Using neutral density grads with digital cameras

[Jonathan Wienke]

With digital, there really isn't much point to getting ND grads; in the vast majority of situations you're better off using a tripod, shooting some bracketed frames, and blending in Photoshop. This allows you to shoot irregularly-shaped subjects, and you have total control over the exposure difference between frames blended. With a filter, you're limited to straight-line transitions, and the choice of a "hard" grad or a "soft" grad will vary dramatically depending on subject matter and the lens focal length and aperture you're using for the shot. IMO ND grads simply aren't worth the bother.

[Jay Patel]

Thanks guys for all the advice (much needed!). I was originally considering the Lee wide adapter to help prevent vignetting on such a wide lens but the consensus seems to be that bracketing and blending may be the better way forward (most of my shots won't include action/movement).

I don't really know much about this technique so I'll check out Michael's tutorial and the Photoshop Action - although the principle sounds simple enough. Will this cause any extra noticeable picture degradation?

Thanks again.
Jay

[didger]

Then, there are times you'd like to have a ND grad.

Yes, no doubt.  I don't think anyone would contest this.  However, when I think of how many folks I've seen fussing with their ND filters and agonizing about just which one and where in the image it should be centered I have to wonder a little about wildlife photography with ND filters.  Well, I'm sure there's times that even an imperfectly placed filter would be better than none.

[didger]

I hear all the definitive statements about GND filters being unnecessary but I have to surmise that this is from folks who obviously don't take photographs with trees in them, have no wind or breezes and no moving clouds ....

I didn't notice all those definitive statements you refer to.  I noticed that we've been agreeing that there's a place for GND filters and a place for digital blending.  Yes, vegetation moving in the wind is a problem and sometimes no matter how long you wait the wind never quits long enough.  As for clouds, however, I've not yet experienced a problem.  Doing bracketed exposures is so fast that clouds don't ever move much in that interval.  Moreover, clouds are not hard edged well defined objects, so blending or clone tooling slight mismatches would not be a problem, not that I've ever had this problem anyway.

I'm sure there could be places or circumstances where bracketing and blending would often not work, but I've taken hundreds of blending shots that do work and encountered few situations where bracketing flat out wasn't feasible, so different strokes for different folks.

[Jay Patel]

Hello,
 I'm planning on buying some neutral density grad filters for use on my Canon EOS 20D with an EF-S 10-22mm wide lens. However, i'm unsure whether to get hard grads or soft. I originally opted for soft because I intend to be shooting more "broken" horizons (with trees etc.) but I've heard that with a digital camera the graduation would appear even softer because a larger part of the frame is covered by the transition area. Can anyone tell me if this is so and how pronounced the effect is (ie would a hard grad effectively become a soft grad when used on digital?).
 
Would stopping the apperture down help prevent the graduation from becoming too soft. Any help out there would be much appreciated.

Jay.

[didger]

Have you looked into bracketing shots and blending over and underexposed images to cover large dynamic range?  If you shoot with a tripod this is very easy and pretty bombproof to do and the blending is no real hassle either, and for this you also don't need to limit yourself to situations where the border between lighter and darker is basically simple and horizontal.

[BryanHansel]

That is a very wide lens and you need to verify that whatever you get doesn't cause vinetting issues.

If it does on your lens, try cutting off the extra filter holders just leaving one to see if this solves the problem.  I assume you are using the Cokin holders to do this.

I only have the soft ones, and they seem to work fine.

[didger]

Shooting two or three exposures and blending is all well and good so long as you've got the time (and skills) for the PS work

I have hundreds of bracketed image pairs and the blending takes mere seconds and no particular skill if you use the layer mask method in Michael's tutorial
As if that weren't easy enough, here's a Photoshop Action that totally automates the procedure.
Compared to the hassle of carrying ND filters and figuring out the best filter recipe for each situation, digital blending is a lot easier.  OK, not so good for moving subjects, but ND filters are a lot more limiting because they only work for certain kinds of simple divisions of light and dark areas.

[didger]

Will this cause any extra noticeable picture degradation?

Absolutely not.  The issues are only that there should not be moving subjects and, obviously, that the camera should not move between shots.  Even the resulting mis-registration from camera motion between shots can be fixed, but not using the automatic action.  I've never had a problem at all so far, and I've done countless such blendings.

I wouldn't say that there's anything like universal agreement here that this is the way to go, but it costs you nothing to try it and you can make up your own mind.

[Jay Patel]

Thanks Didger,
  Looked at the Luminous Landscape and Outdoor Photography tutorials and also some other forums on this issue. You're right about there being disagreement but from what I've seen there does seem to be a definite shift away from the use of neutral grads by those who have switched from film to digital.

But as you say best to try it for myself. Better that than first unnecessarily spending loads on filters that I then won't ever use.

Jay

[Lisa Nikodym]

With digital, there really isn't much point to getting ND grads; in the vast majority of situations you're better off using a tripod, shooting some bracketed frames, and blending in Photoshop.

Great if you can do it, but sometimes you can't because you're photographing wildlife or some other moving object, or are somewhere you can't carry a tripod with you.  Then, there are times you'd like to have a ND grad.

Lisa

[Graham Welland]

I hear all the definitive statements about GND filters being unnecessary but I have to surmise that this is from folks who obviously don't take photographs with trees in them, have no wind or breezes and no moving clouds ....

I use blending when I can but often run into registration problems with foliage, resulting in ugly fringing if the exposure difference is significant and/or ghosting. I can clean this stuff up but its tedious work that requires care to ensure it's not visible.

I often do night illumination shots where I blend tungsten balanced foregrounds against daylight balanced skies - this works extremely well and I would concede isn't the type of thing that you could do easily with filters. Similarly static scenes requiring local balancing works well with blended images. Images with any movement in them, however, are a lot of work to do well. For these, a GND is much simpler and faster.

I don't agree with the premise that selecting a grad is difficult at all. If you can meter a scene and perform range subtraction then it is simple. Similarly positioning a grad isn't that difficult, particularly with a DSLR and hard grads.

Anyway, just my $0.02 on this subject. (again)
 

[Graham Welland]

I didn't notice all those definitive statements you refer to.  I noticed that we've been agreeing that there's a place for GND filters and a place for digital blending.
....
 so different strokes for different folks.

Oh, the definitive statements are here ... not necessarily in this thread nor am I implying by you but cetainly in some of the other threads here.

Anyway, I actually agree that it kind of depends. I'm by no means anti-blending at all, in fact I do it myself more than I care to admit   I just happen to feel that you can get better results in camera with grads a lot of the time. (Playing the devil's advocate too).

I feel like I'm becoming an old film crumudgen ... heck, I've even been using my 5x4 these days in preference to digital! (note to pixel peepers: You can't beat 100MP!).

[Jay Patel]

Another question for you blenders out there although this time not really related to the neutral grad/high contrast issue: if I were to take a nicely exposed image (say of a house or tree, where there were no contrast range problems), make a copy and then simply blend the two together would this in effect double the resolution (and file size I would assume)of the image and enable it to be blown up to a much larger size without considerable loss of quality when printed?

This may be a stupid question with an obvious answer but increased resolution as a side effect of blending is not something I've seen mentioned in any of the blending articles and discussion I've come across.

Jay

[boku]

Caution: try these before you buy. That is a very wide lens and you need to verify that whatever you get doesn't cause vinetting issues. Especially if you use drop in grads with a holder that can't get out of the way.

[Graham Welland]

If you go with Lee filters you can get a special 77mm wide angle ring that is stepped back to help prevent the filter holder falling into view. For an extreme wide angle you'd want to configure the holder with a single slot. You can also get wide angle hoods to fit this combo too.

The downside is that it's a fair investment in LEE filters. Not cheap, but the best.

Shooting two or three exposures and blending is all well and good so long as you've got the time (and skills) for the PS work. It also assumes that your scene is static.

[Jonathan Wienke]

Definitely try before you buy...

[didger]

You get no new information in the new copy, so how could blending give your more resolution?  Definitely no.