Mechanical shutters – set shutter speed before cocking

F L U T O T ‘ S    Helpful Tips

Q What’s your opinion on changing shutter speeds? I’ve heard it both ways:

  1. Don’t change the speed when the shutter is cocked.
  2. Only change the speed after the shutter is cocked.

Which way is correct and why? Answer: It’s safe to move the speed dial first before cocking the shutter on any shutter.

When you cock the shutter, it engages the slow gear train so that a lever is against the speed dial. On some shutters (e.g., Ilex, Betax, Alphax, and Compounds) the dial is just a smooth sloping dial—unless someone has adjusted the dial and made bumps or indents to correct the speeds. With these shutters, it’s possible to get additional speeds in between the marked speeds. For example, if you set it between 1/5 and 1/10 your speed would be 1/8 in most cases, depending on the slop or if it’s been adjusted etc.

Some might say to cock the shutter first so the gear train is already engaged and the speed is set, but this doesn’t always work. So it’s always
best to set the shutter on the speed you want (it can be cocked or not), then trip the shutter, then re-cock it, and then take your pictures. This
way you have a truer speed.

With other shutters (e.g., Compur, Rapax, Prontor, Copal, and Seiko) the dial has steps cut into it and if you try to move the dial while cocked you could break the little pin that rides against the speed dial. These type shutters don’t allow for much correction if the speeds are off. Since there are only steps, the step you are on is the speed you get.

There are at least two levers that control the speed in these shutters—the main one that rides the steps and a second that has its own track—so the steps go up from speeds 1 second to 1/10 or 1/15 than down again at 1/25 or 1/30 and than back up.

One other thing I should mention is with some Compur and Rapax shutters, at the highest speed (1/400 or 1/500), the lever rides up and pushes against a heavy spring and you can feel the tension as you turn it to that speed.

To summarize—and to be really safe—just set the correct shutter speed before cocking. If you set the wrong speed and the shutter is cocked, just fire it off then reset. Better safe than sorry!

Source: F L U T O T ‘ S    Helpful Tips

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.