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View Full Version : Using Lee 4x6 GND density filters with dim slow lenses?



Stephen Willard
6-May-2013, 13:26
I am considering purchasing two sets of Lee 4x6 graduated neutral density filters. One set is hard edged with 0.3, 0.6, and 0.9 filters, and the other set is the same except it is soft edge.

My question is how do I use them with slow lenses that are rather dim to begin with? I do not believe you could easily see the transitional line of the GND filters.

Here is what I am thinking of doing. You are more than welcome to comment on the feasibility of my approach. I will start with a clear piece of 4x6 plexiglass. I will scratch and ink in a line mid way though the 6” dimension of the plexiglass. The line itself will be 4” long. I can then insert the 4x6 plexiglass into my Lee filter holder and position the scratched line on the plexiglass along the horizon where I want the transitional line of the GND filter to be as I look through the back of the camera on the ground glass.

From the front of the camera, I will then insert the GND filter behind the plexiglass and position the transitional line of the GND filter to coincide with the scratch line on the plexiglass. Once this is done, I will remove the plexiglass and the GND filter will be properly positioned.

Clearly there will be some guessing of where the transitional line of the GND lies. There is also a possibility I may not even be able to see the scratch line on the plexiglass when looking through the back of the camera on the ground glass. If that should happen I could cover the upper half of the 4x6 plexiglass with black tape to further help me position the plexiglass along the horizon.

Any comments or alternative methods would be appreciated.

Thanks.

Daniel Stone
6-May-2013, 13:32
use a clear piece of plexi w/ a sharpie'd line on it where your gradation point starts on the filter.

make it thick(like 1/4-3/8) so it visibly(through the lens, on the g/g) blocks light.

-Dan

Eric James
6-May-2013, 13:42
I don't think that slow lenses will necessarily hinder your placement; I generally stop-down to place a grad.

Someone here recommends applying a Post-It Note directly to the GND filter to delineate the transition.

Stephen Willard
6-May-2013, 13:50
Daniel, that is a excellent idea that can be expanded on. I could have two pieces of 4x6 plexiglass. One with a strip of black tape that is as wide as the transitional area of the GND with a hard edge filter, and one with a wider strip of black tape that is as wide as the transitional area of the GND with a soft edge filter.

Eric approach is worth trying as well.

Jim Becia
6-May-2013, 14:41
One simple way to do this would be to cut some black mat board to 4x6, then slide the piece of mat board in the filter holder to the point where you want the transition to start. It will be very noticeable on the ground glass. Then slide your filter into the slot in its place. Most filter holders have several slots, so the positioning should be quite easy.

One thing I have done several times now it to just use my dark slide as a dodging tool. It has worked quite well when the exposures run over about 5 to 6 seconds. Jim

vinny
6-May-2013, 14:54
i use a black piece of card that's the same length as the filter's transition line clipped to the filter. easy

Heroique
6-May-2013, 14:57
I am considering purchasing two sets of Lee 4x6 graduated neutral density filters. One set is hard edged with 0.3, 0.6, and 0.9 filters, and the other set is the same except it is soft edge.

The Lee hard-edged versions are actually pretty soft.

You might consider starting out w/ only the hard-edged set, not both, and see how that works.

My Lee 2-stop hard-edged filter serves as a “soft” version very well.

biedron
6-May-2013, 17:00
I would agree with this. I have both sets, and most of the time I use the hard-edge ones.

Bob


The Lee hard-edged versions are actually pretty soft.

You might consider starting out w/ only the hard-edged set, not both, and see how that works.

My Lee 2-stop hard-edged filter serves as a “soft” version very well.

Stephen Willard
8-May-2013, 15:16
Thanks to all for your helpful comments. Indeed, I will buy the hard edge set first, and go from there.

Thanks again,

-Stephen

Joseph Dickerson
9-May-2013, 08:29
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.

As always, I learned something today...thanks Vinny. :cool:

JD

Stephen Willard
9-May-2013, 10:52
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
9-May-2013, 11:07
You're most welcome...cool place we have here huh?

JD

Corran
9-May-2013, 14:41
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
10-May-2013, 08:03
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.:rolleyes:

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
10-May-2013, 08:48
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
11-May-2013, 02:36
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