (equiv. to 45mm f/1.5 in 35mm)
110mm f/4 1:4 macro 67mm filter, close focus 0.6m (equiv. to 60mm f/2.2 in 35mm)
110mm f/4.5 1:1 macro 72mm filter?, close focus 0.37m, $US2159
- photos on Flickr using the 110mm macro
135mm f/4 67mm filter, close focus 1m, $US2191 (equiv. to 76mm f/2.2 in 35mm)
150mm f/4 67mm filter, close focus 1.5m, $US2372 (equiv. to 85mm f/2.2 in 35mm)
180mm f/4.5 67mm filter, close focus 1m, $US2740 (equiv. to 100mm f/2.5 in 35mm)
200mm f/4 67mm filter, 2.5m close focus $US2531 (equiv. to 110mm f/2.2 in 35mm)
250mm f/5.6 67mm filter, close focus 3m $US2704 (equiv. to 135mm f/3.1 in 35mm)
500mm f/8 $US15688 for flourite PS or $US4229 for S version with 95mm filter (equiv. to 270mm f/4.5 in 35mm)
50-100mm f/4-5.6 with 95mm filter $US2865
1.4x teleconverter $US1307
2x teleconverter $US1277

Older S Lenses:

40mm f/4 82mm filter, 0.4m close focus
50mm f/3.5 67mm filter, 0.5m close focus - some vignetting
80mm f/2.8 67mm filter, 0.8m close focus
105mm f/3.5 67mm filter, 0.85m close focus
150mm f/3.5 67mm filter, 1.5m close focus
200mm f/4.5 67mm filter, 2m close focus
250mm f/5.6 67mm filter, 3m close focus
500mm f/8 95mm filter, 8.5m close focus

Film backs:

the film backs are one of the Bronica's weak points as they tend to develop light leaks after years of use.
there are several types of film backs:
- SQ 6×4.5 120 and 220
- SQ 6×6 120 and 220
- SQAi 6×4.5 120 and 220 - these have a relocated ASA speed dial
- SQAi 6×6 120 and 240 - these have a relocated ASA speed dial
- 135N for 35mm film
  - not sure why anyone would bother with this now that Kodak has stopped making HIE film
- 135W for 35mm film but in wide panorama format (24x56mm frames)
  - may as well just use 120 backs and crop them
- Polaroid backs
  - use 3 1/4“ x 4 1/4” film packs but you only get 2 1/2“ x 2 1/2” images
  - Fujifilm are supplying film packs for Polaroid backs:
    - Fuji FP-100B - B&W ISO 100
    - Fuji FP-100C - color ISO 100 - available glossy or silk
    - Fuji FP-3000B - B&W 3000 ISO
  - old Polaroid film versions compatible:
    - 664 - color ISO 100 short exposures (1/10th sec or faster)
    - 665 - B&W ISO 80
    - 667 - B&W ISO 3000
    - 669 - color ISO 80
    - 672 - B&W ISO 400
    - 679 and 690 - color ISO 100
  - SQ-i version has adjustable ISO values 25-6400 whereas SQ version only has 2 settings - 75 or 3000 ISO.
  - The Polaroid back also requires that the camera’s multiple exposure lever be engaged for proper operation.
  - how to use it (pdf) - http://www.buonaluce.com/Polabacks.pdf
using 120 film in 220 backs:
- there appears to be no focus error issues in using 120 film in Bronica SQ or SQA 220 film backs
- you can also use 120 inserts in 220 backs
- there are 2 main problems:
  - film counter issues:
    - is that the camera will assume you can take 24 images as for 220 film in a 6×6 back instead of only 12 for 120 film (30 on a 6×4.5 220 back instead of only 15 frames on 120 film) and thus unless you are alert to this you will end up taking a lot of blank photos - you need to watch the film counter and stop.
    - You'll have to wind the film out and expose until about the 15th frame before opening the back, you'll feel a reduction in tension if hand winding once end of film is reached.
  - where to start the roll so you don't lose the first one or two frames or the last one or two frames:
    - a suggested technique by Budd Gottesman to check frame spacing is the following:
      - “use a test 120 film which you won't develop to mark the spacing of frames
      - load your 120 roll on your 220 insert as usual but bring the arrows to a point approximately 90 degrees (1/4 turn) BEFORE the start marker on the insert.
      - Wind the camera to #1 as usual.
      - Then without a lens on the camera (set to multi-exposure if necessary) fire a shot and mark ON YOUR WASTE ROLL where the frame is located, so when you then remove it (possibly, and I'd recommend) go thru the rest of the roll marking shot by shot, on the film which will assure you how the “SPACING” is working on this back.
      - BTW: You may need to change the starting point slightly forward/back as you need.
      - If you give the backs/inserts heavy use, I'd DEFINITELY tell you to check the spacing like this on them all every few months.”

Accessories:

speed grip $US416, $A522
motor drive $US1057
SCA flash adapter $US340
SCA flash bracket $US202
professional bellow lens hood $US647
focussing screens $US86
extension tubes 18, 36mm $US769 ea, $A781
bellows $US2670, $A2695
film backs $US815 for 120 or 220 backs in either 6×6 or 645 format, or 135N or 135W (24x56mm frames)
polaroid back SQ-i 6×6 $US680
- see http://www.buonaluce.com/Polabacks.pdf

Troubleshooting the SQAi

Shutter release will not fire

ensure you either have fresh batteries in the camera or fresh batteries in the Motor Drive (you don't need the camera batteries if the Motor Drive is attached and has fresh batteries - 6 x AA)
if you have a film back attached, ensure the dark slide film insert is removed even if there is no film in it
if you have a film back attached and no film in it, or no film back attached, ensure the Multi-Exposure switch on the right side is switched horizontal to ON to display the red dot (a black square will also appear in the viewfinder)
ensure the shutter is cocked by winding the crank (this should be done automatically if Motor Drive is attached)
ensure the shutter release button is not set to Lock (L) on the front right of camera
if shutter is cocked and you move the mirror lockup switch from S or C to N (mirror lockup), this may prevent the shutter from firing, in which case, either:
- by leaving the film back attached and film in it:
  - cover the lens with lens cap (as you will be firing the shutter so you don't want to inadvertently expose film here)
  - ensure mirror lockup is set to N
  - set Multi-Exposure switch to on (red dot will be visible)
  - expose the frame by pressing the shutter release
- or, by removing the film back first:
  - press the shutter release
  - reattach film back

what does the red LED light mean inside the viewfinder?

indicates the exposure has ended - so do not manually crank the film until this occurs on longer exposures
if it comes on when you press the shutter release button this indicates the Multi-Exposure switch is off and you have no film in the film back (if you want to play with the camera without film, you must set Multi to on (red dot visible) )

removing the lens

WARNING BOTH CAMERA AND LENS MUST BE IN THE COCKED POSITION BEFORE REMOVING THE LENS!
if the lens is not cocked when you want to attach it, manually cock it by moving the cocking pit of the lens to between the green dot and the red marker
if the camera is not cocked, wind the film crank

AE Prism Finder

SP-A switch changes between spot and average metering (icon displayed in viewfinder)
M and C buttons allow AEL (press M) and continuous metering (press C)
Exposure compensation dial allows +/- 2EV
Exposure mode is M (manual). Off, or A (aperture priority auto)
shutter speed is displayed but not the aperture
You set the ISO on the film back itself BEFORE attaching it to the camera
there is a diopter setting and a viewfinder blind switch

Motor Drive SQ-i

takes 6 x AA batteries mounted by screw type battery holder on base and is very handy as you no longer need the dodgy camera batteries to function
- “when removing batteries from holder, make it a habit to always remove them from the + side first”
- if using 1.2V NiCd batteries, battery check will not work normally
- can optionally power drive from:
  - an External Battery Pack S with 6 C type batteries
  - external DC power 9V, 5A with EIAJ RC-705 power plug (ensure correct polarity + is outer and - inner part)
has a flash hotshoe mount
mode dial as 3 options: OFF, Single and Continuous
checking the motor drive batteries:
- place mode dial in S or C
- depress the battery check button on the rear, bottom of the motor drive:
  - steady LED light indicates good battery power
  - flickering LED will indicate very limited power remaining but enough for limited operations
  - no LED light indicates flat betteries
attaching the motor drive:
- remove manual crank handle of the camera if it is still there
- ensure motor drive mode is set to OFF otherwise there is risk of activating it
- align guide pins on the camera base then press together and tighten the knob on the base
to perform an initial winding of a new film:
- ensure Multi-exposure is OFF (red button not visible and switch is vertical)
- turn mode dial to S
- press the drive button next to mode dial which will advance film to 1 and cock the shutter ready to take a shot
automatic film winding will NOT take place and you must manually press drive button if
- completion of a Time exposure shot
- resetting of the Multi-exposure lever after completing a multi-exposure shot
- suspension of mirror lockup shooting after the mirror is locked up
- “when film winding does not take place for some reason”
end of film
- motor drive continues winding for 6 secs more to wind up remaining film, once complete, you can then open the film back and change the film.
overload light lights up
- this indicates an abnormal load on the film winding mechanism
- turn Mode dial to OFF and investigate cause and fix, it may be:
  - insufficient power left in batteries
  - abnormal film winding action
when not in use, set mode dial to OFF
do not clean with solvents such as alcohol

camera batteries:

one of the trade offs with Bronica cameras is that you need batteries to take photos as the shutter is electronically timed (most of the SQ series except for SQAi, do allow a fixed 1/500th shutter speed with flat batteries). These cameras have a relatively high amp (~15mA) draw during each shutter release and battery check and thus lithium batteries are not useful.
you do not need these batteries if you are using a motor drive as the batteries in the motor drive power the camera.
if the shutter release is not working, check that the dark slide has been removed and your batteries are not exhausted
- if you have put new batteries in and the battery check light does not work then check the battery contacts are clean, the batteries are inserted the correct way, and if still no response, try pushing on the battery pack with the battery compartment lid open and re-check the battery light - if it now lights, you may need to pack the compartment with a little cardboard on the clip side.
- also, it may be a old speed grip creating contacts which the camera then thinks it is a motor drive and the power source will be coming from the motor drive - remove the speed grip to see if this resolves the problem.
see http://www.tamron.com/bronica/batteries.asp
for best results, it is recommended to use silver oxide batteries:
- SQ-A, SQ-B, SQ-Ai: 4 x MS-76
  - NB. using silver oxide in the SQ-Ai with AE finder may cause transient auto exposure errors when the batteries are near exhaustion.
alternatively, one can use the cheaper alkaline batteries:
- SQ-A, SQ-B, SQ-Ai: 4 x MS-76A

prolonged storage care

according to the official instruction manual:
- ensure any salt water spray has been removed by a damp cloth moistened with fresh water, then dried with a dry cloth
- store in a tin-lined container with plenty of dessicant (eg. silica gel) and in a cool, dry, well ventilated but not windy location
remove batteries in case they leak
lens cocking:
- there does not seem to be specific recommendations regarding whether to store lenses cocked or not cocked, however, it probably makes sense to store them uncocked
camera body cocking:
- seems it is best to have it cocked during transport but uncocked for prolonged storage (and thus the mirror will be locked up)
note that the springs of the shutter mechanism were designed to be kept in tension for extended times
maintain shutter mechanism lubrication by firing shutter once every month or so

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