Using Lee 4x6 GND density filters with dim slow lenses?

[Stephen Willard]

To expand on Eric's contribution...as you stop a lens down the grad area will move (down) into the image area. This means that you have to place the grad with the lens at the shooting aperture. Thus the maximum aperture doesn't matter.

The black card idea is a great one, also a UV filter partially blacked out would work I think.
JD

Joseph, Very interesting note. Thanks.

[Joseph Dickerson]

You're most welcome...cool place we have here huh?

JD

[Corran]

I'm very confused as to how the "grad area will move down into the image area" when stopping down?? The filter doesn't move; that doesn't make any sense.

[Joseph Dickerson]

I guess it's an optical thing...obviously the filter doesn't physically move, but the transition will appear lower in the image.

You can see it happen as you stop the lens down. I'm sure that someone can/will come up with a more technical explanation than that.

So, if you set the grad filter with the lens at f/5.6 and then shoot with the lens at f/22 the darkened section will be greater, farther into the image, than you thought. Ergo, set the grad with the lens at the taking aperture.

JD

[Peter Gomena]

I'll second the suggestions to buy the hard-edged transition filters. On my LF lenses, the transition area of a soft filter is not only very difficult to see, but never reaches full density within the image area I'm photographing. For example, on a 150mm lens, the full density doesn't come into play before the entire area of soft gradation has reached the bottom of the lens bezel. It would be useable on a really large-diameter lens, but I find it generally useless.

[Stephen Willard]

I have just ordered a set of three Lee GND hard edge filters from B&H Photo. They have been shipped and will be arriving soon. From the comments and suggestion made in this thread, I am confident that I will be able to use them in a productive and confident manner.

I will be headed into the backcountry of Colorado and Wyoming with my llamas in late June and returning sometime in late October. My hope is to update this thread on my findings and experiences with the filters in January of 2014 in hopes that others can benefit from mine and your experiences.

Thanks for your considerations and thoughts.

-Stephen