Why shutter priority?

[rpsawin]

I remember Canon claimed that shutter priority was more practical because it cut down on the number of blurred photos. In their SLR line this was apparently appealing to sports photographers, and for consumers it meant that you wouldn't inadvertently shoot with a slow shutter speed and have movement ruin the shot.

I don't know whether this was a marketing rationalization or a design decision. It's hard to tell sometimes.

I think you have it right, especially about consumers and blurred photos.

Bob

 

[FallisPhoto]

I can't help but notice that several of the classic rangefinders had full AE and/or shutter priority, but aperture priority doesn't seem very common. Was shutter priority easier to implement? Or was there another reason they went this route?

Well, I'd assume that, if someone is using autoexposure, he is probably not a professional photographer shooting for National Geographic, so I'd also have to assume that he is probably not familiar with the phrase "depth of field." Amateurs also most likely don't know what aperture does.

 

[ErnestoJL]

For the time most of those cameras were designed and made, mechanical shutter priority AE was the simplest way to achieve it. (Konica Auto S2, Canonet QL17 and others like Minolta Himatics).
There were also some SLRs fitted with it: a meter whose needle is trapped at some position, and a staircase shaped metal piece which "feels" needle position, thus limiting aperture blades movement (Konica Autoreflex and some others).

Yashica Broke the rules in 1966 with the Yashica Electro 35 which brought aperture priority AE in electronic form.

Ernesto

 

[Sonnar Brian]

The other problem with aperture priority is getting a memory lock. The Nikkormat EL has a fairly complex analog circuit to acheive exposure lock.

The Polaroid 100 Land Cameras of 1963 were "aperture priority" even if they only had two apertures per ASA setting. The principal is the same: a capacitor is discharged with a rate controlled by the electric eye. Shutter closes when it is drained. Changing the Aperture moves a secondary aperture in front of the electric eye. This is true of the Yashica GSN as well.

The Yashica LYNX 14 is manual only, not sure about the LYNX 1000. I believe it is manual-only as well.

http://www.rangefinderforum.com/forums/showthread.php?t=390

 

[Kim Coxon]

The Lynx was manual only but based on a system of EV numbers. Once you set the correct EV, you could change the aperture and the speed would be adjusted. MManual for the 1000 and 5000 available here. http://www.pentax-manuals.com/manuals/range/range.htm

Kim

The Yashica LYNX 14 is manual only, not sure about the LYNX 1000. I believe it is manual-only as well.

 

[titrisol]

I think that the problems lies in the complexity of the prontor/compur type shuters
It was a lot simpler and practical to adjust the aperture than it was to adjust the speeds.

 

[40oz]

I think it really has to do with the customer base. I've seen many, many posts on other forums from people using DSLR's in aperture mode who can't grasp the idea that aperture and shutter are linked. They think they can close down the aperture and not get blurred subjects. If they only had shutter priority, they'd have more sharp photos.

It takes experience to know how aperture affects an image, and people buying cameras for their auto functions don't have that, so it's kind of a waste to offer that feature. It takes far less experience and knowledge to figure out that a slow shutter blurs movement.

I don't buy the argument that auto control of a mechanical shutter was too difficult. As has been said, they do exist.

Ultimately, while on one level I wish my Canonet had aperture priority, I don't think it would be very useful. As it is, I set the shutter, the camera tells me what aperture it's going to use, and I can adjust from there if I want. I can freely set the shutter for the subject movement and leave it. With AP, assuming it told me which shutter it'd use, I'd be no better off, and would have to always check to see if the shutter was fast enough. I might as well shoot in manual mode if I'm going to be manipulating the aperture for effect.

 

[Seele]

For a fixed lens non-reflex camera, shutter speed priority automation is very simple to achieve, especially when the shutters can very well be standard bought-in units. The method was the "trap needle" as demonstrated before the war in a Kodak camera.

The ambient light drives a galvanometer whose deflection indicates the appropriate aperture for the situation. As the shutter release button is depressed, the set of linkage progressively closes down (or opens up) the iris diaphragm, and the position of the galvanometer needle stops the iris from being changed further while allowing the shutter to release.

In that sense, the same "trap needle" design can also be used for aperture priority exposure automation but the demand for more complex shutter release linkage to drive the speed setting mechanism would be less economical and less effective in the hands of the average user. Only with the advent of electronically timed shutters can this be truly practical.