Noob Question: BULB

Only recently has long exposure photography caught my eye. I plan on getting the Lee Big Stopper with all the filter holders and such. The only thing is, I don't really know how to use bulb mode.

My question is:
How do you tell how long you need to leave the shutter open? Is it trial and error?

BzBrian wrote in post #12374200
Only recently has long exposure photography caught my eye. I plan on getting the Lee Big Stopper with all the filter holders and such. The only thing is, I don't really know how to use bulb mode.

My question is:
How do you tell how long you need to leave the shutter open? Is it trial and error?

yes.

Pretty much. I'm sure there are some calculations available out there, but I don't know what they are.

And you'll need a shutter release with either a locking switch or an actual timer mode. Otherwise, you have to hold the shutter button the entire time of the exposure.

The Big Stopper comes with a chart. For example, if your correct exposure without the filter is 1/500sec, you'll need a 2sec exposure with the Big Stopper. Actually, each BS isn't exactly 10 stops so you'll need to experiment to see just how dark yours is. Mine is about 10 1/3 stops. I use a shutter release with a timer.

If you've got a few hours to kill have a look at this thread:
https://photography-on-the.net/forum/showthre​ad.php?t=784867

10 stop chart:
https://photography-on-the.net …p?p=9884911&pos​tcount=443
9 stop chart
https://photography-on-the.net …p?p=9884970&pos​tcount=446

Otherwise google ND Filter Calculations, there's a ton of them out there.

Its all calculations and knowing your light. Say you take an exposure at ISO 1600, f/2.8, 1/250 sec. and you want ISO 200 and f/16. Just start counting the stops of light back.

ISO 1600, 800, 400, 200... That brings you to ISO 200, f/2.8 @ ~1/30 sec. Then repeat for the aperture.

f/2.8, f/4, 5.6, 8, 11, 16... takes you to 2 seconds.

BzBrian wrote in post #12374200
Only recently has long exposure photography caught my eye. I plan on getting the Lee Big Stopper with all the filter holders and such. The only thing is, I don't really know how to use bulb mode.

My question is:
How do you tell how long you need to leave the shutter open? Is it trial and error?

You only need bulb mode when your shutter speed is longer than 30-seconds and, no, its not trial and error. As someone has already posted, the Stopper comes with an exposure chart. You can also create your own, especially if you combine other filters, such as a CPL, that increase the total number of stops. I routinely combine a CPL, which gives me 12 stops of reduction...I keep a chart in my bag with the appropriate exposure adjustments, along with my hyperfocal chart. Best to use a cable release, and you can check the time simply with your wristwatch or cell phone (or anything with a minute/seconds time readout for that matter).

I ditched my exposure charts... Exposure time x 1000 for a 10 stops filter will get you within one or two stops, and once you figure it out for your filter, it's a constant. A scene at 1/100th (0.01 seconds) will result in ~10 seconds.
After that it's just some tweaking while keeping an eye on the histogram.
In bright daylight, my meter still works fine with the B+W 10 stops ND on the lens, but it tends to underexpose by about a stop and a half.