Lens shake from copal 3?

[Cloverick]

I'm running sinar 300mm and 360mm lenses on copal 3 shutters. I have a creeping suspicion that I'm getting camera shake from the copals.... They're a big shutter with a big slap. I've got a sensitometer on my iPhone and it registers movement. I suppose I should run some tests between long exposures and 125th etc to see (shoot some film). But I wonder in the meantime if anyone has come across this issue? Any advice?

[BrianShaw]

I've never noticed such a problem. Perhaps you need a more solid tripod or head?

[Leigh]

I agree with Brian. You need a solid camera support. That's true even for smaller lenses.

I shoot Nikkor W 300/5.6 and 360/6.5 lenses, and never noticed a problem.

Those are both huge lenses, well over 1kg each. Heavy lenses are less sensitive to vibration than lighter ones.

On the smaller side, I use a Nikkor M 450/9 in a Copal 3, which weighs only 640gm (most of that is the shutter itself).
I've seen no vibration problem with it either.

- Leigh

[Bob Salomon]

Are you using a cable release with slack in it?

Is your phone touching the shutter while you are measuring the movement? That contact alone could show movement, especially if the phone is being held in your hand while doing the measurement.

[Drew Wiley]

Big shutters do have the potential for increasing vibration, both due to the size of the shutter itself, and due to simply more overall weight on the front standard.
Frankly, I don't like using no.3 shutters on lightwt 4x5 field cameras at all. But I got a lot more "buzz" from a 3 Compur shutter than any Copal.

[AtlantaTerry]

One simple way to test for movement would be to affix a mirror to the front of the lens. Then in a darkened room shine a sharp light at the mirror from an angle. A laser pen would be ideal. Then watch the reflected light beam on a surface such as a wall. When the shutter goes off what happens? Any vibration caused by the shutter will make the light beam move across the wall. (This is the same technique that firms use to draw pictures and images with powerful lasers at concerts and parks.)

[Kirk Gittings]

What camera is it? I've had field cameras that the front standard was so unstable that yes the shutter firing could soften the image very slightly. But rather than a shutter problem I think it is either a camera or tripod problem (as mentioned above).

[Drew Wiley]

It also a matter of what the front standard and camera are made of. Some aluminum materials amplify vibration, whereas wood tends to dampen it. For example, a
no.3 shutter which causes my wooden 8x10 folder no issues whatsoever can be absolutely useless on my field Sinar at long extensions, even my Norma, which is
otherwise a very stable system. The same focal length lens in a no.1 shutter solves the problem completely. That shutters CAN be a problem is a scientific fact that can be proven with an attached vibration meter at the front when it trips. But no need to get this fancy. Just place the back of your fingernail to the front standard and feel if there's a buzz at, say, 1 sec. But you're only as good as your weakest link (hence my refusal to use ball heads).

[Cloverick]

Thanks for all the responses, much appreciated. I'll try the light and mirror trick.... But I think some controlled tests on film will yield some results, I just need to think of something that might also yield a nice picture.
In response to some of the points made;
- I use the largest gitzo carbon fibre tripod, often weighted from the hook. Until recently I've been using the basic sinar head, before that the manfrotto 450(I think it was) and now I have the monster manfrotto- whatever the model is. All solid stuff.
- I've only used the sensitometer on the sinar, a some what rickety but still solid P. And the iPhone was on the film end.
- maybe it is of no concern... It could be happening after the exposure....
- I'll run some tests on the canham too.
- never had the issue with the 4x5 lenses which are all copal 1s.
- maybe I'm OCD and it has no bearing on the final result which is.... Shot on color neg, sometimes 400asa pushed..

Regards.

[Taija71A]

... But rather than a shutter problem I think it is either a camera or tripod problem (as mentioned above).

____

Agreed in full 110%... As per above!
Recommend to look 'elsewhere' in system setup (first)...
--
*Perhaps, remember to always 'lock down tight'... All of the 'controls' on your camera, tripod and tripod head!
--
Regards,

-Tim.
________

[AtlantaTerry]

Thanks for all the responses, much appreciated. I'll try the light and mirror trick.... But I think some controlled tests on film will yield some results, I just need to think of something that might also yield a nice picture.
In response to some of the points made;
- I use the largest gitzo carbon fibre tripod, often weighted from the hook. Until recently I've been using the basic sinar head, before that the manfrotto 450(I think it was) and now I have the monster manfrotto- whatever the model is. All solid stuff.
- I've only used the sensitometer on the sinar, a some what rickety but still solid P. And the iPhone was on the film end.
- maybe it is of no concern... It could be happening after the exposure....
- I'll run some tests on the canham too.
- never had the issue with the 4x5 lenses which are all copal 1s.
- maybe I'm OCD and it has no bearing on the final result which is.... Shot on color neg, sometimes 400asa pushed..

Regards.

OK, it has been almost a month. What are the results of the laser and mirror test?

[Nathan Potter]

A simple test I have used when doing precise scientific photography is to open the shutter on T setting and expose using electronic flash. This gives an image on film which has eliminated all possible sources of camera, tripod and lens vibration. It's really a check of the "system" vibration.

I like the laser and mirror approach also.

Nate Potter, Austin TX., Holliston MA.