ND filters to slow down exposure - help

[durr3]

I want to shoot 4x5 Delta 100 film, with a Wollensak Verito 9 inch f4 lens. The "regular" shutter is erratic so I want to hand expose the shot.
I have three ND filters: a 2X, a 4X and an 8X. Will I be able to slow down Delta 100 to 1 sec or so? Assuming the light cooperates.

Thanks

[David Lobato]

Won't work for 1 second, you will need an 11 stop reduction assuming full daylight at f4 and ISO 100. Your three ND filters total 6 stops, 1+2+3.

[Jac@stafford.net]

I have three ND filters: a 2X, a 4X and an 8X. Will I be able to slow down Delta 100 to 1 sec or so? Assuming the light cooperates.

ND 8 lowers transmission by 3 stops. In a bright situation presuming f/16 is nominal 1/125th of a second, to achieve 1 second you will need at least an ND32 which is 5 stops, or to be safe an ND64, 6 stops. (I would not stack filters.)

[durr3]

What if I stopped the lens down to f6?

[Jac@stafford.net]

What if I stopped the lens down to f6?

No way.

[durr3]

Ha....ok THANKS Guys

[Pere Casals]

I want to shoot 4x5 Delta 100 film, with a Wollensak Verito 9 inch f4 lens. The "regular" shutter is erratic so I want to hand expose the shot.
I have three ND filters: a 2X, a 4X and an 8X. Will I be able to slow down Delta 100 to 1 sec or so? Assuming the light cooperates.

Thanks

I'd suggest to use a Shutter Tester to measure true shutter speeds, even true speeds are far from marked ones it is possible you have a couple of speeds that repeat exposure interval very closely. If you know what are the effective speed you can make perfect exposures without ND the nuisance.

There are shutters testers for $70 (CAM-LITE), there is also one that has a cost of $15 (ebay), this is a bare photocell you can plug to a PC sound card, then you use a free audio app (audacity) to record the signal and see how much time shutter allowed light to reach the photocell.

This is a good practice because mechanical shutters are not as precise as electronic ones, and it is important to know how owned shutters perform.

You also can place a a DSLR (without the DSLR lens) in the back of the view camera, then take and exposure with the Verito shutter, then leave the Verito shutter open and take exposures with the DSLR shutter to find the DSLR speed that is matching the image taken with the verito Shutter, so you'll know the effective speed of the verito shutter.

http://www.kenrockwell.com/tech/expo...rge-format.htm

[Jac@stafford.net]

I'd suggest to use a Shutter Tester to measure true shutter speeds, even true speeds are far from marked ones

The original poster wishes to make exposures of about one second, and in practice probably longer. What good is a shutter tester for such long exposures? If his shutter is so messed-up that 1 second is unreliable, he can revert to B or if his shutter has it, then T.
.

[Pere Casals]

The original poster wishes to make exposures of about one second, and in practice probably longer. What good is a shutter tester for such long exposures? If his shutter is so messed-up that 1 second is unreliable, he can revert to B or if his shutter has it, then T.
.

Hello Jac,

OP says he wants to make long exposures by hand because the Verito shutter is erratic. I suggest knowing true speeds (with a shutter tester) to get right exposures instead going to long hand exposures.

Regards.

[Jac@stafford.net]

Pere, excuse my confusion, please.
The OP wrote, in part,

I want to hand expose the shot. I have three ND filters: a 2X, a 4X and an 8X. Will

I be able to slow down Delta 100 to 1 sec or so?

And my mind went into 'what is reasonable' therefore presumed the unlikely success of a hand held one second exposure. I hope we are okay, Pere.

Best,
Jac