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Lee Big Stopper - (Lots of ND filter)
Is anyone else using the Big Stopper or any other heavy ND filter?
I'm still trying to get the hang of metering for it. As near as I can figure, contrast is increased. Precise metering is critical and it seems to limit the range. I metered f32.3 (1/60 sec) on the building and water. The sky was plus 2 stops. The image on the right is per metering. The image on the left is with the 10 stop ND filter. I figured 16 seconds which, with reciprocity failure correction, is about 52 seconds. If I correct for 1 stop, the images seem to match well. I'll consider treating the Big Stopper as 11 stops for the next experiment.
Has anyone else been through this yet?
Re: Lee Big Stopper - (Lots of ND filter)
What film? Is your reciprocity correction accurate?
Have you tried metering through the filter?
Re: Lee Big Stopper - (Lots of ND filter)
Quote:
Originally Posted by
vinny
What film? Is your reciprocity correction accurate?
Have you tried metering through the filter?
Delta 100. I'm confident in my reciprocity corrections. What I'm not confident in is my note-taking I may have missed a couple of stops in my 10-stop shift. I had 1/15 @f32.3 written down as well as 1/60. On an overcast day with ISO 100, I'm more inclined to believe the 1/15. With this uncertainty, I'm starting over.
to be continued...
2 Attachment(s)
Re: Lee Big Stopper - (Lots of ND filter)
Another try from yesterday...
Shot at 1/30 @ 32.3 with the shadowy part of the rocks at -2, the brighter rocks at -2/3, the sky at +1.5. (left)
The shot on the right was with the Big Stopper using 10 stops (32 seconds) corrected to 2:52 for reciprocity failure. I like the way zones 3-5 held but the sky washed out.
Re: Lee Big Stopper - (Lots of ND filter)
One of the characteristics of reciprocity for many b+w films is an increase in contrast, that's why kodak recommends a reduction in development for long exposures. Your first shot of the water/building is a difficult one since the majority of the subject is in shade while the bright sky and clouds remains just as bright as it would be if the entire scene was lit by the sun. It's a situation where I would hold off for different light, use a grad filter, or use minus development regardless of exposure time.
Re: Lee Big Stopper - (Lots of ND filter)
I don't understand the need for a ND filter unless one is trying to widen the aperture to limit DoF or slow shutter speed to blur movement or deal with a situation like the scene brightness is too much for the available film speed.
I'm guessing that the image in post #4 is really just to get a grasp on how a particular film is behaving with a specific filter?
Re: Lee Big Stopper - (Lots of ND filter)
Reciprocity correction tables generally tell you to reduce development time somewhat in order to reduce contrast, and the tables of time-extensions include some extra time to make up for the reduced development. In other words, getting back to a normal-contrast, normally-exposed negative in the face of extreme reciprocity failure requires:
- increased exposure due to the overall loss of sensitivity
- decreased development to get the contrast under control
- more increased exposure to make up for the reduced development.
In other words, you add on a bunch of time because the film is being slower, then you add on yet more time because you're doing N- development to get the contrast under control.
It sounds like you're following the table of time adjustments but not the table of development adjustments.
Re: Lee Big Stopper - (Lots of ND filter)
Over expose a bit...
Under process somewhat...
Tweak contrast with selenium toner (visual inspection)...
Beautiful open shadows and unblocked highlights...
Happy-happy... joy-joy!!
Throw a wrench in the works (reciprocity effects) and start the machine over again. :)
Re: Lee Big Stopper - (Lots of ND filter)
I have been using it with color negative films. I've recently used the filter with Ektar 100 8x10 at Shell Beach, CA. I will post my results as soon as I process the negs.
-DP
Re: Lee Big Stopper - (Lots of ND filter)
Just a thought but are you sure it's 10 stops. My Lee big stopper is a touch over 11 stops. I've not been very successful metering through the filter but I've used a digital camera to allow me to check the actual strength of the filter and apply that to all my subsequent medium and large format shots.