Gradient ND Filters

[pono]

I want to get a gradient ND filter for shooting sunsets/sunrises. I know there are different strengths but I don't know which one would be ideal. Can somebody please help me out?

[David]

Hi Shane - I'm not sure that there is an "ideal" grad filter that covers all circumstances. Usually, you would want a range to cover very bright to modestly bright differences. I guess in Hawaii you get some powerful sun so you might want something strong. I use the Cokin type and have 4 and 8 grad filters, although I also need a #2. If I had to choose just one it would be the #4.

David

[Dave Humphries]

Hi SHane,

Colin is obviously the expert, but for sunrises/sets, I believe he also often uses a "reverse GND" as well when sun is in shot, since that deals with the very bright bit on the horizon, but doesn't over darken the clouds above.

You probably won't be able to afford these but this shows what they look like and when to us 'em ... http://www.singh-ray.com/reversegrads.html

Don't know if anyone else makes them.

Cheers,

[Mike in UK]

I was recently reading about doing a Graduated ND effect in Photoshop. Maybe worth a look by Googling for articles.

[revi]

That wouldn't give the same effect at all.

The graduated ND filters for shooting are there to limit the dynamic range that is captured to something the camera can handle (no blown skies or black foregrounds), Photoshop graduated ND would 'just' lay a gradient over an existing picture, but can never bring back detail that was outside the dynamic range of the camera (the information just isn't in the file)

Remco

[pono]

I'm probably supposed to know this but I don't. What is a stop? Is one stop higher than f3.5, f4?

[Colin Southern]

That wouldn't give the same effect at all.

The graduated ND filters for shooting are there to limit the dynamic range that is captured to something the camera can handle (no blown skies or black foregrounds), Photoshop graduated ND would 'just' lay a gradient over an existing picture, but can never bring back detail that was outside the dynamic range of the camera (the information just isn't in the file)

Remco

Yes and no. One technique is to bracket a couple of exposures and then use a gradient mask in Photoshop to transition between them - and the technique is also useful for transitioning between two different versions of the same file (it can be easier than trying to accomplish the same thing with global adjustments like fill light and brightness controls).

[Colin Southern]

I'm probably supposed to know this but I don't. What is a stop? Is one stop higher than f3.5, f4?

Hi Shane,

In generic terms it a doubling or halving of something. In terms of F-Stops they go F1, F1.4, F2, F2.8, F4, F5.6, F8, F11, F16, F22, F32, F44, F64 etc.

[Klickit]

Hi Shane,

In generic terms it a doubling or halving of something. In terms of F-Stops they go F1, F1.4, F2, F2.8, F4, F5.6, F8, F11, F16, F22, F32, F44, F64 etc.

....and it doubles or halves the amount of light let into the camera and therefore allowed on the film or sensor.