Problem with Graduated ND Filters..

[CanonTx88]

Hey everyone,

The Situation:
I made my first attempt at photographing a piece of architecture, the Golden Gate Bridge, out in San Francisco, California. This was my first time to use Gradual Neutral Density filters, or any filter for that matter. Because they were shipped to my home the day prior to my departure, I had to literally learn on-the-spot once I was standing infront of the Bridge - never a good way to learn.

Anyway, I was using Lee Soft-Edge Gradual Neutral Density Filters with variations of my 0.9, 0.6 and/or the 0.75.

After spot-metering for the sky and foreground and determing which density (or combination thereof) was necessary for the photograph, I took the image.

Sweet.. everything came out well. I maintained detail in the sky as well as the foreground - histogram checked out okay, etc... However..

The Problem:
The top of the bridge was darker, and lacked vibrance, color and detail as a direct result from the filter. Which lead me to question if this must happen for other subjects as well? Surely this must occur with any subject, for example: a bridge, mountain, rocks, etc., when the subject crosses into the darker areas of the filter(s). When you're using a filter(s)... How do you correct for this problem??

Thanks everyone!

[sandpiper]

The Problem:
The top of the bridge was darker, and lacked vibrance, color and detail as a direct result from the filter. Which lead me to question if this must happen for other subjects as well? Surely this must occur with any subject, for example: a bridge, mountain, rocks, etc., when the subject crosses into the darker areas of the filter(s). When you're using a filter(s)... How do you correct for this problem??

Thanks everyone!

You can't really, unless you make a filter specifically for the subject (i.e. one with a golden gate bridge shaped divider between light and dark).

Filters are great with reasonably straight horizons, but do have this problem with subjects that stick up through the line.

I generally shoot a couple of images (one exposed for the sky, one for - in this case - the bridge) then blend in post processing. Alternatively take one shot and make two versions from the RAW (sky / bridge again) and blend. It's a bit more work, but does the job when filters aren't suitable.

[bjannsen]

I agree with sandpiper; in cases like this with very irregular shapes your best bet is several exposures merged with HDR or with layers in PP.

ND Grads are great tools, but they can't solve all dynamic range issues.

[jrader]

You can't really, unless you make a filter specifically for the subject (i.e. one with a golden gate bridge shaped divider between light and dark).

Filters are great with reasonably straight horizons, but do have this problem with subjects that stick up through the line.

I generally shoot a couple of images (one exposed for the sky, one for - in this case - the bridge) then blend in post processing. Alternatively take one shot and make two versions from the RAW (sky / bridge again) and blend. It's a bit more work, but does the job when filters aren't suitable.

I agree with sandpiper; in cases like this with very irregular shapes your best bet is several exposures merged with HDR or with layers in PP.

ND Grads are great tools, but they can't solve all dynamic range issues.

+1 When the objects you want to shoot aren't generally horizontal, you have no real choice other than to blend shots in PS. Bridges/buildings/cityscapes are notorious for being a pain in the ass. You could always wait till the sun dips below the horizon and the sky becomes more uniform bright, that way you don't blow out the sky.

Good luck.

John

[blackcap]

Check out this thread too: http://photography-on-the.net/forum/showthread.php?t=594152