High shutter speed accuracy?

[MIke Sherck]

I don't recall ever using a shutter speed faster than 1/100 with a large format lens. How common is using a faster shutter speed, anyway?

[Frank Petronio]

If you shoot short depth of field stuff -- or are pretending you are cool with your Aero-Ektar -- you'll use the faster speeds outdoors in Sun, at least that is what I've heard, having not seen the Sun for a few months here in Rochester.

I usually just count 1/250 and 1/500 as half a stop slower. The worst shutters in this regard are the old American ones like the big Acmes, I doubt they ever got faster than 1/50 even if marked higher.

[Ivan J. Eberle]

It's probably not just an artifact of your Calumet tester; springs do weaken with time and top speeds may not have been all that honestly rated. Shutter propagation time can be observed on my shutter tester and my Copals tend to be slower than the speed rating on the fastest speeds. As others have indicated, +/- 30% is tolerable (1/3 stop).

It rarely matters how accurate speeds higher than 1/125 are with LF. These days few shoot press camera style with transparency films (fewer still are current fast ISO transparency films in sheet sizes that'd make it possible) where exposure is all that critical. Largely why high speeds persist since that press era is they function as an ambient light excluder when shooting sync'd flash. If you have a particular scientific technical reason to need a precise shutter at higher speeds, you'll perhaps be better served in a smaller format where quartz oscillator and microprocessor controlled shutter timing is commonplace.

If shooting landscape or location, for instance, what you might rather be more concerned with is the consistency between readings at the same speed, most of these type exposures being between 1/30s down to 8s (timed with a cable release and Mississippi One Mississippi Two is close enough beyond a couple of seconds). Probably worth testing at different temps. A gunky or damp shutter will more readily hang up in the cold.

[Songyun]

Thanks everyone, my intention is to shoot 45 hand held (say with a 150mm lens) I don't know how fast the shutter should be. Assume in 35mm format I should have speed faster than 1/150s, I don't know if that applies to LF or not.

[Bosaiya]

Thanks everyone, my intention is to shoot 45 hand held (say with a 150mm lens) I don't know how fast the shutter should be. Assume in 35mm format I should have speed faster than 1/150s, I don't know if that applies to LF or not.

That really depends on your expectations. The nice thing about LF is that you are not as likely to make the same type of enlargements you would with a mini-cam. So whereas 1/150 might be necassary to achieve the results you are after in 35mm you might find 1/60 perfectly adequate for 4x5.

I recently found myself shooting at 1/15, which is pretty low, I normally shoot handheld at 1/60 and don't experience an unappealing amount of blur. The subject matter lends itself to a certain amount of dynamic appeal so I'm not too worried, your needs may be completely different.

[BetterSense]

I can shoot my speed graphic at 1/30 or maybe even with no detectable handshake to 8x10 ish enlargements. Subject motion of course, is another problem. I just use my FP shutter if I need faster shutter speeds.

[Songyun]

so 1/60 is a good start point to hand held a 150mm lens, sounds good. At least all the shutters I have tested are good at 1/60.

[BetterSense]

It probably depends on how much coffee you drink, how heavy your camera is, and how lucky you are. 1/125 should be a piece of cake, though.

[Mick Noordewier]

Are you using the Calumet instructions, especially important for the higher shutter speeds?

--
Alan

Alan,
I've got a Calumet shutter tester, but no instructions. What are the instructions for higher shutter speeds?
-Mick

[Jim Graves]

One other factor for shutter speed is usage. I've found that when a lens has not been used for awhile it is considerably slower in the first few firings and continues to speed up through 10 firings or so. This is easy to observe with a timer.

When I go out to shoot now I try to remember to fire the shutters at least 5-10 times before actually shooting my first picture. I tend to use fairly old shutters though, so the effect might be exaggerated with my equipment.