IISO flash shoe
Encyclopedia
Minolta
Minolta Co., Ltd. was a Japanese worldwide manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta was founded in Osaka, Japan, in 1928 as . It is perhaps best known for making the first integrated autofocus 35mm SLR camera system...
cameras since the i-series introduced in 1988, and subsequently Konica-Minolta
Konica Minolta
is a Japanese manufacturer of office equipment, medical imaging, graphic imaging, optical devices, and measuring instruments. It is headquartered in the Marunouchi Center Building in Marunouchi, Chiyoda, Tokyo, with a Kansai office in Nishi-ku, Osaka, Osaka Prefecture...
and later Sony α DSLRs
Digital single-lens reflex camera
Most digital single-lens reflex cameras are digital cameras that use a mechanical mirror system and pentaprism to direct light from the lens to an optical viewfinder on the back of the camera....
and NEX-7. In order to speed up and enhance attachment, detachment and latching, it departs from the conventional circa-1913 mechanical design that is presently standardized as ISO 518:2006 and used by other camera systems, including Canon, Nikon
Nikon
, also known as just Nikon, is a multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging. Its products include cameras, binoculars, microscopes, measurement instruments, and the steppers used in the photolithography steps of semiconductor fabrication, of which...
, Pentax
Pentax
Pentax is a brand name used by Hoya Corporation for its medical-related products & services and Pentax Ricoh Imaging Company for cameras, sport optics , etc. Hoya purchased and merged with the Japanese optics company on March 31, 2008. Hoya's Pentax imaging business was sold to Ricoh Company, Ltd...
, Olympus
Olympus Corporation
is a Japan-based manufacturer of optics and reprography products. Olympus was established on 12 October 1919, initially specializing in microscope and thermometer businesses. Its global headquarters are in Shinjuku, Tokyo, Japan, while its USA operations are based in Center Valley, Pennsylvania,...
, and Leica.
History
The mechanical design of the accessory shoe now common on most cameras dates back to 1913, when Oskar BarnackOskar Barnack
Oskar Barnack was a German optical engineer, precision mechanic, industrial designer and the father of 35mm photography....
, the inventor of the Leica, devised it for attaching an accessory viewfinder. By 1940's, with the addition of the central contact, the design became commonly used for attaching and triggering accessory flashes and known as the "hot-shoe"
Hot shoe
A hot shoe is a mounting point on the top of a camera to attach a flash unit.- Design :The hot shoe is shaped somewhat like an inverted, squared-off "U" of metal. The matching adapter on the bottom of the flash unit slides in from the back of the camera and is sometimes secured by a clamping screw...
. Prior to 1988, Minolta
Minolta
Minolta Co., Ltd. was a Japanese worldwide manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta was founded in Osaka, Japan, in 1928 as . It is perhaps best known for making the first integrated autofocus 35mm SLR camera system...
has used that familiar, common hot-shoe design
Hot shoe
A hot shoe is a mounting point on the top of a camera to attach a flash unit.- Design :The hot shoe is shaped somewhat like an inverted, squared-off "U" of metal. The matching adapter on the bottom of the flash unit slides in from the back of the camera and is sometimes secured by a clamping screw...
, adding, just like the other makers, its own proprietary contacts for enhanced control.
In 1988, Minolta
Minolta
Minolta Co., Ltd. was a Japanese worldwide manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta was founded in Osaka, Japan, in 1928 as . It is perhaps best known for making the first integrated autofocus 35mm SLR camera system...
introduced the iISO flash shoe in its new i series
Minolta 7000i
The Minolta Dynax 7000i, is a 24x36mm auto-focus SLR camera, introduced by Minolta in 1988. It was sold in North America as Maxxum 7000i, and in Japan as α-7700i....
of cameras. Reportedly conceived with the input from the late Herbert Keppler
Herbert Keppler
Herbert „Burt“ Keppler was a photographer, author and journalist. His career spanned 57 years, including 37 at Modern Photography and two decades at Popular Photography...
in 1987, the new Minolta patented design featured a push-button latching mechanism, for the purpose of easier and faster flash attachment and removal and a more secure hold.
Mechanical
The use of the button-operated latch, besides facilitating a quick, one-handed flash attachment and detachment, also eliminates the possibility of the flash gradually working itself loose and shifting in the shoe, which on camera systems using the ISO 518 hot-shoeHot shoe
A hot shoe is a mounting point on the top of a camera to attach a flash unit.- Design :The hot shoe is shaped somewhat like an inverted, squared-off "U" of metal. The matching adapter on the bottom of the flash unit slides in from the back of the camera and is sometimes secured by a clamping screw...
can lead to certain contacts being broken, contacts with the wrong pins being made, or in extreme cases the flash sliding off the hot-shoe entirely.
- Attachment
As the flash slides onto the camera body, the sides of the T shaped flange on the body engage the lips of the rotated C shaped profile on the flash. When the flash is fully inserted, a spring-loaded latch on the flash locks into the indentation in the middle of the flash shoe. - Detachment
The user presses the unlock button on the flash body, which, by means of a lever or a wedge mechanism disengages the locking latch, enabling the user to slide off the flash from the camera body.
Electronic Contacts
Listed top-to-bottom (looking at the flash shoe socket as pictured above, or with the camera positioned with the lens pointing up):| Pin | Wire | Analog | Digital |
|---|---|---|---|
| F3 | black | TTL OK | Clock |
| F2 | white | Ready | Bidirectional serial data |
| G | blue | Ground | Ground |
| F1 | red | Sync / trigger flash | -- |
Variations
- Analog and digital control modes
Digital control mode is used if a contemporary flash is detected by the camera. Otherwise, to support basic triggers and legacy and low-end flashes, analog interface is used. - Additional electronic contacts on Minolta 3000i/3700i
This low-end body omitted a built-in flash, and Minolta made available D-314i and D-316i compact and inexpensive flashes especially for it. These flashes relied on camera battery for power delivered via three additional pins on the hot shoe (+5V regulated flash electronics power, and unregulated power and ground wired to the camera's battery to charge the flash). No other camera body to-date has the additional contacts required to support the D-314i and D-316i flashes.
Criticism
iISO hot shoe's introduction left few informed users indifferent - some photographers loved it, while others hated it. The sentiment revolves around these areas:- Legacy support
During its 1988 introduction, the new MinoltaMinoltaMinolta Co., Ltd. was a Japanese worldwide manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta was founded in Osaka, Japan, in 1928 as . It is perhaps best known for making the first integrated autofocus 35mm SLR camera system...
iISO flash shoe presented an inconvenience to users with significant investment in the old, ISO 518 based MinoltaMinoltaMinolta Co., Ltd. was a Japanese worldwide manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta was founded in Osaka, Japan, in 1928 as . It is perhaps best known for making the first integrated autofocus 35mm SLR camera system...
flashes and accessories. The fact that MinoltaMinoltaMinolta Co., Ltd. was a Japanese worldwide manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta was founded in Osaka, Japan, in 1928 as . It is perhaps best known for making the first integrated autofocus 35mm SLR camera system...
chose to offset the new flash shoe introduction by three years from the 1985 MDMinolta MD mountThe Minolta SR mount was the bayonet mounting system used in all 35mm SLR cameras made by Minolta with interchangeable manual focusing lenses. Several iterations of the mounting were produced, for different lenses branded as "SR", "MC", "MD" or "X-600", and the mount itself is sometimes called by...
-to-Minolta-AMinolta AFThe Minolta Alpha camera system was a collection of photographic equipment from Minolta. The system used a lens mount called A-mount, with a flange focal distance 44.50 mm. The new mount was larger than the older SR-mount making old manual lenses incompatible with the new system...
lens mount transition, as opposed to doing both concurrently, may have added insult to injury for some users. To soften the impact, MinoltaMinoltaMinolta Co., Ltd. was a Japanese worldwide manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta was founded in Osaka, Japan, in 1928 as . It is perhaps best known for making the first integrated autofocus 35mm SLR camera system...
had made available a FS-1100 (8825-670) adapter allowing to mount the old flashes and controllers on new bodies, and a FS-1200 (8825-680) to do the reverse. A custom-modified variant of the FS-1100 also featuring a PC sync terminal was made available by the Minolta service at request at least in Germany and the USA, this part was also mentioned in the Minolta USA FAQs under the unofficial name "FS-PC". - Interoperability across systems
It is possible to mount, say, a Canon flash directly on a NikonNikon, also known as just Nikon, is a multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging. Its products include cameras, binoculars, microscopes, measurement instruments, and the steppers used in the photolithography steps of semiconductor fabrication, of which...
body, and trigger it during the exposure. However, the ISO 518 hot-shoe standard does not govern electronic data transfer between the flash and the body (e.g. for charge and exposure status, TTL metering, ratio, focal length, ISO exposure index, distance, pre-flash metering, modeling light, red-eye reduction burst, wireless control). Different camera makers' dedicated flash systems are, in fact, incompatible in terms of both the proprietary contact layout and the communication protocol. That said, many current wireless radio triggers for professional studio strobe systems remain a relevant real-world application of the basic ISO 518 hot-shoeHot shoeA hot shoe is a mounting point on the top of a camera to attach a flash unit.- Design :The hot shoe is shaped somewhat like an inverted, squared-off "U" of metal. The matching adapter on the bottom of the flash unit slides in from the back of the camera and is sometimes secured by a clamping screw...
design. Their use with SonySony, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....
and MinoltaMinoltaMinolta Co., Ltd. was a Japanese worldwide manufacturer of cameras, camera accessories, photocopiers, fax machines, and laser printers. Minolta was founded in Osaka, Japan, in 1928 as . It is perhaps best known for making the first integrated autofocus 35mm SLR camera system...
DSLRs requires either the Minolta FS-1100 adapter, now discontinued, or the Sony FA-HS1AM adapter. There are also various 3rd party adapters such as the Seagull SC-5 or the Yongnuo YN-H3. There are however also wireless radio triggers for the iISO flash shoe available, like the PixelPawn TF-363 albeit at a bit higher price than ISO 518 hot-shoe triggers.