why use a grad filter ?

[eddie1]

anyone advice please
why use a grad filter nowadays when the filter effect can be added in post production ?

[Mike-DT6]

Yes, you can create the equivalent in post processing, which is much more versatile in some ways, but there are times when you will run into serious problems if relying solely on blending bracketed images in Photoshop.

For example, if your intended gradient line in post processing falls in an area where you have moving objects then you will have no end of problems trying to blend the bracketed exposures, due to things being in different places in your bracketed exposures. Tree lines and sea shores fall into this category.

I usually use a combination of gradient-filtered photographs and unfiltered bracketed photographs.

Mike

:-)

[SkipD]

If the contrast in a scene is so great that the camera (film or digital) cannot capture the extremes, the only way to capture it in one exposure is to use something like a graduated neutral density filter to dim the brighter area. Typically this is done for sunrise/sunset scenic shots where the sky (and sun) are extremely bright compared to what's below the horizon.

Without the filtering, it would be impossible to make a single exposure and recover either the blown highlights or black shadowed areas in an image using post-processing techniques.

[sandpiper]

Because, often, when exposing correctly for the ground / subject, the sky can have areas blown out. Photoshop filters are of no use then.

If you can take two shots, one exposed for the subject and one for the sky, then blend in post, you can get around that. It's a lot more work than getting it right in camera though.

It does have the advantage, over a grad, where uneven boundaries are evident though (say a building sticking up into the 'sky' area, which would be part covered by the grad area). You can work around that in post, with the two shot method.

As always, advantages to both methods. use whichever tool / method suits what you are shooting at the time. There is no right or wrong method and grads do have their uses.

[Grimes]

Well, because you really can't duplicate the biggest advantage to using a grad filter - getting the dynamic range of the entire scene into a range that the camera can best record.

A good example is of a landscape with bright sky. If you use a GND filter, you will be able to expose the sky and ground "properly". If you don't use a GND filter, your sky will be be too bright or the ground too dark - one or the other.

You can expose for the sky and then brighten the ground up in software, but it will never look as good as if you did it with a filter!

[Mike-DT6]

Are we talking about trying to salvage something out of a single frame, using a gradient filter tool, such as in Lightroom, or are we talking about blending bracketed images?

[SkipD]

Are we talking about trying to salvage something out of a single frame, using a gradient filter tool, such as in Lightroom, or are we talking about blending bracketed images?Both....

The situation where the graduated ND filter is the only solution for an extreme contrast condition is where a single exposure is made.

Multiple exposures (with different exposure settings for each) can be combined in software to get a similar effect.

As mentioned above, each has its place in the photographic toolbox.

[Mike-DT6]

Yes, I'm familiar with the technical side this. I was asking because I presumed the original poster was referring to combining multiple exposures when he was referring to the effect being added in post processing.

If he wasn't referring to that, then my answer might not have made sense to him. I originally overlooked the ND filter tool for single exposures in Lightroom. On the other hand, if he was referring to bracketing exposures and combining them later in Photoshop then there's no real need to deal with the subject of struggling with the limitations of a single exposure.

Mike

:-)

[yogestee]

Eddie,,I bought a graduated neutral density filter awhile ago so I could give some lift to the sky (especially clouds) when shooting landscapes..

Here are a couple of examples.. Please note,, no post processing was done to the sky..

[eddie1]

Thanks all thats v helpful

[neilwood32]

Jurgen - if you dont mind me saying the first one shows one of the reasons why GND's are not perfect for all situations. The light reduction from the filter is visible on the top of the temple(?) whereas If done with blended exposures, the top would have retained the same tone as the rest of the building.

Saying that, I am considering buying a set for landscapes.

[gorgon2k]

The filters work best for something with a level horizon or atleast close to it.

[yogestee]

Jurgen - if you dont mind me saying the first one shows one of the reasons why GND's are not perfect for all situations. The light reduction from the filter is visible on the top of the temple(?)

I agree Neil.. Bearing in mind this image is virtually straight out of the camera.. With added post processing I could have adjusted the spire of the temple to match rest of the temple..

[Mike R]

A lot of valid points have been made FOR and AGAINST the use of GND filters. I use filters for the reasons listed above and because I would rather be outside enjoying the scene and the time photographing it rather than be in a dimly lit room starring at a monitor any longer than I have to.

[neilwood32]

I agree Neil.. Bearing in mind this image is virtually straight out of the camera.. With added post processing I could have adjusted the spire of the temple to match rest of the temple..

I had realised that it hadn't been edited (apart from for posting). The filters have done a great job on the skies though!

I was just highlighting the issue (as tall buildings/objects are the bane of filter users lifes).

As I said, I'm in the process of considering a set of Cokin GND's for my landscapes (cant justify the cost of Lee etc atm).

[jimmeh]

would you guys always get cokin grad NDs? Just wondering about the fact that you can move the horizon line if you have a square filter, but a screw in thread limits your composition.

[neilwood32]

The square/rectangular grads allow for adjustment of the level of the split (grad/clear) to align with the horizon.

If you buy GND screw-ins, you are limited as to where the graduation is placed (the whole scene has to be adjusted to suit the grad, rather than the ideal which is the grad position being adjusted to suit the scene.

[jimmeh]

The square/rectangular grads allow for adjustment of the level of the split (grad/clear) to align with the horizon.

If you buy GND screw-ins, you are limited as to where the graduation is placed (the whole scene has to be adjusted to suit the grad, rather than the ideal which is the grad position being adjusted to suit the scene.

i realise that, i was asking whether people actively had a problem with using screw in grads for that reason.

[yogestee]

i was asking whether people actively had a problem with using screw in grads for that reason.

Not so much as a problem but a limitation.. When using GNDs you have to have a good look around your viewfinder to see where the graduation lies.. Are you aware GNDs rotate inside their mounts??

[neilwood32]

i realise that, i was asking whether people actively had a problem with using screw in grads for that reason.

I though that although I hadnt answered it directly, my thoughts would convey that I did have a problem with screw-in grads.

Either PP (blending 2 exposures or grad ND filter in PS) or slide in filters for me. Screw-in grads are way too much of a limitation IMHO.

[jimmeh]

Not so much as a problem but a limitation.. When using GNDs you have to have a good look around your viewfinder to see where the graduation lies.. Are you aware GNDs rotate inside their mounts??

the rotation is unlikely to aid you that much though. The real issue is that it means you have to have your horizon halfway.

[jdizzle]

If you wanna learn how to use ND grads, come to this part of the forum. We'll guide you in making the right choice. :)

http://photography-on-the.net/forum/showthread.php?t=224448

Here's a few samples of why I love using GNDs. Enjoy! :)

Singh Ray Color Combo CPL and Singh Ray 2 stop soft GND.
http://i9.photobucket.com/albums/a92/DJJUST/LookingGlass1.jpg[/IMG]

Lee 2 stop hard GND.
http://i9.photobucket.com/albums/a92/DJJUST/B-OvecastSunrisecopy.jpg[/IMG]

Singh Ray Color Combo CPL and Singh Ray 3 stop Reverse GND.
http://i206.photobucket.com/albums/bb83/delarosaIII/Cambriainthemorning.jpg[/IMG]

[yogestee]

the rotation is unlikely to aid you that much though. The real issue is that it means you have to have your horizon halfway.

Not really.. Remember they are graduated but I wouldn't place it below the horizon..

Look,,I don't understand all this tooing and froing.. I picked mine up for about 12 bucks off eBay.. They are a great addition to your camera's kit and a whole lot of fun to use..

The reason I bought mine was, in Laos in the wet season we get these huge thunderheads which look spectacular..