Graduated ND Filters

[rmh159]

Any advice on getting a graduated ND filter? I started looking through them on Adorama.com and was surprised by the selection. Particularly the "light grey ND" and "dark grey ND". I would assume the light grey doesn't block as much light as the dark grey but not sure how much would "enough" for a typical landscape / sunset shot.

Also since a sunset shot would most likely include the sun in frame would the coating of the filter be more important than a filter that's typically not used with the sun in frame (in terms of preventing flare)?

Any advice or specifics that I should consider?

 

[Big Mike]

There are differences in the hardness of the transition. You can get a very gradual transition, which would work better with an uneven horizon (hill, mountains etc.) Or you could get a harder edged transition which would be better for a flat horizon.

Evey situation is unique, so there is no 'best' filter for any situation.

 

[Alex_B]

there are even more decisions to be made ...

do you want a filter which is screwed onto your lens, and hence has the gradient always in the same position (in some situations it could be far from the horizon), or do you want
a filter which you can shift up and down (as in the cokin or lee system.) The latter is easier if the borderline between the dark and the bright part is shifted away from the centre of the scene.

If you go for a filter you cannot shift, I would rather go for a soft gradient, as then things are more relaxed and if the horizon is slightly off the centre it does not really matter. Also a soft gradient helps if the dark/bright borderline is not a straight line but bent considerably (e.g. mountains framing the scene).

but then again everything depends on what you want to shoot...

 

[rmh159]

Thanks for the tips. I think a light grey screw-on filter would probably be the way I'd go for now as it sounds a bit more flexible for my needs.

 

[Big Mike]

The problem with a circular grad filter is that you end up with the horizon in the middle of your shot.

Are you shooting digital or with film?

There is something to be said for getting the shot right, at the time of shooting...but the effect of ND grad filter is very easily duplicated in Photoshop. Not only is it easily duplicated...but it's infinitely flexible. If the range of tones is just too much for one shot, then two shots can easily be merged.

 

[Alex_B]

There is something to be said for getting the shot right, at the time of shooting...but the effect of ND grad filter is very easily duplicated in Photoshop. Not only is it easily duplicated...but it's infinitely flexible. If the range of tones is just too much for one shot, then two shots can easily be merged.

Often the difference in brightness between the bright and the dark part of the image is more than the dynamic range of a digital camera can handle. Same holds for slide film.

PS is of little help then. (I said little, not no help )
If you go for multiple exposures, you need a good tripod and you have to make sure there are no trees on the horizon which move alot in the wind and such.

It all depends on the situation, and there are situations when only a grad ND filter will do the job.

 

[Big Mike]

That's true, grad filters can still be useful in the digital world. Personally, I don't consider using mine unless the horizon is perfectly flat. Even with a soft grad, you are still making a compromise. I find that if the shot is worthy, I'd rather spend the time in the digital darkroom, combining shots or making precise layer masks and/or adding gradients.

Film and especially digital is limited in how wide a range you can capture...but knowing where you can pull extra detail will help a lot.

 

[rmh159]

I'd be using the filter for digital shooting.

I have messed with photoshop and gotten decent results by creating a layer with a black to clear gradient and then setting it to Overlay or Soft Light but I was thinking that the results would be better if I got the affect at the time of the shoot. I definitely don't want to get a filter if 5 minutes in PS can get the same effect but I was thinking that the non-filtered shot might have blown highlights in which case PS wouldn't have the detail available to pull out of the sky.

So in your opinion the final effect would be more easily achieved by combining multiple exposures, blending layers, etc?

Thanks for the insight... very much appreciated.

 

[Big Mike]

but I was thinking that the non-filtered shot might have blown highlights in which case PS wouldn't have the detail available to pull out of the sky.

That's what I meant about knowing where to pull the detail. In most cases, when you have a brighter sky and a darker fore/mid ground...it's works well to expose for the sky and pull up the shadow detail of the ground...in Photoshop. Trying to recover a blown sky is much harder, if not impossible. Also, if you are going to be adjusting the image, you might be bringing out some noise in the image...I'd rather have a little noise in a busy foreground than in a clear sky.

As mentioned, a grad filter can still be very useful...but I feel that a round grad is less useful than the square ones. If you can, go to a used shop (or E-bay) and look for a Cokin holder and some filters...they can be had quite cheap.